Publications

Authors: Type:

2025

    [PDF] [Bibtex] 
    @inproceedings{zhang2025stories,
author = {Zhang, Ke Er Amy and Garrison, Laura},
title = {Modern snapshots in the crafting of a medical illustration},
booktitle = {Proceedings of CHI '25 Workshop "How do design stories work? Exploring narrative forms of knowledge in HCI"},
year = {2025},
numpages = {3},
abstract = {The time-honored practice of medical illustration and visualization, has, like nearly all other disciplines, seen changes in its tooling and development pipeline in step with technological and societal developments. At its core, however, medical visualization remains a discipline focused on telling stories about biology and medicine. The story we tell in this work assumes a more distant vantage point to tell a story about the biomedical storytellers themselves. Our story peers over the shoulders of two medical illustrators in the middle of a project to illustrate a procedure in one of the small blood vessels around the heart, and through the medium of an online chat explores the dialogue, tensions, and goals of such projects in the digital age. We adopt the two-column format of the CHI template, as it is more reminiscent of the width of our usual messaging windows while working. The second part of our submission reflects on these tensions and modes of storytelling from an HCI and Visualization-situated perspective.},
pdf = {pdfs/zhang2025stories.pdf},
images = {images/zhang2025stories.png},
thumbnails = {images/zhang2025stories.png},
project = {VIDI}
}
    [PDF] [DOI] [Bibtex] 
    @article{vandenbossche2025open,
title = {The Open Anatomy Explorer--a journey towards accessible open-source 3D learning environments},
author = {Vandenbossche, Vicky and Van Kenhove, Michiel and Smit, Noeska and Willaert, Wouter and De Turck, Filip and Volckaert, Bruno and Valcke, Martin and Audenaert, Emmanuel},
year = 2025,
journal = {Journal of Visual Communication in Medicine},
publisher = {Taylor \& Francis},
pages = {1--12},
doi = {10.1080/17453054.2024.2446764},
url = {https://www.tandfonline.com/doi/full/10.1080/17453054.2024.2446764},
abstract = {Anatomy learning has traditionally relied on drawings, plastic models, and cadaver dissections/prosections to help students understand the three-dimensional (3D) relationships within the human body. However, the landscape of anatomy education has been transformed with the introduction of digital media. In this light, the Open Anatomy Explorer (OPANEX) was developed. It includes two user interfaces (UI): one for students and one for administrators. The administrator UI offers features such as uploading and labelling of 3D models, and customizing 3D settings. Additionally, the OPANEX facilitates content sharing between institutes through its import-export functionality. To evaluate the integration of OPANEX within the existing array of learning resources, a survey was conducted as part of the osteology course at Ghent University, Belgium. The survey aimed to investigate the frequency of use of five learning resources, attitudes towards 3D environments, and the OPANEX user experience. Analysis revealed that the OPANEX was the most frequently used resource. Students’ attitudes towards 3D learning environments further supported this preference. Feedback on the OPANEX user experience indicated various reasons for its popularity, including the quality of the models, regional annotations, and customized learning content. In conclusion, the outcomes underscore the educational value of the OPANEX, reflecting students’ positive attitudes towards 3D environments in anatomy education.},
images = {images/vandenbossche2025open.png},
thumbnails = {images/vandenbossche2025open.png},
pdf = {pdfs/vandenbossche2025open.pdf}
}
    [PDF] [DOI] [Bibtex] 
    @article{wagner2025mri,
title = {MRI delta radiomics during chemoradiotherapy for prognostication in locally advanced cervical cancer},
author = {Wagner-Larsen, Kari S and Lura, Njål and Gulati, Ankush and Ryste, Stian and Hodneland, Erlend and Fasmer, Kristine E and Woie, Kathrine and Bertelsen, Bjørn I and Salvesen, Øyvind and Halle, Mari K and Smit, Noeska and Krakstad, Camilla and Haldorsen, Ingfrid S},
year = 2025,
journal = {BMC cancer},
volume = 25,
pages = 122,
doi = {10.1186/s12885-025-13509-1},
url = {https://bmccancer.biomedcentral.com/articles/10.1186/s12885-025-13509-1},
abstract = {Effective diagnostic tools for prompt identification of high-risk locally advanced cervical cancer (LACC) patients are needed to facilitate early, individualized treatment. The aim of this work was to assess temporal changes in tumor radiomics (delta radiomics) from T2-weighted imaging (T2WI) during concurrent chemoradiotherapy (CCRT) in LACC patients, and their association with progression-free survival (PFS). Furthermore, to develop, validate, and compare delta- and pretreatment radiomic signatures for prognostic modeling.},
images = {images/wagner2025mri.png},
thumbnails = {images/wagner2025mri.png},
pdf = {pdfs/wagner2025mri.pdf}
}

2024

    [PDF] [DOI] [Bibtex] 
    @article{splechtna2024interactive,
title={Interactive design-of-experiments: optimizing a cooling system},
author={Splechtna, Rainer and Behravan, Majid and Jelovic, Mario and Gracanin, Denis and Hauser, Helwig and Matkovic, Kre{\v{s}}imir},
journal={IEEE Transactions on Visualization and Computer Graphics},
year={2024},
publisher={IEEE},
doi = {10.1109/TVCG.2024.3456356},
url = {https://doi.org/10.1109/TVCG.2024.3456356},
images = {images/splechtna2024cooling.png},
thumbnails = {images/splechtna2024cooling.png},
pdf = {pdfs/splechtna2024cooling.pdf},
abstract = {The optimization of cooling systems is important in many cases, for example for cabin and battery cooling in electric cars. Such an optimization is governed by multiple, conflicting objectives and it is performed across a multi-dimensional parameter space.The extent of the parameter space, the complexity of the non-linear model of the system,as well as the time needed per simulation run and factors that are not modeled in the simulation necessitate an iterative, semi-automatic approach. We present an interactive visual optimization approach, where the user works with a p-h diagram to steer an iterative, guided optimization process. A deep learning (DL) model provides estimates for parameters, given a target characterization of the system, while numerical simulation is used to compute system characteristics for an ensemble of parameter sets. Since the DL model only serves as an approximation of the inverse of the cooling system and since target characteristics can be chosen according to different, competing objectives, an iterative optimization process is realized, developing multiple sets of intermediate solutions, which are visually related to each other.The standard p-h diagram, integrated interactively in this approach, is complemented by a dual, also interactive visual representation of additional expressive measures representing the system characteristics. We show how the known four-points semantic of the p-h diagram meaningfully transfers to the dual data representation.When evaluating this approach in the automotive domain, we found that our solution helped with the overall comprehension of the cooling system and that it lead to a faster convergence during optimization.}
}
    [PDF] [Bibtex] 
    @article{pokojna2024language,
title={The Language of Infographics: Toward Understanding Conceptual Metaphor Use in Scientific Storytelling},
author={Pokojn{\'a}, Hana and Isenberg, Tobias and Bruckner, Stefan and Kozl{\'i}kov{\'a}, Barbora and Garrison, Laura},
journal={IEEE Transactions on Visualization and Computer Graphics},
year={2024},
month={Oct},
publisher={IEEE},
abstract={We apply an approach from cognitive linguistics by mapping Conceptual Metaphor Theory (CMT) to the visualization domain to address patterns of visual conceptual metaphors that are often used in science infographics. Metaphors play an essential part in visual communication and are frequently employed to explain complex concepts. However, their use is often based on intuition, rather than following a formal process. At present, we lack tools and language for understanding and describing metaphor use in visualization to the extent where taxonomy and grammar could guide the creation of visual components, e.g., infographics. Our classification of the visual conceptual mappings within scientific representations is based on the breakdown of visual components in existing scientific infographics. We demonstrate the development of this mapping through a detailed analysis of data collected from four domains (biomedicine, climate, space, and anthropology) that represent a diverse range of visual conceptual metaphors used in the visual communication of science. This work allows us to identify patterns of visual conceptual metaphor use within the domains, resolve ambiguities about why specific conceptual metaphors are used, and develop a better overall understanding of visual metaphor use in scientific infographics. Our analysis shows that ontological and orientational conceptual metaphors are the most widely applied to translate complex scientific concepts. To support our findings we developed a visual exploratory tool based on the collected database that places the individual infographics on a spatio-temporal scale and illustrates the breakdown of visual conceptual metaphors.},
pdf = {pdfs/garrisonVIS24.pdf},
images = {images/garrisonVIS24.png},
thumbnails = {images/garrisonVIS24thumb.png},
project = {VIDI},
git={https://osf.io/8xrjm/}
}
    [PDF] [DOI] [Bibtex] 
    @inproceedings{zimanVCBM2024mobaDash,
booktitle = {Eurographics Workshop on Visual Computing for Biology and Medicine},
editor = {Garrison, Laura and Jönsson, Daniel},
title = {{The MoBa Pregnancy and Child Development Dashboard: A Design Study}},
author = {Ziman, Roxanne and Budich, Beatrice and Vaudel, Marc and Garrison, Laura},
year = {2024},
month = {September},
publisher = {The Eurographics Association},
ISSN = {2070-5786},
ISBN = {978-3-03868-244-8},
DOI = {10.2312/vcbm.20241194},
abstract = {Visual analytics dashboards enable exploration of complex medical and genetic data to uncover underlying patterns and possible relationships between conditions and outcomes. In this interdisciplinary design study, we present a characterization of the domain and expert tasks for the exploratory analysis for a rare maternal disease in the context of the longitudinal Norwegian Mother, Father, and Child (MoBa) Cohort Study. We furthermore present a novel prototype dashboard, developed through an iterative design process and using the Python-based Streamlit App [TTK18] and Vega-Altair [VGH*18] visualization library, to allow domain experts (e.g., bioinformaticians, clinicians, statisticians) to explore possible correlations between women's health during pregnancy and child development outcomes. In conclusion, we reflect on several challenges and research opportunities for not only furthering this approach, but in visualization more broadly for large, complex, and sensitive patient datasets to support clinical research.},
pdf = {pdfs/zimanVCBM24.pdf},
images = {images/zimanVCBM24.png},
thumbnails = {images/zimanVCBM24thumb.png},
project = {VIDI},
git={https://osf.io/u6kdm/}
}
    [PDF] [Bibtex] 
    @MISC{zhang2024ManhattanWheel,
booktitle = {Eurographics Workshop on Visual Computing for Biology and Medicine (Posters)},
title = {{The Manhattan Wheel: A Radial Visualization Story for Genome-wide Association Study Data}},
author = {Zhang, Ke Er and Vaudel, Marc and Garrison, Laura A.},
year = {2024},
howpublished = {Poster presented at VCBM 2024.},
publisher = {The Eurographics Association},
abstract = {Genome-wide association studies (GWAS) are critical to identifying genetic variations associated with a particular trait or disease. It is important to cultivate an awareness of GWAS in the general public as members of this group are key participants of these studies. However, low genetic data literacy and trust in the sharing of genetic data pose challenges to learning and engaging with GWAS concepts. In this design study, we explore design strategies for the public communication of GWAS data. As part of this study, we present an interactive visual prototype that explores the use of narrative structure, linked visualizations through scrollytelling, and plain language to onboard and communicate genetic concepts to a GWAS-naive audience.},
pdf = {pdfs/KEZHANG_VCBM2024_Poster_ManhattanWheel.pdf},
images = {images/zhangManhattanWheel.png},
thumbnails = {images/zhangManhattanWheelthumb.png},
project = {VIDI},
git={https://github.com/amykzhang/manhattan-wheel}
}
    [PDF] [DOI] [Bibtex] 
    @article{zhang2024toolkit,
title={The Visual Science Communication Toolkit: Responding to the Need for Visual Science Communication Training in Undergraduate Life Sciences Education},
author={Zhang, Ke Er and Jenkinson, Jodie},
journal={Education Sciences},
year={2024},
volume={14},
number={3},
pages={296},
publisher={MDPI},
abstract={Visual representations are essential to scientific research and teaching, playing a role in conceptual understanding, knowledge generation, and the communication of discovery and change. Undergraduate students are expected to interpret, use, and create visual representations so they can make their thinking explicit when engaging in discourse with the scientific community. Despite the importance of visualization in the biosciences, students often learn visualization skills in an ad hoc fashion without a clear framework. We used a mixed-methods sequential explanatory study design to explore and assess the pedagogical needs of undergraduate biology students (n = 53), instructors (n = 13), and teaching assistants (n = 8) in visual science communication education. Key themes were identified using inductive grounded theory methods. We found that extrinsic motivations, namely time, financial resources, and grading practices, contribute to a lack of guidance, support, and structure as well as ambiguous expectations and standards perceived by students and instructors. Biology and science visualization instructors cite visual communication assessments as a way of developing and evaluating students’ higher-order thinking skills in addition to their communication competencies. An output of this research, the development of a learning module, the Visual Science Communication Toolkit, is discussed along with design considerations for developing resources for visual science communication education.},
pdf = {pdfs/zhang2024toolkit.pdf},
images = {images/zhang2024toolkit.png},
thumbnails = {images/zhang2024toolkitthumb.png},
issn={2227-7102},
doi={10.3390/educsci14030296},
url={https://www.mdpi.com/2227-7102/14/3/296}
}
    [PDF] [DOI] [Bibtex] 
    @inproceedings{correll2024bodydata,
abstract = {With changing attitudes around knowledge, medicine, art, and technology, the human body has become a source of information and, ultimately, shareable and analyzable data. Centuries of illustrations and visualizations of the body occur within particular historical, social, and political contexts. These contexts are enmeshed in different so-called data cultures: ways that data, knowledge, and information are conceptualized and collected, structured and shared. In this work, we explore how information about the body was collected as well as the circulation, impact, and persuasive force of the resulting images. We show how mindfulness of data cultural influences remain crucial for today's designers, researchers, and consumers of visualizations. We conclude with a call for the field to reflect on how visualizations are not timeless and contextless mirrors on objective data, but as much a product of our time and place as the visualizations of the past.},
author = {Correll, Michael and Garrison, Laura A.},
booktitle = {arXiv, Proc CHI24},
doi = {10.48550/arXiv.2402.05014},
publisher = {arXiv},
title = {When the Body Became Data: Historical Data Cultures and Anatomical Illustration},
year = {2024},
month = {Feb},
pdf = {pdfs/garrisonCHI24.pdf},
images = {images/garrisonCHI24.png},
thumbnails = {images/garrisonCHI24.png},
project = {VIDI}
}

2023

    [PDF] [DOI] [Bibtex] 
    @article{wagner2023mri,
title={MRI-based radiomic signatures for pretreatment prognostication in cervical cancer},
author={Wagner-Larsen, Kari S and Hodneland, Erlend and Fasmer, Kristine E and Lura, Nj{\aa}l and Woie, Kathrine and Bertelsen, Bj{\o}rn I and Salvesen, {\O}yvind and Halle, Mari K and Smit, Noeska and Krakstad, Camilla and others},
journal={Cancer Medicine},
volume={12},
number={20},
pages={20251--20265},
year={2023},
publisher={Wiley Online Library},
doi = {10.1002/cam4.6526},
url = {https://onlinelibrary.wiley.com/doi/full/10.1002/cam4.6526},
images = {images/wagner2023radiomics.PNG},
thumbnails = {images/wagner2023radiomics.PNG},
pdf = {pdfs/wagner2023radiomics.pdf}
}
    [Bibtex] 
    @book{preim2023visualization,
title={Visualization, Visual Analytics and Virtual Reality in Medicine: State-of-the-art Techniques and Applications},
author={Preim, Bernhard and Raidou, Renata and Smit, Noeska and Lawonn, Kai},
year={2023},
publisher={Elsevier},
abstract = {Visualization, Visual Analytics and Virtual Reality in Medicine: State-of-the-art Techniques and Applications describes important techniques and applications that show an understanding of actual user needs as well as technological possibilities. The book includes user research, for example, task and requirement analysis, visualization design and algorithmic ideas without going into the details of implementation. This reference will be suitable for researchers and students in visualization and visual analytics in medicine and healthcare, medical image analysis scientists and biomedical engineers in general. Visualization and visual analytics have become prevalent in public health and clinical medicine, medical flow visualization, multimodal medical visualization and virtual reality in medical education and rehabilitation. Relevant applications now include digital pathology, virtual anatomy and computer-assisted radiation treatment planning.},
images = {images/Smit2023book.png},
thumbnails = {images/Smit2023book.png},
project = {ttmedvis},
url = {https://shop.elsevier.com/books/visualization-visual-analytics-and-virtual-reality-in-medicine/preim/978-0-12-822962-0}
}
    [PDF] [DOI] [Bibtex] 
    @book{zhang2023framework,
title={A Framework for the Design, Production, and Evaluation of Scientific Visualizations},
author={Zhang, Ke Er and Saharan, Shehryar and McGill, Ga{\"e}l and Jenkinson, Jodie},
editor={Shapiro, Leonard},
booktitle={Graphic Medicine, Humanizing Healthcare and Novel Approaches in Anatomical Education},
pages={131--162},
year={2023},
publisher={Springer Nature Switzerland},
address={Cham},
abstract={Visualizations play a critical role in discovering, understanding, interpreting, synthesizing, and communicating scientific knowledge. Effective scientific visualization requires careful attention to a number of factors, in particular, a faithful translation of scientific evidence, understanding of the communication needs of the target audience, and skillful application of visualization design principles. As a result, science visualization projects require a team of contributors with specialized knowledge and technical expertise. Regardless of team size and structure, a clear definition and appreciation of the design process as well as an understanding of the responsibilities of each contributor are imperative to the success of a project. Gaps in understanding often result in conflict between visualizers and stakeholders, compromising the quality of the scientific visualization. Although many companies have developed their own process through trial and error over years of experience, to date, there is no formalized framework for scientific visualization that details the steps of the process and the contributions of each individual. Informed by our examination of case studies, frameworks, and our collective experience as practitioners, we propose a framework tailored to the design, production, and evaluation of scientific visualization that aims to support practitioners in meeting their objectives and facilitating conversations that allow others to better understand the impact of the design process on the final product. We explore underlying drivers of decision-making within the visualization design space, describe the activities and outputs that impact decisions made about the final visualization, and discuss potential applications and limitations of this framework in practice.},
pdf = {pdfs/zhang2023framework.pdf},
images = {images/zhang2023framework.png},
thumbnails = {images/zhang2023frameworkthumb.png},
isbn={978-3-031-39035-7},
doi={10.1007/978-3-031-39035-7_7},
url={https://doi.org/10.1007/978-3-031-39035-7_7}
}
    [PDF] [Bibtex] 
    @MISC {balaka2023MoBaExplorer,
booktitle = {Eurographics Workshop on Visual Computing for Biology and Medicine (Posters)},
editor = {Garrison, Laura and Linares, Mathieu},
title = {{MoBa Explorer: Enabling the navigation of data from the Norwegian Mother, Father, and Child cohort study (MoBa)}},
author = {Balaka, Hanna and Garrison, Laura A. and Valen, Ragnhild and Vaudel, Marc},
year = {2023},
howpublished = {Poster presented at VCBM 2023.},
publisher = {The Eurographics Association},
abstract = {Studies in public health have generated large amounts of data helping researchers to better understand human diseases and improve patient care. The Norwegian Mother, Father and Child Cohort Study (MoBa) has collected information about pregnancy
and childhood to better understand this crucial time of life. However, the volume of the data and its sensitive nature make its
dissemination and examination challenging. We present a work-in-progress design study and accompanying web application,
the MoBa Explorer, which presents aggregated MoBa study data genotypes and phenotypes. Our research explores how to
serve two distinct purposes in one application: (1) allow researchers to interactively explore MoBa data to identify variables of
interest for further study and (2) provide MoBa study details to an interested general public.},
pdf = {pdfs/balaka2023MoBaExplorer.pdf},
images = {images/balaka2023MoBaExplorer.png},
thumbnails = {images/balaka2023MoBaExplorer-thumb.png},
project = {VIDI}
}
    [PDF] [DOI] [Bibtex] 
    @inproceedings {budich2023AIstories,
booktitle = {Eurographics Workshop on Visual Computing for Biology and Medicine},
editor = {Hansen, Christian and Procter, James and Renata G. Raidou and Jönsson, Daniel and Höllt, Thomas},
title = {{Reflections on AI-Assisted Character Design for Data-Driven Medical Stories}},
author = {Budich, Beatrice and Garrison, Laura A. and Preim, Bernhard and Meuschke, Monique},
year = {2023},
publisher = {The Eurographics Association},
ISSN = {2070-5786},
ISBN = {978-3-03868-216-5},
DOI = {10.2312/vcbm.20231216},
abstract = {Data-driven storytelling has experienced significant growth in recent years to become a common practice in various application areas, including healthcare. Within the realm of medical narratives, characters play a pivotal role in connecting audiences with data and conveying complex medical information in an engaging manner that may influence positive behavioral and lifestyle changes on the part of the viewer. However, the process of designing characters that are both informative and engaging remains a challenge. In this paper, we propose an AI-assisted pipeline for character design in the context of data-driven medical stories. Our iterative pipeline blends design sensibilities with automation to reduce the time and artistic expertise needed to develop characters reflective of the underlying data, even when that data is time-oriented as in a cohort study.},
pdf = {pdfs/budichAIstories.pdf},
images = {images/budichAIstories.png},
thumbnails = {images/budichAIstories-thumb.png},
project = {VIDI}
}
    [PDF] [DOI] [Bibtex] 
    @article{mittenentzwei2023heros,
journal = {Computer Graphics Forum},
title = {{Do Disease Stories need a Hero? Effects of Human Protagonists on a Narrative Visualization about Cerebral Small Vessel Disease}},
author = {Mittenentzwei, Sarah and Weiß, Veronika and Schreiber, Stefanie and Garrison, Laura A. and Bruckner, Stefan and Pfister, Malte and Preim, Bernhard and Meuschke, Monique},
year = {2023},
publisher = {The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {10.1111/cgf.14817},
abstract = {Authors use various media formats to convey disease information to a broad audience, from articles and videos to interviews or documentaries. These media often include human characters, such as patients or treating physicians, who are involved with the disease. While artistic media, such as hand-crafted illustrations and animations are used for health communication in many cases, our goal is to focus on data-driven visualizations. Over the last decade, narrative visualization has experienced increasing prominence, employing storytelling techniques to present data in an understandable way. Similar to classic storytelling formats, narrative medical visualizations may also take a human character-centered design approach. However, the impact of this form of data communication on the user is largely unexplored. This study investigates the protagonist's influence on user experience in terms of engagement, identification, self-referencing, emotional response, perceived credibility, and time spent in the story. Our experimental setup utilizes a character-driven story structure for disease stories derived from Joseph Campbell's Hero's Journey. Using this structure, we generated three conditions for a cerebral small vessel disease story that vary by their protagonist: (1) a patient, (2) a physician, and (3) a base condition with no human protagonist. These story variants formed the basis for our hypotheses on the effect of a human protagonist in disease stories, which we evaluated in an online study with 30 participants. Our findings indicate that a human protagonist exerts various influences on the story perception and that these also vary depending on the type of protagonist.},
pdf = {pdfs/garrison-diseasestories.pdf},
images = {images/garrison-diseasestories.png},
thumbnails = {images/garrison-diseasestories-thumb.png},
project = {VIDI}
}
    [PDF] [Bibtex] 
    @incollection{garrison2023narrativemedvisbook,
title = {Current Approaches in Narrative Medical Visualization},
author = {Garrison, Laura Ann and Meuschke, Monique and Preim, Bernhard and Bruckner, Stefan},
year = 2023,
booktitle = {Approaches for Science Illustration and Communication},
publisher = {Springer},
address = {Gewerbestrasse 11, 6330 Cham, Switzerland},
pages = {},
note = {in publication},
editor = {Mark Roughley},
chapter = 4,
pdf = {pdfs/garrison2023narrativemedvisbook.pdf},
images = {images/garrison2023narrativemedvisbook.png},
thumbnails = {images/garrison2023narrativemedvisbook-thumb.png},
project = {VIDI}
}
    [PDF] [DOI] [Bibtex] 
    @article{mittenentzwei2023investigating,
title={Investigating user behavior in slideshows and scrollytelling as narrative genres in medical visualization},
author={Mittenentzwei, Sarah and Garrison, Laura A and M{\"o}rth, Eric and Lawonn, Kai and Bruckner, Stefan and Preim, Bernhard and Meuschke, Monique},
journal={Computers \& Graphics},
year={2023},
publisher={Elsevier},
abstract={In this study, we explore the impact of genre and navigation on user comprehension, preferences, and behaviors when experiencing data-driven disease stories. Our between-subject study (n=85) evaluated these aspects in-the-wild, with results pointing towards some general design considerations to keep in mind when authoring data-driven disease stories. Combining storytelling with interactive new media techniques, narrative medical visualization is a promising approach to communicating topics in medicine to a general audience in an accessible manner. For patients, visual storytelling may help them to better understand medical procedures and treatment options for more informed decision-making, boost their confidence and alleviate anxiety, and promote stronger personal health advocacy. Narrative medical visualization provides the building blocks for producing data-driven disease stories, which may be presented in several visual styles. These different styles correspond to different narrative genres, e.g., a Slideshow. Narrative genres can employ different navigational approaches. For instance, a Slideshow may rely on click interactions to advance through a story, while Scrollytelling typically uses vertical scrolling for navigation. While a common goal of a narrative medical visualization is to encourage a particular behavior, e.g., quitting smoking, it is unclear to what extent the choice of genre influences subsequent user behavior. Our study opens a new research direction into choice of narrative genre on user preferences and behavior in data-driven disease stories.},
pdf = {pdfs/mittenentzwei2023userbehavior.pdf},
images = {images/mittenentzwei2023userbehavior.png},
thumbnails = {images/mittenentzwei2023userbehavior-thumb.png},
project = {VIDI},
doi={10.1016/j.cag.2023.06.011}
}
    [PDF] [DOI] [Bibtex] 
    @article{garrison2023molaesthetics,
author={Garrison, Laura A. and Goodsell, David S. and Bruckner, Stefan},
journal={IEEE Computer Graphics and Applications},
title={Changing Aesthetics in Biomolecular Graphics},
year={2023},
volume={43},
number={3},
pages={94-101},
doi={10.1109/MCG.2023.3250680},
abstract={Aesthetics for the visualization of biomolecular structures have evolved over the years according to technological advances, user needs, and modes of dissemination. In this article, we explore the goals, challenges, and solutions that have shaped the current landscape of biomolecular imagery from the overlapping perspectives of computer science, structural biology, and biomedical illustration. We discuss changing approaches to rendering, color, human–computer interface, and narrative in the development and presentation of biomolecular graphics. With this historical perspective on the evolving styles and trends in each of these areas, we identify opportunities and challenges for future aesthetics in biomolecular graphics that encourage continued collaboration from multiple intersecting fields.},
pdf = {pdfs/garrison-aestheticsmol.pdf},
images = {images/garrison-aestheticsmol.png},
thumbnails = {images/garrison-aestheticsmol-thumb.png},
project = {VIDI}
}

2022

    [PDF] [Bibtex] 
    @phdthesis{moerth2022thesis,
title = {Scaling Up Medical Visualization: Multi-Modal, Multi-Patient, and Multi-Audience Approaches for Medical Data Exploration, Analysis and Communication},
author = {Mörth, Eric},
year = 2022,
month = {September},
isbn = 9788230862193,
url = {https://hdl.handle.net/11250/3014336},
school = {Department of Informatics, University of Bergen, Norway},
abstract = {
Medical visualization is one of the most application-oriented areas of visualization research. Close collaboration with medical experts is essential for interpreting medical imaging data and creating meaningful visualization techniques and visualization applications. Cancer is one of the most common causes of death, and with increasing average age in developed countries, gynecological malignancy case numbers are rising. Modern imaging techniques are an essential tool in assessing tumors and produce an increasing number of imaging data radiologists must interpret. Besides the number of imaging modalities, the number of patients is also rising, leading to visualization solutions that must be scaled up to address the rising complexity of multi-modal and multi-patient data. Furthermore, medical visualization is not only targeted toward medical professionals but also has the goal of informing patients, relatives, and the public about the risks of certain diseases and potential treatments. Therefore, we identify the need to scale medical visualization solutions to cope with multi-audience data.
This thesis addresses the scaling of these dimensions in different contributions we made. First, we present our techniques to scale medical visualizations in multiple modalities. We introduced a visualization technique using small multiples to display the data of multiple modalities within one imaging slice. This allows radiologists to explore the data efficiently without having several juxtaposed windows. In the next step, we developed an analysis platform using radiomic tumor profiling on multiple imaging modalities to analyze cohort data and to find new imaging biomarkers. Imaging biomarkers are indicators based on imaging data that predict clinical outcome related variables. Radiomic tumor profiling is a technique that generates potential imaging biomarkers based on first and second-order statistical measurements. The application allows medical experts to analyze the multi-parametric imaging data to find potential correlations between clinical parameters and the radiomic tumor profiling data. This approach scales up in two dimensions, multi-modal and multi-patient. In a later version, we added features to scale the multi-audience dimension by making our application applicable to cervical and prostate cancer data and the endometrial cancer data the application was designed for. In a subsequent contribution, we focus on tumor data on another scale and enable the analysis of tumor sub-parts by using the multi-modal imaging data in a hierarchical clustering approach. Our application finds potentially interesting regions that could inform future treatment decisions. In another contribution, the digital probing interaction, we focus on multi-patient data. The imaging data of multiple patients can be compared to find interesting tumor patterns potentially linked to the aggressiveness of the tumors. Lastly, we scale the multi-audience dimension with our similarity visualization applicable to endometrial cancer research, neurological cancer imaging research, and machine learning research on the automatic segmentation of tumor data. In contrast to the previously highlighted contributions, our last contribution, ScrollyVis, focuses primarily on multi-audience communication. We enable the creation of dynamic scientific scrollytelling experiences for a specific or general audience. Such stories can be used for specific use cases such as patient-doctor communication or communicating scientific results via stories targeting the general audience in a digital museum exhibition.
Our proposed applications and interaction techniques have been demonstrated in application use cases and evaluated with domain experts and focus groups. As a result, we brought some of our contributions to usage in practice at other research institutes. We want to evaluate their impact on other scientific fields and the general public in future work.
},
pdf = {pdfs/Moerth-PhD-Thesis-2022.pdf},
images = {images/Moerth-PhD-Thesis-2022.PNG},
thumbnails = {images/Moerth-PhD-Thesis-2022.PNG},
project = {ttmedvis}
}
    [PDF] [DOI] [YT] [Bibtex] 
    @inproceedings {Trautner-2022-HCP,
author = {Trautner, Thomas and Sbardellati, Maximilian and Stoppel, Sergej and Bruckner, Stefan},
title = {{Honeycomb Plots: Visual Enhancements for Hexagonal Maps}},
booktitle = {Proc. of VMV 2022: Vision, Modeling, and Visualization},
editor = {Bender, Jan and Botsch, Mario and Keim, Daniel A.},
pages = {65--73},
year = {2022},
publisher = {The Eurographics Association},
ISBN = {978-3-03868-189-2},
DOI = {10.2312/vmv.20221205},
abstract = {Aggregation through binning is a commonly used technique for visualizing large, dense, and overplotted two-dimensional data sets. However, aggregation can hide nuanced data-distribution features and complicates the display of multiple data-dependent variables, since color mapping is the primary means of encoding. In this paper, we present novel techniques for enhancing hexplots with spatialization cues while avoiding common disadvantages of three-dimensional visualizations. In particular, we focus on techniques relying on preattentive features that exploit shading and shape cues to emphasize relative value differences. Furthermore, we introduce a novel visual encoding that conveys information about the data distributions or trends within individual tiles. Based on multiple usage examples from different domains and real-world scenarios, we generate expressive visualizations that increase the information content of classic hexplots and validate their effectiveness in a user study.},
pdf = "pdfs/Trautner-2022-HCP.pdf",
thumbnails = "images/Trautner-2022-HCP-thumb.png",
images = "images/Trautner-2022-HCP-thumb.png",
youtube = "https://youtu.be/mU7QFVP3yKQ",
git = "https://github.com/TTrautner/HoneycombPlots"
}
    [PDF] [Bibtex] 
    @phdthesis{trautner2022thesis,
title = {Visualization Hybridization with Spatialization Cues},
author = {Thomas Bernhard Trautner},
year = 2022,
month = {November},
isbn = 9788230855515,
url = {https://hdl.handle.net/11250/3031041},
school = {Department of Informatics, University of Bergen, Norway},
abstract = {
Visualization as a tool for visual processing of any underlying data has proven to be an accepted and legitimate part of the scientific reasoning process. Many different techniques help gaining new insights from captured phenomena, support the development or evaluation of hypotheses about collected data, reveal potential misconceptions or false assumptions, simplify communicating knowledge and novel findings, and enable a multitude of additional opportunities. The reason for this effectiveness is that the human visual system is ideally suited to capture and process visually encoded data. The development of visualization from a niche to an established scientific field has made a significant contribution to this success story. A large number of journals, conferences, seminars, and workshops regularly publish new results, evaluate presented approaches, and help making knowledge globally accessible. However, this large number of contributions tailored to variable user groups, the underlying data, and the wide variety of tasks that could be performed with them, emphasizes the plethora of available techniques and the resulting difficulty in choosing the most suitable visualizations.
Therefore, we investigated common data sets and analyzed typical tasks normally performed with them. Based on this, we selected well-established and most effective visualization techniques, combining them to form a hybrid representation. The goal of such a visualization hybridization was to merge advantages of individual techniques and, thereby, simultaneously eliminate their limitations. We present so-called hybrid vigors that make the underlying visualizations more widely applicable instead of either having to change required techniques sequentially, or not being able to perform certain tasks at all. Our contributions are intended to simplify the process of finding suitable visualizations for already established data sets. During our research, we focused on two-dimensional point data, depicted on the one hand as scatter plots and, on the other hand, as relationships between consecutive point such as in line charts. Our techniques can be used especially when data sets are so large, dense, and overplotted that conventional techniques reach their limits. We show that hybrid representations are well suited for combining discrete, continuous, or aggregated forms of visual representation. Our hybridizations additionally exploit spatialization cues. Such visual cues emphasize spatiality of the underlying data through shading, without having to embed the data in 3D space including its potential disadvantages. We chose this method of encoding as we consider it the most appropriate choice, given that visualization users interact naturally and preattentively with a spatial world on a daily basis.
},
pdf = {pdfs/Trautner-PhD-Thesis-2022.pdf},
images = {images/Trautner-2022-PhD.png},
thumbnails = {images/Trautner-2022-PhD.png},
project = {MetaVis}
}
    [PDF] [Bibtex] 
    @phdthesis{garrison2022thesis,
title = {
From Molecules to the Masses: Visual Exploration, Analysis, and Communication
of Human Physiology
},
author = {Laura Ann Garrison},
year = 2022,
month = {September},
isbn = 9788230841389,
url = {https://hdl.handle.net/11250/3015990},
school = {Department of Informatics, University of Bergen, Norway},
abstract = {
The overarching theme of this thesis is the cross-disciplinary application of
medical illustration and visualization techniques to address challenges in
exploring, analyzing, and communicating aspects of physiology to audiences
with differing expertise.
Describing the myriad biological processes occurring in living beings over
time, the science of physiology is complex and critical to our understanding
of how life works. It spans many spatio-temporal scales to combine and bridge
the basic sciences (biology, physics, and chemistry) to medicine. Recent
years have seen an explosion of new and finer-grained experimental and
acquisition methods to characterize these data. The volume and complexity of
these data necessitate effective visualizations to complement standard
analysis practice. Visualization approaches must carefully consider and be
adaptable to the user's main task, be it exploratory, analytical, or
communication-oriented. This thesis contributes to the areas of theory,
empirical findings, methods, applications, and research replicability in
visualizing physiology. Our contributions open with a state-of-the-art report
exploring the challenges and opportunities in visualization for physiology.
This report is motivated by the need for visualization researchers, as well
as researchers in various application domains, to have a centralized,
multiscale overview of visualization tasks and techniques. Using a
mixed-methods search approach, this is the first report of its kind to
broadly survey the space of visualization for physiology. Our approach to
organizing the literature in this report enables the lookup of topics of
interest according to spatio-temporal scale. It further subdivides works
according to any combination of three high-level visualization tasks:
exploration, analysis, and communication. This provides an easily-navigable
foundation for discussion and future research opportunities for audience- and
task-appropriate visualization for physiology. From this report, we identify
two key areas for continued research that begin narrowly and subsequently
broaden in scope: (1) exploratory analysis of multifaceted physiology data
for expert users, and (2) communication for experts and non-experts alike.
Our investigation of multifaceted physiology data takes place over two
studies. Each targets processes occurring at different spatio-temporal scales
and includes a case study with experts to assess the applicability of our
proposed method. At the molecular scale, we examine data from magnetic
resonance spectroscopy (MRS), an advanced biochemical technique used to
identify small molecules (metabolites) in living tissue that are indicative
of metabolic pathway activity. Although highly sensitive and specific, the
output of this modality is abstract and difficult to interpret. Our design
study investigating the tasks and requirements for expert exploratory
analysis of these data led to SpectraMosaic, a novel application enabling
domain researchers to analyze any permutation of metabolites in ratio form
for an entire cohort, or by sample region, individual, acquisition date, or
brain activity status at the time of acquisition. A second approach considers
the exploratory analysis of multidimensional physiological data at the
opposite end of the spatio-temporal scale: population. An effective
exploratory data analysis workflow critically must identify interesting
patterns and relationships, which becomes increasingly difficult as data
dimensionality increases. Although this can be partially addressed with
existing dimensionality reduction techniques, the nature of these techniques
means that subtle patterns may be lost in the process. In this approach, we
describe DimLift, an iterative dimensionality reduction technique enabling
user identification of interesting patterns and relationships that may lie
subtly within a dataset through dimensional bundles. Key to this method is
the user's ability to steer the dimensionality reduction technique to follow
their own lines of inquiry.
Our third question considers the crafting of visualizations for communication
to audiences with different levels of expertise. It is natural to expect that
experts in a topic may have different preferences and criteria to evaluate a
visual communication relative to a non-expert audience. This impacts the
success of an image in communicating a given scenario. Drawing from diverse
techniques in biomedical illustration and visualization, we conducted an
exploratory study of the criteria that audiences use when evaluating a
biomedical process visualization targeted for communication. From this study,
we identify opportunities for further convergence of biomedical illustration
and visualization techniques for more targeted visual communication design.
One opportunity that we discuss in greater depth is the development of
semantically-consistent guidelines for the coloring of molecular scenes. The
intent of such guidelines is to elevate the scientific literacy of non-expert
audiences in the context of molecular visualization, which is particularly
relevant to public health communication.
All application code and empirical findings are open-sourced and available
for reuse by the scientific community and public. The methods and findings
presented in this thesis contribute to a foundation of cross-disciplinary
biomedical illustration and visualization research, opening several
opportunities for continued work in visualization for physiology.
},
pdf = {pdfs/garrison-phdthesis.pdf},
images = {images/garrison-thesis.png},
thumbnails = {images/garrison-thesis-thumb.png},
project = {VIDI}
}
    [PDF] [DOI] [Bibtex] 
    @inproceedings {EichnerMoerth2022MuSIC,
booktitle = {Eurographics Workshop on Visual Computing for Biology and Medicine},
editor = {Renata G. Raidou and Björn Sommer and Torsten W. Kuhlen and Michael Krone and Thomas Schultz and Hsiang-Yun Wu},
title = {{MuSIC: Multi-Sequential Interactive Co-Registration for Cancer Imaging Data based on Segmentation Masks}},
author = {Eichner, Tanja* and Mörth, Eric* and Wagner-Larsen, Kari S. and Lura, Njål and Haldorsen, Ingfrid S. and Gröller, Eduard and Bruckner, Stefan and Smit, Noeska N.},
note = {Best Paper Honorable Mention at VCBM2022},
project = {ttmedvis},
year = {2022},
abstract = {In gynecologic cancer imaging, multiple magnetic resonance imaging (MRI) sequences are acquired per patient to reveal different tissue characteristics. However, after image acquisition, the anatomical structures can be misaligned in the various sequences due to changing patient location in the scanner and organ movements. The co-registration process aims to align the sequences to allow for multi-sequential tumor imaging analysis. However, automatic co-registration often leads to unsatisfying results. To address this problem, we propose the web-based application MuSIC (Multi-Sequential Interactive Co-registration). The approach allows medical experts to co-register multiple sequences simultaneously based on a pre-defined segmentation mask generated for one of the sequences. Our contributions lie in our proposed workflow. First, a shape matching algorithm based on dual annealing searches for the tumor position in each sequence. The user can then interactively adapt the proposed segmentation positions if needed. During this procedure, we include a multi-modal magic lens visualization for visual quality assessment. Then, we register the volumes based on the segmentation mask positions. We allow for both rigid and deformable registration. Finally, we conducted a usability analysis with seven medical and machine learning experts to verify the utility of our approach. Our participants highly appreciate the multi-sequential setup and see themselves using MuSIC in the future.
Best Paper Honorable Mention at VCBM2022},
publisher = {The Eurographics Association},
ISSN = {2070-5786},
ISBN = {978-3-03868-177-9},
DOI = {10.2312/vcbm.20221190},
pdf = {pdfs/EichnerMoerth_2022.pdf},
thumbnails = {images/EichnerMoerth_2022.PNG},
images = {images/EichnerMoerth_2022.PNG},
}
    [PDF] [DOI] [Bibtex] 
    @inproceedings {Kleinau2022Tornado,
booktitle = {Eurographics Workshop on Visual Computing for Biology and Medicine},
editor = {Renata G. Raidou and Björn Sommer and Torsten W. Kuhlen and Michael Krone and Thomas Schultz and Hsiang-Yun Wu},
title = {{Is there a Tornado in Alex's Blood Flow? A Case Study for Narrative Medical Visualization}},
project = {ttmedvis},
author = {Kleinau, Anna and Stupak, Evgenia and Mörth, Eric and Garrison, Laura A. and Mittenentzwei, Sarah and Smit, Noeska N. and Lawonn, Kai and Bruckner, Stefan and Gutberlet, Matthias and Preim, Bernhard and Meuschke, Monique},
year = {2022},
abstract = {Narrative visualization advantageously combines storytelling with new media formats and techniques, like interactivity, to create improved learning experiences. In medicine, it has the potential to improve patient understanding of diagnostic procedures and treatment options, promote confidence, reduce anxiety, and support informed decision-making. However, limited scientific research has been conducted regarding the use of narrative visualization in medicine. To explore the value of narrative visualization in this domain, we introduce a data-driven story to inform a broad audience about the usage of measured blood flow data to diagnose and treat cardiovascular diseases. The focus of the story is on blood flow vortices in the aorta, with which imaging technique they are examined, and why they can be dangerous. In an interdisciplinary team, we define the main contents of the story and the resulting design questions. We sketch the iterative design process and implement the story based on two genres. In a between-subject study, we evaluate the suitability and understandability of the story and the influence of different navigation concepts on user experience. Finally, we discuss reusable concepts for further narrative medical visualization projects.},
publisher = {The Eurographics Association},
ISSN = {2070-5786},
ISBN = {978-3-03868-177-9},
DOI = {10.2312/vcbm.20221183},
pdf = {pdfs/Kleinau_2022.pdf},
thumbnails = {images/Kleinau_2022.PNG},
images = {images/Kleinau_2022.PNG},
}
    [PDF] [DOI] [Bibtex] 
    @article{Meuschke2022narrative,
title = {Narrative medical visualization to communicate disease data},
author = {Meuschke, Monique and Garrison, Laura A. and Smit, Noeska N. and Bach, Benjamin and Mittenentzwei, Sarah and Wei{\ss}, Veronika and Bruckner, Stefan and Lawonn, Kai and Preim, Bernhard},
year = 2022,
journal = {Computers & Graphics},
volume = 107,
pages = {144--157},
doi = {10.1016/j.cag.2022.07.017},
issn = {0097-8493},
url = {https://www.sciencedirect.com/science/article/pii/S009784932200139X},
abstract = {This paper explores narrative techniques combined with medical visualizations to tell data-driven stories about diseases for a general audience. The field of medical illustration uses narrative visualization through hand-crafted techniques to promote health literacy. However, data-driven narrative visualization has rarely been applied to medical data. We derived a template for creating stories about diseases and applied it to three selected diseases to demonstrate how narrative techniques could support visual communication and facilitate understanding of medical data. One of our main considerations is how interactive 3D anatomical models can be integrated into the story and whether this leads to compelling stories in which the users feel involved. A between-subject study with 90 participants suggests that the combination of a carefully designed narrative structure, the constant involvement of a specific patient, high-qualitative visualizations combined with easy-to-use interactions, are critical for an understandable story about diseases that would be remembered by participants.},
pdf = {pdfs/Narrative_medical_MEUSCHKE_DOA18072022_AFV.pdf},
thumbnails = {images/Meuschke2022narrative-thumb.png},
images = {images/Meuschke2022narrative.png},
project = {VIDI}
}
    [PDF] [DOI] [Bibtex] 
    @Article{Moerth2022ScrollyVis,
author = {Mörth, Eric and Bruckner, Stefan and Smit, Noeska N.},
title = {ScrollyVis: Interactive visual authoring of guided dynamic narratives for scientific scrollytelling},
journal = {IEEE Transactions on Visualization and Computer Graphics},
year = {2022},
volume = {},
abstract = {Visual stories are an effective and powerful tool to convey specific information to a diverse public. Scrollytelling is a recent visual storytelling technique extensively used on the web, where content appears or changes as users scroll up or down a page. By employing the familiar gesture of scrolling as its primary interaction mechanism, it provides users with a sense of control, exploration and discoverability while still offering a simple and intuitive interface. In this paper, we present a novel approach for authoring, editing, and presenting data-driven scientific narratives using scrollytelling. Our method flexibly integrates common sources such as images, text, and video, but also supports more specialized visualization techniques such as interactive maps as well as scalar field and mesh data visualizations. We show that scrolling navigation can be used to traverse dynamic narratives and demonstrate how it can be combined with interactive parameter exploration. The resulting system consists of an extensible web-based authoring tool capable of exporting stand-alone stories that can be hosted on any web server. We demonstrate the power and utility of our approach with case studies from several diverse scientific fields and with a user study including 12 participants of diverse professional backgrounds. Furthermore, an expert in creating interactive articles assessed the usefulness of our approach and the quality of the created stories.},
project = {ttmedvis},
pdf = {pdfs/Moerth_2022_ScrollyVis.pdf},
thumbnails = {images/Moerth_2022_ScrollyVis.png},
images = {images/Moerth_2022_ScrollyVis.png},
pages={1-12},
doi={10.1109/TVCG.2022.3205769},
}
    [PDF] [DOI] [VID] [Bibtex] 
    @article{Moerth2022ICEVis,
title = {ICEVis: Interactive Clustering Exploration for tumor sub-region analysis in multiparametric cancer imaging},
author = {Mörth, Eric and Eichner, Tanja and Ingfrid, Haldorsen and Bruckner, Stefan and Smit, Noeska N.},
year = 2022,
journal = {Proceedings of the International Symposium on Visual Information Communication and Interaction (VINCI'22)},
volume = {15},
pages = {5},
doi = {10.1145/3554944.3554958},
issn = {},
url = {},
abstract = {Tumor tissue characteristics derived from imaging data are gaining importance in clinical research. Tumor sub-regions may play a critical role in defining tumor types and may hold essential information about tumor aggressiveness. Depending on the tumor’s location within the body, such sub-regions can be easily identified and determined by physiology, but these sub-regions are not readily visible to others. Regions within a tumor are currently explored by comparing the image sequences and analyzing the tissue heterogeneity present. To improve the exploration of such tumor sub-regions, we propose a visual analytics tool called ICEVis. ICEVis supports the identification of tumor sub-regions and corresponding features combined with cluster visualizations highlighting cluster validity. It is often difficult to estimate the optimal number of clusters; we provide rich facilities to support this task, incorporating various statistical measures and interactive exploration of the results. We evaluated our tool with three clinical researchers to show the potential of our approach.
Best Short Paper at VINCI2022},
images = "images/Moerth_2022_ICEVis.png",
thumbnails = "images/Moerth_2022_ICEVis.png",
pdf = {pdfs/Moerth_2022_ICEVis.pdf},
vid = {vids/ICEVis.mp4},
project = "ttmedvis",
}
    [PDF] [Bibtex] 
    @article{Kristiansen2022ContentDriven,
title = {Content-Driven Layout for Visualization Design},
author = {Kristiansen, Yngve and Garrison, Laura and Bruckner, Stefan},
year = 2022,
journal = {Proceedings of the International Symposium on Visual Information Communication and Interaction (to appear)},
volume = {},
pages = {},
doi = {},
issn = {},
url = {},
abstract = {Multi-view visualizations are typically presented in a grid layout with elements positioned according to their bounding rectangles. These rectangles often contain unused white space. In cases where Tufte’s Shrink Principle can be applied to reduce non-data-ink without impairing the communication of information, unused white space can be utilized for the placement of other elements. This is often done in manually “hand-crafted” layouts by designers. However, upon changes to individual elements, this design process has to be repeated. To reduce non-data-ink and repetitive manual design, we contribute a method for automatically turning a grid layout into a content-driven layout, where elements are positioned with respect to their contents. Existing approaches have explored the use of a force simulation in conjunction with proxy geometries to simplify collision handling for irregular shapes. Such customized force directed layouts are usually unstable, and often require additional constraints to run properly. In addition, proxy geometries become less accurate and effective with more irregular shapes. To solve these shortcomings, we contribute an approach for identifying central elements in an original grid layout in order to set up corresponding attractive forces. Furthermore, we utilize an imagebased approach for collision detection and avoidance that works accurately for highly irregular shapes. We demonstrate the utility of our approach with three case studies.},
images = "images/Kristiansen-2022-LungsDt.PNG",
thumbnails = "images/Kristiansen-2022-LungsDt.PNG",
pdf = {pdfs/Kristiansen-2022-CDL.pdf},
project = "MetaVis",
}
    [DOI] [YT] [Bibtex] 
    @article{Sugathan2022Longitudinal,
title = {Longitudinal visualization for exploratory analysis of multiple sclerosis lesions},
author = {Sugathan, Sherin and Bartsch, Hauke and Riemer, Frank and Gr{\"u}ner, Renate and Lawonn, Kai and Smit, Noeska},
year = 2022,
journal = {Computers & Graphics},
volume = 107,
pages = {208--219},
doi = {10.1016/j.cag.2022.07.023},
issn = {0097-8493},
url = {https://www.sciencedirect.com/science/article/pii/S0097849322001479},
images = "images/Sugathan-2022-Longitudinal.PNG",
thumbnails = "images/Sugathan-2022-Longitudinal.PNG",
project = {ttmedvis},
youtube = "https://youtu.be/uwcqSf1W-dc"
}
    [DOI] [Bibtex] 
    @article{VandenBossche2022Digital,
title = {Digital body preservation: Technique and applications},
author = {Vandenbossche, Vicky and Van de Velde, Joris and Avet, Stind and Willaert, Wouter and Soltvedt, Stian and Smit, Noeska and Audenaert, Emmanuel},
year = 2022,
journal = {Anatomical Sciences Education},
volume = {15},
number = {4},
pages = {731--744},
doi = {https://doi.org/10.1002/ase.2199},
url = {https://anatomypubs.onlinelibrary.wiley.com/doi/abs/10.1002/ase.2199},
images = "images/VandenBossche-2022-Digital.PNG",
thumbnails = "images/VandenBossche-2022-Digital.PNG",
project = {ttmedvis}
}
    [DOI] [Bibtex] 
    @article{Wagner2022Interobserver,
title = {Interobserver agreement and prognostic impact for {MRI}--based 2018 {FIGO} staging parameters in uterine cervical cancer},
author = {Wagner-Larsen, Kari S and Lura, Nj{\aa}l and Salvesen, {\O}yvind and Halle, Mari Kylles{\o} and Forsse, David and Trovik, Jone and Smit, Noeska and Krakstad, Camilla and Haldorsen, Ingfrid S},
year = 2022,
journal = {European Radiology},
publisher = {Springer},
pages = {1--12},
doi = {10.1007/s00330-022-08666-x},
url = {https://link.springer.com/article/10.1007/s00330-022-08666-x},
images = "images/Wagner-2022-Interobserver.PNG",
thumbnails = "images/Wagner-2022-Interobserver.PNG",
project = {ttmedvis}
}
    [DOI] [Bibtex] 
    @article{Hodneland2022Fully,
title = {Fully Automatic Whole-Volume Tumor Segmentation in Cervical Cancer},
author = {Hodneland, Erlend and Kaliyugarasan, Satheshkumar and Wagner-Larsen, Kari Str{\o}no and Lura, Nj{\aa}l and Andersen, Erling and Bartsch, Hauke and Smit, Noeska and Halle, Mari Kylles{\o} and Krakstad, Camilla and Lundervold, Alexander Selvikv{\aa}g and Haldorsen, Ingfrid S},
year = 2022,
journal = {Cancers},
publisher = {MDPI},
volume = 14,
number = 10,
pages = 2372,
doi = {10.3390/cancers14102372},
url = {https://pubmed.ncbi.nlm.nih.gov/35625977/},
images = "images/Hodneland-2022-Fully.PNG",
thumbnails = "images/Hodneland-2022-Fully.PNG",
project = {ttmedvis}
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {Garrison2022MolColor,
author = "Laura A. Garrison and Stefan Bruckner",
title = "Considering Best Practices in Color Palettes for Molecular Visualizations",
journal = "Journal of Integrative Bioinformatics",
year = "2022",
abstract = "Biomedical illustration and visualization techniques provide a window into complex molecular worlds that are difficult to capture through experimental means alone. Biomedical illustrators frequently employ color to help tell a molecular story, e.g., to identify key molecules in a signaling pathway. Currently, color use for molecules is largely arbitrary and often chosen based on the client, cultural factors, or personal taste. The study of molecular dynamics is relatively young, and some stakeholders argue that color use guidelines would throttle the growth of the field. Instead, content authors have ample creative freedom to choose an aesthetic that, e.g., supports the story they want to tell. However, such creative freedom comes at a price. The color design process is challenging, particularly for those without a background in color theory. The result is a semantically inconsistent color space that reduces the interpretability and effectiveness of molecular visualizations as a whole. Our contribution in this paper is threefold. We first discuss some of the factors that contribute to this array of color palettes. Second, we provide a brief sampling of color palettes used in both industry and research sectors. Lastly, we suggest considerations for developing best practices around color palettes applied to molecular visualization.",
images = "images/garrison-molecularcolor-full.png",
thumbnails = "images/garrison-molecularcolor-thumb.png",
pdf = "pdfs/garrison-molecularcolor.pdf",
publisher = "De Gruyter",
doi = "10.1515/jib-2022-0016",
project = "VIDI"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {Garrison2022PhysioSTAR,
author = "Laura A. Garrison and Ivan Kolesar and Ivan Viola and Helwig Hauser and Stefan Bruckner",
title = "Trends & Opportunities in Visualization for Physiology: A Multiscale Overview",
journal = "Computer Graphics Forum",
year = "2022",
volume = "41",
number = "3",
publisher = "The Eurographics Association and John Wiley & Sons Ltd.",
pages = "609-643",
doi = "10.1111/cgf.14575",
abstract = "Combining elements of biology, chemistry, physics, and medicine, the science of human physiology is complex and multifaceted. In this report, we offer a broad and multiscale perspective on key developments and challenges in visualization for physiology. Our literature search process combined standard methods with a state-of-the-art visual analysis search tool to identify surveys and representative individual approaches for physiology. Our resulting taxonomy sorts literature on two levels. The first level categorizes literature according to organizational complexity and ranges from molecule to organ. A second level identifies any of three high-level visualization tasks within a given work: exploration, analysis, and communication. The findings of this report may be used by visualization researchers to understand the overarching trends, challenges, and opportunities in visualization for physiology and to provide a foundation for discussion and future research directions in this area. ",
images = "images/garrison-STAR-taxonomy.png",
thumbnails = "images/garrison-STAR-thumb.png",
pdf = "pdfs/Garrison_STAR_cameraready.pdf",
publisher = "The Eurographics Association and John Wiley \& Sons Ltd.",
project = "VIDI"
}

2021

    [PDF] [YT] [Bibtex] 
    @inproceedings{Rijken-2021-Illegible,
title = {Illegible Semantics: Exploring the Design Space of Metal Logos},
author = {Gerrit J. Rijken and Rene Cutura and Frank Heyen and Michael Sedlmair and Michael Correll and Jason Dykes and Noeska Smit},
year = 2021,
booktitle = {Proceedings of the {alt.VIS} workshop at {IEEE VIS}},
eprint = {2109.01688},
archiveprefix = {arXiv},
primaryclass = {cs.HC},
pdf = {pdfs/Rijken-2021-Illegible.pdf},
thumbnails = {images/Rijken-2021-Illegible.png},
images = {images/Rijken-2021-Illegible.png},
abstract = {The logos of metal bands can be by turns gaudy, uncouth, or nearly illegible. Yet, these logos work: they communicate sophisticated notions of genre and emotional affect. In this paper we use the design considerations of metal logos to explore the space of ``illegible semantics'': the ways that text can communicate information at the cost of readability, which is not always the most important objective. In this work, drawing on formative visualization theory, professional design expertise, and empirical assessments of a corpus of metal band logos, we describe a design space of metal logos and present a tool through which logo characteristics can be explored through visualization. We investigate ways in which logo designers imbue their text with meaning and consider opportunities and implications for visualization more widely.},
youtube = "https://youtu.be/BZOdIhU-mrA",
}
    [PDF] [DOI] [YT] [Bibtex] 
    @inproceedings{Smit-2021-DataKnitualization,
title = {Data Knitualization: An Exploration of Knitting as a Visualization Medium},
author = {Noeska Smit},
year = 2021,
booktitle = {Proceedings of the {alt.VIS} workshop at {IEEE VIS}},
doi = {10.31219/osf.io/xahj9},
pdf = {pdfs/Smit-2021-DataKnitualization.pdf},
thumbnails = {images/Smit-2021-DataKnitualization.jpg},
images = {images/Smit-2021-DataKnitualization.jpg},
abstract = {While data visualization can be achieved in many media, from hand-drawn on paper to 3D printed via data physicalization, the ancient craft of knitting is not often considered as a visualization medium. With this work, I explore hand knitting as a potential data visualization medium based on my personal experience as a knitter and visualization researcher.},
youtube = "https://youtu.be/K3D-M7jzbMs",
}
    [PDF] [DOI] [Bibtex] 
    @article{Gillmann-2021-Viewpoints,
author = {C. Gillmann and N. N. Smit and E. Groller and B. Preim and A. Vilanova and T. Wischgoll},
journal = {IEEE Computer Graphics and Applications},
title = {Ten Open Challenges in Medical Visualization},
year = {2021},
volume = {41},
number = {05},
issn = {1558-1756},
pages = {7-15},
keywords = {deep learning;uncertainty;data visualization;medical services;standardization;artificial intelligence;biomedical imaging},
doi = {10.1109/MCG.2021.3094858},
publisher = {IEEE Computer Society},
address = {Los Alamitos, CA, USA},
pdf = {pdfs/Gillmann-2021-Viewpoints.pdf},
thumbnails = {images/Gillmann-2021-Viewpoints.png},
images = {images/Gillmann-2021-Viewpoints.png},
project = {ttmedvis},
abstract = {The medical domain has been an inspiring application area in visualization research for many years already, but many open challenges remain. The driving forces of medical visualization research have been strengthened by novel developments, for example, in deep learning, the advent of affordable VR technology, and the need to provide medical visualizations for broader audiences. At IEEE VIS 2020, we hosted an Application Spotlight session to highlight recent medical visualization research topics. With this article, we provide the visualization community with ten such open challenges, primarily focused on challenges related to the visualization of medical imaging data. We first describe the unique nature of medical data in terms of data preparation, access, and standardization. Subsequently, we cover open visualization research challenges related to uncertainty, multimodal and multiscale approaches, and evaluation. Finally, we emphasize challenges related to users focusing on explainable AI, immersive visualization, P4 medicine, and narrative visualization.}
}
    [PDF] [DOI] [Bibtex] 
    @inproceedings{Hushagen-2021-VCBM,
title = {The Role of Depth Perception in {XR} from a Neuroscience Perspective: A Primer and Survey},
author = {Hushagen, Vetle and Tresselt, Gustav C. and Smit, Noeska N. and Specht, Karsten},
year = 2021,
booktitle = {Eurographics Workshop on Visual Computing for Biology and Medicine},
publisher = {The Eurographics Association},
doi = {10.2312/vcbm.20211344},
isbn = {978-3-03868-140-3},
issn = {2070-5786},
url = {https://diglib.eg.org/handle/10.2312/vcbm20211344},
pdf = {pdfs/Hushagen-2021-VCBM.pdf},
thumbnails = {images/Hushagen-2021-VCBM.png},
images = {images/Hushagen-2021-VCBM.png},
project = {ttmedvis},
abstract = {Augmented and virtual reality (XR) are potentially powerful tools for enhancing the efficiency of interactive visualization of complex data in biology and medicine. The benefits of visualization of digital objects in XR mainly arise from enhanced depth perception due to the stereoscopic nature of XR head mounted devices. With the added depth dimension, XR is in a prime position to convey complex information and support tasks where 3D information is important. In order to inform the development of novel XR applications in the biology and medicine domain, we present a survey which reviews the neuroscientific basis underlying the immersive features of XR. To make this literature more accessible to the visualization community, we first describe the basics of the visual system, highlighting how visual features are combined to objects
and processed in higher cortical areas with a special focus on depth vision. Based on state of the art findings in neuroscience literature related to depth perception, we provide several recommendations for developers and designers. Our aim is to aid development of XR applications and strengthen development of tools aimed at molecular visualization, medical education, and surgery, as well as inspire new application areas.}
}
    [PDF] [DOI] [Bibtex] 
    @inproceedings{Sugathan-2021-VCBM,
title = {Interactive Multimodal Imaging Visualization for Multiple Sclerosis Lesion Analysis},
author = {Sugathan, Sherin and Bartsch, Hauke and Riemer, Frank and Gr{\"u}ner, Renate and Lawonn, Kai and Smit, Noeska N},
year = 2021,
booktitle = {Eurographics Workshop on Visual Computing for Biology and Medicine},
publisher = {The Eurographics Association},
doi = {10.2312/vcbm.20211346},
isbn = {978-3-03868-140-3},
issn = {2070-5786},
url = {https://diglib.eg.org/handle/10.2312/vcbm20211346},
pdf = {pdfs/Sugathan-2021-VCBM.pdf},
thumbnails = {images/Sugathan-2021-VCBM.png},
images = {images/Sugathan-2021-VCBM.png},
project = {ttmedvis},
abstract = {Multiple Sclerosis (MS) is a brain disease that is diagnosed and monitored extensively through MRI scans. One of the criteria is the appearance of so-called brain lesions. The lesions show up on MRI scans as regions with elevated or reduced contrast compared to the surrounding healthy tissue.
Understanding the complex interplay of contrast, location and shape in images from multiple modalities from 2D MRI slices is challenging.
Advanced visualization of appearance- and location-related features of lesions would help researchers in defining better disease characterization through MS research.
Since a permanent cure is not possible in MS and medication-based disease modification is a common treatment path, providing better visualizations would strengthen research which investigates the effect of white matter lesions. Here we present an advanced visualization solution that supports analysis from multiple imaging modalities acquired in a clinical routine examination. The solution holds potential for enabling researchers to have a more intuitive perception of lesion features. As an example for enhancing the analytic possibilities, we demonstrate the benefits of lesion projection using both Diffusion Tensor Imaging (DTI) and gradient-based techniques. This approach enables users to assess brain structures across individuals as the atlas-based analysis provides 3D anchoring and labeling of regions across a series of brain scans from the same participant and across different participants. The projections on the brain surface also enable researchers to conduct detailed studies on the relationship between cognitive disabilities and location of lesions. This allows researchers to correlate lesions to Brodmann areas and related brain functions.
We realize the solutions in a prototype application that supports both DTI and structural data. A qualitative evaluation demonstrates that our approach supports MS researchers by providing new opportunities for MS research.}
}
    [PDF] [DOI] [Bibtex] 
    @article{Beiglboeck2021,
doi = {10.1007/s11695-021-05763-6},
year = {2021},
month = nov,
publisher = {Springer Science and Business Media {LLC}},
author = {Hannes Beiglb\"{o}ck and Eric M\"{o}rth and Berthold Reichardt and Tanja Stamm and Bianca Itariu and J\"{u}rgen Harreiter and Miriam Hufgard-Leitner and Paul Fellinger and Jakob Eichelter and Gerhard Prager and Alexander Kautzky and Alexandra Kautzky-Willer and Peter Wolf and Michael Krebs},
title = {Sex-Specific Differences in Mortality of Patients with a History of Bariatric Surgery: a Nation-Wide Population-Based Study},
journal = {Obesity Surgery},
abstract = {Bariatric surgery reduces mortality in patients with severe obesity and is predominantly performed in women.
Therefore, an analysis of sex-specific differences after bariatric surgery in a population-based dataset from Austria was
performed. The focus was on deceased patients after bariatric surgery.
The Austrian health insurance funds cover about 98% of the Austrian population. Medical health
claims data of all Austrians who underwent bariatric surgery from 01/2010 to 12/2018 were analyzed. In total, 19,901 patients
with 107,806 observed years postoperative were eligible for this analysis. Comorbidities based on International Classification
of Diseases (ICD)-codes and drug intake documented by Anatomical Therapeutical Chemical (ATC)-codes were analyzed
in patients deceased and grouped according to clinically relevant obesity-associated comorbidities: diabetes mellitus (DM),
cardiovascular disease (CV), psychiatric disorder (PSY), and malignancy (M).
In total, 367 deaths were observed (1.8%) within the observation period from 01/2010 to 04/2020. The overall
mortality rate was 0.34% per year of observation and significantly higher in men compared to women (0.64 vs. 0.24%;
p < 0.001(Chi-squared)). Moreover, the 30-day mortality was 0.19% and sixfold higher in men compared to women (0.48
vs. 0.08%; p < 0.001). CV (82%) and PSY (55%) were the most common comorbidities in deceased patients with no sex-
specific differences. Diabetes (38%) was more common in men (43 vs. 33%; p = 0.034), whereas malignant diseases (36%)
were more frequent in women (30 vs. 41%; p = 0.025).
After bariatric surgery, short-term mortality as well as long-term mortality was higher in men compared to
women. In deceased patients, diabetes was more common in men, whereas malignant diseases were more common in women.},
pdf = {pdfs/Beiglboeck2021_Article_Sex-SpecificDifferencesInMorta.pdf},
thumbnails = {images/2021-Moerth-Diabetes-thumb.png},
images = {images/2021-Moerth-Diabetes.png},
keywords = {Bariatric surgery, Sex differences, Mortality, Population-based registry analysis, Comorbidities, Healthcare, research},
}
    [PDF] [DOI] [VID] [Bibtex] 
    @Article{Kristiansen-2021-SSG,
author = {Kristiansen, Y. S. and Garrison, L. and Bruckner, S.},
title = {Semantic Snapping for Guided Multi-View Visualization Design},
journal = {IEEE Transactions on Visualization and Computer Graphics},
year = {2021},
volume = {},
pages = {},
doi = {},
abstract = {Visual information displays are typically composed of multiple visualizations that are used to facilitate an understanding of the underlying data. A common example are dashboards, which are frequently used in domains such as finance, process monitoring and business intelligence. However, users may not be aware of existing guidelines and lack expert design knowledge when composing such multi-view visualizations. In this paper, we present semantic snapping, an approach to help non-expert users design effective multi-view visualizations from sets of pre-existing views. When a particular view is placed on a canvas, it is “aligned” with the remaining views–not with respect to its geometric layout, but based on aspects of the visual encoding itself, such as how data dimensions are mapped to channels. Our method uses an on-the-fly procedure to detect and suggest resolutions for conflicting, misleading, or ambiguous designs, as well as to provide suggestions for alternative presentations. With this approach, users can be guided to avoid common pitfalls encountered when composing visualizations. Our provided examples and case studies demonstrate the usefulness and validity of our approach.},
note = {Accepted for publication, to be presented at IEEE VIS 2021},
project = {MetaVis,VIDI},
pdf = {pdfs/Kristiansen-2021-SSG.pdf},
vid = {vids/Kristiansen-2021-SSG.mp4},
thumbnails = {images/Kristiansen-2021-SSG.png},
images = {images/Kristiansen-2021-SSG.jpg},
keywords = {tabular data, guidelines, mixed initiative human-machine analysis, coordinated and multiple views},
doi = {10.1109/TVCG.2021.3114860},
}
    [PDF] [Bibtex] 
    @InProceedings{Garrison-2021-EPP,
author = {Laura Garrison and Monique Meuschke and Jennifer Fairman and Noeska Smit and Bernhard Preim and Stefan Bruckner},
title = {An Exploration of Practice and Preferences for the Visual Communication of Biomedical Processes},
booktitle = {Proceedings of VCBM},
year = {2021},
pages = {},
doi = {},
abstract = {The visual communication of biomedical processes draws from diverse techniques in both visualization and biomedical illustration. However, matching these techniques to their intended audience often relies on practice-based heuristics or narrow-scope evaluations. We present an exploratory study of the criteria that audiences use when evaluating a biomedical process visualization targeted for communication. Designed over a series of expert interviews and focus groups, our study focuses on common communication scenarios of five well-known biomedical processes and their standard visual representations. We framed these scenarios in a survey with participant expertise spanning from minimal to expert knowledge of a given topic. Our results show frequent overlap in abstraction preferences between expert and non-expert audiences, with similar prioritization of clarity and the ability of an asset to meet a given communication objective. We also found that some illustrative conventions are not as clear as we thought, e.g., glows have broadly ambiguous meaning, while other approaches were unexpectedly preferred, e.g., biomedical illustrations in place of data-driven visualizations. Our findings suggest numerous opportunities for the continued convergence of visualization and biomedical illustration techniques for targeted visualization design.
Best Paper Honorable Mention at VCBM 2021},
note = {Accepted for publication, to be presented at VCBM 2021},
project = {VIDI,ttmedvis},
pdf = {pdfs/Garrison-2021-EPP.pdf},
thumbnails = {images/Garrison-2021-EPP.png},
images = {images/Garrison-2021-EPP.jpg},
url = {https://github.com/lauragarrison87/Biomedical_Process_Vis},
keywords = {biomedical illustration, visual communication, survey},
}
    [PDF] [DOI] [Bibtex] 
    @article{brushingComparison,
author={Fan, Chaoran and Hauser, Helwig},
journal={IEEE Computer Graphics and Applications},
title={On sketch-based selections from scatterplots using KDE, compared to Mahalanobis and CNN brushing},
year={2021},
volume={},
number={},
pages={1-13},
doi={10.1109/MCG.2021.3097889},
abstract = {"Fast and accurate brushing is crucial in visual data exploration and sketch-based solutions are successful methods. In this paper, we detail a solution, based on kernel density estimation (KDE), which computes a data subset selection in a scatterplot from a simple click-and-drag interaction. We explain, how this technique relates to two alternative approaches, i.e., Mahalanobis brushing and CNN brushing. To study this relation, we conducted two user studies and present both a quantitative three-fold comparison as well as additional details about the prevalence of all possible cases in that each technique succeeds/fails. With this, we also provide a comparison between empirical modeling and implicit modeling by deep learning in terms of accuracy, efficiency, generality and interpretability."},
pdf = "pdfs/Fan-2021-brushingComparison.pdf",
images = "images/Fan-2021-brushingComparison.png",
thumbnails = "images/Fan-2021-brushingComparison.png",
}
    [DOI] [Bibtex] 
    @incollection{Smit-2021-COMULIS,
author = {Smit, Noeska and Bühler, Katja and Vilanova, Anna and Falk, Martin},
title = {Visualisation for correlative multimodal imaging},
booktitle = {Imaging Modalities for Biological and Preclinical Research: A Compendium, Volume 2},
publisher = {IOP Publishing},
year = {2021},
series = {2053-2563},
type = {Book Chapter},
pages = {III.4.e-1 to III.4.e-10},
abstract = {In this chapter, we describe several approaches to interactive imaging data visualization in general, highlight several strategies for visualizing correlative multimodal imaging data, and provide examples and practical recommendations.},
url = {http://dx.doi.org/10.1088/978-0-7503-3747-2ch28},
doi = {10.1088/978-0-7503-3747-2ch28},
isbn = {978-0-7503-3747-2},
thumbnails = "images/Smit-2021-COMULIS.PNG",
images = "images/Smit-2021-COMULIS.PNG",
project = "ttmedvis",
abstract = {The field of visualisation deals with finding appropriate visual representations of data so people can effectively carry out tasks related to data exploration, analysis, or presentation using the power of the human visual perceptual system. In the context of biomedical imaging data, interactive visualisation techniques can be employed, for example, to visually explore data, as image processing quality assurance, or in publications to communicate findings. When dealing with correlative imaging, challenges arise in how to effectively convey the information from multiple sources. In particular, the information density leads to the need for a critical reflection on the visual design with respect to which parts of the data are important to show and at what level of importance they should be visualised. In this chapter, we describe several approaches to interactive imaging data visualisation in general, highlight several strategies for visualising correlative multimodal imaging data, and provide examples and practical recommendations.}
}
    [PDF] [DOI] [VID] [YT] [Bibtex] 
    @article{Trautner-2021-LWI,
author = {Trautner, Thomas and Bruckner, Stefan},
title = {Line Weaver: Importance-Driven Order Enhanced Rendering of Dense Line Charts},
journal = {Computer Graphics Forum},
volume = {40},
number = {3},
pages = {399--410},
keywords = {information visualization, visualization techniques, line charts},
doi = {10.1111/cgf.14316},
abstract = {Line charts are an effective and widely used technique for visualizing series of ordered two-dimensional data points. The relationship between consecutive points is indicated by connecting line segments, revealing potential trends or clusters in the underlying data. However, when dealing with an increasing number of lines, the render order substantially influences the resulting visualization. Rendering transparent lines can help but unfortunately the blending order is currently either ignored or naively used, for example, assuming it is implicitly given by the order in which the data was saved in a file. Due to the noncommutativity of classic alpha blending, this results in contradicting visualizations of the same underlying data set, so-called "hallucinators". In this paper, we therefore present line weaver, a novel visualization technique for dense line charts. Using an importance function, we developed an approach that correctly considers the blending order independently of the render order and without any prior sorting of the data. We allow for importance functions which are either explicitly given or implicitly derived from the geometric properties of the data if no external data is available. The importance can then be applied globally to entire lines, or locally per pixel which simultaneously supports various types of user interaction. Finally, we discuss the potential of our contribution based on different synthetic and real-world data sets where classic or naive approaches would fail.},
year = {2021},
pdf = "pdfs/Trautner-2021-LWI.pdf",
thumbnails = "images/Trautner-2021-LWI-thumb.png",
images = "images/Trautner-2021-LWI-thumb.png",
vid = "vids/Trautner_2021_LineWeaver_video.mp4",
youtube = "https://youtu.be/-hLF5XSR_ws",
project = "MetaVis",
git = "https://github.com/TTrautner/LineWeaver"
}
    [PDF] [VID] [Bibtex] 
    @article{Diehl-2021-HTC,
author = {Alexandra Diehl and Rodrigo Pelorosso and Juan Ruiz and Renato Pajarola and Meister Eduard Gr\"{o}ller and Stefan Bruckner},
title = {Hornero: Thunderstorms Characterization using Visual Analytics},
journal = {Computer Graphics Forum},
volume = {40},
number = {3},
pages = {},
keywords = {visual analytics, weather forecasting, nowcasting},
doi = {},
abstract = {Analyzing the evolution of thunderstorms is critical in determining the potential for the development of severe weather events. Existing visualization systems for short-term weather forecasting (nowcasting) allow for basic analysis and prediction of storm developments. However, they lack advanced visual features for efficient decision-making. We developed a visual analytics tool for the detection of hazardous thunderstorms and their characterization, using a visual design centered on a reformulated expert task workflow that includes visual features to overview storms and quickly identify high-impact weather events, a novel storm graph visualization to inspect and analyze the storm structure, as well as a set of interactive views for efficient identification of similar storm cells (known as analogs) in historical data and their use for nowcasting. Our tool was designed with and evaluated by meteorologists and expert forecasters working in short-term operational weather forecasting of severe weather events. Results show that our solution suits the forecasters’ workflow. Our visual design is expressive, easy to use, and effective for prompt analysis and quick decision-making in the context of short-range operational weather forecasting.},
year = {2021},
pdf = "pdfs/Diehl-2021-HTC.pdf",
thumbnails = "images/Diehl-2021-HTC.png",
images = "images/Diehl-2021-HTC.jpg",
vid = "vids/Diehl-2021-HTC.mp4",
project = "MetaVis"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Garrison-2021-DimLift,
author = {Garrison, Laura and M\"{u}ller, Juliane and Schreiber, Stefanie and Oeltze-Jafra, Steffen and Hauser, Helwig and Bruckner, Stefan},
title = {DimLift: Interactive Hierarchical Data Exploration through Dimensional Bundling},
journal={IEEE Transactions on Visualization and Computer Graphics},
year = {2021},
abstract = {The identification of interesting patterns and relationships is essential to exploratory data analysis. This becomes increasingly difficult in high dimensional datasets. While dimensionality reduction techniques can be utilized to reduce the analysis space, these may unintentionally bury key dimensions within a larger grouping and obfuscate meaningful patterns. With this work we introduce DimLift, a novel visual analysis method for creating and interacting with dimensional bundles. Generated through an iterative dimensionality reduction or user-driven approach, dimensional bundles are expressive groups of dimensions that contribute similarly to the variance of a dataset. Interactive exploration and reconstruction methods via a layered parallel coordinates plot allow users to lift interesting and subtle relationships to the surface, even in complex scenarios of missing and mixed data types. We exemplify the power of this technique in an expert case study on clinical cohort data alongside two additional case examples from nutrition and ecology.},
volume = {27},
number = {6},
pages = {2908--2922},
pdf = {pdfs/garrison-2021-dimlift.pdf},
images = {images/garrison_dimlift.jpg},
thumbnails = {images/garrison_dimlift_thumb.jpg},
youtube = {https://youtu.be/JSZuhnDyugA},
doi = {10.1109/TVCG.2021.3057519},
git = {https://github.com/lauragarrison87/DimLift},
project = {VIDI},
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {Mueller-2021-IDA,
author = {M\"{u}ller, Juliane and Garrison, Laura and Ulbrich, Philipp and Schreiber, Stefanie and Bruckner, Stefan and Hauser, Helwig and Oeltze-Jafra, Steffen},
title = {Integrated Dual Analysis of Quantitative and Qualitative High-Dimensional Data},
journal={IEEE Transactions on Visualization and Computer Graphics},
year = {2021},
abstract = {The Dual Analysis framework is a powerful enabling technology for the exploration of high dimensional quantitative data by treating data dimensions as first-class objects that can be explored in tandem with data values. In this work, we extend the Dual Analysis framework through the joint treatment of quantitative (numerical) and qualitative (categorical) dimensions. Computing common measures for all dimensions allows us to visualize both quantitative and qualitative dimensions in the same view. This enables a natural joint treatment of mixed data during interactive visual exploration and analysis. Several measures of variation for nominal qualitative data can also be applied to ordinal qualitative and quantitative data. For example, instead of measuring variability from a mean or median, other measures assess inter-data variation or average variation from a mode. In this work, we demonstrate how these measures can be integrated into the Dual Analysis framework to explore and generate hypotheses about high-dimensional mixed data. A medical case study using clinical routine data of patients suffering from Cerebral Small Vessel Disease (CSVD), conducted with a senior neurologist and a medical student, shows that a joint Dual Analysis approach for quantitative and qualitative data can rapidly lead to new insights based on which new hypotheses may be generated.},
volume = {27},
number = {6},
pages = {2953--2966},
pdf = {pdfs/Mueller_2020_IDA.pdf},
images = {images/Mueller_2020_IDA.jpg},
thumbnails = {images/Mueller_2020_IDA.png},
doi = {10.1109/TVCG.2021.3056424},
git = {https://github.com/JulianeMu/IntegratedDualAnalysisAproach_MDA},
project = {VIDI},
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE{Palenik-2020-IsoTrotter,
author={P\'{a}lenik, Juraj and Spengler, Thomas and Hauser, Helwig},
journal={IEEE Transactions on Visualization and Computer Graphics},
title={{IsoTrotter: Visually Guided Emprical Modelling of Atmospheric Convection}},
abstract={Empirical models, fitted to data from observations, are often used in natural sciences to describe physical behaviour and support discoveries. However, with more complex models, the regression of parameters quickly becomes insufficient, requiring a visual parameter space analysis to understand and optimize the models. In this work, we present a design study for building a model describing atmospheric convection. We present a mixed-initiative approach to visually guided modelling, integrating an interactive visual parameter space analysis with partial automatic parameter optimization. Our approach includes a new, semi-automatic technique called IsoTrotting, where we optimize the procedure by navigating along isocontours of the model. We evaluate the model with unique observational data of atmospheric convection based on flight trajectories of paragliders.},
year={2021},
volume={27},
number={2},
pages={775-784},
doi={10.1109/TVCG.2020.3030389},
pdf={pdfs/2020-10-20-Palenik-IsoTrotter.pdf},
images={images/IsoTrotter2020.png},
thumbnails={images/IsoTrotter2020.png}
}
    [PDF] [DOI] [Bibtex] 
    @article{bolte2020splitstreams,
author= {Bolte, Fabian and Nourani, Mahsan and Ragan, Eric and Bruckner, Stefan},
journal= {IEEE Transactions on Visualization and Computer Graphics},
title= {SplitStreams: A Visual Metaphor for Evolving Hierarchies},
year= {2021},
keywords= {Information Visualization, Trees, Data Structures and Data Types, Visualization Techniques and Methodologies},
doi= {10.1109/TVCG.2020.2973564},
url= {https://arxiv.org/pdf/2002.03891.pdf},
volume = {27},
number = {8},
doi = {10.1109/TVCG.2020.2973564},
abstract= {The visualization of hierarchically structured data over time is an ongoing challenge and several approaches exist trying to solve it. Techniques such as animated or juxtaposed tree visualizations are not capable of providing a good overview of the time series and lack expressiveness in conveying changes over time. Nested streamgraphs provide a better understanding of the data evolution, but lack the clear outline of hierarchical structures at a given timestep. Furthermore, these approaches are often limited to static hierarchies or exclude complex hierarchical changes in the data, limiting their use cases. We propose a novel visual metaphor capable of providing a static overview of all hierarchical changes over time, as well as clearly outlining the hierarchical structure at each individual time step. Our method allows for smooth transitions between tree maps and nested streamgraphs, enabling the exploration of the trade-off between dynamic behavior and hierarchical structure. As our technique handles topological changes of all types, it is suitable for a wide range of applications. We demonstrate the utility of our method on several use cases, evaluate it with a user study, and provide its full source code.},
pdf= {pdfs/Bolte-2020-SplitStreams.pdf},
images= {images/Bolte-2020-SplitStreams.png},
thumbnails= {images/Bolte-2020-SplitStreams_thumb.png},
project = "MetaVis",
git = "https://github.com/cadanox/SplitStreams"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @article{bolte2019visavis,
author= {Bolte, Fabian and Bruckner, Stefan},
journal= {IEEE Transactions on Visualization and Computer Graphics},
title= {Vis-a-Vis: Visual Exploration of Visualization Source Code Evolution},
year= {2021},
keywords= {Visualization System and Toolkit Design;User Interfaces;Integrating Spatial and Non-Spatial Data Visualization;Software Visualization},
doi= {10.1109/TVCG.2019.2963651},
issn= {2160-9306},
url= {https://arxiv.org/pdf/2001.02092.pdf},
abstract= {Developing an algorithm for a visualization prototype often involves the direct comparison of different development stages and design decisions, and even minor modifications may dramatically affect the results. While existing development tools provide visualizations for gaining general insight into performance and structural aspects of the source code, they neglect the central importance of result images unique to graphical algorithms. In this paper, we present a novel approach that enables visualization programmers to simultaneously explore the evolution of their algorithm during the development phase together with its corresponding visual outcomes by providing an automatically updating meta visualization. Our interactive system allows for the direct comparison of all development states on both the visual and the source code level, by providing easy to use navigation and comparison tools. The on-the-fly construction of difference images, source code differences, and a visual representation of the source code structure further enhance the user's insight into the states' interconnected changes over time. Our solution is accessible via a web-based interface that provides GPU-accelerated live execution of C++ and GLSL code, as well as supporting a domain-specific programming language for scientific visualization.},
pdf= {pdfs/Bolte-2019-Visavis.pdf},
images= {images/Bolte-2019-Visavis.png},
thumbnails= {images/Bolte-2019-Visavis_thumb.png},
youtube= {https://www.youtube.com/watch?v=5XO6BU4j1KQ},
volume = {27},
number = {7},
pages = {3153--3167},
project = "MetaVis"
}

2020

    [PDF] [DOI] [Bibtex] 
    @article{sketchingQuery,
author={Fan, Chaoran and Matkovic, Kresimir and Hauser, Helwig},
journal={IEEE Transactions on Visualization and Computer Graphics},
title={Sketch-based fast and accurate querying of time series using parameter-sharing LSTM networks},
year={2020},
volume={},
number={},
pages={1-12},
doi={10.1109/TVCG.2020.3002950},
abstract = {"Sketching is one common approach to query time series data for patterns of interest. Most existing solutions for matching the data with the interaction are based on an empirically modeled similarity function between the user's sketch and the time series data with limited efficiency and accuracy. In this paper, we introduce a machine learning based solution for fast and accurate querying of time series data based on a swift sketching interaction. We build on existing LSTM technology (long short-term memory) to encode both the sketch and the time series data in a network with shared parameters. We use data from a user study to let the network learn a proper similarity function. We focus our approach on perceived similarities and achieve that the learned model also includes a user-side aspect. To the best of our knowledge, this is the first data-driven solution for querying time series data in visual analytics. Besides evaluating the accuracy and efficiency directly in a quantitative way, we also compare our solution to the recently published Qetch algorithm as well as the commonly used dynamic time warping (DTW) algorithm.."},
pdf = "pdfs/Fan-2020-sketchingQuery.pdf",
images = "images/Fan-2020-sketchingQuery.png",
thumbnails = "images/Fan-2020-sketchingQuery.png",
}
    [PDF] [DOI] [Bibtex] 
    @article{Garrison-2020-IVE,
author = {Garrison, Laura and Va\v{s}\'{i}\v{c}ek, Jakub and Craven, Alex R. and Gr\"{u}ner, Renate and Smit, Noeska and Bruckner, Stefan},
title = {Interactive Visual Exploration of Metabolite Ratios in MR Spectroscopy Studies},
journal = {Computers \& Graphics},
volume = {92},
pages = {1--12},
keywords = {medical visualization, magnetic resonance spectroscopy data, information visualization, user-centered design},
doi = {10.1016/j.cag.2020.08.001},
abstract = {Magnetic resonance spectroscopy (MRS) is an advanced biochemical technique used to identify metabolic compounds in living tissue. While its sensitivity and specificity to chemical imbalances render it a valuable tool in clinical assessment, the results from this modality are abstract and difficult to interpret. With this design study we characterized and explored the tasks and requirements for evaluating these data from the perspective of a MRS research specialist. Our resulting tool, SpectraMosaic, links with upstream spectroscopy quantification software to provide a means for precise interactive visual analysis of metabolites with both single- and multi-peak spectral signatures. Using a layered visual approach, SpectraMosaic allows researchers to analyze any permutation of metabolites in ratio form for an entire cohort, or by sample region, individual, acquisition date, or brain activity status at the time of acquisition. A case study with three MRS researchers demonstrates the utility of our approach in rapid and iterative spectral data analysis.},
year = {2020},
pdf = "pdfs/Garrison-2020-IVE.pdf",
thumbnails = "images/Garrison-2020-IVE.png",
images = "images/Garrison-2020-IVE.jpg",
project = "VIDI",
git = "https://github.com/mmiv-center/spectramosaic-public",
}
    [PDF] [DOI] [Bibtex] 
    @article{Kristiansen-2020-VIV,
author = {Yngve Sekse Kristiansen and Stefan Bruckner},
title = {Visception: An Interactive Visual Framework for Nested Visualization Design},
journal = {Computers \& Graphics},
volume = {92},
pages = {13--27},
keywords = {information visualization, nested visualizations, nesting},
doi = {10.1016/j.cag.2020.08.007},
abstract = {Nesting is the embedding of charts into the marks of another chart. Related to principles such as Tufte’s rule of utilizing micro/macro readings, nested visualizations have been employed to increase information density, providing compact representations of multi-dimensional and multi-typed data entities. Visual authoring tools are becoming increasingly prevalent, as they make visualization technology accessible to non-expert users such as data journalists, but existing frameworks provide no or only very limited functionality related to the creation of nested visualizations. In this paper, we present an interactive visual approach for the flexible generation of nested multilayer visualizations. Based on a hierarchical representation of nesting relationships coupled with a highly customizable mechanism for specifying data mappings, we contribute a flexible framework that enables defining and editing data-driven multi-level visualizations. As a demonstration of the viability of our framework, we contribute a visual builder for exploring, customizing and switching between different designs, along with example visualizations to demonstrate the range of expression. The resulting system allows for the generation of complex nested charts with a high degree of flexibility and fluidity using a drag and drop interface.},
year = {2020},
pdf = "pdfs/Kristiansen-2020-VIV.pdf",
thumbnails = "images/Kristiansen-2020-VIV.png",
images = "images/Kristiansen-2020-VIV.jpg",
project = "MetaVis"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @article{RadEx,
author = {M\"{o}rth, E. and Wagner-Larsen, K. and Hodneland, E. and Krakstad, C. and Haldorsen, I. S. and Bruckner, S. and Smit, N. N.},
title = {RadEx: Integrated Visual Exploration of Multiparametric Studies for Radiomic Tumor Profiling},
journal = {Computer Graphics Forum},
volume = {39},
number = {7},
year = {2020},
pages = {611--622},
abstract = {Better understanding of the complex processes driving tumor growth and metastases is critical for developing targeted treatment strategies in cancer. Radiomics extracts large amounts of features from medical images which enables radiomic tumor profiling in combination with clinical markers. However, analyzing complex imaging data in combination with clinical data is not trivial and supporting tools aiding in these exploratory analyses are presently missing. In this paper, we present an approach that aims to enable the analysis of multiparametric medical imaging data in combination with numerical, ordinal, and categorical clinical parameters to validate established and unravel novel biomarkers. We propose a hybrid approach where dimensionality reduction to a single axis is combined with multiple linked views allowing clinical experts to formulate hypotheses based on all available imaging data and clinical parameters. This may help to reveal novel tumor characteristics in relation to molecular targets for treatment, thus providing better tools for enabling more personalized targeted treatment strategies. To confirm the utility of our approach, we closely collaborate with experts from the field of gynecological cancer imaging and conducted an evaluation with six experts in this field.},
pdf = "pdfs/Moerth-2020-RadEx.pdf",
images = "images/Moerth-2020-RadEx.jpg",
youtube = "https://youtu.be/zwtDzwwX790",
thumbnails = "images/Moerth-2020-RadEx-thumb.jpg",
project = "ttmedvis",
doi = {10.1111/cgf.14172}
}
    [PDF] [DOI] [YT] [Bibtex] 
    @INPROCEEDINGS{Moerth-2020-CGI,
author = "M\"{o}rth, E. and Haldorsen, I.S. and Bruckner, S. and Smit, N.N.",
title = "ParaGlyder: Probe-driven Interactive Visual Analysis for Multiparametric Medical Imaging Data",
booktitle = "Proceedings of Computer Graphics International",
pages = "351--363",
year = "2020",
abstract = "Multiparametric medical imaging describes approaches that include multiple imaging sequences acquired within the same imaging examination, as opposed to one single imaging sequence or imaging from multiple imaging modalities. Multiparametric imaging in cancer has been shown to be useful for tumor detection and may also depict functional tumor characteristics relevant for clinical phenotypes. However, when confronted with datasets consisting of multiple values per voxel, traditional reading of the imaging series fails to capture complicated patterns. Those patterns of potentially important imaging properties of the parameter space may be critical for the analysis. Standard approaches, such as transfer functions and juxtapositioned visualizations, fail to convey the shape of the multiparametric parameter distribution in sufficient detail. For these reasons, in this paper we present an approach that aims to enable the exploration and analysis of such multiparametric studies using an interactive visual analysis application to remedy the trade-offs between details in the value domain and in spatial resolution. Interactive probing within or across subjects allows for a digital biopsy that is able to uncover multiparametric tissue properties. This may aid in the discrimination between healthy and cancerous tissue, unravel radiomic tissue features that could be linked to targetable pathogenic mechanisms, and potentially highlight metastases that evolved from the primary tumor. We conducted an evaluation with eleven domain experts from the field of gynecological cancer imaging, neurological imaging, and machine learning research to confirm the utility of our approach.",
note= "The final authenticated version is available online at https://doi.org/10.1007/978-3-030-61864-3_29",
pdf = "pdfs/Moerth-2020-CGI-ParaGlyder.pdf",
images = "images/Moerth-2020-ParaGlyder.PNG",
thumbnails = "images/Moerth-2020-ParaGlyder-thumb.png",
youtube = "https://youtu.be/S_M4CWXKz0U",
publisher = "LNCS by Springer",
project = "ttmedvis",
doi = "10.1007/978-3-030-61864-3_29"
}
    [PDF] [DOI] [Bibtex] 
    @article{StormFurru-2020-VGT,
author = {Syver Storm-Furru and Stefan Bruckner},
title = {VA-TRAC: Geospatial Trajectory Analysis for Monitoring, Identification, and Verification in Fishing Vessel Operations},
journal = {Computer Graphics Forum},
volume = {39},
number = {3},
pages = {101--114},
keywords = {visual analytics, fisheries, monitoring},
doi = {10.1111/cgf.13966},
abstract = {In order to ensure sustainability, fishing operations are governed by many rules and regulations that restrict the use of certain techniques and equipment, specify the species and size of fish that can be harvested, and regulate commercial activities based on licensing schemes. As the world's second largest exporter of fish and seafood products, Norway invests a significant amount of effort into maintaining natural ecosystem dynamics by ensuring compliance with its constantly evolving sciencebased regulatory body. This paper introduces VA-TRAC, a geovisual analytics application developed in collaboration with the Norwegian Directorate of Fisheries in order to address this complex task. Our approach uses automatic methods to identify possible catch operations based on fishing vessel trajectories, embedded in an interactive web-based visual interface used to explore the results, compare them with licensing information, and incorporate the analysts' domain knowledge into the decision making process. We present a data and task analysis based on a close collaboration with domain experts, and the design and implementation of VA-TRAC to address the identified requirements.},
year = {2020},
pdf = "pdfs/StormFurru-2020-VGT.pdf",
thumbnails = "images/StormFurru-2020-VGT.png",
images = "images/StormFurru-2020-VGT.jpg",
project = "MetaVis"
}
    [PDF] [DOI] [VID] [YT] [Bibtex] 
    @article{Trautner-2020-SunspotPlots,
author = {Trautner, T. and Bolte, F. and Stoppel, S. and Bruckner, S.},
title = {Sunspot Plots: Model-based Structure Enhancement for Dense Scatter Plots},
journal = {Computer Graphics Forum},
volume = {39},
number = {3},
pages = {551--563},
keywords = {information visualization, scatterplots, kernel density estimation},
doi = {10.1111/cgf.14001},
abstract = {Scatter plots are a powerful and well-established technique for visualizing the relationships between two variables as a collection of discrete points. However, especially when dealing with large and dense data, scatter plots often exhibit problems such as overplotting, making the data interpretation arduous. Density plots are able to overcome these limitations in highly populated regions, but fail to provide accurate information of individual data points. This is particularly problematic in sparse regions where the density estimate may not provide a good representation of the underlying data. In this paper, we present sunspot plots, a visualization technique that communicates dense data as a continuous data distribution, while preserving the discrete nature of data samples in sparsely populated areas. We furthermore demonstrate the advantages of our approach on typical failure cases of scatter plots within synthetic and real-world data sets and validate its effectiveness in a user study.},
year = {2020},
pdf = "pdfs/Trautner_2020_SunspotPlots_PDF.pdf",
thumbnails = "images/Trautner_2020_SunspotPlots_thumb.png",
images = "images/Trautner_2020_SunspotPlots_thumb.png",
vid = "vids/Trautner_2020_SunspotPlots_video.mp4",
youtube = "https://youtu.be/G6l-y6YGjzQ",
project = "MetaVis"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Bolte-2020-ONC,
author = "Fabian Bolte and Stefan Bruckner",
title = "Organic Narrative Charts",
booktitle = "Proceedings of Eurographics 2020 (Short Papers)",
year = "2020",
pages = "93--96",
doi = "10.2312/egs.20201026",
month = "may",
abstract = "Storyline visualizations display the interactions of groups and entities and their development over time. Existing approaches have successfully adopted the general layout from hand-drawn illustrations to automatically create similar depictions. Ward Shelley is the author of several diagrammatic paintings that show the timeline of art-related subjects, such as Downtown Body, a history of art scenes. His drawings include many stylistic elements that are not covered by existing storyline visualizations, like links between entities, splits and merges of streams, and tags or labels to describe the individual elements. We present a visualization method that provides a visual mapping for the complex relationships in the data, creates a layout for their display, and adopts a similar styling of elements to imitate the artistic appeal of such illustrations.We compare our results to the original drawings and provide an open-source authoring tool prototype.",
pdf = "pdfs/Bolte-2020-ONC.pdf",
images = "images/Bolte-2020-ONC.jpg",
thumbnails = "images/Bolte-2020-ONC.png",
event = "Eurographics 2020",
keywords = "narrative charts, storylines, aesthetics",
project = "MetaVis",
git = "https://github.com/cadanox/orcha"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE{Palenik-2019-Splatting,
author={J. P\'{a}lenik and J. By\v{s}ka and S. Bruckner and H. Hauser},
journal={IEEE Transactions on Visualization and Computer Graphics},
title={Scale-Space Splatting: Reforming Spacetime for Cross-Scale Exploration of Integral Measures in Molecular Dynamics},
year={2020},
volume={26},
number={1},
pages={643--653},
keywords={Data visualization;Computational modeling;Time series analysis;Atmospheric measurements;Particle measurements;Analytical models;Kernel;Scale space;time-series;scientific simulation;multi-scale analysis;space-time cube;molecular dynamics},
doi={10.1109/TVCG.2019.2934258},
ISSN={1077-2626},
month={},
pdf = "pdfs/scale-space-splatting.pdf",
images = "images/scale-space-teaser.png",
thumbnails = "images/scale-space-teaser-thumb.png",
abstract = "Understanding large amounts of spatiotemporal data from particle-based simulations, such as molecular dynamics, often relies on the computation and analysis of aggregate measures. These, however, by virtue of aggregation, hide structural information about the space/time localization of the studied phenomena. This leads to degenerate cases where the measures fail to capture distinct behaviour. In order to drill into these aggregate values, we propose a multi-scale visual exploration technique. Our novel representation, based on partial domain aggregation, enables the construction of a continuous scale-space for discrete datasets and the simultaneous exploration of scales in both space and time. We link these two scale-spaces in a scale-space space-time cube and model linked views as orthogonal slices through this cube, thus enabling the rapid identification of spatio-temporal patterns at multiple scales. To demonstrate the effectiveness of our approach, we showcase an advanced exploration of a protein-ligand simulation.",
}
    [PDF] [DOI] [Bibtex] 
    @incollection {Bolte-2019-MVS,
author = {Bolte, Fabian and Bruckner, Stefan},
title = {Measures in Visualization Space},
booktitle = {Foundations of Data Visualization},
chapter = {3},
publisher = {Springer},
year = {2020},
pdf = {pdfs/Bolte-2019-MVS.pdf},
images = {images/Bolte-2019-MVS.png},
thumbnails = {images/Bolte-2019-MVS.png},
abstract = {Measurement is an integral part of modern science, providing the fundamental means for evaluation, comparison, and prediction. In the context of visualization, several different types of measures have been proposed, ranging from approaches that evaluate particular aspects of individual visualization techniques, their perceptual characteristics, and even economic factors. Furthermore, there are approaches that attempt to provide means for measuring general properties of the visualization process as a whole. Measures can be quantitative or qualitative, and one of the primary goals is to provide objective means for reasoning about visualizations and their effectiveness. As such, they play a central role in the development of scientific theories for visualization. In this chapter, we provide an overview of the current state of the art, survey and classify different types of visualization measures, characterize their strengths and drawbacks, and provide an outline of open challenges for future research.},
note = {This is a preprint of a chapter for a planned book that was initiated by participants of the Dagstuhl Seminar 18041 ("Foundations of Data Visualization") and that is expected to be published by Springer. The final book chapter will differ from this preprint.},
url = {https://arxiv.org/abs/1909.05295},
project = "MetaVis",
isbn = {978-3-030-34443-6},
doi = {10.1007/978-3-030-34444-3_3}
}
    [PDF] [DOI] [Bibtex] 
    @article{Solteszova-2019-MLT,
author = {Solteszova, V. and Smit, N. N. and Stoppel, S. and Gr\"{u}ner, R. and Bruckner, S.},
title = {Memento: Localized Time-Warping for Spatio-Temporal Selection},
journal = {Computer Graphics Forum},
volume = {39},
number = {1},
pages = {231--243},
year = {2020},
keywords = {interaction, temporal data, visualization, spatio-temporal projection},
images = "images/Solteszova-2019-MLT.jpg",
thumbnails = "images/Solteszova-2019-MLT-1.jpg",
pdf = "pdfs/Solteszova-2019-MLT.pdf",
doi = {10.1111/cgf.13763},
abstract = {Abstract Interaction techniques for temporal data are often focused on affecting the spatial aspects of the data, for instance through the use of transfer functions, camera navigation or clipping planes. However, the temporal aspect of the data interaction is often neglected. The temporal component is either visualized as individual time steps, an animation or a static summary over the temporal domain. When dealing with streaming data, these techniques are unable to cope with the task of re-viewing an interesting local spatio-temporal event, while continuing to observe the rest of the feed. We propose a novel technique that allows users to interactively specify areas of interest in the spatio-temporal domain. By employing a time-warp function, we are able to slow down time, freeze time or even travel back in time, around spatio-temporal events of interest. The combination of such a (pre-defined) time-warp function and brushing directly in the data to select regions of interest allows for a detailed review of temporally and spatially localized events, while maintaining an overview of the global spatio-temporal data. We demonstrate the utility of our technique with several usage scenarios.},
project = "MetaVis,ttmedvis,VIDI"
}

2019

    [PDF] [DOI] [Bibtex] 
    @article{Byska-2019-LongMolecularDynamicsSimulations,
author = {Byška, J. and Trautner, T. and Marques, S.M. and Damborský, J. and Kozlíková, B. and Waldner, M.},
title = {Analysis of Long Molecular Dynamics Simulations Using Interactive Focus+Context Visualization},
journal = {Computer Graphics Forum},
volume = {38},
number = {3},
pages = {441-453},
keywords = {CCS Concepts, Human-centered computing -- Scientific visualization; User centered design},
doi = {10.1111/cgf.13701},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/cgf.13701},
eprint = {https://onlinelibrary.wiley.com/doi/pdf/10.1111/cgf.13701},
abstract = {Abstract Analyzing molecular dynamics (MD) simulations is a key aspect to understand protein dynamics and function. With increasing computational power, it is now possible to generate very long and complex simulations, which are cumbersome to explore using traditional 3D animations of protein movements. Guided by requirements derived from multiple focus groups with protein engineering experts, we designed and developed a novel interactive visual analysis approach for long and crowded MD simulations. In this approach, we link a dynamic 3D focus+context visualization with a 2D chart of time series data to guide the detection and navigation towards important spatio-temporal events. The 3D visualization renders elements of interest in more detail and increases the temporal resolution dependent on the time series data or the spatial region of interest. In case studies with different MD simulation data sets and research questions, we found that the proposed visual analysis approach facilitates exploratory analysis to generate, confirm, or reject hypotheses about causalities. Finally, we derived design guidelines for interactive visual analysis of complex MD simulation data.},
year = {2019},
pdf = "pdfs/AnalysisOfLongMolecularDynamicsSimulationsUsingInteractiveFocusAndContextVisualization_Trautner.pdf",
images = "images/Byska-2019-LongMolecularDynamicsSimulations.png",
thumbnails = "images/Byska-2019-LongMolecularDynamicsSimulations.png"
}
    [PDF] [DOI] [Bibtex] 
    @inproceedings {Bartsch-2019-MVA,
booktitle = {Proceedings of VCBM 2019 (Short Papers)},
title = {MedUse: A Visual Analysis Tool for Medication Use Data in the ABCD Study},
author = {Bartsch, Hauke and Garrison, Laura and Bruckner, Stefan and Wang, Ariel and Tapert, Susan F. and Gr\"{u}ner, Renate},
abstract = {The RxNorm vocabulary is a yearly-published biomedical resource providing normalized names for medications. It is used to capture medication use in the Adolescent Brain Cognitive Development (ABCD) study, an active and publicly available longitudinal research study following 11,800 children over 10 years. In this work, we present medUse, a visual tool allowing researchers to explore and analyze the relationship of drug category to cognitive or imaging derived measures using ABCD study data. Our tool provides position-based context for tree traversal and selection granularity of both study participants and drug category. Developed as part of the Data Exploration and Analysis Portal (DEAP), medUse is available to more than 600 ABCD researchers world-wide. By integrating medUse into an actively used research product we are able to reach a wide audience and increase the practical relevance of visualization for the biomedical field.},
year = {2019},
pages = {97--101},
images = "images/Bartsch-2019-MVA.jpg",
thumbnails = "images/Bartsch-2019-MVA.png",
pdf = "pdfs/Bartsch-2019-MVA.pdf",
publisher = {The Eurographics Association},
ISSN = {2070-5786},
ISBN = {978-3-03868-081-9},
DOI = {10.2312/vcbm.20191236},
project = {VIDI}
}
    [DOI] [Bibtex] 
    @article{kraima2019role,
title={The role of the longitudinal muscle in the anal sphincter complex: Implications for the Intersphincteric Plane in Low Rectal Cancer Surgery?},
author={Kraima, Anne C and West, Nicholas P and Roberts, Nicholas and Magee, Derek R and Smit, Noeska N and van de Velde, Cornelis JH and DeRuiter, Marco C and Rutten, Harm J and Quirke, Philip},
journal={Clinical Anatomy},
year={2019},
doi="10.1002/ca.23444",
url = "https://onlinelibrary.wiley.com/doi/full/10.1002/ca.23444",
publisher={Wiley Online Library},
project = "ttmedvis",
images = {images/kraima-2019-role.png},
thumbnails = {images/kraima-2019-role.png},
abstract = {Intersphincteric resection (ISR) enables radical sphincter-preserving surgery in a subset of low rectal tumors impinging on the anal sphincter complex (ASC). Excellent anatomical knowledge is essential for optimal ISR. This study describes the role of the longitudinal muscle (LM) in the ASC and implications for ISR and other low rectal and anal pathologies. Six human adult en bloc cadaveric specimens (three males, three females) were obtained from the University of Leeds GIFT Research Tissue Programme. Paraffin-embedded mega blocks containing the ASC were produced and serially sectioned at 250?µm intervals. Whole mount microscopic sections were histologically stained and digitally scanned. The intersphincteric plane was shown to be potentially very variable. In some places adipose tissue is located between the external anal sphincter (EAS) and internal anal sphincter (IAS), whereas in others the LM interdigitates to obliterate the plane. Elsewhere the LM is (partly) absent with the intersphincteric plane lying on the IAS. The LM gave rise to the formation of the submucosae and corrugator ani muscles by penetrating the IAS and EAS. In four of six specimens, striated muscle fibers from the EAS curled around the distal IAS reaching the anal submucosa. The ASC formed a complex structure, varying between individuals with an inconstant LM affecting the potential location of the intersphincteric plane as well as a high degree of intermingling striated and smooth muscle fibers potentially further disrupting the plane. The complexity of identifying the correct pathological staging of low rectal cancer is also demonstrated.}
}
    [PDF] [DOI] [YT] [Bibtex] 
    @INPROCEEDINGS {Garrison2019SM,
author = {Garrison, Laura and Va\v{s}\'{\i}\v{c}ek, Jakub and Gr\"{u}ner, Renate and Smit, Noeska and Bruckner, Stefan},
title = {SpectraMosaic: An Exploratory Tool for the Interactive Visual Analysis of Magnetic Resonance Spectroscopy Data},
journal = {Computer Graphics Forum},
month = {sep},
year = {2019},
booktitle = {Proceedings of VCBM 2019},
pages = {1--10},
event = "VCBM 2019",
proceedings = "Proceedings of the 9th Eurographics Workshop on Visual Computing in Biology and Medicine",
keywords = {medical visualization, magnetic resonance spectroscopy data, information visualization, user-centered design},
images = "images/garrison_VCBM19spectramosaic_full.PNG",
thumbnails = "images/garrison_VCBM19spectramosaic_thumb.png",
pdf = "pdfs/garrison_VCBM19spectramosaic.pdf",
youtube = "https://www.youtube.com/watch?v=Rzl7sl4WvdQ",
abstract = {Magnetic resonance spectroscopy (MRS) allows for assessment of tissue metabolite characteristics used often for early detection and treatment evaluation of brain-related pathologies. However, meaningful variations in ratios of tissue metabolites within a sample area are difficult to capture with current visualization tools. Furthermore, the learning curve to interpretation is steep and limits the more widespread adoption of MRS in clinical practice. In this design study, we collaborated with domain experts to design a novel visualization tool for the exploration of tissue metabolite concentration ratios in spectroscopy clinical and research studies. We present a data and task analysis for this domain, where MRS data attributes can be categorized into tiers of visual priority. We furthermore introduce a novel set of visual encodings for these attributes. Our result is SpectraMosaic (see Figure~\ref{fig:teaser}), an interactive insight-generation tool for rapid exploration and comparison of metabolite ratios. We validate our approach with two case studies from MR spectroscopy experts, providing early qualitative evidence of the efficacy of the system for visualization of spectral data and affording deeper insights into these complex heterogeneous data.},
git = "https://git.app.uib.no/Laura.Garrison/spectramosaic",
doi = "0.2312/vcbm.20191225",
project = "VIDI"
}
    [DOI] [Bibtex] 
    @incollection{Smit-2019-AtlasVis,
title={Towards Advanced Interactive Visualization for Virtual Atlases},
author={Smit, Noeska and Bruckner, Stefan},
booktitle={Biomedical Visualisation},
pages={85--96},
year={2019},
publisher={Springer},
doi = {10.1007/978-3-030-19385-0_6},
url = "http://noeskasmit.com/wp-content/uploads/2019/07/Smit_AtlasVis_2019.pdf",
images = "images/Smit-2019-AtlasVis.png",
thumbnails = "images/Smit-2019-AtlasVis.png",
abstract = "An atlas is generally defined as a bound collection of tables, charts or illustrations describing a phenomenon. In an anatomical atlas for example, a collection of representative illustrations and text describes anatomy for the purpose of communicating anatomical knowledge. The atlas serves as reference frame for comparing and integrating data from different sources by spatially or semantically relating collections of drawings, imaging data, and/or text. In the field of medical image processing, atlas information is often constructed from a collection of regions of interest, which are based on medical images that are annotated by domain experts. Such an atlas may be employed for example for automatic segmentation of medical imaging data. The combination of interactive visualization techniques with atlas information opens up new possibilities for content creation, curation, and navigation in virtual atlases. With interactive visualization of atlas information, students are able to inspect and explore anatomical atlases in ways that were not possible with the traditional method of presenting anatomical atlases in book format, such as viewing the illustrations from other viewpoints. With advanced interaction techniques, it becomes possible to query the data that forms the basis for the atlas, thus empowering researchers to access a wealth of information in new ways. So far, atlasbased visualization has been employed for mainly medical education, as well as biological research. In this survey, we provide an overview of current digital biomedical atlas tasks and applications and summarize relevant visualization techniques. We discuss recent approaches for providing next-generation visual interfaces to navigate atlas data that go beyond common text-based search and hierarchical lists. Finally, we reflect on open challenges and opportunities for the next steps in interactive atlas visualization. ",
project = "ttmedvis,MetaVis,VIDI"
}
    [DOI] [Bibtex] 
    @article{Meuschke-2019-EvalViz,
title = {EvalViz--Surface Visualization Evaluation Wizard for Depth and Shape Perception Tasks},
author = {Meuschke, Monique and Smit, Noeska N and Lichtenberg, Nils and Preim, Bernhard and Lawonn, Kai},
journal = {Computers \& Graphics},
year = {2019},
publisher = {Elsevier},
number = "1",
volume = "82",
DOI = {10.1016/j.cag.2019.05.022},
images = "images/Meuschke_EvalViz_2019.png",
thumbnails = "images/Meuschke_EvalViz_2019.png",
abstract = "User studies are indispensable for visualization application papers in order to assess the value and limitations of the presented approach. Important aspects are how well depth and shape information can be perceived, as coding of these aspects is essential to enable an understandable representation of complex 3D data. In practice, there is usually little time to perform such studies, and the establishment and conduction of user studies can be labour-intensive. In addition, it can be difficult to reach enough participants to obtain expressive results regarding the quality of different visualization techniques.
In this paper, we propose a framework that allows visualization researchers to quickly create task-based user studies on depth and shape perception for different surface visualizations and perform the resulting tasks via a web interface. With our approach, the effort for generating user studies is reduced and at the same time the web-based component allows researchers to attract more participants to their study. We demonstrate our framework by applying shape and depth evaluation tasks to visualizations of various surface representations used in many technical and biomedical applications.",
project = "ttmedvis"
}
    [PDF] [YT] [Bibtex] 
    @MISC {Garrison2019SM_eurovis,
title = {A Visual Encoding System for Comparative Exploration of Magnetic Resonance Spectroscopy Data},
author = {Garrison, Laura and Va\v{s}\'{\i}\v{c}ek, Jakub and Gr\"{u}ner, Renate and Smit, Noeska and Bruckner, Stefan},
abstract = "Magnetic resonance spectroscopy (MRS) allows for assessment of tissue metabolite characteristics used often for early detection and treatment evaluation of intracranial pathologies. In particular, this non-invasive technique is important in the study of metabolic changes related to brain tumors, strokes, seizure disorders, Alzheimer's disease, depression, as well as other diseases and disorders affecting the brain. However, meaningful variations in ratios of tissue metabolites within a sample area are difficult to capture with current visualization tools. Furthermore, the learning curve to interpretation is steep and limits the more widespread adoption of MRS in clinical practice. In this work we present a novel, tiered visual encoding system for multi-dimensional MRS data to aid in the visual exploration of metabolite concentration ratios. Our system was developed in close collaboration with domain experts including detailed data and task analyses. This visual encoding system was subsequently realized as part of an interactive insight-generation tool for rapid exploration and comparison of metabolite ratio variation for deeper insights to these complex data.",
booktitle = {Proceedings of the EuroVis Conference - Posters (EuroVis 2019)},
year = {2019},
howpublished = "Poster presented at the EuroVis conference 2019",
keywords = {medical visualization, magnetic resonance spectroscopy data, information visualization, user-centered design},
images = "images/garrison_eurovis2019_SM_encodings.png",
thumbnails = "images/garrison_eurovis2019_SM_encodings.png",
pdf = "pdfs/garrison_eurovis2019_SM.pdf",
youtube = "https://youtu.be/Rzl7sl4WvdQ",
project = "VIDI"
}
    [PDF] [DOI] [Bibtex] 
    @inproceedings {Smit-2019-DBP,
booktitle = {Eurographics 2019 - Dirk Bartz Prize},
editor = {Bruckner, Stefan and Oeltze-Jafra, Steffen},
title = {{Model-based Visualization for Medical Education and Training}},
author = {Smit, Noeska and Lawonn, Kai and Kraima, Annelot and deRuiter, Marco and Bruckner, Stefan and Eisemann, Elmar and Vilanova, Anna},
year = {2019},
publisher = {The Eurographics Association},
ISSN = {1017-4656},
DOI = {10.2312/egm.20191033},
pdf = "pdfs/Smit_DBPrize_2019.pdf",
images = "images/Smit_DBPrize_2019.png",
thumbnails = "images/Smit_DBPrize_2019.png",
abstract = "Anatomy, or the study of the structure of the human body, is an essential component of medical education. Certain parts of human anatomy are considered to be more complex to understand than others, due to a multitude of closely related structures. Furthermore, there are many potential variations in anatomy, e.g., different topologies of vessels, and knowledge of these variations is critical for many in medical practice.
Some aspects of individual anatomy, such as the autonomic nerves, are not visible in individuals through medical imaging techniques or even during surgery, placing these nerves at risk for damage.
3D models and interactive visualization techniques can be used to improve understanding of this complex anatomy, in combination with traditional medical education paradigms.
We present a framework incorporating several advanced medical visualization techniques and applications for teaching and training purposes, which is the result of an interdisciplinary project.
In contrast to previous approaches which focus on general anatomy visualization or direct visualization of medical imaging data, we employ model-based techniques to represent variational anatomy, as well as anatomy not visible from imaging. Our framework covers the complete spectrum including general anatomy, anatomical variations, and anatomy in individual patients.
Applications within our framework were evaluated positively with medical users, and our educational tool for general anatomy is in use in a Massive Open Online Course (MOOC) on anatomy, which had over 17000 participants worldwide in the first run.",
project = "ttmedvis,VIDI"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Stoppel-2019-LFL,
author = "Stoppel, Sergej and Bruckner, Stefan",
title = "LinesLab: A Flexible Low-Cost Approach for the Generation of Physical Monochrome Art",
journal = "Computer Graphics Forum",
year = "2019",
abstract = "The desire for the physical generation of computer art has seen a significant body of research that has resulted in sophisticated robots and painting machines, together with specialized algorithms mimicking particular artistic techniques. The resulting setups are often expensive and complex, making them unavailable for recreational and hobbyist use. In recent years, however, a new class of affordable low-cost plotters and cutting machines has reached the market. In this paper, we present a novel system for the physical generation of line and cut-out art based on digital images, targeted at such off-the-shelf devices. Our approach uses a meta-optimization process to generate results that represent the tonal content of a digital image while conforming to the physical and mechanical constraints of home-use devices. By flexibly combining basic sets of positional and shape encodings, we are able to recreate a wide range of artistic styles. Furthermore, our system optimizes the output in terms of visual perception based on the desired viewing distance, while remaining scalable with respect to the medium size.",
pdf = "pdfs/Stoppel-2019-LFL.pdf",
images = "images/Stoppel-2019-LFL.jpg",
thumbnails = "images/Stoppel-2019-LFL.png",
publisher = "The Eurographics Association and John Wiley and Sons Ltd.",
doi = "10.1111/cgf.13609",
youtube = "https://www.youtube.com/watch?v=WdZJmU6fOAY",
project = "MetaVis"
}
    [PDF] [Bibtex] 
    @article{fan2019personalized,
title={Personalized Sketch-Based Brushing in Scatterplots},
author={Chaoran Fan and Helwig Hauser},
journal={IEEE Computer Graphics and Applications},
volume={39},
number={4},
pages={28--39},
year={2019},
publisher={IEEE},
pdf="pdfs/personalizedBrush.pdf",
images="images/personalizedBrush.png",
thumbnails = "images/personalizedBrush.png",
abstract="Brushing is at the heart of most modern visual analytics solutions and effective and efficient brushing is crucial for successful interactive data exploration and analysis. As the user plays a central role in brushing, several data-driven brushing tools have been designed that are based on predicting the user’s brushing goal. All of these general brushing models learn the users’ average brushing preference, which is not optimal for every single user. In this paper, we propose an innovative framework that offers the user opportunities to improve the brushing technique while using it. We realized this framework with a CNN-based brushing technique and the result shows that with additional data from a particular user, the model can be refined (better performance in terms of accuracy), eventually converging to a personalized model based on a moderate amount of retraining."
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Fan-2019-KDE,
author = "Chaoran Fan and Helwig Hauser",
title = "On KDE-based brushing in scatterplots and how it compares to CNN-based brushing",
booktitle = "Proceedings of MLVis: Machine Learning Methods in Visualisation for Big Data",
year = "2019",
publisher = "Eurographics Association",
abstract = "In this paper, we investigate to which degree the human should be involved into the model design and how good the empirical model can be with more careful design. To find out, we extended our previously published Mahalanobis brush (the best current empirical model in terms of accuracy for brushing points in a scatterplot) by further incorporating the data distribution information that is captured by the kernel density estimation (KDE). Based on this work, we then include a short discussion between the empirical model, designed in detail by an expert and the deep learning-based model that is learned from user data directly",
pdf = "pdfs/On-KDE-based-brushing-in-scatterplotsand-how-it-compares-to-CNN-based-brushing.pdf",
images = "images/pic-2.png",
thumbnails = "images/pic-2.png",
doi = "10.2312/mlvis.20191157",
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Bruckner-2019-DVM,
author = "Bruckner, Stefan",
title = "Dynamic Visibility-Driven Molecular Surfaces",
journal = "Computer Graphics Forum",
year = "2019",
volume = "38",
number = "2",
pages = "317--329",
abstract = "Molecular surface representations are an important tool for the visual analysis of molecular structure and function. In this paper, we present a novel method for the visualization of dynamic molecular surfaces based on the Gaussian model. In contrast to previous approaches, our technique does not rely on the construction of intermediate representations such as grids or triangulated surfaces. Instead, it operates entirely in image space, which enables us to exploit visibility information to efficiently skip unnecessary computations. With this visibility-driven approach, we can visualize dynamic high-quality surfaces for molecules consisting of millions of atoms. Our approach requires no preprocessing, allows for the interactive adjustment of all properties and parameters, and is significantly faster than previous approaches, while providing superior quality.",
pdf = "pdfs/Bruckner-2019-DVM.pdf",
images = "images/Bruckner-2019-DVM-1.jpg",
thumbnails = "images/Bruckner-2019-DVM.png",
publisher = "The Eurographics Association and John Wiley and Sons Ltd.",
doi = "10.1111/cgf.13640",
youtube = "https://www.youtube.com/watch?v=aZmDhTbJlAM",
git = "https://github.com/sbruckner/dynamol.git",
project = "MetaVis"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {Bruckner-2018-MSD,
author = "Stefan Bruckner and Tobias Isenberg and Timo Ropinski and Alexander Wiebel",
title = "A Model of Spatial Directness in Interactive Visualization",
journal = "IEEE Transactions on Visualization and Computer Graphics",
volume = "25",
number = "8",
year = "2019",
abstract = "We discuss the concept of directness in the context of spatial interaction with visualization. In particular, we propose a modelthat allows practitioners to analyze and describe the spatial directness of interaction techniques, ultimately to be able to better understandinteraction issues that may affect usability. To reach these goals, we distinguish between different types of directness. Each type ofdirectness depends on a particular mapping between different spaces, for which we consider the data space, the visualization space, theoutput space, the user space, the manipulation space, and the interaction space. In addition to the introduction of the model itself, we alsoshow how to apply it to several real-world interaction scenarios in visualization, and thus discuss the resulting types of spatial directness,without recommending either more direct or more indirect interaction techniques. In particular, we will demonstrate descriptive andevaluative usage of the proposed model, and also briefly discuss its generative usage.",
pdf = "pdfs/Bruckner-2018-MSD.pdf",
images = "images/Bruckner-2018-MSD.jpg",
thumbnails = "images/Bruckner-2018-MSD.png",
doi = "10.1109/TVCG.2018.2848906",
project = "MetaVis"
}
    [PDF] [DOI] [VID] [Bibtex] 
    @ARTICLE {Stoppel-2019-FVI,
author = "Sergej Stoppel and Magnus Paulson Erga and Stefan Bruckner",
title = "Firefly: Virtual Illumination Drones for Interactive Visualization",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2019",
volume = "25",
pages = "1204-1213",
abstract = "Light specification in three dimensional scenes is a complex problem and several approaches have been presented that aim to automate this process. However, there are many scenarios where a static light setup is insufficient, as the scene content and camera position may change. Simultaneous manual control over the camera and light position imposes a high cognitive load on the user. To address this challenge, we introduce a novel approach for automatic scene illumination with Fireflies. Fireflies are intelligent virtual light drones that illuminate the scene by traveling on a closed path. The Firefly path automatically adapts to changes in the scene based on an outcome-oriented energy function. To achieve interactive performance, we employ a parallel rendering pipeline for the light path evaluations. We provide a catalog of energy functions for various application scenarios and discuss the applicability of our method on several examples.",
pdf = "pdfs/VIS2018-Firefly.pdf",
vid = "vids/FinalVideo.mp4",
images = "images/Teaser.png",
thumbnails = "images/HeadRightCroppedThumbnail.png",
doi = "10.1109/TVCG.2018.2864656",
project = "MetaVis"
}
    [PDF] [DOI] [Bibtex] 
    @inproceedings {Moerth-2019-VCBM,
booktitle = "Eurographics Workshop on Visual Computing for Biology and Medicine",
editor = "Kozlíková, Barbora and Linsen, Lars and Vázquez, Pere-Pau and Lawonn, Kai and Raidou, Renata Georgia",
abstract = "Three-dimensional (3D) ultrasound imaging and visualization
is often used in medical diagnostics, especially in prenatal
screening. Screening the development of the fetus is
important to assess possible complications early on. State
of the art approaches involve taking standardized
measurements to compare them with standardized tables. The
measurements are taken in a 2D slice view, where precise
measurements can be difficult to acquire due to the fetal
pose. Performing the analysis in a 3D view would enable the
viewer to better discriminate between artefacts and
representative information. Additionally making data
comparable between different investigations and patients is
a goal in medical imaging techniques and is often achieved
by standardization. With this paper, we introduce a novel
approach to provide a standardization method for 3D
ultrasound fetus screenings. Our approach is called “The
Vitruvian Baby” and incorporates a complete pipeline for
standardized measuring in fetal 3D ultrasound. The input of
the method is a 3D ultrasound screening of a fetus and the
output is the fetus in a standardized T-pose. In this pose,
taking measurements is easier and comparison of different
fetuses is possible. In addition to the transformation of
the 3D ultrasound data, we create an abstract representation
of the fetus based on accurate measurements. We demonstrate
the accuracy of our approach on simulated data where the
ground truth is known.",
title = "The Vitruvian Baby: Interactive Reformation of Fetal Ultrasound Data to a T-Position",
author = "M\"{o}rth, Eric and Raidou, Renata Georgia and Viola, Ivan and Smit, Noeska",
year = "2019",
publisher = "The Eurographics Association",
ISSN = "2070-5786",
ISBN = "978-3-03868-081-9",
DOI = "10.2312/vcbm.20191245",
pdf = "pdfs/VCBM_TheVitruvianBaby_ShortPaper_201-205.pdf",
images = "images/vcbmVitruvianBaby.jpg",
thumbnails = "images/vcbmVitruvianBaby.jpg",
url = "https://diglib.eg.org/handle/10.2312/vcbm20191245",
project = {VIDI}
}
    [PDF] [DOI] [Bibtex] 
    @MISC {Moerth-2019-EUROVIS,
booktitle = "EuroVis 2019 - Posters",
editor = "Madeiras Pereira, João and Raidou, Renata Georgia",
title = "The Vitruvian Baby: Interactive Reformation of Fetal Ultrasound Data to a T-Position",
author = "M\"{o}rth, Eric and Raidou, Renata Georgia and Smit, Noeska and Viola, Ivan",
year = "2019",
abstract = "Three dimensional (3D) ultrasound is commonly used in prenatal screening, because it provides insight into the shape as well
as the organs of the fetus. Currently, gynecologists take standardized measurements of the fetus and check for abnormalities by
analyzing the data in a 2D slice view. The fetal pose may complicate taking precise measurements in such a view. Analyzing the
data in a 3D view would enable the viewer to better distinguish between artefacts and representative information. Standardization
in medical imaging techniques aims to make the data comparable between different investigations and patients. It is
already used in different medical applications for example in magnetic resonance imaging (MRI). With this work, we introduce
a novel approach to provide a standardization method for 3D ultrasound screenings of fetuses. The approach consists of six
steps and is called “The Vitruvian Baby”. The input is the data of the 3D ultrasound screening of a fetus and the output shows
the fetus in a standardized T-pose in which measurements can be made. The precision of standardized measurements compared
to the gold standard is for the finger to finger span 91,08% and for the head to toe measurement 94,05%.",
publisher = "The Eurographics Association",
howpublished = "Poster presented at the EuroVis conference 2019",
ISBN = "978-3-03868-088-8",
DOI = "10.2312/eurp.20191147",
pdf = "pdfs/EUROVIS_TheVitruvianBaby_Poster.pdf",
images = "images/EUROVISTheVitruvianBabyPoster.png",
thumbnails = "images/EUROVISTheVitruvianBabyPoster.png",
url = "https://diglib.eg.org/handle/10.2312/eurp20191147"
}

2018

    [Bibtex] 
    @ARTICLE {PhDThesis2018Stoppel,
author = "Stoppel, Sergej",
title = "User-Centric Parameter Specification for Interactive Virtual and Physical Visual Representations",
journal = "Universitetet i Bergen",
year = "2018"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {hauser2018foundations,
author = "Hauser, Helwig and Rheingans, Penny and Scheuermann, Gerik",
title = "Foundations of Data Visualization (Dagstuhl Seminar 18041)",
booktitle = "Dagstuhl Reports",
year = "2018",
volume = "8",
organization = "Schloss Dagstuhl-Leibniz-Zentrum fuer Informatik",
abstract = "This report documents the program and the outcomes of Dagstuhl Seminar 18041 “Foundations
of Data Visualization”. It includes a discussion of the motivation and overall organization, an
abstract from each of the participants, and a report about each of the working groups.",
pdf = "pdfs/foundations.pdf",
thumbnails = "images/foundations.png",
number = "1"
}
    [Bibtex] 
    @ARTICLE {Jurcik2018Caver,
author = "Adam Jur\v{c}\'{i}k and David Bedn\'{a}\v{r} and Jan By\v{s}ka and Sergio M. Marques and Katar\'{i}na Furmanov\'{a} and Luk\'{a}\v{s} Daniel and Piia Kokkonen and Jan Brezovsk\'{y} and Ond\v{r}ej Strnad and Jan \v{s}\v{t}oura\v{c} and Anton\'{i}n Pavelka and Martin Ma\v{n}\'{a}k and Ji\v{r}\'{i} Damborsk\'{y} and Barbora Kozl\'{i}kov\'{a}",
title = "CAVER Analyst 2.0: analysis and visualization of channels and tunnels in protein structures and molecular dynamics trajectories",
journal = "Bioinformatics",
year = "2018",
abstract = "MOTIVATION:Studying the transport paths of ligands, solvents, or ions in transmembrane proteins and proteins with buried binding sites is fundamental to the understanding of their biological function. A detailed analysis of the structural features influencing the transport paths is also important for engineering proteins for biomedical and biotechnological applications.RESULTS:CAVER Analyst 2.0 is a software tool for quantitative analysis and real-time visualization of tunnels and channels in static and dynamic structures. This version provides the users with many new functions, including advanced techniques for intuitive visual inspection of the spatiotemporal behavior of tunnels and channels. Novel integrated algorithms allow efficient analysis and data reduction in large protein structures and molecular dynamics simulations.",
images = "images/analyst.jpg",
thumbnails = "images/analyst.jpg"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @INPROCEEDINGS {Meuschke2018VCBM,
author = "Monique Meuschke and Noeska N. Smit and Nils Lichtenberg and Bernhard Preim and Kai Lawonn",
title = "Automatic Generation of Web-Based User Studies to Evaluate Depth Perception in Vascular Surface Visualizations",
booktitle = "Proceedings of VCBM 2018",
year = "2018",
editor = "Anna Puig Puig and Thomas Schultz and Anna Vilanova and Ingrid Hotz and Barbora Kozlikova and Pere-Pau Vázquez",
pages = "033-044",
address = "Granada, Spain",
publisher = "Eurographics Association",
abstract = "User studies are often required in biomedical visualization application papers in order to provide evidence for the utility of the presented approach. An important aspect is how well depth information can be perceived, as depth encoding is important to enable an understandable representation of complex data.Unfortunately, in practice there is often little time available to perform such studies, and setting up and conducting user studies may be labor-intensive. In addition, it can be challenging to reach enough participants to support the contribution claims of the paper. In this paper, we propose a system that allows biomedical visualization researchers to quickly generate perceptual task-based user studies for novel surface visualizations, and to perform the resulting experiment via a web interface. This approach helps to reduce effort in the setup of user studies themselves, and at the same time leverages a web-based approach that can help researchers attract more participants to their study. We demonstrate our system using the specific application of depth judgment tasks to evaluate vascular surface visualizations, since there is a lot of recent interest in this area.However, the system is also generally applicable for conducting other task-baseduser studies in biomedical visualization.",
pdf = "pdfs/meuschke2018VCBM.pdf",
images = "images/vcbm2018.png",
thumbnails = "images/vcbm2018.png",
youtube = "https://www.youtube.com/watch?v=8lns8GGpPJI",
crossref = "VCBM-proc",
doi = "10.2312/vcbm.20181227",
project = "ttmedvis"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Magnus-2018-VPI,
author = "Jens G. Magnus and Stefan Bruckner",
title = "Interactive Dynamic Volume Illumination with Refraction and Caustics",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2018",
volume = "24",
number = "1",
pages = "984--993",
month = "jan",
abstract = "In recent years, significant progress has been made indeveloping high-quality interactive methods for realistic volumeillumination. However, refraction -- despite being an important aspectof light propagation in participating media -- has so far only receivedlittle attention. In this paper, we present a novel approach forrefractive volume illumination including caustics capable of interactiveframe rates. By interleaving light and viewing ray propagation, ourtechnique avoids memory-intensive storage of illumination informationand does not require any precomputation. It is fully dynamic and allparameters such as light position and transfer function can be modifiedinteractively without a performance penalty.",
pdf = "pdfs/Magnus-2018-IDV.pdf",
images = "images/Magnus-2018-IDV.jpg",
thumbnails = "images/Magnus-2018-IDV.png",
youtube = "https://www.youtube.com/watch?v=3tn6sSXw4NQ",
doi = "10.1109/TVCG.2017.2744438",
event = "IEEE SciVis 2017",
keywords = "interactive volume rendering, illumination, refraction, shadows, caustics",
location = "Phoenix, USA",
project = "MetaVis"
}
    [PDF] [YT] [Bibtex] 
    @ARTICLE {lichtenbergsmithansenlawonn2018,
author = "Nils Lichtenberg and Noeska Smit and Christian Hansen and Kai Lawonn",
title = "Real-time field aligned stripe patterns",
journal = "Computers & Graphics",
year = "2018",
volume = "74",
pages = "137-149",
month = "aug",
abstract = "In this paper, we present a parameterization technique that can be applied to surface meshes in real-time without time-consuming preprocessing steps. The parameterization is suitable for the display of (un-)oriented patterns and texture patches, and to sample a surface in a periodic fashion. The method is inspired by existing work that solves a global optimization problem to generate a continuous stripe pattern on the surface, from which texture coordinates can be derived. We propose a local optimization approach that is suitable for parallel execution on the GPU, which drastically reduces computation time. With this, we achieve on-the-fly texturing of 3D, medium-sized (up to 70k vertices) surface meshes. The algorithm takes a tangent vector field as input and aligns the texture coordinates to it. Our technique achieves real-time parameterization of the surface meshes by employing a parallelizable local search algorithm that converges to a local minimum in a few iterations. The calculation in real-time allows for live parameter updates and determination of varying texture coordinates. Furthermore, the method can handle non-manifold meshes. The technique is useful in various applications, e.g., biomedical visualization and flow visualization. We highlight our method\s potential by providing usage scenarios for several applications.A PDF of the accepted manuscript is available via noeskasmit.com/wp-content/uploads/2018/08/lichtenberg_2018.pdf.",
pdf = "pdfs/lichtenberg_2018.pdf",
images = "images/Selection_384.png",
thumbnails = "images/1-s2.0-S0097849318300591-fx1_lrg.jpg",
youtube = "https://www.youtube.com/watch?v=7CpkHy8KPK8",
project = "ttmedvis"
}
    [PDF] [Bibtex] 
    @MISC {Smit18MMIV,
author = "N. N. Smit and S. Bruckner and H. Hauser and I. Haldorsen and A. Lundervold and A. S. Lundervold and E. Hodneland and L. Oltedal and K. Specht and E. R. Gruner",
title = "Research Agenda of the Mohn Medical Imaging and Visualization Centre in Bergen, Norway",
howpublished = "Poster presented at the EG VCBM workshop 2018",
month = "September",
year = "2018",
abstract = "The Mohn Medical Imaging and Visualization Centre (MMIV) was recently established in collaboration between the University of Bergen, Norway, and the Haukeland University Hospital in Bergen with generous financial support from the Bergen Research Foundation (BFS) to conduct cross-disciplinary research related to state-of-the-art medical imaging, including preclinical and clinical high-field MRI, CT and hybrid PET/CT/MR.The overall goal of the Centre is to research new methods in quantitative imaging and interactive visualization to predict changes in health and disease across spatial and temporal scales. This encompasses research in feature detection, feature extraction, and feature prediction, as well as on methods and techniques for the interactive visualization of spatial and abstract data related to and derived from these features.With special emphasis on the natural and medical sciences, the long-term goal of the Centre is to consolidate excellence in the interplay between medical imaging (physics, chemistry, radiography, radiology), and visualization (computer science and mathematics) and develop novel and refined imaging methods that may ultimately improve patient care. In this poster, we describe the overall research agenda of MMIV and describe the four core projects in the centre.",
pdf = "pdfs/smit2018posterabstract.pdf",
images = "images/MMIVPoster.png",
thumbnails = "images/MMIVPoster.png",
location = "Granada, Spain",
project = "VIDI"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {cnn-brush,
author = "Fan, Chaoran and Hauser, Helwig",
title = "{Fast and Accurate CNN-based Brushing in Scatterplots}",
journal = "Computer Graphics Forum (Eurovis 2018)",
year = "2018",
abstract = "Brushing plays a central role in most modern visual analytics solutions and effective and efficient techniques for data selection are key to establishing a successful human-computer dialogue. With this paper, we address the need for brushing techniques that are both fast, enabling a fluid interaction in visual data exploration and analysis, and also accurate, i.e., enabling the user to effectively select specific data subsets, even when their geometric delimination is non-trivial. We present a new solution for a near-perfect sketch-based brushing technique, where we exploit a convolutional neural network (CNN) for estimating the intended data selection from a fast and simple click-and-drag interaction and from the data distribution in the visualization. Our key contributions include a drastically reduced error rate-now below 3%, i.e., less than half of the so far best accuracy- and an extension to a larger variety of selected data subsets, going beyond previous limitations due to linear estimation models.",
pdf = "pdfs/eurovis18.pdf",
images = "images/cnn.png",
thumbnails = "images/cnn.png",
publisher = "The Eurographics Association and John Wiley and Sons Ltd.",
issn = "1467-8659",
doi = "10.1111/cgf.13405"
}
    [Bibtex] 
    @ARTICLE {Furmanova2018COZOID,
author = "Furmanov{\'a}, Katar{\'\i}na and By{\v{s}}ka, Jan and Gr{\"o}ller, Eduard M and Viola, Ivan and Pale{\v{c}}ek, Jan J and Kozl{\'i}kov{\'a}, Barbora",
title = "COZOID: contact zone identifier for visual analysis of protein-protein interactions",
journal = "BMC bioinformatics",
year = "2018",
abstract = "BackgroundStudying the patterns of protein-protein interactions (PPIs) is fundamental for understanding the structure and function of protein complexes. The exploration of the vast space of possible mutual configurations of interacting proteins and their contact zones is very time consuming and requires the proteomic expert knowledge.ResultsIn this paper, we propose a novel tool containing a set of visual abstraction techniques for the guided exploration of PPI configuration space. It helps proteomic experts to select the most relevant configurations and explore their contact zones at different levels of detail. The system integrates a set of methods that follow and support the workflow of proteomics experts. The first visual abstraction method, the Matrix view, is based on customized interactive heat maps and provides the users with an overview of all possible residue-residue contacts in all PPI configurations and their interactive filtering. In this step, the user can traverse all input PPI configurations and obtain an overview of their interacting amino acids. Then, the models containing a particular pair of interacting amino acids can be selectively picked and traversed. Detailed information on the individual amino acids in the contact zones and their properties is presented in the Contact-Zone list-view. The list-view provides a comparative tool to rank the best models based on the similarity of their contacts to the template-structure contacts. All these techniques are interactively linked with other proposed methods, the Exploded view and the Open-Book view, which represent individual configurations in three-dimensional space. These representations solve the high overlap problem associated with many configurations. Using these views, the structural alignment of the best models can also be visually confirmed.ConclusionsWe developed a system for the exploration of large sets of protein-protein complexes in a fast and intuitive way. The usefulness of our system has been tested and verified on several docking structures covering the three major types of PPIs, including coiled-coil, pocket-string, and surface-surface interactions. Our case studies prove that our tool helps to analyse and filter protein-protein complexes in a fraction of the time compared to using previously available techniques.",
images = "images/cozoid.jpg",
thumbnails = "images/cozoid.jpg"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @INPROCEEDINGS {Stoppel-2018-SSW,
author = "Sergej Stoppel and Stefan Bruckner",
title = "Smart Surrogate Widgets for Direct Volume Manipulation",
booktitle = "Proceedings of IEEE PacificVis 2018",
year = "2018",
pages = "36--45",
month = "apr",
abstract = "Interaction is an essential aspect in volume visualization, yet commonmanipulation tools such as bounding boxes or clipping planewidgets provide rather crude tools as they neglect the complex structureof the underlying data. In this paper, we introduce a novelvolume interaction approach based on smart widgets that are automaticallyplaced directly into the data in a visibility-driven manner.By adapting to what the user actually sees, they act as proxies thatallow for goal-oriented modifications while still providing an intuitiveset of simple operations that is easy to control. In particular, ourmethod is well-suited for direct manipulation scenarios such as touchscreens, where traditional user interface elements commonly exhibitlimited utility. To evaluate out approach we conducted a qualitativeuser study with nine participants with various backgrounds.",
pdf = "pdfs/Stoppel-2018-SSW.pdf",
images = "images/Stoppel-2018-SSW.jpg",
thumbnails = "images/Stoppel-2018-SSW.png",
youtube = "https://www.youtube.com/watch?v=wMRw-W0SrLk",
event = "IEEE PacificVis 2018",
keywords = "smart interfaces, volume manipulation, volume visualization",
doi = "10.1109/PacificVis.2018.00014",
project = "MetaVis"
}

2017

    [Bibtex] 
    @ARTICLE {UiB2017Ivan,
author = "Kolesar, Ivan",
title = "Partial Spatiotemporal Abstraction for Comparative Visualization of Molecular Processes",
journal = "Universitetet i Bergen",
year = "2017"
}
    [PDF] [Bibtex] 
    @ARTICLE {matkovic2017quantitative,
author = "Matkovi{\'c}, Kre{\v{s}}imir and Abraham, Hrvoje and Jelovi{\'c}, Mario and Hauser, Helwig",
title = "Quantitative externalization of visual data analysis results using local regression models",
journal = "International Cross-Domain Conference for Machine Learning and Knowledge Extraction",
year = "2017",
pages = "199-218",
abstract = "Both interactive visualization and computational analysis
methods are useful for data studies and an integration of both approaches
is promising to successfully combine the benefits of both methodologies.
In interactive data exploration and analysis workflows, we need successful
means to quantitatively externalize results from data studies, amounting
to a particular challenge for the usually qualitative visual data analysis.
In this paper, we propose a hybrid approach in order to quantitatively
externalize valuable findings from interactive visual data exploration and
analysis, based on local linear regression models. The models are built on
user-selected subsets of the data, and we provide a way of keeping track
of these models and comparing them. As an additional benefit, we also
provide the user with the numeric model coefficients. Once the models are
available, they can be used in subsequent steps of the workflow. A modelbased
optimization can then be performed, for example, or more complex
models can be reconstructed using an inversion of the local models. We
study two datasets to exemplify the proposed approach, a meteorological
data set for illustration purposes and a simulation ensemble from the
automotive industry as an actual case study.",
pdf = "pdfs/Matkovic2017.pdf",
thumbnails = "images/matkovic_10.png"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Stoppel-2017-VPI,
author = "Sergej Stoppel and Stefan Bruckner",
title = "Vol²velle: Printable Interactive Volume Visualization",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2017",
volume = "23",
number = "1",
pages = "861--870",
month = "jan",
abstract = "Interaction is an indispensable aspect of data visualization. The  presentation of volumetric data, in particular, often significantly  benefits from interactive manipulation of parameters such as transfer  functions, rendering styles, or clipping planes. However, when we  want to create hardcopies of such visualizations, this essential  aspect is lost. In this paper, we present a novel approach for creating  hardcopies of volume visualizations which preserves a certain degree  of interactivity. We present a method for automatically generating  Volvelles, printable tangible wheel charts that can be manipulated  to explore different parameter settings. Our interactive system allows  the flexible mapping of arbitrary visualization parameters and supports  advanced features such as linked views. The resulting designs can  be easily reproduced using a standard printer and assembled within  a few minutes.",
pdf = "pdfs/Stoppel-2017-VPI.pdf",
images = "images/Stoppel-2017-VPI.jpg",
thumbnails = "images/Stoppel-2017-VPI.png",
youtube = "https://www.youtube.com/watch?v=Z1K8t-FCiXI",
doi = "10.1109/TVCG.2016.2599211",
event = "IEEE SciVis 2016",
keywords = "physical visualization, interaction, volume visualization, illustrative visualization",
location = "Baltimore, USA"
}
    [PDF] [Bibtex] 
    @ARTICLE {Furmanova2017Ligand,
author = "Furmanov{\'a}, Katar{\'\i}na and Jare{\v{s}}ov{\'a}, Miroslava and By{\v{s}}ka, Jan and Jur{\v{c}}{\'i}k, Adam and Parulek, J{\'u}lius and Hauser, Helwig and Kozl{\'i}kov{\'a}, Barbora",
title = "Interactive exploration of ligand transportation through protein tunnels",
journal = "BMC Bioinformatics",
year = "2017",
volume = "18(Suppl 2)",
number = "22",
month = "feb",
abstract = "Background: Protein structures and their interaction with ligands have been in the focus of biochemistry andstructural biology research for decades. The transportation of ligand into the protein active site is often complexprocess, driven by geometric and physico-chemical properties, which renders the ligand path full of jitter andimpasses. This prevents understanding of the ligand transportation and reasoning behind its behavior along the path.Results: To address the needs of the domain experts we design an explorative visualization solution based on amulti-scale simplification model. It helps to navigate the user to the most interesting parts of the ligand trajectory byexploring different attributes of the ligand and its movement, such as its distance to the active site, changes of aminoacids lining the ligand, or ligand “stuckness�. The process is supported by three linked views – 3D representation of thesimplified trajectory, scatterplot matrix, and bar charts with line representation of ligand-lining amino acids.Conclusions: The usage of our tool is demonstrated on molecular dynamics simulations provided by the domainexperts. The tool was tested by the domain experts from protein engineering and the results confirm that it helps tonavigate the user to the most interesting parts of the ligand trajectory and to understand the ligand behavior",
pdf = "pdfs/Furmanova2017.pdf",
images = "images/Furmanova2016Interactive.png",
thumbnails = "images/Furmanova2016Interactive.png",
note = "https://doi.org/10.1186/s12859-016-1448-0"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {newMahalanobisBrush,
author = "Fan, Chaoran and Hauser, Helwig",
title = "{User-study Based Optimization of Fast and Accurate Mahalanobis Brushing in Scatterplots}",
booktitle = "Vision, Modeling & Visualization",
year = "2017",
editor = "Matthias Hullin and Reinhard Klein and Thomas Schultz and Angela Yao",
publisher = "The Eurographics Association",
abstract = "Brushing is at the heart of most modern visual analytics solutions with coordinated, multiple views and effective brushing is crucial for swift and efficient processes in data exploration and analysis. Given a certain data subset that the user wishes to brush in a data visualization, traditional brushes are usually either accurate (like the lasso) or fast (e.g., a simple geometry like a rectangle or circle). In this paper, we now present a new, fast and accurate brushing technique for scatterplots, based on the Mahalanobis brush, which we have extended and then optimized using data from a user study. We explain the principal, sketchbased model of our new brushing technique (based on a simple click-and-drag interaction), the details of the user study and the related parameter optimization, as well as a quantitative evaluation, considering efficiency, accuracy, and also a comparison with the original Mahalanobis brush.",
pdf = "pdfs/vmv-final.pdf",
images = "images/Mahalanobis.png",
thumbnails = "images/Mahalanobis.png",
isbn = "978-3-03868-049-9",
doi = "10.2312/vmv.20171262"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Smit-2017-PAS,
author = "Noeska Smit and Kai Lawonn and Annelot Kraima and Marco DeRuiter and Hessam Sokooti and Stefan Bruckner and Elmar Eisemann and Anna Vilanova",
title = "PelVis: Atlas-based Surgical Planning for Oncological Pelvic Surgery",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2017",
volume = "23",
number = "1",
pages = "741--750",
month = "jan",
abstract = "Due to the intricate relationship between the pelvic organs and vital  structures, such as vessels and nerves, pelvic anatomy is often considered  to be complex to comprehend. In oncological pelvic surgery, a trade-off  has to be made between complete tumor resection and preserving function  by preventing damage to the nerves. Damage to the autonomic nerves  causes undesirable post-operative side-effects such as fecal and  urinal incontinence, as well as sexual dysfunction in up to 80 percent  of the cases. Since these autonomic nerves are not visible in pre-operative  MRI scans or during surgery, avoiding nerve damage during such a  surgical procedure becomes challenging. In this work, we present  visualization methods to represent context, target, and risk structures  for surgical planning. We employ distance-based and occlusion management  techniques in an atlas-based surgical planning tool for oncological  pelvic surgery. Patient-specific pre-operative MRI scans are registered  to an atlas model that includes nerve information. Through several  interactive linked views, the spatial relationships and distances  between the organs, tumor and risk zones are visualized to improve  understanding, while avoiding occlusion. In this way, the surgeon  can examine surgically relevant structures and plan the procedure  before going into the operating theater, thus raising awareness of  the autonomic nerve zone regions and potentially reducing post-operative  complications. Furthermore, we present the results of a domain expert  evaluation with surgical oncologists that demonstrates the advantages  of our approach.",
pdf = "pdfs/Smit-2017-PAS.pdf",
images = "images/Smit-2017-PAS.jpg",
thumbnails = "images/Smit-2017-PAS.png",
youtube = "https://www.youtube.com/watch?v=vHp05I5-hp8",
doi = "10.1109/TVCG.2016.2598826",
event = "IEEE SciVis 2016",
keywords = "atlas, surgical planning, medical visualization",
location = "Baltimore, USA"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {Lind-2017-CCR,
author = "Andreas Johnsen Lind and Stefan Bruckner",
title = "Comparing Cross-Sections and 3D Renderings for Surface Matching Tasks using Physical Ground Truths",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2017",
volume = "23",
number = "1",
pages = "781--790",
month = "jan",
abstract = "Within the visualization community there are some well-known techniques  for visualizing 3D spatial data and some general assumptions about  how perception affects the performance of these techniques in practice.  However, there is a lack of empirical research backing up the possible  performance differences among the basic techniques for general tasks.  One such assumption is that 3D renderings are better for obtaining  an overview, whereas cross sectional visualizations such as the commonly  used Multi- Planar Reformation (MPR) are better for supporting detailed  analysis tasks. In the present study we investigated this common  assumption by examining the difference in performance between MPR  and 3D rendering for correctly identifying a known surface. We also  examined whether prior experience working with image data affects  the participant’s performance, and whether there was any difference  between interactive or static versions of the visualizations. Answering  this question is important because it can be used as part of a scientific  and empirical basis for determining when to use which of the two  techniques. An advantage of the present study compared to other studies  is that several factors were taken into account to compare the two  techniques. The problem was examined through an experiment with 45  participants, where physical objects were used as the known surface  (ground truth). Our findings showed that: 1. The 3D renderings largely  outperformed the cross sections; 2. Interactive visualizations were  partially more effective than static visualizations; and 3. The high  experience group did not generally outperform the low experience  group.",
pdf = "pdfs/Lind-2017-CCR.pdf",
images = "images/Lind-2017-CCR.jpg",
thumbnails = "images/Lind-2017-CCR.png",
doi = "10.1109/TVCG.2016.2598602",
event = "IEEE SciVis 2016",
keywords = "human-computer interaction, quantitative evaluation, volume visualization",
location = "Baltimore, USA"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {LawonnSmit-2017-Survey,
author = "Lawonn, K. and Smit, N.N. and B{\"u}hler, K. and Preim, B.",
title = "A Survey on Multimodal Medical Data Visualization",
journal = "Computer Graphics Forum",
year = "2017",
volume = "37",
number = "1",
pages = "413-438",
abstract = "Multi-modal data of the complex human anatomy contain a wealth of information. To visualize and explore such data, techniques for emphasizing important structures and controlling visibility are essential. Such fused overview visualizations guide physicians to suspicious regions to be analysed in detail, e.g. with slice-based viewing. We give an overview of state of the art in multi-modal medical data visualization techniques. Multi-modal medical data consist of multiple scans of the same subject using various acquisition methods, often combining multiple complimentary types of information. Three-dimensional visualization techniques for multi-modal medical data can be used in diagnosis, treatment planning, doctor–patient communication as well as interdisciplinary communication. Over the years, multiple techniques have been developed in order to cope with the various associated challenges and present the relevant information from multiple sources in an insightful way. We present an overview of these techniques and analyse the specific challenges that arise in multi-modal data visualization and how recent works aimed to solve these, often using smart visibility techniques. We provide a taxonomy of these multi-modal visualization applications based on the modalities used and the visualization techniques employed. Additionally, we identify unsolved problems as potential future research directions.",
pdf = "pdfs/LawonnSmit-2017-MULTI.pdf",
images = "images/LawonnSmit-2017-MULTI.jpg",
thumbnails = "images/LawonnSmit-2017-MULTI-TN.png",
issn = "1467-8659",
url = "http://dx.doi.org/10.1111/cgf.13306",
doi = "10.1111/cgf.13306",
keywords = "medical imaging, visualization, scientific visualization, visualization, volume visualization, visualization, Medical Imaging [Visualization], Scientific Visualization [Visualization], Volume Visualization [Visualization], Multimodal Medical Data"
}
    [PDF] [Bibtex] 
    @ARTICLE {Kocincova2017SS,
author = "Kocincov{\'a}, Lucia and Jare{\v{s}}ov{\'a}, Miroslava and By{\v{s}}ka, Jan and Parulek, J{\'u}lius and Hauser, Helwig and Kozl{\'i}kov{\'a}, Barbora",
title = "Comparative visualization of protein secondary structures",
journal = "BMC Bioinformatics",
year = "2017",
volume = "18(Suppl 2)",
number = "23",
month = "feb",
abstract = "Background: Protein function is determined by many factors, namely by its constitution, spatial arrangement, anddynamic behavior. Studying these factors helps the biochemists and biologists to better understand the proteinbehavior and to design proteins with modified properties. One of the most common approaches to these studies is tocompare the protein structure with other molecules and to reveal similarities and differences in their polypeptidechains.Results: We support the comparison process by proposing a new visualization technique that bridges the gapbetween traditionally used 1D and 3D representations. By introducing the information about mutual positions ofprotein chains into the 1D sequential representation the users are able to observe the spatial differences between theproteins without any occlusion commonly present in 3D view. Our representation is designed to serve namely forcomparison of multiple proteins or a set of time steps of molecular dynamics simulation.Conclusions: The novel representation is demonstrated on two usage scenarios. The first scenario aims to compare aset of proteins from the family of cytochromes P450 where the position of the secondary structures has a significantimpact on the substrate channeling. The second scenario focuses on the protein flexibility when by comparing a setof time steps our representation helps to reveal the most dynamically changing parts of the protein chain.",
pdf = "pdfs/Kocincova2017.pdf",
images = "images/Lucia2016Comparative.png",
thumbnails = "images/Lucia2016Comparative.png",
note = "https://doi.org/10.1186/s12859-016-1449-z"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Solteszova-2017-OFS,
author = "Veronika \v{S}olt{\'e}szov{\'a} and {\AA}smund Birkeland and Sergej Stoppel and Ivan Viola and Stefan Bruckner",
title = "Output-Sensitive Filtering of Streaming Volume Data",
journal = "Computer Graphics Forum",
year = "2017",
volume = "36",
number = "1",
pages = "249--262",
month = "jan",
abstract = "Real-time volume data acquisition poses substantial challenges for  the traditional visualization pipeline where data enhancement is  typically seen as a pre-processing step. In the case of 4D ultrasound  data, for instance, costly processing operations to reduce noise  and to remove artifacts need to be executed for every frame. To enable  the use of high quality filtering operations in such scenarios, we  propose an output-sensitive approach to the visualization of streaming  volume data. Our method evaluates the potential contribution of all  voxels to the final image, allowing us to skip expensive processing  operations that have little or no effect on the visualization. As  filtering operations modify the data values which may affect the  visibility, our main contribution is a fast scheme to predict their  maximum effect on the final image. Our approach prioritizes filtering  of voxels with high contribution to the final visualization based  on a maximal permissible error per pixel. With zero permissible error,  the optimized filtering will yield a result identical to filtering  of the entire volume. We provide a thorough technical evaluation  of the approach and demonstrate it on several typical scenarios that  require on-the-fly processing.",
pdf = "pdfs/Solteszova-2017-OFS.pdf",
images = "images/Solteszova-2017-OFS.jpg",
thumbnails = "images/Solteszova-2017-OFS.png",
youtube = "https://www.youtube.com/watch?v=xGPs560ttp0",
doi = "10.1111/cgf.12799",
keywords = "output-sensitive processing, volume data, filtering"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Mindek-2017-DVN,
author = "Peter Mindek and Gabriel Mistelbauer and Meister Eduard Gr{\"o}ller and Stefan Bruckner",
title = "Data-Sensitive Visual Navigation",
journal = "Computers \& Graphics",
year = "2017",
volume = "67",
pages = "77--85",
month = "oct",
abstract = "In visualization systems it is often the case that thechanges of the input parameters are not proportional to the visualchange of the generated output. In this paper, we propose a model forenabling data-sensitive navigation for user-interface elements. Thismodel is applied to normalize the user input according to the visualchange, and also to visually communicate this normalization. In thisway, the exploration of heterogeneous data using common interactionelements can be performed in an efficient way. We apply our model to thefield of medical visualization and present guided navigation tools fortraversing vascular structures and for camera rotation around 3Dvolumes. The presented examples demonstrate that the model scales touser-interface elements where multiple parameters are setsimultaneously.",
pdf = "pdfs/Mindek-2017-DVN.pdf",
images = "images/Mindek-2017-DVN.jpg",
thumbnails = "images/Mindek-2017-DVN.png",
youtube = "https://www.youtube.com/watch?v=FnhbjX7BRXI",
note = "SCCG 2017 Best Paper Award",
doi = "10.1016/j.cag.2017.05.012",
event = "SCCG 2017",
keywords = "navigation, exploration, medical visualization",
location = "Mikulov, Czech Republic",
project = "MetaVis"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {vad_viktor-2017-WVE,
author = "Viktor Vad and Jan By\v{s}ka and Adam Jur\v{c}\'{i}k and Ivan Viola and Meister Eduard Gr{\"o}ller and Helwig Hauser and Sergio M. Margues and Ji\v{r}\'{i} Damborsk\'{y} and Barbora Kozl\'{i}kov\'{a}",
title = "Watergate: Visual Exploration of Water Trajectories in Protein Dynamics",
booktitle = "Eurographics Workshop on Visual Computing for Biology and Medicine 2017",
year = "2017",
pages = "33--42",
abstract = "The function of proteins is tightly related to their interactions with other molecules. The study of such interactions often requires to track the molecules that enter or exit specific regions of the proteins. This is investigated with molecular dynamics simulations, producing the trajectories of thousands of water molecules during hundreds of thousands of time steps. To ease the exploration of such rich spatio-temporal data, we propose a novel workflow for the analysis and visualization of large sets of water-molecule trajectories. Our solution consists of a set of visualization techniques, which help biochemists to classify, cluster, and filter the trajectories and to explore the properties and behavior of selected subsets in detail. Initially, we use an interactive histogram and a time-line visualization to give an overview of all water trajectories and select the interesting ones for further investigation. Further, we depict clusters of trajectories in a novel 2D representation illustrating the flows of water molecules. These views are interactively linked with a 3D representation where we show individual paths, including their simplification, as well as extracted statistical information displayed by isosurfaces. The proposed solution has been designed in tight collaboration with experts to support specific tasks in their scientific workflows. They also conducted several case studies to evaluate the usability and effectiveness of our new solution with respect to their research scenarios. These confirmed that our proposed solution helps in analyzing water trajectories and in extracting the essential information out of the large amount of input data.",
pdf = "pdfs/Vad_Victor2017.pdf",
images = "images/Watergate.png",
thumbnails = "images/Watergate.png",
proceedings = "In Proceedings of Eurographics Workshop on Visual Computing for Biology and Medicine",
location = "September, 2017 Bremen, Germany",
url = "https://www.cg.tuwien.ac.at/research/publications/2017/vad_viktor-2017-WVE/"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Diehl-2017-AVA,
author = "Alexandra Diehl and Leandro Pelorosso and Kresimir Matkovic and Juan Ruiz and Meister Eduard Gr{\"o}ller and Stefan Bruckner",
title = "Albero: A Visual Analytics Approach for Probabilistic Weather Forecasting",
journal = "Computer Graphics Forum",
year = "2017",
volume = "36",
number = "7",
pages = "135--144",
month = "oct",
abstract = "Probabilistic weather forecasts are amongst the most popularways to quantify numerical forecast uncertainties. The analogregression method can quantify uncertainties and express them asprobabilities. The method comprises the analysis of errorsfrom a large database of past forecasts generated with a specificnumerical model and observational data. Current visualizationtools based on this method are essentially automated and provide limitedanalysis capabilities. In this paper, we propose a novelapproach that breaks down the automatic process using the experience andknowledge of the users and creates a new interactivevisual workflow. Our approach allows forecasters to study probabilisticforecasts, their inner analogs and observations, theirassociated spatial errors, and additional statistical information bymeans of coordinated and linked views. We designed thepresented solution following a participatory methodology together withdomain experts. Several meteorologists with differentbackgrounds validated the approach. Two case studies illustrate thecapabilities of our solution. It successfully facilitates theanalysis of uncertainty and systematic model biases for improveddecision-making and process-quality measurements.",
pdf = "pdfs/Diehl-2017-AVA.pdf",
images = "images/Diehl-2017-AVA.jpg",
thumbnails = "images/Diehl-2017-AVA.png",
youtube = "https://www.youtube.com/watch?v=-yqoeEgkz28",
doi = "10.1111/cgf.13279",
keywords = "visual analytics, weather forecasting, uncertainty",
project = "MetaVis"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Swoboda-2017-VQI,
author = "Nicolas Swoboda and Judith Moosburner and Stefan Bruckner and Jai Y. Yu and Barry J. Dickson and Katja B{\"u}hler",
title = "Visualization and Quantification for Interactive Analysis of Neural Connectivity in Drosophila",
journal = "Computer Graphics Forum",
year = "2017",
volume = "36",
number = "1",
pages = "160--171",
month = "jan",
abstract = "Neurobiologists investigate the brain of the common fruit fly Drosophila  melanogaster to discover neural circuits and link them to complex  behavior. Formulating new hypotheses about connectivity requires  potential connectivity information between individual neurons, indicated  by overlaps of arborizations of two or more neurons. As the number  of higher order overlaps (i.e., overlaps of three or more arborizations)  increases exponentially with the number of neurons under investigation,  visualization is impeded by clutter and quantification becomes a  burden. Existing solutions are restricted to visual or quantitative  analysis of pairwise overlaps, as they rely on precomputed overlap  data. We present a novel tool that complements existing methods for  potential connectivity exploration by providing for the first time  the possibility to compute and visualize higher order arborization  overlaps on the fly and to interactively explore this information  in both its spatial anatomical context and on a quantitative level.  Qualitative evaluation by neuroscientists and non-experts demonstrated  the utility and usability of the tool",
pdf = "pdfs/Swoboda-2017-VQI.pdf",
images = "images/Swoboda-2017-VQI.jpg",
thumbnails = "images/Swoboda-2017-VQI.png",
youtube = "https://www.youtube.com/watch?v=bycWGQQpqks",
doi = "10.1111/cgf.12792",
keywords = "visual analysis, neurobiology"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {Turkay2017VIS,
author = "C. Turkay and E. Kaya and S. Balcisoy and H. Hauser",
title = "Designing Progressive and Interactive Analytics Processes for High-Dimensional Data Analysis",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2017",
volume = "PP",
number = "99",
pages = "1-1",
month = "jan",
abstract = "In interactive data analysis processes, the dialogue between the human and the computer is the enabling mechanism that can lead to actionable observations about the phenomena being investigated. It is of paramount importance that this dialogue is not interrupted by slow computational mechanisms that do not consider any known temporal human-computer interaction characteristics that prioritize the perceptual and cognitive capabilities of the users. In cases where the analysis involves an integrated computational method, for instance to reduce the dimensionality of the data or to perform clustering, such non-optimal processes are often likely. To remedy this, progressive computations, where results are iteratively improved, are getting increasing interest in visual analytics. In this paper, we present techniques and design considerations to incorporate progressive methods within interactive analysis processes that involve high-dimensional data. We define methodologies to facilitate processes that adhere to the perceptual characteristics of users and describe how online algorithms can be incorporated within these. A set of design recommendations and according methods to support analysts in accomplishing high-dimensional data analysis tasks are then presented. Our arguments and decisions here are informed by observations gathered over a series of analysis sessions with analysts from finance. We document observations and recommendations from this study and present evidence on how our approach contribute to the efficiency and productivity of interactive visual analysis sessions involving high-dimensional data.",
pdf = "pdfs/Turkay2017VIS.pdf",
images = "images/Turkay-2017-VIS.png",
thumbnails = "images/Turkay-2017-VIS.png",
doi = "10.1109/TVCG.2016.2598470",
issn = "1077-2626"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Kolesar-2017-FCC,
author = "Ivan Kolesar and Stefan Bruckner and Ivan Viola and Helwig Hauser",
title = "A Fractional Cartesian Composition Model for Semi-spatial Comparative Visualization Design",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2017",
volume = "23",
number = "1",
pages = "851--860",
month = "jan",
abstract = "The study of spatial data ensembles leads to substantial visualization  challenges in a variety of applications. In this paper, we present  a model for comparative visualization that supports the design of  according ensemble visualization solutions by partial automation.  We focus on applications, where the user is interested in preserving  selected spatial data characteristics of the data as much as possible—even  when many ensemble members should be jointly studied using comparative  visualization. In our model, we separate the design challenge into  a minimal set of user-specified parameters and an optimization component  for the automatic configuration of the remaining design variables.  We provide an illustrated formal description of our model and exemplify  our approach in the context of several application examples from  different domains in order to demonstrate its generality within the  class of comparative visualization problems for spatial data ensembles.",
pdf = "pdfs/Kolesar-2017-FCC.pdf",
images = "images/Kolesar-2017-FCC.jpg",
thumbnails = "images/Kolesar-2017-FCC.png",
youtube = "https://www.youtube.com/watch?v=_zk67fmryok",
doi = "10.1109/TVCG.2016.2598870",
event = "IEEE SciVis 2016",
keywords = "visualization models, integrating spatial and non-spatial data visualization, design methodologies",
location = "Baltimore, USA",
project = "physioillustration"
}

2016

    [Bibtex] 
    @MISC {moller2016winter,
author = "Moller, Torsten and Brambilla, Andrea and Hotz, Ingrid and Gordon, Kindlmann and Schulz, Hans Jorg and Hauser, Helwig and Brodtkorb, Andre",
title = "Geilo Winter School in eScience on Scientific Visualization",
year = "2016",
thumbnails = "images/winter.png",
note = "https://www.cs.ubc.ca/~tmm/talks.html",
journal = "Geilo Winter School of eSience"
}
    [PDF] [Bibtex] 
    @ARTICLE {preim2016visual,
author = "Preim, Bernhard and Klemm, Paul and Hauser, Helwig and Hegenscheid, Katrin and Oeltze, Steffen and Toennies, Klaus and V{\"o}lzke, Henry",
title = "Visual analytics of image-centric cohort studies in epidemiology",
journal = "Visualization in Medicine and Life Sciences III, Springer",
year = "2016",
pages = "221-248",
abstract = "Epidemiology characterizes the influence of causes to disease and health conditions of defined populations. Cohort studies are population-based studies involving usually large numbers of randomly selected individuals and comprising numerous attributes, ranging from self-reported interview data to results from various medical examinations, e.g., blood and urine samples. Since recently, medical imaging has been used as an additional instrument to assess risk factors and potential prognostic information. In this chapter, we discuss such studies and how the evaluation may benefit from visual analytics. Cluster analysis to define groups, reliable image analysis of organs in medical imaging data and shape space exploration to characterize anatomical shapes are among the visual analytics tools that may enable epidemiologists to fully exploit the potential of their huge and complex data. To gain acceptance, visual analytics tools need to complement more classical epidemiologic tools, primarily hypothesis-driven statistical analysis.",
pdf = "pdfs/Preim2016_Centric.pdf",
thumbnails = "images/Preim2016_Centric_1.png"
}
    [PDF] [Bibtex] 
    @ARTICLE {brambilla2016comparative,
author = "Brambilla, Andrea and Angelelli, Paolo and Andreassen, yvind and Hauser, Helwig",
title = "Comparative visualization of multiple time surfaces by planar surface reformation",
journal = "Pacific Visualization Symposium (PacificVis), 2016 IEEE",
year = "2016",
pages = "88--95",
abstract = "Comparing time surfaces at different integration time points, or
from different seeding areas, can provide valuable insight into
transport phenomena of fluid flows. Such a comparative study is
challenging due to the often convoluted shapes of these surfaces.
We propose a new approach for comparative flow visualization
based on time surfaces, which exploits the idea of embedding the
surfaces in a carefully designed, reformed 2D visualization space.
Such an embedding enables new opportunities for comparative flow
visualization. We present three different strategies for comparative
flow visualization that take advantage of the reformation. By reforming the time surfaces, we not only mitigate occlusion issues,
but we can devote also the third dimension of the visualization
space to the comparative aspects of the visualization. Our approach
is effective in a variety of flow study cases. The direct comparison
of individual time surfaces reveals small scale differences and fine
details about the fluid’s motion. The concurrent study of multiple
surface families enables the identification and the comparison of
the most prominent motion patterns. This work was developed in
close collaboration with an expert in fluid dynamics, who assessed
the potential usefulness of this approach in his field.",
pdf = "pdfs/bambarilla.pdf",
thumbnails = "images/bambarilla_1.png"
}
    [PDF] [Bibtex] 
    @ARTICLE {radovs2016towards,
author = "Rado{\v{s}}, Sanjin and Splechtna, Rainer and Matkovi{\'c}, K and Juras, M and Gr{\"o}ller, Eduard and Hauser, Helwig",
title = "Towards quantitative visual analytics with structured brushing and linked statistics",
journal = "Computer Graphics Forum",
year = "2016",
volume = "35",
number = "3",
pages = "251--260",
abstract = "Until now a lot of visual analytics predominantly delivers qualitative results—based, for example, on a continuous color map or a detailed spatial encoding. Important target applications, however, such as medical diagnosis and decision making, clearly benefit from quantitative analysis results. In this paper we propose several specific extensions to the well-established concept oflinking&brushing in order to make the analysis results more quantitative. We structure the brushing space in order to improvethe reproducibility of the brushing operation, e.g., by introducing the percentile grid. We also enhance the linked visualization with overlaid descriptive statistics to enable a more quantitative reading of the resulting focus+context visualization. Addition-ally, we introduce two novel brushing techniques: the percentile brush and the Mahalanob is brush. Both use the underlying data to support statistically meaningful interactions with the data. We illustrate the use of the new techniques in the context of two case studies, one based on meteorological data and the other one focused on data from the automotive industry where we evaluate a shaft design in the context of mechanical power transmission in cars.",
pdf = "pdfs/Rado-_et_al-2016-Computer_Graphics_Forum.pdf",
thumbnails = "images/Rado-_et_al-2016-Computer_Graphics_Forum_1.png"
}
    [DOI] [Bibtex] 
    @ARTICLE {Michael2016Visual,
author = "Michael Krone and Barbora Kozlikova and Norbert Lindow and Marc Baaden and Daniel Baum, and Julius Parulek and Hans-Christian Hege and Ivan Viola",
title = "Visual Analysis of Biomolecular Cavities: State of the Art",
journal = "Computer Graphics Forum",
year = "2016",
abstract = "In this report we review and structure the branch of molecular visualization that is concerned with the visual analysis of cavities in macromolecular protein structures. First the necessary background, the domain terminology, and the goals of analytical reasoning are introduced. Based on a comprehensive collection of relevant research works, we present a novel classification for cavity detection approaches and structure them into four distinct classes: grid-based, Voronoi-based, surface-based, and probe-based methods. The subclasses are then formed by their combinations. We match these approaches with corresponding visualization technologies starting with direct 3D visualization, followed with non-spatial visualization techniques that for example abstract the interactions between structures into a relational graph, straighten the cavity of interest to see its profile in one view, or aggregate the time sequence into a single contour plot. We also discuss the current state of methods for the visual analysis of cavities in dynamic data such as molecular dynamics simulations. Finally, we give an overview of the most common tools that are actively developed and used in the structural biology and biochemistry research. Our report is concluded by an outlook on future challenges in the field.",
images = "images/STARcavities2016.png",
thumbnails = "images/STARcavities2016.png",
publisher = "The Eurographics Association and John Wiley \& Sons Ltd.",
issn = "1467-8659",
doi = "10.1111/cgf.12928",
project = "physioillustration"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @INPROCEEDINGS {Stoppel-2016-GIR,
author = "Sergej Stoppel and Erlend Hodneland and Helwig Hauser and Stefan Bruckner",
title = "Graxels: Information Rich Primitives for the Visualization of Time-Dependent Spatial Data",
booktitle = "Proceedings of VCBM 2016",
year = "2016",
pages = "183--192",
month = "sep",
abstract = "Time-dependent volumetric data has important applications in areas  as diverse as medicine, climatology, and engineering. However, the  simultaneous quantitative assessment of spatial and temporal features  is very challenging. Common visualization techniques show either  the whole volume in one time step (for example using direct volume  rendering) or let the user select a region of interest (ROI) for  which a collection of time-intensity curves is shown. In this paper,  we propose a novel approach that dynamically embeds quantitative  detail views in a spatial layout. Inspired by the concept of small  multiples, we introduce a new primitive graxel (graph pixel). Graxels  are view dependent primitives of time-intensity graphs, generated  on-the-fly by aggregating per-ray information over time and image  regions. Our method enables the detailed feature-aligned visual analysis  of time-dependent volume data and allows interactive refinement and  filtering. Temporal behaviors like frequency relations, aperiodic  or periodic oscillations and their spatial context are easily perceived  with our method. We demonstrate the power of our approach using examples  from medicine and the natural sciences.",
pdf = "pdfs/Stoppel-2016-GIR.pdf",
images = "images/Stoppel-2016-GIR.jpg",
thumbnails = "images/Stoppel-2016-GIR.png",
youtube = "https://www.youtube.com/watch?v=UsClj3ytd0Y",
doi = "10.2312/vcbm.20161286",
event = "VCBM 2016",
keywords = "time-dependent data, volume data, small multiples",
location = "Bergen, Norway"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {Labschuetz-2016-JJC,
author = "Matthias Labsch{\"u}tz and Stefan Bruckner and Meister Eduard Gr{\"o}ller and Markus Hadwiger and Peter Rautek",
title = "JiTTree: A Just-in-Time Compiled Sparse GPU Volume Data Structure",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2016",
volume = "22",
number = "1",
pages = "1025--1034",
month = "jan",
abstract = "Abstract—Sparse volume data structures enable the efficient representation  of large but sparse volumes in GPU memory for com putation and visualization.  However, the choice of a specific data structure for a given data  set depends on several factors, such as the memory budget, the sparsity  of the data, and data access patterns. In general, there is no single  optimal sparse data structure, but a set of several candidates with  individual strengths and drawbacks. One solution to this problem  are hybrid data structures which locally adapt themselves to the  sparsity. However, they typically suffer from increased traversal  overhead which limits their utility in many applications. This paper  presents JiTTree, a novel sparse hybrid volume data structure that  uses just-in-time compilation to overcome these problems. By combining  multiple sparse data structures and reducing traversal overhead we  leverage their individual advantages. We demonstrate that hybrid  data structures adapt well to a large range of data sets. They are  especially superior to other sparse data structures for data sets  that locally vary in sparsity. Possible optimization criteria are  memory, performance and a combination thereof. Through just-in-time  (JIT) compilation, JiTTree reduces the traversal overhead of the  resulting optimal data structure. As a result, our hybrid volume  data structure enables efficient computations on the GPU, while being  superior in terms of memory usage when compared to non-hybrid data  structures.",
pdf = "pdfs/Labschuetz-2016-JJC.pdf",
images = "images/Labschuetz-2016-JJC.jpg",
thumbnails = "images/Labschuetz-2016-JJC.png",
doi = "10.1109/TVCG.2015.2467331",
event = "IEEE SciVis 2015",
keywords = "data transformation and representation, GPUs and multi-core architectures, volume rendering",
location = "Chicago, USA"
}
    [Bibtex] 
    @INPROCEEDINGS {Kolesar2016VCBM,
author = "Ivan Kolesar and Jan By\v{s}ka and Julius Parulek and Helwig Hauser and Barbora Kozl\'{i}kov\'{a}",
title = "Unfolding and Interactive Exploration of Protein Tunnels andtheir Dynamics",
booktitle = "Eurographics Workshop on Visual Computing for Biology and Medicine",
year = "2016",
pages = "1--10",
month = "sep",
abstract = "The presence of tunnels in protein structures substantially influences their reactivity with other molecules. Therefore, studying their properties and changes over time has been in the scope of biochemists for decades. In this paper we introduce a novel approach for comparative visualization and exploration of ensembles of tunnels. Our goal is to overcome occlusion problems present in traditional tunnel representations while providing users a quick way to navigate through the input dataset to identify potentially interesting tunnels. First, we unfold the input tunnels to a 2D representation enabling to observe the mutual position of amino acids forming the tunnel surface and the amount of surface they influence. These 2D images are subsequently described by image moments commonly used in image processing. This way we are able to detect similarities and outliers in the dataset, which are visualized as clusters in a scatterplot graph. The same coloring scheme is used in the linked bar chart enabling to detect the position of the cluster members over time. These views provide a way to select a subset of potentially interesting tunnels that can be further explored in detail using the 2D unfolded view and also traditional 3D representation. The usability of our approach is demonstrated on case studies conducted by the domain experts.",
images = "images/Kolesar-2016-VCBM.png",
thumbnails = "images/Kolesar-2016-VCBM-thumbnail.jpg",
proceedings = "Proceedings of Eurographics Workshop on Visual Computing in Biology and Medicine",
keywords = "unfolding, storytelling, game visualization",
location = "Bergen, Norway",
project = "physioillustration"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {Smit2016SLINE,
author = "Nils Lichtenberg and Noeska Smit and Christian Hansen and Kai Lawonn",
title = "Sline: Seamless Line Illustration for Interactive Biomedical Visualization",
booktitle = "Proceedings of VCBM 2016",
year = "2016",
month = "sep",
abstract = "In medical visualization of surface information, problems often arise when visualizing several overlapping structures simultaneously. There is a trade-off between visualizing multiple structures in a detailed way and limiting visual clutter, in order to allow users to focus on the main structures. Illustrative visualization techniques can help alleviate these problems by defining a level of abstraction per structure. However, clinical uptake of these advanced visualization techniques so far has been limited due to the complex parameter settings required. To bring advanced medical visualization closer to clinical application, we propose a novel illustrative technique that offers a seamless transition between various levels of abstraction and detail. Using a single comprehensive parameter, users are able to quickly define a visual representation per structure that fits the visualization requirements for focus and context structures. This technique can be applied to any biomedical context in which multiple surfaces are routinely visualized, such as neurosurgery, radiotherapy planning or drug design. Additionally, we introduce a novel hatching technique, that runs in real-time and does not require texture coordinates. An informal evaluation with experts from different biomedical domains reveals that our technique allows users to design focus-and-context visualizations in a fast and intuitive manner.",
pdf = "pdfs/Lichtenberg-2016-SLINE.pdf",
images = "images/Smit-2016-SLINE.PNG",
thumbnails = "images/Smit-2016-SLINE.jpg",
proceedings = "Proceedings of Eurographics Workshop on Visual Computing in Biology and Medicine",
event = "VCBM 2016",
keywords = "surface rendering, medical visualization, illustrative rendering",
location = "Bergen, Norway"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Klein-2016-TIV,
author = "Tobias Klein and Stefan Bruckner and Meister Eduard Gr{\"o}ller and Markus Hadwiger and Peter Rautek",
title = "Towards Interactive Visual Exploration of Parallel Programs using a Domain-Specific Language",
booktitle = "Proceedings of the International Workshop on OpenCL 2016",
year = "2016",
month = "apr",
abstract = "The use of GPUs and the massively parallel computing paradigm have  become wide-spread. We describe a framework for the interactive visualization  and visual analysis of the run-time behavior of massively parallel  programs, especially OpenCL kernels. This facilitates understanding  a program's function and structure, finding the causes of possible  slowdowns, locating program bugs, and interactively exploring and  visually comparing different code variants in order to improve performance  and correctness. Our approach enables very specific, user-centered  analysis, both in terms of the recording of the run-time behavior  and the visualization itself. Instead of having to manually write  instrumented code to record data, simple code annotations tell the  source-to-source compiler which code instrumentation to generate  automatically. The visualization part of our framework then enables  the interactive analysis of kernel run-time behavior in a way that  can be very specific to a particular problem or optimization goal,  such as analyzing the causes of memory bank conflicts or understanding  an entire parallel algorithm.",
pdf = "pdfs/Klein-2016-TIV.pdf",
images = "images/Klein-2016-TIV.jpg",
thumbnails = "images/Klein-2016-TIV.png",
doi = "10.1145/2909437.2909459",
event = "IWOCL 2016",
extra = "pdfs/Klein-2016-TIV-Poster.pdf",
keywords = "domain specific languages, GPU programming, visual exploration",
location = "Vienna, Austria",
owner = "bruckner"
}
    [Bibtex] 
    @MISC {Stoppel2015ConfReport,
author = "Sergej Stoppel",
title = "Conference Report IEEE VIS 2014",
month = "January",
year = "2016",
abstract = "Conference report about the IEEE VIS 2014 in Paris.",
images = "images/Shneiderman_Gerson_Pushups.PNG",
thumbnails = "images/Shneiderman_Gerson_Pushups.PNG",
url = "http://www.norsigd.no/norsigd_info/nsi-1-15.pdf"
}
    [PDF] [Bibtex] 
    @ARTICLE {Byska2016AnimoAminoMiner,
author = "Jan By{\v{s}}ka and Mathieu Le Muzic and Eduard M. Gr{\"o}ller and Ivan Viola and Barbora Kozl{\'i}kov{\'a}",
title = "AnimoAminoMiner: Exploration of Protein Tunnels and their Properties in Molecular Dynamics",
journal = "Visualization and Computer Graphics, IEEE Transactions on",
year = "2016",
volume = "22",
number = "1",
pages = "747--756",
abstract = "In this paper we propose a novel method for the interactive exploration of protein tunnels. The basic principle of our approach is that we entirely abstract from the 3D/4D space the simulated phenomenon is embedded in. A complex 3D structure and its curvature information is represented only by a straightened tunnel centerline and its width profile. This representation focuses on a key aspect of the studied geometry and frees up graphical estate to key chemical and physical properties represented by surroundingamino acids. The method shows the detailed tunnel profile and its temporal aggregation. The profile is interactively linked with a visual overview of all amino acids which are lining the tunnel over time. In this overview, each amino acid is represented by a set of colored lines depicting the spatial and temporal impact of the amino acid on the corresponding tunnel. This representation clearly shows the importance of amino acids with respect to selected criteria. It helps the biochemists to select the candidate amino acids for mutation which changes the protein function in a desired way. The AnimoAminoMiner was designed in close cooperation with domain experts. Its usefulness is documented by their feedback and a case study, which are included.",
pdf = "pdfs/2016-Byska-AnimoAminoMiner.pdf",
images = "images/IvanViola2016.png",
thumbnails = "images/IvanViola2016.png",
publisher = "IEEE"
}

2015

    [PDF] [Bibtex] 
    @ARTICLE {Angelelli-2015-PQA,
author = "Paolo Angelelli and Stefan Bruckner",
title = "Performance and Quality Analysis of Convolution-Based Volume Illumination",
journal = "Journal of WSCG",
year = "2015",
volume = "23",
number = "2",
pages = "131--138",
month = "jun",
abstract = "Convolution-based techniques for volume rendering are among the fastest  in the on-the-fly volumetric illumination category. Such methods,  however, are still considerably slower than conventional local illumination  techniques. In this paper we describe how to adapt two commonly used  strategies for reducing aliasing artifacts, namely pre-integration  and supersampling, to such techniques. These strategies can help  reduce the sampling rate of the lighting information (thus the number  of convolutions), bringing considerable performance benefits. We  present a comparative analysis of their effectiveness in offering  performance improvements. We also analyze the (negligible) differences  they introduce when comparing their output to the reference method.  These strategies can be highly beneficial in setups where direct  volume rendering of continuously streaming data is desired and continuous  recomputation of full lighting information is too expensive, or where  memory constraints make it preferable not to keep additional precomputed  volumetric data in memory. In such situations these strategies make  single pass, convolution-based volumetric illumination models viable  for a broader range of applications, and this paper provides practical  guidelines for using and tuning such strategies to specific use cases.",
pdf = "pdfs/Angelelli-2015-PQA.pdf",
images = "images/Angelelli-2015-PQA.jpg",
thumbnails = "images/Angelelli-2015-PQA.png",
keywords = "volume rendering, global illumination, scientific visualization, medical visualization"
}
    [DOI] [Bibtex] 
    @INPROCEEDINGS {eurovisstar20151112,
author = "Kozlikova, Barbora and Krone, Michael and Lindow, Norbert and Falk, Martin and Baaden, Marc and Baum, Daniel and Viola, Ivan and Parulek, Julius and Hege, Hans-Christian",
title = "Visualization of Biomolecular Structures: State of the Art",
booktitle = "Eurographics Conference on Visualization (EuroVis) - STARs",
year = "2015",
editor = "R. Borgo and F. Ganovelli and I. Viola",
volume = "-",
publisher = "The Eurographics Association",
abstract = "Structural properties of molecules are of primary concern in many fields. This report provides a comprehensiveoverview on techniques that have been developed in the fields of molecular graphics and visualization with a focuson applications in structural biology. The field heavily relies on computerized geometric and visual representationsof three-dimensional, complex, large, and time-varying molecular structures. The report presents a taxonomy thatdemonstrates which areas of molecular visualization have already been extensively investigated and where the fieldis currently heading. It discusses visualizations for molecular structures, strategies for efficient display regardingimage quality and frame rate, covers different aspects of level of detail, and reviews visualizations illustrating thedynamic aspects of molecular simulation data. The report concludes with an outlook on promising and importantresearch topics to enable further success in advancing the knowledge about interaction of molecular structures.",
images = "images/molvis_star.png",
thumbnails = "images/molvis_star.png",
proceedings = "Eurographics Conference on Visualization (EuroVis) - STARs",
doi = "10.2312/eurovisstar.20151112",
journal = "-",
number = "-",
keywords = "-",
project = "physioillustration"
}
    [DOI] [Bibtex] 
    @ARTICLE {Byska2015MC,
author = "Jan By\v{s}ka and Adam Jur\v{c}\'{i}­k and Eduard M. Gr{\"o}ller and Ivan Viola and Barbora Kozl{\'i}kov{\'a}",
title = "MoleCollar and Tunnel Heat Map Visualizations for Conveying Spatio-Temporo-Chemical Properties Across and Along Protein Voids",
journal = "Computer Graphics Forum",
year = "2015",
volume = "34",
number = "3",
pages = "1--10",
abstract = "Studying the characteristics of proteins and their inner void space, including their geometry,physico-chemical properties and dynamics are instrumental for evaluating the reactivity of theprotein with other small molecules. The analysis of long simulations of molecular dynamics produces a large number of voids which have to be further explored and evaluated. In this paper we propose three new methods: two of them convey important properties along the long axis of a selected void during molecular dynamics and one provides a comprehensive picture across the void. The first two proposed methods use a specific heat map to present two types of information: an overview of all detected tunnels in the dynamics and their bottleneck width andstability over time, and an overview of a specific tunnel in the dynamics showing the bottleneck position and changes of the tunnel length over time. These methods help to select asmall subset of tunnels, which are explored individually and in detail. For this stage we propose the third method, which shows in one static image the temporal evolvement of the shapeof the most critical tunnel part, i.e., its bottleneck. This view is enriched with abstractdepictions of different physicochemical properties of the amino acids surrounding the bottleneck. The usefulness of our newly proposed methods is demonstrated on a case study andthe feedback from the domain experts is included. The biochemists confirmed that our novel methods help to convey the information about the appearance and properties of tunnels in a very intuitive and comprehensible manner.",
images = "images/cgf12612-fig-0001.png",
thumbnails = "images/cgf12612-fig-0001.png",
issn = "1467-8659",
url = "http://dx.doi.org/10.1111/cgf.12612",
doi = "10.1111/cgf.12612",
keywords = "Categories and Subject Descriptors (according to ACM CCS), I.3.6 [Computer Graphics]: Picture/Image Generation—Line and curve generation"
}
    [Bibtex] 
    @INPROCEEDINGS {cellVIEW_2015,
author = "Mathieu Le Muzic and Ludovic Autin and Julius Parulek and Ivan Viola",
title = "cellVIEW: a Tool for Illustrative and Multi-Scale Rendering of Large Biomolecular Datasets",
booktitle = "EG Workshop on Visual Computing for Biology and Medicine",
year = "2015",
month = "sep",
abstract = "In this article we introduce cellVIEW, a new system to interactively visualize large biomolecular datasets on the atomic level. Our tool is unique and has been specifically designed to match the ambitions of our domain experts to model and interactively visualize structures comprised of several billions atom. The cellVIEW system integrates acceleration techniques to allow for real-time graphics performance of 60 Hz display rate on datasets representing large viruses and bacterial organisms. Inspired by the work of scientific illustrators, we propose a level-of-detail scheme which purpose is two-fold: accelerating the rendering and reducing visual clutter. The main part of our datasets is made out of macromolecules, but it also comprises nucleic acids strands which are stored as sets of control points. For that specific case, we extend our rendering method to support the dynamic generation of DNA strands directly on the GPU. It is noteworthy that our tool has been directly implemented inside a game engine. We chose to rely on a third party engine to reduce software development work-load and to make bleeding-edge graphics techniques more accessible to the end-users. To our knowledge cellVIEW is the only suitable solution for interactive visualization of large bimolecular landscapes on the atomic level and is freely available to use and extend.",
images = "images/cellview2015.png",
thumbnails = "images/cellview2015.png",
proceedings = "Proceedings of Eurographics Workshop on Visual Computing in Biology and Medicine",
project = "physioillustration"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Mindek-2015-ASM,
author = "Peter Mindek and Ladislav \v{C}mol{\'i}k and Ivan Viola and Meister Eduard Gr{\"o}ller and Stefan Bruckner",
title = "Automatized Summarization of Multiplayer Games",
booktitle = "Proceedings of SCCG 2015",
year = "2015",
pages = "93--100",
month = "apr",
abstract = "We present a novel method for creating automatized gameplay dramatization  of multiplayer video games. The dramatization serves as a visual  form of guidance through dynamic 3D scenes with multiple foci, typical  for such games. Our goal is to convey interesting aspects of the  gameplay by animated sequences creating a summary of events which  occurred during the game. Our technique is based on processing many  cameras, which we refer to as a flock of cameras, and events captured  during the gameplay, which we organize into a so-called event graph.  Each camera has a lifespan with a certain time interval and its parameters  such as position or look-up vector are changing over time. Additionally,  during its lifespan each camera is assigned an importance function,  which is dependent on the significance of the structures that are  being captured by the camera. The images captured by the cameras  are composed into a single continuous video using a set of operators  based on cinematographic effects. The sequence of operators is selected  by traversing the event graph and looking for specific patterns corresponding  to the respective operators. In this way, a large number of cameras  can be processed to generate an informative visual story presenting  the gameplay. Our compositing approach supports insets of camera  views to account for several important cameras simultaneously. Additionally,  we create seamless transitions between individual selected camera  views in order to preserve temporal continuity, which helps the user  to follow the virtual story of the gameplay.",
pdf = "pdfs/Mindek-2015-ASM.pdf",
images = "images/Mindek-2015-ASM.jpg",
thumbnails = "images/Mindek-2015-ASM.png",
note = "SCCG 2015 Best Paper Award",
doi = "10.1145/2788539.2788549",
keywords = "animation, storytelling, game visualization",
location = "Smolenice, Slovakia",
owner = "bruckner",
timestamp = "2015.06.08",
url = "http://www.cg.tuwien.ac.at/research/publications/2015/mindek-2015-mc/"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {PBVRVis2015026,
author = "Matkovic, K and Gracanin, D and Jelovi{\'{c}}, M and Hauser, H",
title = "Interactive Visual Analysis of Large Simulation Ensembles",
booktitle = "Proceedings of Winter Simulation Conference (WSC 2015, to appear)",
year = "2015",
abstract = "Recent advancements in simulation and computing make it possible to compute large simulation ensembles. A simulation ensemble consists of multiple simulation runs of the same model with different values of control parameters. In order to cope with ensemble data, a modern analysis methodology is necessary. In this paper, we present our experience with simulation ensemble exploration and steering by means of interactive visual analysis. We describe our long-term collaboration with fuel injection experts from the automotive industry. We present how interactive visual analysis can be used to gain a deep understanding in the ensemble data, and how it can be used, in a combination with automatic methods, to steer the ensemble creation, even for very complex systems. Very positive feedback from domain experts motivated us, a team of visualization and simulation experts, to present this research to the simulation community.",
pdf = "pdfs/matkovic_2015_winter_simConf.pdf",
images = "images/IVA_matkovic.png",
thumbnails = "images/IVA_matkovic.png"
}
    [DOI] [Bibtex] 
    @INPROCEEDINGS {7156384,
author = "Le Muzic, Mathieu and Waldner, Manuela and Parulek, Julius and Viola, Ivan",
title = "Illustrative Timelapse: A technique for illustrative visualization of particle-based simulations",
booktitle = "Visualization Symposium (PacificVis), 2015 IEEE Pacific",
year = "2015",
pages = "247-254",
month = "April",
abstract = "Animated movies are a popular way to communicate complex phenomena in cell biology to the broadaudience. Animation artists apply sophisticated illustration techniques to communicate a story, while trying to maintain a realistic representation of a complex dynamic environment. Since suchhand-crafted animations are time-consuming and cost-intensive to create, our goal is to formalizeillustration techniques used by artists to facilitate the automatic creation of visualizations generated from mesoscale particle-based molecular simulations. Our technique Illustrative Timelapse supports visual exploration of complex biochemical processes in dynamic environments by(1) seamless temporal zooming to observe phenomena in different temporal resolutions, (2) visualabstraction of molecular trajectories to ensure that observers are able to visually follow themain actors, (3) increased visual focus on events of interest, and (4) lens effects to preserve arealistic representation of the environment in the context. Results from a first user studyindicate that visual abstraction of trajectories improves the ability to follow a story and isalso appreciated by users. Lens effects increased the perceived amount of molecular motion in theenvironment while trading off traceability of individual molecules.",
images = "images/illustrative_timelapse.png",
thumbnails = "images/illustrative_timelapse.png",
proceedings = "Proceedings of IEEE Pacific Visualization",
keywords = "Biological system modeling;Data models;Data visualization;Lenses;Trajectory;Videos;Visualization;I.3.7[COMPUTER GRAPHICS]: Three-Dimensional Graphics and Realism—Animation;I.6.3 [SIMULATION AND MODELING]: Applications—",
doi = "10.1109/PACIFICVIS.2015.7156384",
project = "physioillustration"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {alsallakh2015state,
author = "Alsallakh, Bilal and Micallef, Luana and Aigner, Wolfgang and Hauser, Helwig and Miksch, Silvia and Rodgers, Peter",
title = "The State-of-the-Art of Set Visualization",
journal = "Computer Graphics Forum",
year = "2015",
abstract = "Sets comprise a generic data model that has been used in a variety of data analysis problems. Such problems involve analysing and visualizing set relations between multiple sets defined over the same collection of elements. However, visualizing sets is a non-trivial problem due to the large number of possible relations between them. We provide a systematic overview of state-of-the-art techniques for visualizing different kinds of set relations. We classify these techniques into six main categories according to the visual representations they use and the tasks they support. We compare the categories to provide guidance for choosing an appropriate technique for a given problem. Finally, we identify challenges in this area that need further research and propose possible directions to address these challenges. Further resources on set visualization are available at http://www.setviz.net.",
pdf = "pdfs/Alsallakh_et_al-2016-Computer_Graphics_Forum.pdf",
images = "images/ThumbNailIMG-SetVisSTAR.png",
thumbnails = "images/ThumbNailIMG-SetVisSTAR.png",
organization = "Wiley Online Library",
booktitle = "Computer Graphics Forum",
doi = "10.1111/cgf.12722"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Diehl-2015-VAS,
author = "Alexandra Diehl and Leandro Pelorosso and Claudio Delrieux and Celeste Saulo and Juan Ruiz and Meister Eduard Gr{\"o}ller and Stefan Bruckner",
title = "Visual Analysis of Spatio-Temporal Data: Applications in Weather Forecasting",
journal = "Computer Graphics Forum",
year = "2015",
volume = "34",
number = "3",
pages = "381--390",
month = "may",
abstract = "Weather conditions affect multiple aspects of human life such as economy,  safety, security, and social activities. For this reason, weather  forecast plays a major role in society. Currently weather forecasts  are based on Numerical Weather Prediction (NWP) models that generate  a representation of the atmospheric flow. Interactive visualization  of geo-spatial data has been widely used in order to facilitate the  analysis of NWP models. This paper presents a visualization system  for the analysis of spatio-temporal patterns in short-term weather  forecasts. For this purpose, we provide an interactive visualization  interface that guides users from simple visual overviews to more  advanced visualization techniques. Our solution presents multiple  views that include a timeline with geo-referenced maps, an integrated  webmap view, a forecast operation tool, a curve-pattern selector,  spatial filters, and a linked meteogram. Two key contributions of  this work are the timeline with geo-referenced maps and the curve-pattern  selector. The latter provides novel functionality that allows users  to specify and search for meaningful patterns in the data. The visual  interface of our solution allows users to detect both possible weather  trends and errors in the weather forecast model.We illustrate the  usage of our solution with a series of case studies that were designed  and validated in collaboration with domain experts.",
pdf = "pdfs/Diehl-2015-VAS.pdf",
images = "images/Diehl-2015-VAS.jpg",
thumbnails = "images/Diehl-2015-VAS.png",
youtube = "https://www.youtube.com/watch?v=hhQwsuXpHo8",
doi = "10.1111/cgf.12650",
event = "EuroVis 2015",
keywords = "weather forecasting, visual analysis, spatiotemporal data",
location = "Cagliari, Italy",
owner = "bruckner",
timestamp = "2015.06.08"
}
    [PDF] [Bibtex] 
    @MISC {Hauser2015IRIS,
author = "Helwig Hauser",
title = "Medical Visualization Research at the VisGroup @ UiB.no/ii",
howpublished = "Invited talk at IRIS",
month = "November",
year = "2015",
abstract = "Established about eight years ago, the Visualization Research Group is the youngest of six research groups at the Department of Informatics, UiB, focusing on application-oriented basic research in visualization. Medicine and related disciplines (such as biomedicine, biology, etc.) stand for a growing number of grand visualization challenges and the vivid interdisciplinary MedViz network in Bergen gives ample opportunities for internationally recognized visualization research. In this talk, an overview of the visualization research group [1] is given, together with a short review of selected research projects in medical visualization.",
pdf = "pdfs/2015-11-25-HH-IRIS.pdf",
images = "images/ThumbNailIRIS.jpg",
thumbnails = "images/ThumbNailIRIS.jpg",
day = "25",
location = "Bergen, Norway"
}
    [DOI] [Bibtex] 
    @ARTICLE {Brambilla15Expressive,
author = "Andrea Brambilla and Helwig Hauser",
title = "Expressive Seeding of Multiple Stream Surfaces for Interactive Flow Exploration",
journal = "Computers \& Graphics",
year = "2015",
volume = "47",
pages = "123--134",
abstract = "Integral surfaces, such as stream and path surfaces, are highly effective in the context of the exploration and the analysis of the long-term behavior of three-dimensional flows. However, specifying the seeding curves that lead to an expressive set of integral surfaces is a challenging and cumbersome task. In this paper, we propose an algorithm for automatically seeding multiple stream surfaces around a user-specified location of interest. The process is guided by a streamline similarity measure. Within the resulting integral surfaces, adjacent streamlines are as similar as possible to each other. In addition, we aim at conveying different aspects of the flow behavior with each surface. This is achieved by maximizing the dissimilarity between streamlines from different stream surfaces. The capabilities of our technique are demonstrated on a number of application cases. We provide a qualitative comparison with two state-of-the-art approaches. We report from our detailed exchange with a domain expert concerning the expressiveness and usefulness of our approach. A thorough analysis of the few parameters involved is provided. ",
images = "images/Brambilla15Expressive01.png, images/Brambilla15Expressive02.png",
thumbnails = "images/Brambilla15Expressive01_thumb.png, images/Brambilla15Expressive02_thumb.png",
publisher = "Elsevier",
doi = "http://dx.doi.org/10.1016/j.cag.2015.01.002",
url = "http://www.sciencedirect.com/science/article/pii/S0097849315000035",
keywords = "Flow visualization; Stream surface selection; Visibility management"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {splechtna2015interactive,
author = "Splechtna, Rainer and Matkovic, Kresimir and Gracanin, Denis and Jelovic, Mario and Hauser, Helwig",
title = "Interactive visual steering of hierarchical simulation ensembles",
booktitle = "Visual Analytics Science and Technology (VAST), 2015 IEEE Conference on",
year = "2015",
pages = "89--96",
organization = "IEEE",
abstract = "Multi-level simulation models, i.e., models where different components are simulated using sub-models of varying levels of complexity, belong to the current state-of-the-art in simulation. The existing analysis practice for multi-level simulation results is to manually compare results from different levels of complexity, amounting to a very tedious and error-prone, trial-and-error exploration process. In this paper, we introduce hierarchical visual steering, a new approach to the exploration and design of complex systems. Hierarchical visual steering makes it possible to explore and analyze hierarchical simulation ensembles at different levels of complexity. At each level, we deal with a dynamic simulation ensemble - the ensemble grows during the exploration process. There is at least one such ensemble per simulation level, resulting in a collection of dynamic ensembles, analyzed simultaneously. The key challenge is to map the multi-dimensional parameter space of one ensemble to the multi-dimensional parameter space of another ensemble (from another level). In order to support the interactive visual analysis of such complex data we propose a novel approach to interactive and semi-automatic parameter space segmentation and comparison. The approach combines a novel interaction technique and automatic, computational methods - clustering, concave hull computation, and concave polygon overlapping - to support the analysts in the cross-ensemble parameter space mapping. In addition to the novel parameter space segmentation we also deploy coordinated multiple views with standard plots. We describe the abstract analysis tasks, identified during a case study, i.e., the design of a variable valve actuation system of a car engine. The study is conducted in cooperation with experts from the automotive industry. Very positive feedback indicates the usefulness and efficiency of the newly proposed approach.",
pdf = "pdfs/Splechtna_2015.pdf",
images = "images/ThumbNailIMG-HierSteering.png",
thumbnails = "images/ThumbNailIMG-HierSteering.png",
doi = "10.1109/VAST.2015.7347635"
}
    [PDF] [Bibtex] 
    @MISC {Hauser2015Austria,
author = "Helwig Hauser",
title = "Integrating Spatial \& Non-spatial Data in Visualization",
howpublished = "Invited talk",
month = "October",
year = "2015",
abstract = "New opportunities in data science, such as the consideration of cohort study data, require new approaches to the appropriate design of an effective visualization. We need to capitalize on successful solutions from previous research, of course, but we should also explore new strategies that challenge our already established mindset in visualization. In this talk, I address the specific challenge of integrating spatial and non-spatial data in visualization, in particular, when the spatial aspect of the data is of great importance to the user---this could relate to the morphological information in a 3D medical scan or the geometrical aspects of flow features in a CFD simulation. In data visualizaiton, the actual mapping step---from data to a visual form---is certainly crucial and we should strive to optimally exploit the great opportunities that we have in designing this step. In data-intensive sciences, the study objects of interest are increasingly often represented by extensive and rich datasets (aka. big data)---while traditionally the focus of visualization was on individual, static datasets, we now face dynamic data, representing entire ensembles of study entities, etc. Visualization gets a lot harder, when facing such new 'big data' challenges---both on the designer sider as well as also on the user side. At the same time, however, also the potential for impact is increasing, which amounts to a fantastic motivation for new basic research in visualization.",
pdf = "pdfs/2015-10-14-HHauser-InvTalk.pdf",
images = "images/ThumbPicHHAustria2015.png",
thumbnails = "images/ThumbPicHHAustria2015.png",
location = "Vienna, Austria"
}
    [PDF] [Bibtex] 
    @MISC {Hauser2015VIS,
author = "Helwig Hauser",
title = "From Anatomy to Physiology in Medical Visualization",
howpublished = "Tutorial talk at IEEE VIS 2015",
month = "October",
year = "2015",
abstract = "Generally, medical visualization assists the diagnosis of diseases as well as the treatment of patients. Capturing the patients anatomy, which to a large degree is in the focus of traditional MedViz, certainly is one important key to the success of medical visualization. At least equally important, if not even more, is the consideration of physiology, entailing the complex of function (or malfunction) of the patient. Modern imaging modalities extend beyond the simple depiction of static anatomical snapshots to capturing temporal processes as well as to covering multiple scales of physiology eventually linking molecular biology to medicine. The visualization of human physiology complements other techniques, for example lab tests for quantifying certain physiological functions. We deem ourselves at the beginning of an interesting extension of MedViz research to increasingly capture physiology in addition to anatomy.",
pdf = "pdfs/2015-10-25-VIS2015-TutTalkHH-print2up.pdf",
images = "images/ThumbnailVisTut.png",
thumbnails = "images/ThumbnailVisTut.png",
day = "25",
location = "Chicago, Illinois, USA"
}
    [PDF] [Bibtex] 
    @MISC {Hauser2015SUBSEA,
author = "Helwig Hauser",
title = "Big Data - visualization and visual analytics",
howpublished = "Invited talk at the NCE Subsea Forum",
month = "March",
year = "2015",
pdf = "pdfs/2015-03-19-NCE-BigDataVA-print2up.pdf",
images = "images/ThumbnailBigData.jpg",
thumbnails = "images/ThumbnailBigData.jpg",
day = "19",
location = "Bergen, Norway"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Karimov-2015-GVE,
author = "Alexey Karimov and Gabriel Mistelbauer and Thomas Auzinger and Stefan Bruckner",
title = "Guided Volume Editing based on Histogram Dissimilarity",
journal = "Computer Graphics Forum",
year = "2015",
volume = "34",
number = "3",
pages = "91--100",
month = "may",
abstract = "Segmentation of volumetric data is an important part of many analysis  pipelines, but frequently requires manual inspection and correction.  While plenty of volume editing techniques exist, it remains cumbersome  and error-prone for the user to find and select appropriate regions  for editing. We propose an approach to improve volume editing by  detecting potential segmentation defects while considering the underlying  structure of the object of interest. Our method is based on a novel  histogram dissimilarity measure between individual regions, derived  from structural information extracted from the initial segmentation.  Based on this information, our interactive system guides the user  towards potential defects, provides integrated tools for their inspection,  and automatically generates suggestions for their resolution. We  demonstrate that our approach can reduce interaction effort and supports  the user in a comprehensive investigation for high-quality segmentations.",
pdf = "pdfs/Karimov-2015-GVE.pdf",
images = "images/Karimov-2015-GVE.jpg",
thumbnails = "images/Karimov-2015-GVE.png",
youtube = "https://www.youtube.com/watch?v=zjTYkXTm_dM",
doi = "10.1111/cgf.12621",
event = "EuroVis 2015",
keywords = "medical visualization, segmentation, volume editing, interaction",
location = "Cagliari, Italy",
owner = "bruckner",
timestamp = "2015.06.08",
url = "http://www.cg.tuwien.ac.at/research/publications/2015/karimov-2015-HD/"
}

2014

    [PDF] [Bibtex] 
    @MISC {Hauser2014BigData,
author = "Helwig Hauser",
title = "Big Data - a threat or an opportunity for our modern society?",
howpublished = "Invited talk at the Alumni Event of the University of Bergen, Norway",
month = "May",
year = "2014",
abstract = "Invited talk at the Alumni Event of the University of Bergen, Norway",
pdf = "pdfs/2014-05-10-UiB-Alumni-BigDataTalkHH-print2up.pdf",
images = "images/2014-05-10-UiB-Alumni-BigDataTalkHH-print2up_Image_0003.jpg",
thumbnails = "images/2014-05-10-UiB-Alumni-BigDataTalkHH-print2up_Image_0003.jpg",
location = "Bergen, Norway"
}
    [PDF] [Bibtex] 
    @ARTICLE {Natali14Rapid,
author = "Mattia Natali and Julius Parulek and Daniel Patel",
title = "Rapid Modelling of Interactive Geological Illustrations with Faults and Compaction",
journal = "Proceedings of Spring Conference on Computer Graphics (SCCG)",
year = "2014",
abstract = "In this paper, we propose new methods for building geological illustrations and animations. We focus on allowing geologists to create their subsurface models by means of sketches, to quickly communicate concepts and ideas rather than detailed information. The result of our sketch-based modelling approach is a layer-cake volume representing geological phenomena, where each layer is rock material which has accumulated due to a user-defined depositional event. Internal geological structures can be inspected by different visualization techniques that we employ. Faulting and compaction of rock layers are important processes in geology. They can be modelled and visualized with our technique. Our representation supports non-planar faults that a user may define by means of sketches. Real-time illustrative animations are achieved by our GPU accelerated approach.",
pdf = "pdfs/Natali14Rapid.pdf",
images = "images/Natali2014Rapid0.png, images/Natali2014Rapid1.png",
thumbnails = "images/Natali2014Rapid0.png, images/Natali2014Rapid1.png",
url = "http://dx.doi.org/10.1145/2643188.2643201",
project = "geoillustrator"
}
    [Bibtex] 
    @ARTICLE {alsallakh2014visual,
author = "Alsallakh, Bilal and Hanbury, Allan and Hauser, Helwig and Miksch, Silvia and Rauber, Andreas",
title = "Visual methods for analyzing probabilistic classification data",
journal = "Visualization and Computer Graphics, IEEE Transactions on",
year = "2014",
volume = "20",
number = "12",
pages = "1703--1712",
abstract = "Multi-class classifiers often compute scores for the classification samples describing probabilities to belong to different classes. In order to improve the performance of such classifiers, machine learning experts need to analyze classification results for a large number of labeled samples to find possible reasons for incorrect classification. Confusion matrices are widely used for this purpose. However, they provide no information about classification scores and features computed for the samples. We propose a set of integrated visual methods for analyzing the performance of probabilistic classifiers. Our methods provide insight into different aspects of the classification results for a large number of samples. One visualization emphasizes at which probabilities these samples were classified and how these probabilities correlate with classification error in terms of false positives and false negatives. Another view emphasizes the features of these samples and ranks them by their separation power between selected true and false classifications. We demonstrate the insight gained using our technique in a benchmarking classification dataset, and show how it enables improving classification performance by interactively defining and evaluating post-classification rules.",
images = "images/alsallakh2014visual3.jpg, images/alsallakh2014visual1.jpg, images/alsallakh2014visual2.jpg",
thumbnails = "images/alsallakh2014visual3.jpg",
publisher = "IEEE"
}
    [PDF] [DOI] [Bibtex] 
    @MISC {Hauser2014SIBGRAPI,
author = "Helwig Hauser",
title = "Interactive Visual Exploration and Analysis of Multi-Faceted Scientific Data",
howpublished = "Invited talk at SIBGRAPI Conference on Graphics, Patterns and Images in Rio de Janeiro, Brazil",
month = "August",
year = "2014",
abstract = "Invited talk at SIBGRAPI Conference on Graphics, Patterns and Images in Rio de Janeiro, Brazil",
pdf = "pdfs/2014-08-30-Rio-SIBGRAPI-invited-talk-print-new-new-2up.pdf",
images = "images/2014-08-30-Rio-SIBGRAPI-invited-talk-print-new-new-2up_Image_0003.jpg, images/2014-08-30-Rio-SIBGRAPI-invited-talk--print-new-new-2up_Image_0001.jpg, images/2014-08-30-Rio-SIBGRAPI-invited-talk-print-new-new-2up_Image_0001(2).jpg, images/2014-08-30-Rio-SIBGRAPI-invited-talk-print-new-new-2up_Image_0001(3).jpg, images/2014-08-30-Rio-SIBGRAPI-invited-talk-print-new-new-2up_Image_0001(4).jpg",
thumbnails = "images/2014-08-30-Rio-SIBGRAPI-invited-talk-print-new-new-2up_Image_0003.jpg",
location = "Rio de Janeiro, Brazil",
doi = "10.1007/978-1-4471-6497-5_15"
}
    [Bibtex] 
    @MISC {Kingman14GenomeMaking,
author = "Pina Kingman",
title = "Our Resilient Genome: The Making of a Science Film",
howpublished = "Presentation in the EG VCBM workshop 2014",
month = "September",
year = "2014",
abstract = "Every single human cell has to fix 10,000 to 20,000 lesions in its DNA every day. Our cells are constantly exposed to many different types of threats that damage our genome. These lesions could cause mutations in our DNA, potentially leading to cancer and other diseases. With such continuous onslaught, how can our cells possibly protect our DNA from damage and mutations? This presentation will showcase the first public screening of a short film about DNA repair, which blends computer graphics and biology to communicate exciting up-and-coming research. This film was developed in conjunction with the Department of Informatics and the Department of Molecular Biology at the University of Bergen, and the Institute of Computer Graphics and Algorithms at the Vienna University of Technology. Along with a discussion on the visualisation process, I will also talk about the intersection between film and science that helps us communicate complex information.",
images = "images/no_thumb.png",
thumbnails = "images/no_thumb.png",
location = "Wien, Austria",
project = "physioillustration"
}
    [PDF] [Bibtex] 
    @MISC {LeMusic14Temporal,
author = "Mathieu Le Muzic and Julius Parulek and Manuela Waldner and Ivan Viola",
title = "Illustrative Visualization of Biochemical Processes Featuring Multiple Temporal Scales",
howpublished = "Poster presented at the EG VCBM workshop 2014",
month = "September",
year = "2014",
pdf = "pdfs/LeMusic14Temporal.pdf",
images = "images/LeMuzic14Temporal.png",
thumbnails = "images/LeMuzic14Temporal_thumb.png",
location = "Wien, Austria",
project = "physioillustration"
}
    [DOI] [Bibtex] 
    @INPROCEEDINGS {alsallakh2014visualizing,
author = "Alsallakh, Bilal and Micallef, Luana and Aigner, Wolfgang and Hauser, Helwig and Miksch, Silvia and Rodgers, Peter",
title = "Visualizing sets and set-typed data: State-of-the-art and future challenges",
booktitle = "Eurographics conference on Visualization (EuroVis)--State of The Art Reports",
year = "2014",
pages = "1--21",
abstract = "A variety of data analysis problems can be modelled by defining multiple sets over a collection of elements and analyzing the relations between these sets. Despite their simple concept, visualizing sets is a non-trivial problem due to the large number of possible relations between them. We provide a systematic overview of state-of-theart techniques for visualizing different kinds of set relations. We classify these techniques into 7 main categories according to the visual representations they use and the tasks they support. We compare the categories to provide guidance for choosing an appropriate technique for a given problem. Finally, we identify challenges in this area that need further research and propose possible directions to address with these challenges.",
images = "images/img_Page_13_Image_0001.jpg",
thumbnails = "images/img_Page_13_Image_0001.jpg",
proceedings = "Eurographics conference on Visualization (EuroVis)--stars",
doi = "dx.doi.org/10.2312/eurovisstar.20141170"
}
    [Bibtex] 
    @MISC {Kingman14Integrating,
author = "Pina Kingman and Anne-Kristin Stavrum and Ivan Viola and Helwig Hauser",
title = "Integrating 2D and 3D Animation to Comprehensively Communicate Biology",
howpublished = "Poster presented at the VizBi conference 2014",
month = "March",
year = "2014",
abstract = "As research in cellular and molecular biology advances, so does the need to educated both the science research community and the general public. The former must be aware of developments in associated fields, the latter must be able to take responsibility for their own well-being. In both cases, we have a willing and capable audience, ready to delve deeper into the biological sciences. To exploit this opportunity, we need to research new and advanced visual language techniques to further improve communication. We are therefore investigating novel visual communication techniques to advance knowledge translation methods, focusing on effectively communicating abstract functional aspects of biological systems. To this end, we are creating several short animations, each one exploring different design solutions. These design solutions incorporate 2D motion graphics, information visualization, 3D animation, and can be applied to any biological story. In addition to our short animations, this research will culminate in a short film describing NAD-dependent DNA Repair, intended for the general public and researchers interested in these molecular systems.",
images = "images/Kingman13Integrating.png",
thumbnails = "images/Kingman13Integrating_thumb.jpg",
location = "Heidelberg, Germany",
project = "physioillustration"
}
    [PDF] [Bibtex] 
    @MISC {Hauser2014USP,
author = "Helwig Hauser",
title = "About Visualization in Bergen and Interactive Visual Analysis",
howpublished = "Invited talk at Institute of Computing and Mathematical Sciences, University of São Paolo, in São Carlos, Brazil",
month = "August",
year = "2014",
abstract = "Invited talk at Institute of Computing and Mathematical Sciences, University of São Paolo, in São Carlos, Brazil",
pdf = "pdfs/2014-08-26-SaoCarlos-USP-inv-talk-print2up.pdf",
images = "images/2014-08-26-SaoCarlos-USP-invtalk-print2up_Image_0001.jpg, images/2014-08-26--SaoCarlos-USP-inv-talk-print2up_Image_0001(2).jpg, images/2014-08-26-SaoCarlos-USP-inv-talk-print2up_Image_0001(3).jpg, images/2014-08-26-SaoCarlos-USP-inv-talk-print2up_Image_0001(4).jpg, images/2014-08-26-SaoCarlos-USP-inv-talk-print2up_Image_0002.jpg, images/2014-08-26-SaoCarlos-USP-inv-talk-print2up_Image_0003.jpg, images/2014-08-26-SaoCarlos-USP-inv-talk-print2up_Image_0003(2).jpg, images/2014-08-26-SaoCarlos-USP-inv-talk-print2up_Image_0002(2).jpg, images/2014-08-26-SaoCarlos-USP-inv-talk-print2up_Image_0002(3).jpg",
thumbnails = "images/2014-08-26-SaoCarlos-USP-invtalk-print2up_Image_0001.jpg",
location = "São Carlos, Brazil"
}
    [PDF] [Bibtex] 
    @MISC {Hauser2014NCE,
author = "Helwig Hauser",
title = "About Visual Computing",
howpublished = "Invited talk at the NCE Subsea Theme Meeting on Visual Computing in Bergen, Norway",
month = "April",
year = "2014",
abstract = "Invited talk at the NCE Subsea Theme Meeting on Visual Computing in Bergen, Norway",
pdf = "pdfs/2014-04-08-VisCompTalk-HH-print2up.pdf",
images = "images/2014-04-08-VisCompTalk-HH-print2up_Image_0004.jpg, images/2014-04-08-VisCompTalk-HH-print2up_Image_0006.jpg, images/2014-04-08-VisCompTalk-HH-print2up_Image_0010.jpg, images/2014-04-08-VisCompTalk-HH-print2up_Image_0002.jpg",
thumbnails = "images/2014-04-08-VisCompTalk-HH-print2up_Image_0010.jpg",
location = "Bergen, Norway"
}
    [Bibtex] 
    @PHDTHESIS {brambilla14thesis,
author = "Andrea Brambilla",
title = "Visibility-oriented Visualization Design for Flow Illustration",
school = "Department of Informatics, University of Bergen, Norway",
year = "2014",
month = "December",
abstract = "Flow phenomena are ubiquitous in our world and they affect many aspects of our daily life. For this reason, they are the subject of extensive studies in several research fields. In medicine, the blood flow through our vessels can reveal important information about cardiovascular diseases. The air flow around a vehicle and the motion of fluids in a combustion engine are examples of relevant flow phenomena in engineering disciplines. Meteorologists, climatologists and oceanographers are instead concerned with winds and water currents. Thanks to the recent advancements in computational fluid dynamics and to the increasing power of modern hardware, accurate simulations of flow phenomena are feasible nowadays. The evolution of multiple flow attributes, such as velocity, temperature and pressure, can be simulated over large spatial and temporal domains (4D). The amount of data generated by this process is massive, therefore visualization techniques are often adopted in order to ease the analysis phase. The overall goal is to convey information about the phenomena of interest through a suitable representation of the data at hand. Due to the multivariate and multidimensional nature of the data, visibility issues (such as cluttering and occlusion), represent a significant challenge. Flow visualization can greatly benefit from studying and addressing visibility issues already in the design phase. In this thesis we investigate and demonstrate the effectiveness of taking visibility management into account early in the design process. We apply this principle to three characteristic flow visualization scenarios: (1) The simultaneous visualization of multiple flow attributes. (2) The visual inspection of single and multiple integral surfaces. (3) The selection of seeding curves for constructing families of integral surfaces. Our techniques result in clutter- and occlusion-free visualizations, which effectively illustrate the key aspects of the flow behavior. For demonstration purposes, we have applied our approaches to a number of application cases. Additionally, we have discussed our visualization designs with domain experts. They showed a genuine interest in our work and provided insightful suggestions for future research directions.",
images = "images/brambilla14thesis_0.png, images/brambilla14thesis_1.png,",
thumbnails = "images/brambilla14thesis_0_thumb.png, images/brambilla14thesis_1_thumb.png,",
isbn = "978-82-308-2753-6",
url = "http://hdl.handle.net/1956/8961"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @INPROCEEDINGS {Schmidt-2014-YMC,
author = "Johanna Schmidt and Reinhold Preiner and Thomas Auzinger and Michael Wimmer and Meister Eduard Gr{\"o}ller and Stefan Bruckner",
title = "YMCA - Your Mesh Comparison Application",
booktitle = "Proceedings of IEEE VAST 2014",
year = "2014",
pages = "153--62",
month = "nov",
abstract = "Polygonal meshes can be created in several different ways. In this  paper we focus on the reconstruction of meshes from point clouds,  which are sets of points in 3D. Several algorithms that tackle this  task already exist, but they have different benefits and drawbacks,  which leads to a large number of possible reconstruction results  (i.e., meshes). The evaluation of those techniques requires extensive  comparisons between different meshes which is up to now done by either  placing images of rendered meshes side-by-side, or by encoding differences  by heat maps. A major drawback of both approaches is that they do  not scale well with the number of meshes. This paper introduces a  new comparative visual analysis technique for 3D meshes which enables  the simultaneous comparison of several meshes and allows for the  interactive exploration of their differences. Our approach gives  an overview of the differences of the input meshes in a 2D view.  By selecting certain areas of interest, the user can switch to a  3D representation and explore the spatial differences in detail.  To inspect local variations, we provide a magic lens tool in 3D.  The location and size of the lens provide further information on  the variations of the reconstructions in the selected area. With  our comparative visualization approach, differences between several  mesh reconstruction algorithms can be easily localized and inspected.",
pdf = "pdfs/Schmidt-2014-YMC.pdf",
images = "images/Schmidt-2014-YMC.jpg",
thumbnails = "images/Schmidt-2014-YMC.png",
youtube = "https://www.youtube.com/watch?v=1s-AmFCQRzM",
doi = "10.1109/VAST.2014.7042491",
event = "IEEE VIS 2014",
keywords = "visual analysis, comparative visualization, 3D data exploration, focus+context, mesh comparison",
location = "Paris, France",
proceedings = "Proceedings of IEEE VAST 2014",
url = "http://www.cg.tuwien.ac.at/research/publications/2014/ymca/"
}
    [DOI] [VID] [Bibtex] 
    @ARTICLE {Natali14Sketch,
author = "Mattia Natali and Tore Grane Klausen and Daniel Patel",
title = "Sketch-Based Modelling and Visualization of Geological Deposition",
journal = "Computers \& Geosciences",
year = "2014",
volume = "67C",
pages = "40--48",
abstract = "We propose a method for sketching and visualizing geological models by sequentially defining stratigraphic layers, where each layer represents a unique erosion or deposition event. Evolution of rivers and deltas is important for geologists when interpreting the stratigraphy of the subsurface, in particular for hydrocarbon exploration. We illustratively visualize mountains, basins, lakes, rivers and deltas, and how they change the morphology of a terrain during their evolution. We present a compact representation of the model and a novel rendering algorithm that allows us to obtain an interactive and illustrative layer-cake visualization. A user study has been performed to evaluate our method.",
vid = "vids/Natali2014Sketch.mp4",
images = "images/Natali2014Sketch0.png, images/Natali2014Sketch1.png",
thumbnails = "images/Natali2014Sketch0.png, images/Natali2014Sketch1.png",
doi = "10.1016/j.cageo.2014.02.010",
url = "http://www.sciencedirect.com/science/article/pii/S0098300414000508",
project = "geoillustrator"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Waldner-2014-GHI,
author = "Manuela Waldner and Stefan Bruckner and Ivan Viola",
title = "Graphical Histories of Information Foraging",
booktitle = "Proceedings of NordiCHI 2014",
year = "2014",
pages = "295--304",
month = "oct",
abstract = "During information foraging, knowledge workers iteratively seek, filter,  read, and extract information. When using multiple information sources  and different applications for information processing, re-examination  of activities for validation of previous decisions or re-discovery  of previously used information sources is challenging. In this paper,  we present a novel representation of cross-application histories  to support recall of past operations and re-discovery of information  resources. Our graphical history consists of a cross-scale visualization  combining an overview node-link diagram of used desktop resources  with nested (animated) snapshot sequences, based on a recording of  the visual screen output during the users’ desktop work. This representation  makes key elements of the users’ tasks visually stand out, while  exploiting the power of visual memory to recover subtle details of  their activities. In a preliminary study, users found our graphical  history helpful to recall details of an information foraging task  and commented positively on the ability to expand overview nodes  into snapshot and video sequences.",
pdf = "pdfs/Waldner-2014-GHI.pdf",
images = "images/Waldner-2014-GHI.jpg",
thumbnails = "images/Waldner-2014-GHI.png",
doi = "10.1145/2639189.2641202",
keywords = "interaction history, graph visualization, provenance",
owner = "bruckner",
timestamp = "2014.12.30",
url = "http://www.cg.tuwien.ac.at/research/publications/2014/waldner-2014-ghi/"
}
    [PDF] [Bibtex] 
    @PHDTHESIS {natali14thesis,
author = "Mattia Natali",
title = "Sketch-based Modelling and Conceptual Visualization of Geomorphological Processes for Interactive Scientific Communication",
school = "Department of Informatics, University of Bergen, Norway",
year = "2014",
month = "September",
abstract = "Throughout this dissertation, solutions for rapid digitalization of ideas will be defined.More precisely, the focus is on interactive scientific sketching and communication of geology, where theresult is a digital illustrative 3D model. Results are achieved through a sketch-based modellingapproach which gives the user a more natural and intuitive modelling process, hence leading to aquicker definition of a geological illustration. To be able to quickly externalize and communicate onesideas as a digital 3D model, can be of importance. For instance, students may profit from explanationssupported by interactive illustrations. Exchange of information and hypotheses between domain expertsis also a targeted situation in our work. Furthermore, illustrative models are frequently employed in business, when decisional meetings take place for convincing the management that a project is worth to be funded. An advantage of digital models is that they can be saved and they are easy to distribute. In contrast to 2D images or paper sketches, one can interact with digital 3D models, and they can be transferred on portable devices for easy access (for instance during geological field studies). Another advantage, compared to standard geological illustrations, is that if a model has been created with internal structures, it can be arbitrarily cut and inspected. Different solutions for different aspects of subsurface geology are presented in this dissertation. To express folding and faulting processes, a first modelling approach based on cross-sectional sketches is introduced. User defined textures can be associated to each layer, and can then be deformed with sketch strokes, for communicating layer properties such as rock type and grain size. A following contribution includes a simple and compact representation to model and visualize 3D stratigraphic models. With this representation, erosion and deposition offluvial systems are easy to specify and display. Ancient river channels and other geological features, which are present in the subsurface, can be accessed by means of a volumetric representation. Geological models are obtained and visualized by sequentially defining stratigraphic layers, where each layer represents a unique erosion or deposition event. Evolution of rivers and deltas is important for geologists when interpreting the stratigraphy of the subsurface, in particular because it changes the landscape morphology and because river deposits are potential hydrocarbon reservoirs. Time plays a fundamental role in geological processes. Animations are well suited for communicating temporal change and a contribution in this direction is also given. With the techniques developed in this thesis, it becomes possible to produce a range of geological scenarios. The focus is on enabling geologists tocreate their subsurface models by means of sketches, to quickly communicate concepts and ideasrather than detailed information. Although the proposed techniques are simple to use and requirelittle design effort, complex models can be realized. ",
pdf = "pdfs/natali14thesis.pdf",
images = "images/Natali2014Rapid0.png, images/Natali2014Sketch0.png,",
thumbnails = "images/Natali2014Rapid0.png, images/Natali2014Sketch0.png,",
isbn = "?? ",
url = "https://bora.uib.no/handle/1956/8570",
project = "geoillustrator"
}
    [Bibtex] 
    @MISC {Kingman14ResilientGenome,
author = "Pina Kingman",
title = "Our Resilient Genome",
howpublished = "Talk in the Forshkningsdagene UNG 2014",
month = "September",
year = "2014",
abstract = "Motivation: Make science research accessible to the public through film. Inspire and instil an interest in science and molecular biology. Story: The short animated film will describe the molecular pathways involved in single strand break DNA repair. Every single human cell has to repair an estimated 10,000-20,000 DNA lesion every day. DNA is constantly exposed to a variety of genotoxic events, leading to many different types of lesions. If the damage is not repaired, these lesions may lead to mutations that in turn lead to cancer and ageing. Your cells, however, have fine tuned mechanisms that maintain the integrity of our genome. This film describes one of those mechanisms. Length: About 3 minutes. Audience: We are aiming for the type of person who would attend a science film festival. We are thus assuming an interest in biology and medicine, at least a high-school degree (with the high probability of intending to continue to higher education), and a basic understanding of biology. Timeline: The film is currently in production and will be finished mid/late summer.",
images = "images/no_thumb.png",
thumbnails = "images/no_thumb.png",
location = "Bergen, Norway",
project = "physioillustration"
}
    [DOI] [Bibtex] 
    @INCOLLECTION {RobertLaramee2014HSH,
author = "Robert Laramee and Hamish Carr and Min Chen and Helwig Hauser and Lars Linsen and Klaus Mueller and Vijay Natarajan and Harald Obermaier and Ronald Peikert and Eugene Zhang.",
title = "Future Challenges and Unsolved Problems in Multi-field Visualization",
booktitle = "Scientific Visualization: Uncertainty, Multifield, Biomedical, and  Scalable Visualization",
publisher = "Springer",
year = "2014",
editor = "Min Chen and Hans Hagen and Charles D. Hansen and Christopher R.  Johnson and Arie E. Kaufman",
series = "Mathematics and Visualization",
chapter = "19",
pages = "205-211",
month = "sep",
images = "images/no_thumb.png",
thumbnails = "images/no_thumb.png",
doi = "10.1007/978-1-4471-6497-5_19",
keywords = "uncertainty, heuristics, problem solving",
owner = "hausser",
timestamp = "2015.02.06",
isbn = "978-1-4471-6496-8",
url = "http://www.springer.com/mathematics/computational+science+%26+engineering/book/978-1-4471-6496-8"
}
    [PDF] [VID] [Bibtex] 
    @INPROCEEDINGS {Kolesar-2014-IPT,
author = "Ivan Kolesar and Julius Parulek and Ivan Viola and Stefan Bruckner and Anne-Kristin Stavrum and Helwig Hauser",
title = "Illustrating Polymerization using Three-level Model Fusion",
booktitle = "Proceedings of IEEE BioVis 2014",
year = "2014",
month = "aug",
abstract = "Research in cell biology is steadily contributing new knowledge about  many different aspects of physiological processes like polymerization,  both with respect to the involved molecular structures as well as  their related function. Illustrations of the spatio-temporal development  of such processes are not only used in biomedical education, but  also can serve scientists as an additional platform for in-silico  experiments. In this paper, we contribute a new, three-level modeling  approach to illustrate physiological processes from the class of  polymerization at different time scales. We integrate physical and  empirical modeling, according to which approach suits the different  involved levels of detail best, and we additionally enable a simple  form of interactive steering while the process is illustrated. We  demonstrate the suitability of our approach in the context of several  polymerization processes and report from a first evaluation with  domain experts.",
pdf = "pdfs/Kolesar-2014-IPT.pdf",
vid = "vids/Kolesar14Polymers.mp4",
images = "images/Kolesar-2014-IPT.jpg",
thumbnails = "images/Kolesar-2014-IPT.png",
keywords = "biochemical visualization, L-system modeling, multi-agent modeling, visualization of physiology, polymerization",
owner = "bruckner",
project = "physioillustration",
timestamp = "2014.12.29"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {Parulek-2014-CLV,
author = "Julius Parulek and Daniel J{\"o}nsson and Timo Ropinski and Stefan Bruckner and Anders Ynnerman and Ivan Viola",
title = "Continuous Levels-of-Detail and Visual Abstraction for Seamless Molecular Visualization",
journal = "Computer Graphics Forum",
year = "2014",
volume = "33",
number = "6",
pages = "276--287",
month = "sep",
abstract = "Molecular visualization is often challenged with rendering of large  molecular structures in real time. We introduce a novel approach  that enables us to show even large protein complexes. Our method  is based on the level-of-detail concept, where we exploit three different  abstractions combined in one visualization. Firstly, molecular surface  abstraction exploits three different surfaces, solvent-excluded surface  (SES), Gaussian kernels and van der Waals spheres, combined as one  surface by linear interpolation. Secondly, we introduce three shading  abstraction levels and a method for creating seamless transitions  between these representations. The SES representation with full shading  and added contours stands in focus while on the other side a sphere  representation of a cluster of atoms with constant shading and without  contours provide the context. Thirdly, we propose a hierarchical  abstraction based on a set of clusters formed on molecular atoms.  All three abstraction models are driven by one importance function  classifying the scene into the near-, mid- and far-field. Moreover,  we introduce a methodology to render the entire molecule directly  using the A-buffer technique, which further improves the performance.  The rendering performance is evaluated on series of molecules of  varying atom counts.",
pdf = "pdfs/Parulek-2014-CLV.pdf",
images = "images/Parulek-2014-CLV.jpg",
thumbnails = "images/Parulek-2014-CLV.png",
issn = "1467-8659",
doi = "10.1111/cgf.12349",
keywords = "level of detail algorithms, implicit surfaces, clustering, scientific visualization",
project = "physioillustration"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @INPROCEEDINGS {Swoboda-2014-VQA,
author = "Nicolas Swoboda and Judith Moosburner and Stefan Bruckner and Jai Y. Yu and Barry J. Dickson and Katja B{\"u}hler",
title = "Visual and Quantitative Analysis of Higher Order Arborization Overlaps for Neural Circuit Research",
booktitle = "Proceedings of VCBM 2014",
year = "2014",
pages = "107--116",
month = "sep",
abstract = "Neuroscientists investigate neural circuits in the brain of the common  fruit fly Drosophila melanogaster to discover how complex behavior  is generated. Hypothesis building on potential connections between  individual neurons is an essential step in the discovery of circuits  that govern a specific behavior. Overlaps of arborizations of two  or more neurons indicate a potential anatomical connection, i.e.  the presence of joint synapses responsible for signal transmission  between neurons. Obviously, the number of higher order overlaps (i.e.  overlaps of three and more arborizations) increases exponentially  with the number of neurons under investigation making it almost impossible  to precompute quantitative information for all possible combinations.  Thus, existing solutions are restricted to pairwise comparison of  overlaps as they are relying on precomputed overlap quantification.  Analyzing overlaps by visual inspection of more than two arborizations  in 2D sections or in 3D is impeded by visual clutter or occlusion.  This work contributes a novel tool that complements existing methods  for potential connectivity exploration by providing for the first  time the possibility to compute and visualize higher order arborization  overlaps on the fly and to interactively explore this information  in its spatial anatomical context and on a quantitative level. Qualitative  evaluation with neuroscientists and non-expert users demonstrated  the utility and usability of the tool.",
pdf = "pdfs/Swoboda-2014-VQA.pdf",
images = "images/Swoboda-2014-VQA.jpg",
thumbnails = "images/Swoboda-2014-VQA.png",
youtube = "https://www.youtube.com/watch?v=iW2iVppPnsE",
note = "VCBM 2014 Best Paper Honorable Mention",
doi = "10.2312/vcbm.20141189",
event = "VCBM 2014",
keywords = "visual analysis, neurobiology",
location = "Vienna, Austria"
}
    [Bibtex] 
    @MISC {Brambilla14Video,
author = "Andrea Brambilla",
title = "Video Visualization: An Overview",
howpublished = "Trial lecture, University of Bergen",
month = "November",
year = "2014",
abstract = "Videos are one of the most widespread media for collecting, communicating and archiving information. Nowadays, acquiring videos is a relatively straightforward process, and this explains their success in the context of entertainment, surveillance, sport events, and so on. On the other hand, watching and extracting information from a video stream is a lengthy process. Automatic techniques are only partially sucessful because of the intrinsic complexity of this kind of data. Video visualization is a growing research field which aims at easying the study of video data. It relies on both automatic techniques and user interaction, exploiting the best of both worlds. In this talk, I will introduce this field, focusing on its evolution from computer vision. I will discuss the main challenges and present an overview of the state-of-the-art. The talk will conclude with a discussion of the open problems and the expected future developments.",
images = "images/Brambilla14Video.png",
thumbnails = "images/Brambilla14Video.png",
location = "Bergen, Norway",
pres = "pdfs/Brambilla14Video.pptx"
}
    [PDF] [DOI] [Bibtex] 
    @INCOLLECTION {Amirkhanov-2014-HSH,
author = "Artem Amirkhanov and Stefan Bruckner and Christoph Heinzl and Meister Eduard Gr{\"o}ller",
title = "The Haunted Swamps of Heuristics: Uncertainty in Problem Solving",
booktitle = "Scientific Visualization: Uncertainty, Multifield, Biomedical, and Scalable Visualization",
publisher = "Springer",
year = "2014",
editor = "Min Chen and Hans Hagen and Charles D. Hansen and Christopher R. Johnson and Arie E. Kaufman",
series = "Mathematics and Visualization",
chapter = "5",
pages = "51--60",
month = "sep",
abstract = "In scientific visualization the key task of research is the provision  of insight into a problem. Finding the solution to a problem may  be seen as finding a path through some rugged terrain which contains  mountains, chasms, swamps, and few flatlands. This path - an algorithm  discovered by the researcher - helps users to easily move around  this unknown area. If this way is a wide road paved with stones it  will be used for a long time by many travelers. However, a narrow  footpath leading through deep forests and deadly swamps will attract  only a few adventure seekers. There are many different paths with  different levels of comfort, length, and stability, which are uncertain  during the research process. Finding a systematic way to deal with  this uncertainty can greatly assist the search for a safe path which  is in our case the development of a suitable visualization algorithm  for a specific problem. In this work we will analyze the sources  of uncertainty in heuristically solving visualization problems and  will propose directions to handle these uncertainties.",
pdf = "pdfs/Amirkhanov-2014-HSH.pdf",
images = "images/Amirkhanov-2014-HSH.jpg",
thumbnails = "images/Amirkhanov-2014-HSH.png",
doi = "10.1007/978-1-4471-6497-5_5",
keywords = "uncertainty, heuristics, problem solving",
owner = "bruckner",
timestamp = "2014.12.30",
url = "http://www.springer.com/mathematics/computational+science+%26+engineering/book/978-1-4471-6496-8"
}
    [DOI] [Bibtex] 
    @INCOLLECTION {turkay2014computationally,
author = "Turkay, Cagatay and Jeanquartier, Fleur and Holzinger, Andreas and Hauser, Helwig",
title = "On computationally-enhanced visual analysis of heterogeneous data and its application in biomedical informatics",
booktitle = "Interactive Knowledge Discovery and Data Mining in Biomedical Informatics",
publisher = "Springer",
year = "2014",
pages = "117--140",
abstract = "With the advance of new data acquisition and generation technologies, the biomedical domain is becoming increasingly data-driven. Thus, understanding the information in large and complex data sets has been in the focus of several research fields such as statistics, data mining, machine learning, and visualization. While the first three fields predominantly rely on computational power, visualization relies mainly on human perceptual and cognitive capabilities for extracting information. Data visualization, similar to Human–Computer Interaction, attempts an appropriate interaction between human and data to interactively exploit data sets. Specifically within the analysis of complex data sets, visualization researchers have integrated computational methods to enhance the interactive processes. In this state-of-the-art report, we investigate how such an integration is carried out. We study the related literature with respect to the underlying analytical tasks and methods of integration. In addition, we focus on how such methods are applied to the biomedical domain and present a concise overview within our taxonomy. Finally, we discuss some open problems and future challenges.",
images = "images/img_Page_12_Image_0001.jpg, images/img_Page_12_Image_0002.jpg, images/img_Page_12_Image_0003.jpg",
thumbnails = "images/img_Page_12_Image_0001.jpg",
doi = "10.1007/978-3-662-43968-5_7)"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {Sedlmair-2014-VPS,
author = "Michael Sedlmair and Christoph Heinzl and Stefan Bruckner and Harald Piringer and Torsten M{\"o}ller",
title = "Visual Parameter Space Analysis: A Conceptual Framework",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2014",
volume = "20",
number = "12",
pages = "2161--2170",
month = "dec",
abstract = "Various case studies in different application domains have shown the  great potential of visual parameter space analysis to support validating  and using simulation models. In order to guide and systematize research  endeavors in this area, we provide a conceptual framework for visual  parameter space analysis problems. The framework is based on our  own experience and a structured analysis of the visualization literature.  It contains three major components: (1) a data flow model that helps  to abstractly describe visual parameter space analysis problems independent  of their application domain; (2) a set of four navigation strategies  of how parameter space analysis can be supported by visualization  tools; and (3) a characterization of six analysis tasks. Based on  our framework, we analyze and classify the current body of literature,  and identify three open research gaps in visual parameter space analysis.  The framework and its discussion are meant to support visualization  designers and researchers in characterizing parameter space analysis  problems and to guide their design and evaluation processes.",
pdf = "pdfs/Sedlmair-2014-VPS.pdf",
images = "images/Sedlmair-2014-VPS.jpg",
thumbnails = "images/Sedlmair-2014-VPS.png",
doi = "10.1109/TVCG.2014.2346321",
event = "IEEE VIS 2014",
keywords = "parameter space analysis, input-output model, simulation, task characterization, literature analysis",
location = "Paris, France"
}
    [PDF] [Bibtex] 
    @MISC {Hauser2014Dagstuhl,
author = "Helwig Hauser",
title = "Semi-abstract visualization of rich scientific data",
howpublished = "Invited talk at the Dagstuhl 14231 Seminar on Scientific Visualization, Dagstuhl, Germany",
month = "June",
year = "2014",
abstract = "Invited talk at the Dagstuhl 14231 Seminar on Scientific Visualization, Dagstuhl, Germany",
pdf = "pdfs/2014-06-06-Dagstuhl-SemiAbstractSciVis-print2up.pdf",
images = "images/2014-06-06-Dagstuhl-SemiAbstractSciVis-print2up_Image_0002(3).jpg, images/2014-06-06-Dagstuhl-SemiAbstractSciVis-print2up_Image_0002(2).jpg, images/2014-06-06-Dagstuhl-SemiAbstractSciVis-print2up_Image_0002.jpg, images/2014-06-06-Dagstuhl-SemiAbstractSciVis-print2up_Image_0008.jpg",
thumbnails = "images/2014-06-06-Dagstuhl-SemiAbstractSciVis-print2up_Image_0002(3).jpg",
location = "Dagstuhl, Germany"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Rautek-2014-VSI,
author = "Peter Rautek and Stefan Bruckner and Meister Eduard Gr{\"o}ller and Markus Hadwiger",
title = "ViSlang: A System for Interpreted Domain-Specific Languages for Scientific Visualization",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2014",
volume = "20",
number = "12",
pages = "2388--2396",
month = "dec",
abstract = "Researchers from many domains use scientific visualization in their  daily practice. Existing implementations of algorithms usually come  with a graphical user interface (high-level interface), or as software  library or source code (low-level interface). In this paper we present  a system that integrates domain-specific languages (DSLs) and facilitates  the creation of new DSLs. DSLs provide an effective interface for  domain scientists avoiding the difficulties involved with low-level  interfaces and at the same time offering more flexibility than high-level  interfaces. We describe the design and implementation of ViSlang,  an interpreted language specifically tailored for scientific visualization.  A major contribution of our design is the extensibility of the ViSlang  language. Novel DSLs that are tailored to the problems of the domain  can be created and integrated into ViSlang. We show that our approach  can be added to existing user interfaces to increase the flexibility  for expert users on demand, but at the same time does not interfere  with the user experience of novice users. To demonstrate the flexibility  of our approach we present new DSLs for volume processing, querying  and visualization. We report the implementation effort for new DSLs  and compare our approach with Matlab and Python implementations in  terms of run-time performance.",
pdf = "pdfs/Rautek-2014-VSI.pdf",
images = "images/Rautek-2014-VSI.jpg",
thumbnails = "images/Rautek-2014-VSI.png",
youtube = "https://www.youtube.com/watch?v=DbWazwyMRNw",
doi = "10.1109/TVCG.2014.2346318",
event = "IEEE VIS 2014",
keywords = "domain-specific languages, volume visualization, volume visualization framework",
location = "Paris, France",
url = "http://vcc.kaust.edu.sa/Pages/Pub-ViSlang-Sys-Int-Dom-Spe-Lang-SC.aspx"
}
    [PDF] [DOI] [Bibtex] 
    @INCOLLECTION {Pfister-2014-VIC,
author = "Hanspeter Pfister and Verena Kaynig and Charl P. Botha and Stefan Bruckner and Vincent J. Dercksen and Hans-Christian Hege and Jos B.T.M. Roerdink",
title = "Visualization in Connectomics",
booktitle = "Scientific Visualization: Uncertainty, Multifield, Biomedical, and Scalable Visualization",
publisher = "Springer",
year = "2014",
editor = "Min Chen and Hans Hagen and Charles D. Hansen and Christopher R. Johnson and Arie E. Kaufman",
series = "Mathematics and Visualization",
chapter = "21",
pages = "221--245",
month = "sep",
abstract = "Connectomics is a branch of neuroscience that attempts to create a  connectome, i.e., a completemap of the neuronal system and all connections  between neuronal structures. This representation can be used to understand  how functional brain states emerge from their underlying anatomical  structures and how dysfunction and neuronal diseases arise. We review  the current state-of-the-art of visualization and image processing  techniques in the field of connectomics and describe a number of  challenges. After a brief summary of the biological background and  an overview of relevant imaging modalities, we review current techniques  to extract connectivit",
pdf = "pdfs/Pfister-2014-VIC.pdf",
images = "images/Pfister-2014-VIC.jpg",
thumbnails = "images/Pfister-2014-VIC.png",
doi = "10.1007/978-1-4471-6497-5_21",
keywords = "connectomics, neuroscience, visualization, imaging",
owner = "bruckner",
timestamp = "2014.12.30",
url = "http://www.springer.com/mathematics/computational+science+%26+engineering/book/978-1-4471-6496-8"
}
    [DOI] [Bibtex] 
    @ARTICLE {turkay2014characterizing,
author = "Turkay, Cagatay and Lex, Alexander and Streit, Marc and Pfister, Hanspeter and Hauser, Helwig",
title = "Characterizing cancer subtypes using dual analysis in caleydo stratomex",
journal = "Computer Graphics and Applications, IEEE",
year = "2014",
volume = "34",
number = "2",
pages = "38--47",
abstract = "Dual analysis uses statistics to describe both the dimensions and rows of a high-dimensional dataset. Researchers have integrated it into StratomeX, a Caleydo view for cancer subtype analysis. In addition, significant-difference plots show the elements of a candidate subtype that differ significantly from other subtypes, thus letting analysts characterize subtypes. Analysts can also investigate how data samples relate to their assigned subtype and other groups. This approach lets them create well-defined subtypes based on statistical properties. Three case studies demonstrate the approach's utility, showing how it reproduced findings from a published subtype characterization.",
images = "images/img_Page_08_Image_0001.jpg, images/img_Page_04_Image_0001.jpg",
thumbnails = "images/img_Page_08_Image_0001.jpg",
publisher = "IEEE",
doi = "10.1109/MCG.2014.1"
}
    [Bibtex] 
    @MISC {Brambilla14Visualizing,
author = "Andrea Brambilla",
title = "Visualizing the Long-term Behavior of 3D Fluid Flows",
howpublished = "Presentation at the Konversatorium, Institute for Computer Graphics and Algorithm, TU Wien",
month = "April",
year = "2014",
abstract = "The study of the long-term behavior of 3D fluid flows can provide useful insights into transport phenomena, which are of central importance in many fields, such as medicine and engineering. Such a study is normally based on the integration of the flow field. The resulting integral structures are indeed highly expressive, but their direct visualization often suffers from cluttering and occlusion issues. In this talk I will present my recent (and future) work addressing this problem. Three projects will be covered: (1) A seeding strategy for families of integral surfaces, which captures the predominant aspects of the long-term flow behavior. (2) A technique for easing the investigation and comparison of surface families, based on a 2D reformation process. (3) The work I am carrying out here at the TU, aimed at quantifying transport phenomena and depicting them using Sankey diagrams.",
images = "images/Brambilla14Visualizing.png",
thumbnails = "images/Brambilla14Visualizing.png",
location = "Wien, Austria",
url = "http://www.cg.tuwien.ac.at/courses/konversatorium/2014-04-25",
pres = "pdfs/Brambilla14Visualizing.pdf"
}
    [DOI] [Bibtex] 
    @INCOLLECTION {peikert2014comparison,
author = "Ronald Peikert and Armin Pobitzer and Filip Sadlo and Benjamin Schindler",
title = "A Comparison of Finite-Time and Finite-Size Lyapunov Exponents",
booktitle = "Topological Methods in Data Analysis and Visualization III",
publisher = "Springer International Publishing",
year = "2014",
editor = "Peer-Timo Bremer and Ingrid Hotz and Valerio Pascucci and Ronald Peikert",
series = "Mathematics and Visualization",
pages = "187--200",
images = "images/peikert2014comparison.png",
thumbnails = "images/peikert2014comparison_thumb.png",
doi = "10.1007/978-3-319-04099-8_12",
url = "http://dx.doi.org/10.1007/978-3-319-04099-8_12",
isbn = "978-3-319-04098-1"
}
    [Bibtex] 
    @ARTICLE {lemuzic2014ivm,
author = "Mathieu Le Muzic and Julius Parulek and Anne-Kristin Stavrum and Ivan Viola",
title = "Illustrative Visualization of Molecular Reactions using Omniscient Intelligence and Passive Agents ",
journal = "Computer Graphics Forum",
year = "2014",
volume = "33",
number = "3",
pages = "141--150",
month = "jun",
abstract = "In this paper we propose a new type of a particle systems, tailored for illustrative visualization purposes, in particular for visualizing molecular reactions in biological networks. Previous visualizations of biochemical processes were exploiting the results of agent-based modeling. Such modeling aims at reproducing accurately the stochastic nature of molecular interactions. However, it is impossible to expect events of interest happening at a certain time and location, which is impractical for storytelling. To obtain the means of controlling molecular interactions, we propose to govern passive agents with an omniscient intelligence, instead of giving to the agents the freedom of initiating reaction autonomously. This makes it possible to generate illustrative animated stories that communicate the functioning of the molecular machinery. The rendering performance delivers for interactive framerates of massive amounts of data, based on the dynamic tessellation capabilities of modern graphics cards. Finally, we report an informal expert feedback we obtained from the potential users.",
images = "images/Lemuzic14Illustrative.png, images/Lemuzic14Illustrative.png",
thumbnails = "images/Lemuzic14Illustrative0_thumb.png, images/Lemuzic14Illustrative1_thumb.png",
event = "EuroVis",
url = "http://www.cg.tuwien.ac.at/research/publications/2014/lemuzic-2014-ivm/",
project = "physioillustration"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Angelelli-2014-LUP,
author = "Paolo Angelelli and Sten Roar Snare and Siri Ann Nyrnes and Stefan Bruckner and Helwig Hauser and Lasse L{\o}vstakken",
title = "Live Ultrasound-based Particle Visualization of Blood Flow in the Heart",
booktitle = "Proceedings of SCCG 2014",
year = "2014",
pages = "42--49",
month = "may",
abstract = "We introduce an integrated method for the acquisition, processing  and visualization of live, in-vivo blood flow in the heart. The method  is based on ultrasound imaging, using a plane wave acquisition acquisition  protocol, which produces high frame rate ensemble data that are efficiently  processed to extract directional flow information not previously  available based on conventional Doppler imaging. These data are then  visualized using a tailored pathlet-based visualization approach,  to convey the slice-contained dynamic movement of the blood in the  heart. This is especially important when imaging patients with possible  congenital heart diseases, who typically exhibit complex flow patterns  that are challenging to interpret. With this approach, it now is  possible for the first time to achieve a real-time integration-based  visualization of 2D blood flow aspects based on ultrasonic imaging.  We demonstrate our solution in the context of selected cases of congenital  heart diseases in neonates, showing how our technique allows for  a more accurate and intuitive visualization of shunt flow and vortices.",
pdf = "pdfs/Angelelli-2014-LUP.pdf",
images = "images/Angelelli-2014-LUP.jpg",
thumbnails = "images/Angelelli-2014-LUP.png",
doi = "10.1145/2643188.2643200",
keywords = "ultrasound medical visualization, real-time visualization, blood flow visualization",
url = "http://dx.doi.org/10.1145/2643188.2643200"
}
    [PDF] [Bibtex] 
    @MISC {Hauser2014HiB,
author = "Helwig Hauser",
title = "Interactive Visual Analysis of Rich Scientific Data",
howpublished = "Invited talk at the Bergen University College in Bergen, Norway",
month = "November",
year = "2014",
abstract = "Invited talk at the Bergen University College in Bergen, Norway",
pdf = "pdfs/2014-11-25-BergenHIB-InvitedTalk-print2up-web.pdf",
images = "images/2014-11-25-BergenHIB-InvitedTalk-print2up-web_Image_0002.jpg, images/2014-11-25-BergenHIB-InvitedTalk-print2up-web_Image_0003.jpg, images/2014-11-25-BergenHIB-InvitedTalk-print2up-web_Image_0005.jpg, images/2014-11-25-BergenHIB-InvitedTalk-print2up-web_Image_0002(2).jpg, images/2014-11-25-BergenHIB-InvitedTalk-print2up-web_Image_0009.jpg, images/2014-11-25-BergenHIB-InvitedTalk-print2up-web_Image_0002(3).jpg, images/2014-11-25-BergenHIB-InvitedTalk-print2up-web_Image_0009(2).jpg, images/2014-11-25-BergenHIB-InvitedTalk-print2up-web_Image_0003(2).jpg, images/2014-11-25-BergenHIB-InvitedTalk-print2u--web_Image_0007.jpg, images/2014-11-25-BergenHIB-InvitedTalk-print2up-web_Image_0005(2).jpg",
thumbnails = "images/2014-11-25-BergenHIB-InvitedTalk-print2up-web_Image_0002.jpg",
location = "Bergen, Norway"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Kolesar-2014-IIP,
author = "Ivan Kolesar and Julius Parulek and Ivan Viola and Stefan Bruckner and Anne-Kristin Stavrum and Helwig Hauser",
title = "Interactively Illustrating Polymerization using Three-level Model Fusion",
journal = "BMC Bioinformatics",
year = "2014",
volume = "15",
pages = "345",
month = "oct",
abstract = "Research in cell biology is steadily contributing new knowledge about  many aspects of physiological processes, both with respect to the  involved molecular structures as well as their related function.  Illustrations of the spatio-temporal development of such processes  are not only used in biomedical education, but also can serve scientists  as an additional platform for in-silico experiments. Results In this  paper, we contribute a new, three-level modeling approach to illustrate  physiological processes from the class of polymerization at different  time scales. We integrate physical and empirical modeling, according  to which approach best suits the different involved levels of detail,  and we additionally enable a form of interactive steering, while  the process is illustrated. We demonstrate the suitability of our  approach in the context of several polymerization processes and report  from a first evaluation with domain experts. Conclusion We conclude  that our approach provides a new, hybrid modeling approach for illustrating  the process of emergence in physiology, embedded in a densely filled  environment. Our approach of a complementary fusion of three systems  combines the strong points from the different modeling approaches  and is capable to bridge different spatial and temporal scales.",
pdf = "pdfs/Kolesar-2014-IIP.pdf",
images = "images/Kolesar-2014-IIP.jpg",
thumbnails = "images/Kolesar-2014-IIP.png",
youtube = "https://www.youtube.com/watch?v=iMl5nDicmhg",
doi = "10.1186/1471-2105-15-345",
keywords = "biochemical visualization, L-system modeling, multi-agent modeling, visualization of physiology, polymerization",
owner = "bruckner",
project = "physioillustration",
timestamp = "2014.12.29",
url = "http://www.ii.uib.no/vis/projects/physioillustration/research/interactive-molecular-illustration.html"
}
    [Bibtex] 
    @MISC {Kingman14PARP1,
author = "Pina Kingman and Anne-Kristin Stavrum and Ivan Viola and Helwig Hauser",
title = "PARP-1 Binds Damaged DNA",
howpublished = "Poster presented at the VizBi conference 2014",
month = "March",
year = "2014",
abstract = "This image is an excerpt from the animation entitled Negative charge and poly(ADP)-ribosylation: a scientific animation. The molecules where uploaded from the Protein Data Bank using the Embedded Python Molecular Viewer plug-in for Autodesk Maya (Johnson et al. 2001; Sanner et al. 1996). The scene was rendered using Maxon Cinema 4D and composited in Adobe Photoshop. Subsurface Scattering was chosen to give the molecules a translucent appearance. Two PARP-1 molecules are shown bound to damaged DNA (Coquelle and Glover 2012). This work has been carried out within the PhysioIllustration project (funded by NFR, project #218023).",
images = "images/Kingman13PARP1.jpg",
thumbnails = "images/Kingman13PARP1_thumb.jpg",
location = "Heidelberg, Germany",
project = "physioillustration"
}
    [Bibtex] 
    @ARTICLE {matkovic2014visual,
author = "Matkovic, Kresimir and Gracanin, Denis and Splechtna, Rainer and Jelovic, Mario and Stehno, Benedikt and Hauser, Helwig and Purgathofer, Werner",
title = "Visual analytics for complex engineering systems: Hybrid visual steering of simulation ensembles",
journal = "Visualization and Computer Graphics, IEEE Transactions on",
year = "2014",
volume = "20",
number = "12",
pages = "1803--1812",
abstract = "In this paper we propose a novel approach to hybrid visual steering of simulation ensembles. A simulation ensemble is a collection of simulation runs of the same simulation model using different sets of control parameters. Complex engineering systems have very large parameter spaces so a naïve sampling can result in prohibitively large simulation ensembles. Interactive steering of simulation ensembles provides the means to select relevant points in a multi-dimensional parameter space (design of experiment). Interactive steering efficiently reduces the number of simulation runs needed by coupling simulation and visualization and allowing a user to request new simulations on the fly. As system complexity grows, a pure interactive solution is not always sufficient. The new approach of hybrid steering combines interactive visual steering with automatic optimization. Hybrid steering allows a domain expert to interactively (in a visualization) select data points in an iterative manner, approximate the values in a continuous region of the simulation space (by regression) and automatically find the “best� points in this continuous region based on the specified constraints and objectives (by optimization). We argue that with the full spectrum of optimization options, the steering process can be improved substantially. We describe an integrated system consisting of a simulation, a visualization, and an optimization component. We also describe typical tasks and propose an interactive analysis workflow for complex engineering systems. We demonstrate our approach on a case study from automotive industry, the optimization of a hydraulic circuit in a high pressure common rail Diesel injection system.",
images = "images/matkovic2014visual1.jpg, images/matkovic2014visual2.jpg",
thumbnails = "images/matkovic2014visual1.jpg",
publisher = "IEEE"
}
    [Bibtex] 
    @MISC {Brambilla14Visibility,
author = "Andrea Brambilla",
title = "Visibility Management in Integration-based Flow Visualization",
howpublished = "Talk at the Department of Informatics, Systems and Communication, University of Milano - Bicocca",
month = "June",
year = "2014",
abstract = "The analysis of flow phenomena holds an important role in several fields, such as engineering and medicine. Flow visualization techniques aim at easing the investigation process by depicting the flow data through graphical entities. Specifically, integration-based methods employ lines and surfaces in order to visualize the long-term behavior of fluid particles. In this talk, I will give a brief introduction to integration-based flow visualization, present its advantages and discuss its main limitations, i.e., cluttering and occlusion. I will then present my recent work addressing these limitations. Two projects will be described: (1) A selection strategy for integral surfaces, which aims at detecting a small number of highly informative integral surfaces. (2) A technique for easing the investigation and comparison of surface families, based on a 2D reformation process.",
images = "images/Brambilla14Visualizing.png",
thumbnails = "images/Brambilla14Visualizing.png",
location = "Milan, Italy",
pres = "pdfs/Brambilla14Visibility.pdf"
}
    [DOI] [VID] [Bibtex] 
    @ARTICLE {Angelelli14Interactive,
author = "Paolo Angelelli and Steffen Oeltze and Cagatay Turkay and Judit Haasz and Erlend Hodneland and Arvid Lundervold and Astri Johansen Lundervold and Bernhard Preim and Helwig Hauser",
title = "Interactive Visual Analysis of Heterogeneous Cohort Study Data",
journal = "Computer Graphics and Applications, IEEE",
year = "2014",
volume = "PP",
number = "99",
pages = "1-1",
abstract = "Cohort studies are used in medicine to enable the study of medical hypotheses in large samples. Often, a large amount of heterogeneous data is acquired from many subjects. The analysis is usually hypothesis-driven, i.e., a specific subset of such data is studied to confirm or reject specific hypotheses. In this paper, we demonstrate how we enable the interactive visual exploration and analysis of such data, helping with the generation of new hypotheses and contributing to the process of validating them. We propose a data-cube based model which allows to handle partially overlapping data subsets during the interactive visualization. This model enables the seamless integration of the heterogeneous data, as well as the linking of spatial and non-spatial views on these data. We implemented this model in an application prototype, and used it to analyze data acquired in the context of a cohort study on cognitive aging. In this paper we present a case-study analysis of selected aspects of brain connectivity by using a prototype implementation of the presented model, to demonstrate its potential and flexibility.",
vid = "vids/angelelli14CohortExplorer.wmv",
images = "images/angelelli14Cohort.png",
thumbnails = "images/angelelli14Cohort.png",
doi = "10.1109/MCG.2014.40",
url = "http://dx.doi.org/10.1109/MCG.2014.40"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Mindek-2014-MSS,
author = "Peter Mindek and Meister Eduard Gr{\"o}ller and Stefan Bruckner",
title = "Managing Spatial Selections with Contextual Snapshots",
journal = "Computer Graphics Forum",
year = "2014",
volume = "33",
number = "8",
pages = "132--144",
month = "dec",
abstract = "Spatial selections are a ubiquitous concept in visualization. By localizing  particular features, they can be analysed and compared in different  views. However, the semantics of such selections often depend on  specific parameter settings and it can be difficult to reconstruct  them without additional information. In this paper, we present the  concept of contextual snapshots as an effective means for managing  spatial selections in visualized data. The selections are automatically  associated with the context in which they have been created. Contextual  snapshots can also be used as the basis for interactive integrated  and linked views, which enable in-place investigation and comparison  of multiple visual representations of data. Our approach is implemented  as a flexible toolkit with well-defined interfaces for integration  into existing systems. We demonstrate the power and generality of  our techniques by applying them to several distinct scenarios such  as the visualization of simulation data, the analysis of historical  documents and the display of anatomical data.",
pdf = "pdfs/Mindek-2014-MSS.pdf",
images = "images/Mindek-2014-MSS.jpg",
thumbnails = "images/Mindek-2014-MSS.png",
youtube = "https://www.youtube.com/watch?v=rxEf-Okp8Xo",
doi = "10.1111/cgf.12406",
keywords = "interaction, visual analytics, spatial selections, annotations",
url = "http://www.cg.tuwien.ac.at/downloads/csl/"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @INPROCEEDINGS {Solteszova-2014-VPS,
author = "Veronika \v{S}olt{\'e}szov{\'a} and {\AA}smund Birkeland and Ivan Viola and Stefan Bruckner",
title = "Visibility-Driven Processing of Streaming Volume Data",
booktitle = "Proceedings of VCBM 2014",
year = "2014",
pages = "127--136",
month = "sep",
abstract = "In real-time volume data acquisition, such as 4D ultrasound, the raw  data is challenging to visualize directly without additional processing.  Noise removal and feature detection are common operations, but many  methods are too costly to compute over the whole volume when dealing  with live streamed data. In this paper, we propose a visibility-driven  processing scheme for handling costly on-the-fly processing of volumetric  data in real-time. In contrast to the traditional visualization pipeline,  our scheme utilizes a fast computation of the potentially visible  subset of voxels which significantly reduces the amount of data required  to process. As filtering operations modify the data values which  may affect their visibility, our method for visibility-mask generation  ensures that the set of elements deemed visible does not change after  processing. Our approach also exploits the visibility information  for the storage of intermediate values when multiple operations are  performed in sequence, and can therefore significantly reduce the  memory overhead of longer filter pipelines. We provide a thorough  technical evaluation of the approach and demonstrate it on several  typical scenarios where on-the-fly processing is required.",
pdf = "pdfs/Solteszova-2014-VPS.pdf",
images = "images/Solteszova-2014-VPS.jpg",
thumbnails = "images/Solteszova-2014-VPS.png",
youtube = "https://www.youtube.com/watch?v=WJgc6BX1qig",
note = "VCBM 2014 Best Paper Award",
doi = "10.2312/vcbm.20141198",
event = "VCBM 2014",
keywords = "ultrasound, visibility-driven processing, filtering",
location = "Vienna, Austria"
}
    [DOI] [Bibtex] 
    @ARTICLE {turkay2014attribute,
author = "Turkay, Cagatay and Slingsby, Aidan and Hauser, Helwig and Wood, Jo and Dykes, Jason",
title = "Attribute signatures: Dynamic visual summaries for analyzing multivariate geographical data",
journal = "Visualization and Computer Graphics, IEEE Transactions on",
year = "2014",
volume = "20",
number = "12",
pages = "2033--2042",
abstract = "The visual analysis of geographically referenced datasets with a large number of attributes is challenging due to the fact that the characteristics of the attributes are highly dependent upon the locations at which they are focussed, and the scale and time at which they are measured. Specialized interactive visual methods are required to help analysts in understanding the characteristics of the attributes when these multiple aspects are considered concurrently. Here, we develop attribute signatures-interactively crafted graphics that show the geographic variability of statistics of attributes through which the extent of dependency between the attributes and geography can be visually explored. We compute a number of statistical measures, which can also account for variations in time and scale, and use them as a basis for' our visualizations. We then employ different graphical configurations to show and compare both continuous and discrete variation of location and scale. Our methods allow variation in multiple statistical summaries of multiple attributes to be considered concurrently and geographically, as evidenced by examples in which the census geography of London and the wider UK are explored.",
images = "images/img_Page_06_Image_0003.jpg, images/img_Page_01_Image_0002.jpg, images/img_Page_01_Image_0005.jpg, images/img_Page_07_Image_0003.jpg",
thumbnails = "images/img_Page_06_Image_0003.jpg",
publisher = "IEEE",
doi = "10.1109/TVCG.2014.2346265"
}

2013

    [DOI] [Bibtex] 
    @ARTICLE {Lidal13Geological,
author = "Endre M. Lidal and Mattia Natali and Daniel Patel and Helwig Hauser and Ivan Viola",
title = "Geological storytelling",
journal = "Computers \& Graphics",
year = "2013",
volume = "37",
number = "5",
pages = "445--459 ",
abstract = "Developing structural geological models from exploratory subsea imaging is difficult and an ill-posed process. The structural geological processes that take place in the subsurface are both complex and time-dependent. We present Geological Storytelling, a novel graphical system for performing rapid and expressive geomodeling. Geologists can convey geological stories that externalize both their model and the reasoning process behind it through our simple, yet expressive sketch-based, flip-over canvases. This rapid modeling interface makes it easy to construct a large variety of geological stories, and our story tree concept facilitates easy management and the exploration of these alternatives. The stories are then animated and the geologists can examine and compare them to identify the most plausible models. Finally, the geological stories can be presented as illustrative animations of automatically synthesized 3D models, which efficiently communicate the complex geological evolution to non-experts and decision makers. Geological storytelling provides a complete pipeline from the ideas and knowledge in the mind of the geologist, through externalized artifacts specialized for discussion and knowledge dissemination among peer-experts, to automatically rendered illustrative 3D animations for communication to lay audience. We have developed geological storytelling in collaboration with domain experts that work with the modeling challenges on a daily basis. For evaluation, we have developed a geological storytelling prototype and presented it to experts and academics from the geosciences. In their feedback, they acknowledge that the rapid and expressive sketching of stories can make them explore more alternatives and that the 3D illustrative animations assist in communicating their models.",
images = "images/Lidal13Geological01.jpg, images/Lidal13Geological02.png",
thumbnails = "images/Lidal13Geological01.jpg, images/Lidal13Geological02.png",
issn = "0097-8493",
doi = "http://dx.doi.org/10.1016/j.cag.2013.01.010",
url = "http://www.sciencedirect.com/science/article/pii/S0097849313000125",
keywords = "Sketch-based modeling; Externalization of mental processes; Storytelling; 3D model synthesis; Animation; Alternatives exploration; Geology; Structural geological models",
project = "geoillustrator"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Natali13Modeling,
author = "Mattia Natali and Endre M. Lidal and Julius Parulek and Ivan Viola and Daniel Patel",
title = "Modeling Terrains and Subsurface Geology",
booktitle = "EuroGraphics 2013 State of the Art Reports (STARs)",
year = "2013",
pages = "155--173",
abstract = "The process of creating terrain and landscape models is important in a variety of computer graphics and visualization applications, from films and computer games, via flight simulators and landscape planning, to scientific visualization and subsurface modelling. Interestingly, the modelling techniques used in this large range of application areas have started to meet in the last years. In this state-of-the-art report, we present two taxonomies of different modelling methods. Firstly we present a data oriented taxonomy, where we divide modelling into three different scenarios: the data-free, the sparse-data and the dense-data scenario. Then we present a workflow oriented taxonomy, where we divide modelling into the separate stages necessary for creating a geological model. We start the report by showing that the new trends in geological modelling are approaching the modelling methods that have been developed in computer graphics. We then give an introduction to the process of geological modelling followed by our two taxonomies with descriptions and comparisons of selected methods. Finally we discuss the challenges and trends in geological modelling.",
pdf = "pdfs/Natali13Modeling.pdf",
images = "images/Natali13Modeling.png",
thumbnails = "images/Natali13Modeling.png",
proceedings = "EuroGraphics 2013 State of the Art Reports (STARs)",
url = "http://diglib.eg.org/EG/DL/conf/EG2013/stars/155-173.pdf",
doi = "10.2312/conf/EG2013/stars/155-173",
location = "Girona, Spain",
project = "geoillustrator"
}
    [PDF] [Bibtex] 
    @MISC {Hauser2013SouthCHI,
author = "Helwig Hauser",
title = "Integrating Interactive and Computational Analysis in Visualization",
howpublished = "Keynote talk at SouthCHI 2013 in Maribor, Slovenia.",
month = "June",
year = "2013",
abstract = "Keynote talk at SouthCHI 2013 in Maribor, Slovenia.",
pdf = "pdfs/2013-07-02-Maribor-SouthCHI-Keynote-IVA-print2up.pdf",
images = "images/2013-07-02-Maribor-SouthCHI-Keynote-IVA-print2up_Image_0001(6).jpg, images/2013-07-02-Maribor-SouthCHI-Keynote-IVA-print2up_Image_0001(5).jpg, images/2013-07-02-Maribor-SouthCHI-Keynote-IVA-print2up_Image_0001(4).jpg, images/2013-07-02-Maribor-SouthCHI-Keynote-IVA-print2up_Image_0001(3).jpg, images/2013-07-02-Maribor-SouthCHI-Keynote-IVA-print2up_Image_0001(2).jpg, images/2013-07-02-Maribor-SouthCHI-Keynote-IVA-print2up_Image_0001.jpg, images/2013-07-02-Maribor-SouthCHI-Keynote-IVA-print2up_Image_0003.jpg",
thumbnails = "images/2013-07-02-Maribor-SouthCHI-Keynote-IVA-print2up_Image_0001(6).jpg"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @INPROCEEDINGS {Mindek-2013-CSE,
author = "Peter Mindek and Stefan Bruckner and Meister Eduard Gr{\"o}ller",
title = "Contextual Snapshots: Enriched Visualization with Interactive Spatial Annotations",
booktitle = "Proceedings of SCCG 2013",
year = "2013",
pages = "59--66",
month = "may",
abstract = "Spatial selections are a ubiquitous concept in visualization. By localizing  particular features, they can be analyzed and compared in different  views. However, the semantics of such selections are often dependent  on other parameter settings and it can be difficult to reconstruct  them without additional information. In this paper, we present the  concept of contextual snapshots as an effective means for managing  spatial selections in visualized data. The selections are automatically  associated with the context in which they have been created. Contextual  snapshots can be also used as the basis for interactive integrated  and linked views, which enable in-place investigation and comparison  of multiple visual representations of data. Our approach is implemented  as a flexible toolkit with welldefined interfaces for integration  into existing systems. We demonstrate the power and generality of  our techniques by applying them to several distinct scenarios such  as the visualization of simulation data and the analysis of historical  documents.",
pdf = "pdfs/Mindek-2013-CSE.pdf",
images = "images/Mindek-2013-CSE.jpg",
thumbnails = "images/Mindek-2013-CSE.png",
youtube = "https://www.youtube.com/watch?v=djuqJgixUCs",
note = "SCCG 2013 Best Paper Award",
doi = "10.1145/2508244.2508251",
keywords = "spatial selections, annotations, linked views, provenance",
location = "Smolenice, Slovakia",
url = "http://www.cg.tuwien.ac.at/research/publications/2013/mindek-2013-csl/"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Auzinger-2013-VVC,
author = "Thomas Auzinger and Gabriel Mistelbauer and Ivan Baclija and R{\"u}diger Schernthaner and Arnold K{\"o}chl and Michael Wimmer and Meister Eduard Gr{\"o}ller and Stefan Bruckner",
title = "Vessel Visualization using Curved Surface Reformation",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2013",
volume = "19",
number = "12",
pages = "2858--2867",
month = "dec",
abstract = "Visualizations of vascular structures are frequently used in radiological  investigations to detect and analyze vascular diseases. Obstructions  of the blood flow through a vessel are one of the main interests  of physicians, and several methods have been proposed to aid the  visual assessment of calcifications on vessel walls. Curved Planar  Reformation (CPR) is a wide-spread method that is designed for peripheral  arteries which exhibit one dominant direction. To analyze the lumen  of arbitrarily oriented vessels, Centerline Reformation (CR) has  been proposed. Both methods project the vascular structures into  2D image space in order to reconstruct the vessel lumen. In this  paper, we propose Curved Surface Reformation (CSR), a technique that  computes the vessel lumen fully in 3D. This offers high-quality interactive  visualizations of vessel lumina and does not suffer from problems  of earlier methods such as ambiguous visibility cues or premature  discretization of centerline data. Our method maintains exact visibility  information until the final query of the 3D lumina data. We also  present feedback from several domain experts.",
pdf = "pdfs/Auzinger-2013-VVC.pdf",
images = "images/Auzinger-2013-VVC.jpg",
thumbnails = "images/Auzinger-2013-VVC.png",
youtube = "https://www.youtube.com/watch?v=rESIFaO_-Gs",
doi = "10.1109/TVCG.2013.215",
event = "IEEE VIS 2013",
keywords = "volume Rendering, reformation, vessel, surface approximation",
url = "http://www.cg.tuwien.ac.at/research/publications/2013/Auzinger_Mistelbauer_2013_CSR/"
}
    [Bibtex] 
    @MISC {Kingman13ScienceFilm,
author = "Pina Kingman",
title = "Animating Biology: The making of a science film",
howpublished = "Presentation in the VisBio 2013",
month = "September",
year = "2013",
abstract = "Biology is complicated. Understanding cellular and molecular biology is particularly difficult. Amongst the many effective communication tools at our disposal, animated film is at the forefront. Animation brings biological stories to life, and thus aids in our understanding of biological structure and function. Whether used to inform patients, to teach undergraduate biology, or to disseminate advances in research, animated film is a tool worth employing. But what goes into an animation? I will explain the step-by-step process of creating animations and show a lot of inspiring examples.",
images = "images/no_thumb.png",
thumbnails = "images/no_thumb.png",
location = "Bergen, Norway",
project = "physioillustration"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {Parulek13Seamless,
author = "Julius Parulek and Timo Ropinski and Ivan Viola",
title = "Seamless Abstraction of Molecular Surfaces",
booktitle = "Proceedings of the 29th Spring Conference on Computer Graphics",
year = "2013",
series = "SCCG '13",
pages = "120--127",
abstract = "Molecular visualization is often challenged with rendering of large sequences of molecular simulations in real time. We introduce a novel approach that enables us to show even large protein complexes over time in real-time. Our method is based on the level-ofdetail concept, where we exploit three different molecular surface models, solvent excluded surface (SES), Gaussian kernels and van der Waals spheres combined in one visualization. We introduce three shading levels that correspond to their geometric counterparts and a method for creating seamless transition between these representations. The SES representation with full shading and added contours stands in focus while on the other side a sphere representation with constant shading and without contours provide the context. Moreover, we introduce a methodology to render the entire molecule directly using the A-buffer technique, which further improves the performance. The rendering performance is evaluated on series of molecules of varying atom counts. ",
pdf = "pdfs/Parulek13Seamless.pdf",
images = "images/Parulek13Seamless01.png, images/Parulek13Seamless02.png",
thumbnails = "images/Parulek13Seamless01_thumb.png, images/Parulek13Seamless02.png",
proceedings = "Proceedings of the 29th Spring Conference on Computer Graphics",
isbn = "978-80-223-3377-1",
location = "Smolenice, Slovak Republic",
numpages = "8",
project = "physioillustration"
}
    [Bibtex] 
    @MISC {Kolesar13HumanPhysiology,
author = "Ivan Kolesar",
title = "Approaches for Visualizing Human Physiology",
howpublished = "Presentation in the VisBio 2013",
month = "September",
year = "2013",
abstract = "Physiology is scientific study of function in living systems. All in all, we presents several visual abstractions used to communicate physiological processes through different functional human systems in different scales from molecules to whole human body. However there are still several challenges for visualizing multi-scale physiological processes.",
images = "images/no_thumb.png",
thumbnails = "images/Kolesar13HumanPhysiology.jpg",
location = "Bergen, Norway",
project = "physioillustration"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Brambilla13Integrated,
author = "Andrea Brambilla and {\O }yvind Andreassen and Helwig Hauser",
title = "Integrated Multi-aspect visualization of 3D Fluid Flows",
booktitle = "Proc. of VMV 2013: Vision, Modeling \& Visualization",
year = "2013",
pages = "1--9",
month = "Sept.",
abstract = "The motion of a fluid is affected by several intertwined flow aspects. Analyzing one aspect at a time can only yield partial information about the flow behavior. More details can be revealed by studying their interactions. Our approach enables the investigation of these interactions by simultaneously visualizing meaningful flow aspects, such as swirling motion and shear strain. We adopt the notions of relevance and coherency. Relevance identifies locations where a certain flow aspect is deemed particularly important. The related piece of information is visualized by a specific visual entity, placed at the corresponding location. Coherency instead represents the homogeneity of a flow property in a local neighborhood. It is exploited in order to avoid visual redundancy and to reduce occlusion and cluttering. We have applied our approach to three CFD datasets, obtaining meaningful insights.",
pdf = "pdfs/Brambilla13Integrated.pdf",
images = "images/Brambilla13Integrated_00.png, images/Brambilla13Integrated_01.png",
thumbnails = "images/Brambilla13Integrated_thumb00.png, images/Brambilla13Integrated_thumb01.png",
proceedings = "Proc. of VMV 2013: Vision, Modeling \& Visualization",
url = "http://diglib.eg.org/EG/DL/PE/VMV/VMV13/001-009.pdf",
doi = "10.2312/PE.VMV.VMV13.001-009",
location = "Lugano, Switzerland",
pres = "pdfs/Brambilla13Integrated.pptx",
extra = "extra/Brambilla13Integrated_extra.pdf"
}
    [DOI] [Bibtex] 
    @ARTICLE {Parulek13Visual,
author = "Julius Parulek and Cagatay Turkay and Nathalie Reuter and Ivan Viola",
title = "Visual cavity analysis in molecular simulations",
journal = "BMC Bioinformatics",
year = "2013",
volume = "14",
number = "Suppl 19",
pages = "S4",
month = "Nov.",
abstract = "Molecular surfaces provide a useful mean for analyzing interactions between biomolecules; such as identification and characterization of ligand binding sites to a host macromolecule. We present a novel technique, which extracts potential binding sites, represented by cavities, and characterize them by 3D graphs and by amino acids. The binding sites are extracted using an implicit function sampling and graph algorithms. We propose an advanced cavity exploration technique based on the graph parameters and associated amino acids. Additionally, we interactively visualize the graphs in the context of the molecular surface. We apply our method to the analysis of MD simulations of Proteinase 3, where we verify the previously described cavities and suggest a new potential cavity to be studied.",
images = "images/Parulek13Visual01.png, images/Parulek13Visual02.png",
thumbnails = "images/Parulek13Visual01_thumb.png, images/Parulek13Visual02_thumb.png",
url = "http://www.biomedcentral.com/1471-2105/14/S19/S4",
doi = "10.1186/1471-2105-14-S19-S4",
issn = "1471-2105",
project = "physioillustration"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Patel-2013-ICS,
author = "Daniel Patel and Veronika \v{S}olt{\'e}szov{\'a} and Jan Martin Nordbotten and Stefan Bruckner",
title = "Instant Convolution Shadows for Volumetric Detail Mapping",
journal = "ACM Transactions on Graphics",
year = "2013",
volume = "32",
number = "5",
pages = "154:1--154:18",
month = "sep",
abstract = "In this article, we present a method for rendering dynamic scenes  featuring translucent procedural volumetric detail with all-frequency  soft shadows being cast from objects residing inside the view frustum.  Our approach is based on an approximation of physically correct shadows  from distant Gaussian area light sources positioned behind the view  plane, using iterative convolution. We present a theoretical and  empirical analysis of this model and propose an efficient class of  convolution kernels which provide high quality at interactive frame  rates. Our GPU-based implementation supports arbitrary volumetric  detail maps, requires no precomputation, and therefore allows for  real-time modi?cation of all rendering parameters.",
pdf = "pdfs/Patel-2013-ICS.pdf",
images = "images/Patel-2013-ICS.jpg",
thumbnails = "images/Patel-2013-ICS.png",
youtube = "https://www.youtube.com/watch?v=lhGWgew3HXY,https://www.youtube.com/watch?v=XrhYjgQxfb0",
doi = "10.1145/2492684",
keywords = "shadows, volumetric effects, procedural texturing, filtering",
project = "geoillustrator",
url = "http://dl.acm.org/citation.cfm?id=2492684"
}
    [PDF] [Bibtex] 
    @MISC {Parulek13Importance,
author = "Julius Parulek and Timo Ropinski and Ivan Viola",
title = "Importance Driven Visualization of Molecular Surfaces",
howpublished = "Poster presented at the BioVis conference 2013",
month = "October",
year = "2013",
pdf = "pdfs/Parulek13Importance.pdf",
images = "images/Parulek13Importance.png",
thumbnails = "images/Parulek13Importance.png",
location = "Atlanta (GA)",
project = "physioillustration"
}
    [Bibtex] 
    @MISC {Parulek13Analysis,
author = "Julius Parulek",
title = "Interactive Visual Exploration and Analysis of High-Dimensional, Temporal, and Heterogeneous Biological Data",
howpublished = "Presentation in the VisBio 2013",
month = "September",
year = "2013",
abstract = "High-dimensional data (hundreds of dimensions, or more) and temporal data (thousands of time frames) pose substantial challenges for both computational and interactive analysis. To reveal relevant intrinsic relations between items or dimensions, the utilization of only computational methods or standard visualization techniques is not enough. In this talk, we introduce the concept of interactive visual analysis (IVA) that enables us to combine computational methods with the user knowledge through a system of multiple linked views on the data and advanced interaction mechanisms. Our approach allows us to interact with the data on the level of individual items and also on the level of dimensions, exploiting a number of useful statistical methods in addition. To improve the understanding of temporal data, we utilize clustering methods, where the user is provided means to understand the internal cluster structure. Moreover, we also showcase how IVA can be beneficial when analyzing molecular dynamics.",
images = "images/no_thumb.png",
thumbnails = "images/no_thumb.png",
location = "Bergen, Norway",
project = "physioillustration"
}
    [PDF] [Bibtex] 
    @PHDTHESIS {lidal13thesis,
author = "Endre M. Lidal",
title = "Sketch-based Storytelling for Cognitive Problem Solving",
school = "Department of Informatics, University of Bergen, Norway",
year = "2013",
month = "June",
abstract = "Problem solving is an important part of all engineering and scienti�c activities. It is present, for instance, when experts want to develop more fuel- ef�cient cars or when they are searching for oil and gas in the subsurface. Many alternatives have to be examined and evaluated before the optimal solution is found. Solving such problems is not only performed inside the mind of the scientist, but it is also an interaction between mind and scribbles, sketches, or visualizations on papers, on blackboards, and on computers. For problem solving in expert teams, this externalization through sketches and visualizations also plays an important communicative role. This dissertation presents research for assisting the problem- solving process on the computer, through novel technological advances in the �elds of illustrative visualization and sketch-based modeling. Speci�cally, it targets problems that are related to evolutionary processes. Firstly, inspired by storytelling, the domain experts can express their ideas for solution as stories. These stories are based on sketches that the experts draw, utilizing a novel temporal-sketching interface inspired by a flip-over canvas metaphor. Further, the dissertation describes a set of sketching proxy geometries, such as the box-proxy geometry, that the experts can take advantage of when drawing three-dimensional (3D) sketches. These proxy geometries support the task of mapping a two-dimensional input (2D), e.g., a mouse or a digitizer tablet, to a 3D sketch. Solving dif�cult problems require that many different solutions are evaluated to identify the most optimal one. This dissertation introduces the story-tree, a tree-graph data structure and visualization, which manages and provides access to an ensemble of alternative stories. The story- tree also provides an interface where the stories can be evaluated and compared. This playback of the stories is done through automatic animations of the 2D sketches. The third challenge addressed in this dissertation is to communicate the optimal solution to decision-makers and laymen. By combining the animated 2D story sketches with illustrative visualization techniques it is possible to automatically synthesize and animate 3D models. These animations can be combined with new cutaway visualization techniques to reveal features hidden inside such 3D models. All of these contributions have been investigated in the context of the problemsolving tasks relevant to the early phase of petroleum exploration. This phase is characterized by having very little ground-through data available. Thus, a large solution space needs to be explored. Even so, the geologists need to produce models that can predict if petroleum is present. In addition to working with few data, the geologists also work under heavy time constraints because of the competition between the oil companies exploring the same area. The contributions from this dissertation have created enthusiasm among the domain experts and already, a new research initiative has materialized from the work described in this dissertation. Based on the feedback from the domain experts, we can conclude that the contributions presented in this dissertation form a valuable step towards better tools for problem solving, involving the computer, for the domain investigated here. ",
pdf = "pdfs/lidal13thesis.pdf",
images = "images/lidal13thesis.png",
thumbnails = "images/lidal13thesis.png",
isbn = "978-82-308-2330-9",
project = "geoillustrator"
}
    [DOI] [Bibtex] 
    @ARTICLE {Alsallakh13Radial,
author = "B. Alsallakh and W. Aigner and S. Miksch and H. Hauser",
title = "Radial Sets: Interactive Visual Analysis of Large Overlapping Sets",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2013",
volume = "19",
number = "12",
pages = "2496-2505",
abstract = "In many applications, data tables contain multi-valued attributes that often store the memberships of the table entities to multiple sets such as which languages a person masters, which skills an applicant documents, or which features a product comes with. With a growing number of entities, the resulting element-set membership matrix becomes very rich of information about how these sets overlap. Many analysis tasks targeted at set-typed data are concerned with these overlaps as salient features of such data. This paper presents Radial Sets, a novel visual technique to analyze set memberships for a large number of elements. Our technique uses frequency-based representations to enable quickly finding and analyzing different kinds of overlaps between the sets, and relating these overlaps to other attributes of the table entities. Furthermore, it enables various interactions to select elements of interest, find out if they are over-represented in specific sets or overlaps, and if they exhibit a different distribution for a specific attribute compared to the rest of the elements. These interactions allow formulating highly-expressive visual queries on the elements in terms of their set memberships and attribute values. As we demonstrate via two usage scenarios, Radial Sets enable revealing and analyzing a multitude of overlapping patterns between large sets, beyond the limits of state-of-the-art techniques.",
images = "images/Alsallakh13Radial_3.jpg, images/Alsallakh13Radial_1.jpg, images/Alsallakh13Radial_2.jpg",
thumbnails = "images/Alsallakh13Radial_3_thumb.png, images/Alsallakh13Radial_1_thumb.png, images/Alsallakh13Radial_2_thumb.png",
url = "http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6634104",
doi = "10.1109/TVCG.2013.184",
issn = "1077-2626"
}
    [PDF] [Bibtex] 
    @ARTICLE {Parulek13Fast,
author = "Julius Parulek and Andrea Brambilla",
title = "Fast Blending Scheme for Molecular Surface Representation",
journal = "Visualization and Computer Graphics, IEEE Transactions on",
year = "2013",
pages = "2653--2662",
month = "Dec.",
abstract = "Representation of molecular surfaces is a well established way to study the interaction of molecules. The state-of-theart molecular representation is the SES model, which provides a detailed surface visualization. Nevertheless, it is computationally expensive, so the less accurate Gaussian model is traditionally preferred. We introduce a novel surface representation that resembles the SES and approaches the rendering performance of the Gaussian model. Our technique is based on the iterative blending of implicit functions and avoids any pre-computation. Additionally, we propose a GPU-based ray-casting algorithm that efficiently visualize our molecular representation. A qualitative and quantitative comparison of our model with respect to the Gaussian and SES models is presented. As showcased in the paper, our technique is a valid and appealing alternative to the Gaussian representation. This is especially relevant in all the applications where the cost of the SES is prohibitive.",
pdf = "pdfs/Parulek13Fast.pdf",
images = "images/Parulek13Fast01.png, images/Parulek13Fast02.png",
thumbnails = "images/Parulek13Fast01_thumb.png, images/Parulek13Fast02_thumb.png",
event = "Vis2013",
project = "physioillustration",
extra = "extra/Parulek13Fast_code.pdf"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Matkovic13Interactive,
author = "Kresimir Matkovic and Mario Duras and Denis Gracanin and Rainer Splechtna and Benedikt Stehno and Helwig Hauser ",
title = "Interactive Visual Analysis in the Concept Stage of a Hybrid-Vehicle Design",
booktitle = "EuroVis Workshop on Visual Analytics",
year = "2013",
pages = "61--65",
address = "Leipzig, Germany",
publisher = "Eurographics Association",
abstract = "The design of modern, hybrid vehicles is an active area of research. As the whole field is new, engineers need intuitive and powerful support tools. In this application paper, we illustrate an application of interactive visual analysis in the concept phase of a hybrid-vehicle design. We exploit coordinated multiple views to explore and analyze a simulation ensemble - a set of simulation runs of the same simulation model. Once we reduce the ensemble to a single run we use a detailed view, including an energy flow graph and a vehicle drive animation. Very positive feedback from domain experts and opportunities for additional improvements encourage further research.",
pdf = "pdfs/Matkovic13Interactive.pdf",
images = "images/Matkovic13Interactive_0.jpg, images/Matkovic13Interactive_1.jpg, images/Matkovic13Interactive_2.jpg, images/Matkovic13Interactive_3.jpg",
thumbnails = "images/Matkovic13Interactive_0_thumb.jpg, images/Matkovic13Interactive_1.jpg, images/Matkovic13Interactive_2.jpg, images/Matkovic13Interactive_3.jpg",
url = "http://diglib.eg.org/EG/DL/PE/EuroVAST/EuroVA13/061-065.pdf",
doi = "10.2312/PE.EuroVAST.EuroVA13.061-065",
isbn = "978-3-905674-55-2"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {Birkeland13Doppler,
author = "{\AA}smund Birkeland and Dag Magne Ulvang and Kim Nylund and Trygve Hausken and Odd Helge Gilja and Ivan Viola",
title = "Doppler-based 3D Blood Flow Imaging and Visualization",
booktitle = "Proceedings of the 29th Spring Conference on Computer Graphics",
year = "2013",
abstract = "Blood flow is a very important part of human physiology. In this paper, we present a new method for estimating and visualizing 3D blood flow on-the-fly based on Doppler ultrasound. We add semantic information about the geometry of the blood vessels in order to recreate the actual velocities of the blood. Assuming a laminar flow, the flow direction is related to the general direction of the vessel. Based on the center line of the vessel, we create a vector field representing the direction of the vessel at any given point. The actual flow velocity is then estimated from the Doppler ultrasound signal by back-projecting the velocity in the measured direction, onto the vessel direction. Additionally, we estimate the flux at user-selected cross-sections of the vessel by integrating the velocities over the area of the cross- section. In order to visualize the flow and the flux, we propose a visualization design based on traced particles colored by the flux. The velocities are visualized by animating particles in the flow field. Further, we propose a novel particle velocity legend as a means for the user to estimate the numerical value of the current velocity. Finally, we perform an evaluation of the technique where the accuracy of the velocity estimation is measured using a 4D MRI dataset as a basis for the ground truth.",
pdf = "pdfs/Birkeland13Doppler.pdf",
images = "images/Birkeland13Doppler01.png, images/Birkeland13Doppler02.png",
thumbnails = "images/Birkeland13Doppler01_thumb.png, images/Birkeland13Doppler02_thumb.png",
project = "illustrasound,medviz,illvis"
}
    [DOI] [Bibtex] 
    @ARTICLE {Sima13Computer,
author = "Aleksandra Sima and Xavier Bonaventura and Miquel Feixas and Mateu Sbert and John Howell and Ivan Viola and Simon Buckley",
title = "Computer-aided image geometry analysis and subset selection for optimizing texture quality in photorealistic models",
journal = "Computers and Geosciences",
year = "2013",
volume = "52",
pages = "281-291",
abstract = "Photorealistic 3D models are used for visualization, interpretation and spatial measurement in many disciplines, such as cultural heritage, archaeology and geoscience. Using modern image- and laser-based 3D modelling techniques, it is normal to acquire more data than is finally used for 3D model texturing, as images may be acquired from multiple positions, with large overlap, or with different cameras and lenses. Such redundant image sets require sorting to restrict the number of images, increasing the processing efficiency and realism of models. However, selection of image subsets optimized for texturing purposes is an example of complex spatial analysis. Manual selection may be challenging and time-consuming, especially for models of rugose topography, where the user must account for occlusions and ensure coverage of all relevant model triangles. To address this, this paper presents a framework for computer- aided image geometry analysis and subset selection for optimizing texture quality in photorealistic models. The framework was created to offer algorithms for candidate image subset selection, whilst supporting refinement of subsets in an intuitive and visual manner. Automatic image sorting was implemented using algorithms originating in computer science and information theory, and variants of these were compared using multiple 3D models and covering image sets, collected for geological applications. The image subsets provided by the automatic procedures were compared to manually selected sets and their suitability for 3D model texturing was assessed. Results indicate that the automatic sorting algorithms are a promising alternative to manual methods. An algorithm based on a greedy solution to the weighted set-cover problem provided image sets closest to the quality and size of the manually selected sets. The improved automation and more reliable quality indicators make the photorealistic model creation workflow more accessible for application experts, increasing the user’s confidence in the final textured model completeness.",
images = "images/Sima13Computer01.png, images/Sima13Computer02.png",
thumbnails = "images/Sima13Computer01_thumb.png, images/Sima13Computer02_thumb.png",
doi = "10.1016/j.cageo.2012.11.004",
url = "http://www.sciencedirect.com/science/article/pii/S0098300412003743"
}
    [DOI] [Bibtex] 
    @INPROCEEDINGS {Glasser13VisualAnalysis,
author = "Sylvia Glasser and Steffen Oeltze and Uta Preim and Atle Bj{\O }rnerud and Helwig Hauser and Bernhard Preim",
title = "Visual analysis of longitudinal brain tumor perfusion",
booktitle = "Proc. SPIE",
year = "2013",
volume = "8670",
pages = "86700Z-86700Z-11",
abstract = "In clinical research on diagnosis and evaluation of brain tumors, longitudinal perfusion MRI studies are acquired for tumor grading as well as to monitor and assess treatment response and patient prognosis. Within this work, we demonstrate how visual analysis techniques can be adapted to multidimensional datasets from such studies within a framework to support the computer-aided diagnosis of brain tumors. Our solution builds on two innovations: First, we introduce a pipeline yielding comparative, co-registered quantitative perfusion parameter maps over all time steps of the longitudinal study. Second, based on these time-dependent parameter maps, visual analysis methods were developed and adapted to reveal valuable insight into tumor progression, especially regarding the clinical research area of low grade glioma transformation into high grade gliomas. Our examination of four longitudinal brain studies demonstrates the suitability of the presented visual analysis methods and comprises new possibilities for the clinical researcher to characterize the development of low grade gliomas.",
images = "images/Glasser13VisualAnalysis_0.jpg, images/Glasser13VisualAnalysis_1.jpg",
thumbnails = "images/Glasser13VisualAnalysis_0.jpg, images/Glasser13VisualAnalysis_1.jpg",
doi = "10.1117/12.2007878",
url = "http://dx.doi.org/10.1117/12.2007878",
project = "yggdrasil, medviz"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Borgo13GlyphBased,
author = "Rita Borgo and Johannes Kehrer and David H. S. Chung and Eamonn Maguire and Robert S. Laramee and Helwig Hauser and Matthew Ward and Min Chen ",
title = "Glyph-based Visualization: Foundations, Design Guidelines, Techniques and Applications",
booktitle = "EuroGraphics 2013 State-of-the-Art Reports (STARs)",
year = "2013",
pages = "39--63",
address = "Girona, Spain",
publisher = "Eurographics Association",
abstract = "This state of the art report focuses on glyph-based visualization, a common form of visual design where a data set is depicted by a collection of visual objects referred to as glyphs. Its major strength is that patterns of multivariate data involving more than two attribute dimensions can often be more readily perceived in the context of a spatial relationship, whereas many techniques for spatial data such as direct volume rendering find difficult to depict with multivariate or multi-field data, and many techniques for non-spatial data such as parallel coordinates are less able to convey spatial relationships encoded in the data. This report fills several major gaps in the literature, drawing the link between the fundamental concepts in semiotics and the broad spectrum of glyph-based visualization, reviewing existing design guidelines and implementation techniques, and surveying the use of glyph-based visualization in many applications.",
pdf = "pdfs/Borgo13GlyphBased.pdf",
images = "images/Borgo13GlyphBased.jpg",
thumbnails = "images/Borgo13GlyphBased.jpg",
url = "http://diglib.eg.org/EG/DL/conf/EG2013/stars/039-063.pdf",
issn = "1017-4656",
doi = "10.2312/conf/EG2013/stars/039-063"
}
    [PDF] [Bibtex] 
    @MISC {Smestad13Advanced,
author = "Geir Smestad and Paolo Angelelli and Helwig Hauser",
title = "Advanced data fusion in 4-D color doppler volume visualization",
howpublished = "Poster presented at the MedIm conference 2013",
month = "October",
year = "2013",
pdf = "pdfs/Smestad13Advanced.pdf",
images = "images/Smestad13Advanced.jpg",
thumbnails = "images/Smestad13Advanced_thumb.jpg",
location = "Troms{\O }",
project = "bia"
}
    [DOI] [Bibtex] 
    @INPROCEEDINGS {Viola2013Dirk,
author = "Ivan Viola and {\AA},smund Birkeland and Veronika \v{S},olt{\'e},szov{\'a}, and Linn Helljesen and Helwig Hauser and Spiros Kotopoulis and Kim Nylund and Dag M. Ulvang and Ola K. {\O }ye and Trygve Hausken and Odd H. Gilja",
title = "High-Quality 3{D} Visualization of In-Situ Ultrasonography",
booktitle = "EG 2013---Dirk Bartz Prize",
year = "2013",
pages = "1-4",
abstract = "In recent years medical ultrasound has experienced a rapid development in the quality of real-time 3D ultrasound (US) imaging. The image quality of the 3D volume that was previously possible to achieve within the range of a few seconds, is now possible in a fraction of a second. This technological advance offers entirely new opportunities for the use of US in the clinic. In our project, we investigate how real-time 3D US can be combined with high-performance processing of today's graphics hardware to allow for high-quality 3D visualization and precise navigation during the examination. ",
images = "images/2013-05-08-DirkBartzPrizeComb.jpg",
thumbnails = "images/2013-05-08-DirkBartzPrizeComb.jpg",
doi = "10.2312/conf/EG2013/med/001-004",
url = "http://diglib.eg.org/EG/DL/conf/EG2013/med/001-004.pdf.abstract.pdf;internal\&action=action.digitallibrary.ShowPaperAbstract",
project = "illustrasound,medviz,illvis"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Mistelbauer-2013-VVC,
author = "Gabriel Mistelbauer and Anca Morar and Andrej Varchola and R{\"u}diger Schernthaner and Ivan Baclija and Arnold K{\"o}chl and Armin Kanitsar and Stefan Bruckner and Meister Eduard Gr{\"o}ller",
title = "Vessel Visualization using Curvicircular Feature Aggregation",
journal = "Computer Graphics Forum",
year = "2013",
volume = "32",
number = "3",
pages = "231--240",
month = "jun",
abstract = "Radiological investigations are common medical practice for the diagnosis  of peripheral vascular diseases. Existing visualization methods such  as Curved Planar Reformation (CPR) depict calcifications on vessel  walls to determine if blood is still able to flow. While it is possible  with conventional CPR methods to examine the whole vessel lumen by  rotating around the centerline of a vessel, we propose Curvicircular  Feature Aggregation (CFA), which aggregates these rotated images  into a single view. By eliminating the need for rotation, vessels  can be investigated by inspecting only one image. This method can  be used as a guidance and visual analysis tool for treatment planning.  We present applications of this technique in the medical domain and  give feedback from radiologists.",
pdf = "pdfs/Mistelbauer-2013-VVC.pdf",
images = "images/Mistelbauer-2013-VVC.jpg",
thumbnails = "images/Mistelbauer-2013-VVC.png",
youtube = "https://www.youtube.com/watch?v=WwF5GPOs1pA",
doi = "10.1111/cgf.12110",
event = "EuroVis 2013",
keywords = "medical visualization, vessel visualization, vessel reformation",
location = "Leipzig, Germany",
url = "http://www.cg.tuwien.ac.at/research/publications/2013/mistelbauer-2013-cfa/"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {Lidal13Rapid,
author = "Endre Lidal and Daniel Patel and Morten Bendiksen and Tor Langeland and Ivan Viola",
title = "Rapid Sketch-based 3D Modeling of Geology",
booktitle = "Proceedings of EnvirVis Short Papers 2013",
year = "2013",
abstract = "We present and compare two different approaches for performing rapid 3D geological modeling. The ad-hoc approach is based on a composition of many specialized modeling functions, while the generic approach provides one powerful, generic modeling function. Our experiences after developing these two approaches are that the solution space of 3D geological modeling is more extensive than we initially expected and most likely larger than for other modeling domains such as architecture. Further, more research is needed to investigate whether it is possible to �nd one well de�ned toolset of sketching metaphors that is able to cover all of geological modeling.",
pdf = "pdfs/Lidal13Rapid.pdf",
images = "images/Lidal13Rapid01.png",
thumbnails = "images/Lidal13Rapid01_thumb.png",
project = "geoillustrator"
}
    [DOI] [Bibtex] 
    @ARTICLE {Lovset13Rule,
author = "Tyge L{\o }vset and Dag Magne Ulvang and Tor Christian Bekkvik and K{\aa}re Villanger and Ivan Viola",
title = "Rule-based method for automatic scaffold assembly from 3D building models",
journal = "Computers \& Graphics",
year = "2013",
volume = "37",
number = "4",
pages = "256--268",
abstract = "To manually specify an optimal scaffold assembly for a given building geometry is a time consuming task. Our goal is to automate the process of selecting and placing scaffold components in order to design an optimal scaffold assembly for a specific building. The resulting assembly must be possible to construct in practice, should be practical to use for the workers, must satisfy governmental rules and regulations and should ideally result in minimum accumulated component cost. We propose a novel procedural modeling pipeline based on an input house model. First we extract vital coordinates from the house model that define the 3D scaffold placement. These coordinates are the basis for defining the positioning of scaffold cells. In the next step we populate the cells with actual scaffold components geometry. The resulting model is visualized to assist the assembly process. Additionally it is decomposed into elementary building blocks to produce assembly component lists to estimate the scaffold cost estimates, compute the weight for transportation and packing of components from a warehouse. The result from the automated process is compared to scaffold design produced manually by a professional scaffold designer.",
images = "images/Lovset13Rule01.png, images/Lovset13Rule02.png",
thumbnails = "images/Lovset13Rule01_thumb.png, images/Lovset13Rule02_thumb.png",
issn = "0097-8493",
doi = "10.1016/j.cag.2013.01.007",
url = "http://www.sciencedirect.com/science/article/pii/S0097849313000095"
}
    [Bibtex] 
    @MISC {Hauser13VisTutorial,
author = "Steffen Oeltze and Johannes Kehrer and Helwig Hauser",
title = "Interactive Visual Analysis of Scientific Data",
howpublished = "Tutorial at the IEEE VisWeek 2013",
month = "October",
year = "2013",
abstract = "In a growing number of application areas, a subject or phenomenon is investigated by means of multiple datasets being acquired over time (spatiotemporal), comprising several attributes per data point (multi-variate), stemming from different data sources (multi-modal) or multiple simulation runs (multi-run/ensemble) [KH13]. Interactive visual analysis (IVA) comprises concepts and techniques for a user-guided knowledge discovery in such complex data. Through a tight feedback loop of computation, visualization and user interaction, it provides new insight into the data and serves as a vehicle for hypotheses generation or validation. It is often implemented via a multiple coordinated view framework where each view is equipped with interactive drill-down operations for focusing on data features. Two classes of views are integrated: physical views, such as direct volume rendering, show information in the context of the spatiotemporal observation space while attribute views, such as scatter plots and parallel coordinates, show relationships between multiple data attributes. The user may drill-down the data by selecting interesting regions of the observation space or attribute ranges leading to a consistent highlighting of this selection in all other views (brushing-and-linking). Three patterns of explorative/analytical procedures may be accomplished by doing so. In a feature localization, the user searches for places in the 3D/4D observation space where certain attribute values are present. In a multi-variate analysis, relations between data attributes are investigated, e.g., by searching for correlations. In a local investigation, the user inspects the values of selected attributes with respect to certain spatiotemporal subsets of the observation space. In this tutorial, we discuss examples for successful applications of IVA to scientific data from various fields: climate research, medicine, epidemiology, and flow simulation / computation, in particular for automotive engineering. We base our discussions on a theoretical foundation of IVA which helps the tutorial attendees in transferring the subject matter to their own data and application area. In the course of the tutorial, the attendees will become acquainted with techniques from statistics and knowledge discovery, which proved to be particularly useful for a specific IVA application. The tutorial further comprises an overview of off-the-shelf IVA solutions, which may be be particularly interesting for visualization practitioners. It is concluded by a summary of the gained knowledge and a discussion of open problems in IVA of scientific data.",
images = "images/",
thumbnails = "images/iva_scientificdata_proposal_2013_Image.png",
location = "Atlanta (GA), USA",
pres = "pdfs/iva_scientificdata_proposal_2013.pdf"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Karimov-2013-VSV,
author = "Alexey Karimov and Gabriel Mistelbauer and Johanna Schmidt and Peter Mindek and Elisabeth Schmidt and Timur Sharipov and Stefan Bruckner and Meister Eduard Gr{\"o}ller",
title = "ViviSection: Skeleton-based Volume Editing",
journal = "Computer Graphics Forum",
year = "2013",
volume = "32",
number = "3",
pages = "461--470",
month = "jun",
abstract = "Volume segmentation is important in many applications, particularly  in the medical domain. Most segmentation techniques, however, work  fully automatically only in very restricted scenarios and cumbersome  manual editing of the results is a common task. In this paper, we  introduce a novel approach for the editing of segmentation results.  Our method exploits structural features of the segmented object to  enable intuitive and robust correction and verification. We demonstrate  that our new approach can significantly increase the segmentation  quality even in difficult cases such as in the presence of severe  pathologies.",
pdf = "pdfs/Karimov-2013-VSV.pdf",
images = "images/Karimov-2013-VSV.jpg",
thumbnails = "images/Karimov-2013-VSV.png",
youtube = "https://www.youtube.com/watch?v=4s12ZbUyHiY",
doi = "10.1111/cgf.12133",
event = "EuroVis 2013",
keywords = "volume visualization, volume editing, segmentation, interaction",
location = "Leipzig, Germany",
url = "http://www.cg.tuwien.ac.at/research/publications/2013/karimov-2013-vivisection/"
}
    [PDF] [YT] [Bibtex] 
    @ARTICLE {Mindek-2013-VPE,
author = "Peter Mindek and Stefan Bruckner and Peter Rautek and Meister Eduard Gr{\"o}ller",
title = "Visual Parameter Exploration in {GPU} Shader Space",
journal = "Journal of WSCG",
year = "2013",
volume = "21",
number = "3",
pages = "225--234",
month = "jun",
abstract = "The wide availability of high-performance GPUs has made the use of  shader programs in visualization ubiquitous.Understanding shaders  is a challenging task. Frequently it is difficult to mentally reconstruct  the nature and types of transformations applied to the underlying  data during the visualization process. We propose a method for the  visual analysis of GPU shaders, which allows the flexible exploration  and investigation of algorithms, parameters, and their effects. We  introduce a method for extracting feature vectors composed of several  attributes of the shader, as well as a direct manipulation interface  for assigning semantics to them. The user interactively classifies  pixels of images which are rendered with the investigated shader.  The two resulting classes, a positive class and a negative one, are  employed to steer the visualization. Based on this information, we  can extract a wide variety of additional attributes and visualize  their relation to this classification. Our system allows an interactive  exploration of shader space and we demonstrate its utility for several  different applications.",
pdf = "pdfs/Mindek-2013-VPE.pdf",
images = "images/Mindek-2013-VPE.jpg",
thumbnails = "images/Mindek-2013-VPE.png",
youtube = "https://www.youtube.com/watch?v=Sk7EXvqCoxs",
keywords = "parameter space exploration, shader augmentation",
url = "http://www.cg.tuwien.ac.at/research/publications/2013/mindek-2013-pel/"
}
    [PDF] [Bibtex] 
    @PHDTHESIS {turkay13thesis,
author = "Cagatay Turkay",
title = "Integrating Computational Tools in Interactive and Visual Methods for Enhancing High-dimensional Data and Cluster Analysis",
school = "Department of Informatics, University of Bergen, Norway",
year = "2013",
month = "November",
abstract = "With the advance of new data acquisition and generation technologies, our society is becoming increasingly information-driven. The datasets are getting larger and more complex as new technologies emerge and they are posing new challenges to the analysts who are trying to build an understanding of them. Automated computational approaches and interactive visual methods have been widely used to extract and interpret the relevant information in data analysis. However when these methods are used alone on complex datasets, their effectivity is limited due to several factors. Most of the commonly used computational tools often lead to hard to interpret results that may not be reliable most of the time. This thesis aims to enhance data analysis procedures by integrating computational tools with interactive visual methodologies. The contributions of this thesis are mainly focused on the analysis of (very) high-dimensional data, i.e., hundreds and even thousands of dimensions, and cluster analysis. We introduce the dual analysis approach that makes it possible to analyze the items and the dimensions of a dataset in parallel in two linked visualization spaces. This methodology provides a basis to visually characterize and investigate dimensions as first-order analysis objects. We describe structure-aware analysis procedures that are facilitated by representative factors. Moreover, we present several mechanisms to achieve outlier-aware analysis routines. We describe the notion of outlyingness for the dimensions of a dataset and discuss how they can be determined and treated properly. We then focus on enhancing the dialogue between the analyst and the computer when computational methods are used interactively. We describe how different human factors come into play in visual analysis applications and propose optimized analytical processes that try to comply with the human capabilities. All these different approaches are demonstrated with various use-cases performed mostly together with experts from medical, genetic, and molecular biology domain. ",
pdf = "pdfs/turkay13thesis.pdf",
images = "images/turkay13thesis.png",
thumbnails = "images/turkay13thesis.png",
isbn = "?? ",
project = "medviz"
}
    [DOI] [Bibtex] 
    @INCOLLECTION {Turkay13Hypothesis,
author = "Cagatay Turkay and Arvid Lundervold and Astri Johansen Lundervold and Helwig Hauser",
title = "Hypothesis Generation by Interactive Visual Exploration of Heterogeneous Medical Data",
booktitle = "Human-Computer Interaction and Knowledge Discovery in Complex, Unstructured, Big Data",
publisher = "Springer Berlin Heidelberg",
year = "2013",
editor = "Holzinger, Andreas and Pasi, Gabriella",
volume = "7947",
series = "Lecture Notes in Computer Science",
pages = "1--12",
images = "images/Turkay13Hypothesis_01.png",
thumbnails = "images/Turkay13Hypothesis_01.png",
isbn = "978-3-642-39145-3",
doi = "10.1007/978-3-642-39146-0_1",
url = "http://dx.doi.org/10.1007/978-3-642-39146-0_1",
keywords = "interactive visual analysis; high dimensional medical data",
pres = "pdfs/Turkay13Hypothesis.pdf"
}
    [DOI] [Bibtex] 
    @ARTICLE {Hauser13GuestEditors,
author = "Helwig Hauser and Stephen Kobourov and Huamin Qu",
title = "Guest Editors' Introduction: Special Section on the IEEE Pacific Visualization Symposium 2012",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2013",
volume = "19",
number = "6",
pages = "898-899",
images = "images/Gno_thumb.png",
thumbnails = "images/no_thumb.png",
issn = "1077-2626",
url = "http://doi.ieeecomputersociety.org/10.1109/TVCG.2013.70",
doi = "http://doi.ieeecomputersociety.org/10.1109/TVCG.2013.70",
publisher = "IEEE Computer Society",
address = "Los Alamitos, CA, USA"
}
    [PDF] [Bibtex] 
    @MISC {Hauser2013VISU,
author = "Helwig Hauser",
title = "Interactive Visual Analysis of Scientific Data",
howpublished = "Keynote talk at VISU 2013 in Paris, France",
month = "November",
year = "2013",
abstract = "Keynote talk at VISU 2013 in Paris, France",
pdf = "pdfs/2013-11-06-Paris-Visu2013-SciDataIVA-print2up-web.pdf",
images = "images/2013-11-06-Paris-Visu2013-SciDataIVA-print2up-web_Image_0003.jpg, images/2013-11-06-Paris-Visu2013-SciDataIVA-print2up-web_Image_0006.jpg, images/2013-11-06-Paris-Visu2013-SciDataIVA-print2up-web_Image_0002.jpg, images/2013-11-06-Paris-Visu2013-SciDataIVA-print2up-web_Image_0002(2).jpg, images/2013-11-06-Paris-Visu2013-SciDataIVA-print2up-web_Image_0010.jpg, images/2013-11-06-Paris-Visu2013-SciDataIVA-print2up-web_Image_0008.jpg, images/2013-11-06-Paris-Visu2013-SciDataIVA-print2up-web_Image_0009.jpg, images/2013-11-06-Paris-Visu2013-SciDataIVA-print2up-web_Image_0002(3).jpg, images/2013-11-06-Paris-Visu2013-SciDataIVA-print2up-web_Image_0002(4).jpg, images/2013-11-06-Paris-Visu2013-SciDataIVA-print2up-web_Image_0006(2).jpg",
thumbnails = "images/2013-11-06-Paris-Visu2013-SciDataIVA-print2up-web_Image_0003.jpg",
location = "Paris, France"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Schmidt-2013-VVA,
author = "Johanna Schmidt and Meister Eduard Gr{\"o}ller and Stefan Bruckner",
title = "VAICo: Visual Analysis for Image Comparison",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2013",
volume = "19",
number = "12",
pages = "2090--2099",
month = "dec",
abstract = "Scientists, engineers, and analysts are confronted with ever larger  and more complex sets of data, whose analysis poses special challenges.  In many situations it is necessary to compare two or more datasets.  Hence there is a need for comparative visualization tools to help  analyze differences or similarities among datasets. In this paper  an approach for comparative visualization for sets of images is presented.  Well-established techniques for comparing images frequently place  them side-by-side. A major drawback of such approaches is that they  do not scale well. Other image comparison methods encode differences  in images by abstract parameters like color. In this case information  about the underlying image data gets lost. This paper introduces  a new method for visualizing differences and similarities in large  sets of images which preserves contextual information, but also allows  the detailed analysis of subtle variations. Our approach identifies  local changes and applies cluster analysis techniques to embed them  in a hierarchy. The results of this process are then presented in  an interactive web application which allows users to rapidly explore  the space of differences and drill-down on particular features. We  demonstrate the flexibility of our approach by applying it to multiple  distinct domains.",
pdf = "pdfs/Schmidt-2013-VVA.pdf",
images = "images/Schmidt-2013-VVA.jpg",
thumbnails = "images/Schmidt-2013-VVA.png",
youtube = "https://www.youtube.com/watch?v=wfBqKZLVszk",
doi = "10.1109/TVCG.2013.213",
event = "IEEE VIS 2013",
keywords = "focus+context visualization, image set comparison, comparative visualization",
url = "http://www.cg.tuwien.ac.at/research/publications/2013/schmidt-2013-vaico/"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {Kehrer13VisualizationAnd,
author = "Johannes Kehrer and Helwig Hauser",
title = "Visualization and Visual Analysis of Multi-faceted Scientific Data: a Survey",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2013",
volume = "19",
number = "3",
pages = "495-513",
abstract = "Visualization and visual analysis play important roles in exploring, analyzing and presenting scientific data. In many disciplines, data and model scenarios are becoming multi-faceted: data are often spatio-temporal and multi-variate; they stem from different data sources (multi-modal data), from multiple simulation runs (multi-run/ensemble data), or from multi-physics simulations of interacting phenomena (multi-model data resulting from coupled simulation models). Also, data can be of different dimensionality or structured on various types of grids that need to be related or fused in the visualization. This heterogeneity of data characteristics presents new opportunities as well as technical challenges for visualization research. Visualization and interaction techniques are thus often combined with computational analysis. In this survey, we study existing methods for visualization and interactive visual analysis of multi-faceted scientific data. Based on a thorough literature review, a categorization of approaches is proposed. We cover a wide range of fields and discuss to which degree the different challenges are matched with existing solutions for visualization and visual analysis. This leads to conclusions with respect to promising research directions, for instance, to pursue new solutions for multi-run and multi-model data as well as techniques that support a multitude of facets.",
pdf = "pdfs/Kehrer13VisualizationAnd.pdf",
images = "images/Kehrer13VisualizationAnd01.png",
thumbnails = "images/Kehrer13VisualizationAnd01_thumb.png",
issn = "1077-2626",
doi = "http://doi.ieeecomputersociety.org/10.1109/TVCG.2012.110",
publisher = "IEEE Computer Society",
address = "Los Alamitos, CA, USA"
}
    [PDF] [Bibtex] 
    @MISC {Hauser2013IHCI,
author = "Helwig Hauser",
title = "Integrating Interactive and Computational Analysis in Visual Analytics",
howpublished = "Keynote talk at IHCI 2013 in Prague, Czech Republic.",
month = "July",
year = "2013",
abstract = "Keynote talk at IHCI 2013 in Prague, Czech Republic.",
pdf = "pdfs/2013-07-22-Prague-IHCI-Keynote-IVA-print2up.pdf",
images = "images/2013-07-22-Prague-IHCI-Keynote-IVA-print2up_Image_0001(2).jpg, images/2013-07-22-Prague-IHCI-Keynote-IVA-print2up_Image_0001(3).jpg, images/2013-07-22-Prague--IHCI-Keynote-IVA-print2up_Image_0001(4).jpg, images/2013-07-22-Prague-IHCI-Keynote-IVA-print2up_Image_0001(5).jpg, images/2013-07-22-Prague-IHCI-Keynote-IVA-print2up_Image_0001(6).jpg, images/2013-07-22-Prague-IHCI-Keynote-IVA-print2up_Image_0003.jpg",
thumbnails = "images/2013-07-22-Prague-IHCI-Keynote-IVA-print2up_Image_0001(2).jpg"
}

2012

    [PDF] [Bibtex] 
    @ARTICLE {Helljesen12Klinisk,
author = "Linn Emilie S{\ae}vil Helljesen and Spiros Kotopoulis and Kim Nylund and Ivan Viola and Trygve Hausken and Odd Helge Gilja",
title = "Klinisk bruk av 3D-ultralyd",
journal = "Kirurgen",
year = "2012",
volume = "2",
pages = "118--120",
month = "June",
pdf = "pdfs/Helljesen12Klinisk.pdf",
images = "images/Helljesen12Klinisk01.png, images/Helljesen12Klinisk02.png",
thumbnails = "images/Helljesen12Klinisk01_thumb.png, images/Helljesen12Klinisk02_thumb.png",
url = "http://www.kirurgen.no/fagstoff/teknologiutvikling/klinisk-bruk-av-3d-ultralyd",
project = "illustrasound,medviz"
}
    [PDF] [Bibtex] 
    @PHDTHESIS {angelelli12thesis,
author = "Paolo Angelelli",
title = "Visual Exploration of Human Physiology: Visualizing Perfusion, Blood Flow and Aging",
school = "Department of Informatics, University of Bergen, Norway",
year = "2012",
month = "Apr",
abstract = "With the technological advancements in medical imaging, it is nowadayspossible to capture in-vivo information related to different human physiologicalsystems. Such data extends the more traditional anatomical scans,but add size, complexity and heterogeneity. In addition, while anatomydata is defined in three-dimensional space, and 3D graphics techniques canbe used to represent it on the screen, physiology information is often moreabstract, and require tailored solutions to be represented in combinationwith their anatomical context.This thesis presents solutions for visualizing selected aspects in threedomains of physiology: blood flow, perfusion and aging. With respect toblood flow, it includes a technique to enhance the side-by-side visualizationof the tubular flow in vessels. This result is achieved with a methodthat generates straightened visualizations of the flow in its context, whichcan be easily aligned and then related to each other. With respect to perfusion,this thesis includes an interactive visual analysis solution that easeand improve the exploration, segmentation and analysis of perfusion dataacquired using contrast-enhanced ultrasound. This result is achieved byusing a statistical framework to extract enhancement information, and aninteractive, correlation-based approach to classify the tissue based on similarity.Finally, with respect to aging, two solutions to help exploring largedata collections of repeated examinations are presented. In one, interactivevisual analysis methods are employed to explore and analyze cohort studydata, while the other focuses on the guided exploration of repeated ultrasoundexaminations. Demonstration case studies are include to exemplifythe utility of the presented work.",
pdf = "pdfs/angelelli12thesis.pdf",
images = "images/angelelli12thesis.png",
thumbnails = "images/angelelli12thesis_thumb.png",
isbn = "978-82-308-2073-5"
}
    [PDF] [DOI] [VID] [Bibtex] 
    @ARTICLE {Turkay12Representative,
author = "Cagatay Turkay and Arvid Lundervold and Astri Johansen Lundervold and Helwig Hauser",
title = "Representative Factor Generation for the Interactive Visual Analysis of High-Dimensional Data",
journal = "Visualization and Computer Graphics, IEEE Transactions on",
year = "2012",
volume = "18",
number = "12",
pages = "2621--2630",
month = "December",
abstract = "Datasets with a large number of dimensions per data item (hundreds or more) are challenging both for computational and visual analysis. Moreover, these dimensions have different characteristics and relations that result in sub-groups and/or hierarchies over the set of dimensions. Such structures lead to heterogeneity within the dimensions. Although the consideration of these structures is crucial for the analysis, most of the available analysis methods discard the heterogeneous relations among the dimensions. In this paper, we introduce the construction and utilization of representative factors for the interactive visual analysis of structures in high-dimensional datasets. First, we present a selection of methods to investigate the sub-groups in the dimension set and associate representative factors with those groups of dimensions. Second, we introduce how these factors are included in the interactive visual analysis cycle together with the original dimensions. We then provide the steps of an analytical procedure that iteratively analyzes the datasets through the use of representative factors. We discuss how our methods improve the reliability and interpretability of the analysis process by enabling more informed selections of computational tools. Finally, we demonstrate our techniques on the analysis of brain imaging study results that are performed over a large group of subjects.",
pdf = "pdfs/Turkay12Representative.pdf",
vid = "vids/Turkay12Representative.avi",
images = "images/Turkay12Representative01.png, images/Turkay12Representative02.png",
thumbnails = "images/Turkay12Representative01_thumb.png, images/Turkay12Representative02_thumb.png",
event = "IEEE Information Visualization Conference 2012",
location = "Seattle, WA, USA",
doi = "10.1109/TVCG.2012.256",
issn = "1077-2626"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Lidal12Geological,
author = "Endre M. Lidal and Helwig Hauser and Ivan Viola ",
title = "Geological Storytelling - Graphically Exploring and Communicating Geological Sketches",
booktitle = "Proceedings of Sketch-Based Interfaces and Modeling (SBIM 2012)",
year = "2012",
pages = "11--20",
abstract = "Developing structural geological models from exploratory subsea imaging is difficult and an ill-posed process. Therefore, in practice several experts generate a larger number of geological interpretations. This leads to the situation that a number of geological sketches are prepared and examined for the next steps in the oil and gas exploration pipeline. In this paper, we present Geological Storytelling, a novel graphical approach for performing rapid and expressive geomodeling of a multitude of model variations. The solution builds on a flip-over metaphor for sketching the individual steps in a story that externalizes the mental steps the modeler performs when developing the model. The stories, through the discrete story steps, are then visualized in a Story Tree for easy access and management. This tree also provides the interface for individual story playback and examination, or comparative visualization of several stories. With our approach, the experts can rapidly sketch geological stories that both visualize the proposed model of today's geology and visualize how the expert derived this model. Presenting the model as a visual story helps the peers to evaluate the geological soundness of the model. We have developed geological storytelling in collaboration with domain experts that work with such challenges on a daily basis. Our focus of this work has been on models derived from single seismic slices. We have implemented a prototype of Geological Storytelling to demonstrate our concept and to get domain expert feedback.",
pdf = "pdfs/Lidal12Geological.pdf",
images = "images/Lidal12Geological01.png, images/Lidal12Geological02.png",
thumbnails = "images/Lidal12Geological01_thumb.png, images/Lidal12Geological02_thumb.png",
url = "http://diglib.eg.org/EG/DL/WS/SBM/SBM12/011-020.pdf",
doi = "10.2312/SBM/SBM12/011-020",
project = "geoillustrator"
}
    [Bibtex] 
    @ARTICLE {Birkeland12TheUltrasound,
author = "{\AA}smund Birkeland and Veronika \v{S}olt{\'e}szov{\'a} and Dieter H{\"o}nigmann and Odd Helge Gilja and Svein Brekke and Timo Ropinski and Ivan Viola",
title = "The Ultrasound Visualization Pipeline - A Survey",
journal = "CoRR",
year = "2012",
volume = "abs/1206.3975",
abstract = "Ultrasound is one of the most frequently used imaging modality in medicine. The high spatial resolution, its interactive nature and non-invasiveness makes it the first choice in many examinations. Image interpretation is one of ultrasounds main challenges. Much training is required to obtain a confident skill level in ultrasound-based diagnostics. State-of-the-art graphics techniques is needed to provide meaningful visualizations of ultrasound in real-time. In this paper we present the process-pipeline for ultrasound visualization, including an overview of the tasks performed in the specific steps. To provide an insight into the trends of ultrasound visualization research, we have selected a set of significant publications and divided them into a technique-based taxonomy covering the topics pre-processing, segmentation, registration, rendering and augmented reality. For the different technique types we discuss the difference between ultrasound-based techniques and techniques for other modalities.",
images = "images/Birkeland2012TheUltrasound.png",
thumbnails = "images/Birkeland2012TheUltrasound_thumb.png",
url = "http://arxiv.org/abs/1206.3975",
project = "illustrasound,medviz,illvis"
}
    [PDF] [DOI] [VID] [YT] [Bibtex] 
    @ARTICLE {Birkeland-2012-IMC,
author = "{\AA}smund Birkeland and Stefan Bruckner and Andrea Brambilla and Ivan Viola",
title = "Illustrative Membrane Clipping",
journal = "Computer Graphics Forum",
year = "2012",
volume = "31",
number = "3",
pages = "905--914",
month = "jun",
abstract = "Clipping is a fast, common technique for resolving occlusions. It  only requires simple interaction, is easily understandable, and thus  has been very popular for volume exploration. However, a drawback  of clipping is that the technique indiscriminately cuts through features.  Illustrators, for example, consider the structures in the vicinity  of the cut when visualizing complex spatial data and make sure that  smaller structures near the clipping plane are kept in the image  and not cut into fragments. In this paper we present a new technique,  which combines the simple clipping interaction with automated selective  feature preservation using an elastic membrane. In order to prevent  cutting objects near the clipping plane, the deformable membrane  uses underlying data properties to adjust itself to salient structures.  To achieve this behaviour, we translate data attributes into a potential  field which acts on the membrane, thus moving the problem of deformation  into the soft-body dynamics domain. This allows us to exploit existing  GPU-based physics libraries which achieve interactive frame rates.  For manual adjustment, the user can insert additional potential fields,  as well as pinning the membrane to interesting areas. We demonstrate  that our method can act as a flexible and non-invasive replacement  of traditional clipping planes.",
pdf = "pdfs/Birkeland-2012-IMC.pdf",
vid = "vids/Birkeland12Illustrative.avi",
images = "images/Birkeland12Illustrative01.png, images/Birkeland12Illustrative02.png, images/Birkeland12Illustrative03.png",
thumbnails = "images/Birkeland-2012-IMC.png",
youtube = "https://www.youtube.com/watch?v=I89_--zul6c",
note = "presented at EuroVis 2012",
doi = "10.1111/j.1467-8659.2012.03083.x",
event = "EuroVis 2012",
keywords = "clipping, volume rendering, illustrative visualization",
location = "Vienna, Austria",
project = "illustrasound,medviz,illvis",
url = "http://www.cg.tuwien.ac.at/research/publications/2012/Birkeland-2012-IMC/"
}
    [PDF] [VID] [Bibtex] 
    @INPROCEEDINGS {Solteszova12Stylized,
author = "Veronika \v{S}olt{\'e}szov{\'a} and Ruben Patel and Helwig Hauser and Ivanko Viola",
title = "Stylized Volume Visualization of Streamed Sonar Data",
booktitle = "Proceedings of Spring Conference on Computer Graphics (SCCG 2012)",
year = "2012",
pages = "13--20",
month = "May",
abstract = "Current visualization technology implemented in the software for 2D sonars used in marine research is limited to slicing whilst volume visualization is only possible as post processing. We designed and implemented a system which allows for instantaneous volume visualization of streamed scans from 2D sonars without prior resampling to a voxel grid. The volume is formed by a set of most recent scans which are being stored. We transform each scan using its associated transformations to the view-space and slice their bounding box by view-aligned planes. Each slicing plane is reconstructed from the underlying scans and directly used for slice-based volume rendering. We integrated a low frequency illumination model which enhances the depth perception of noisy acoustic measurements. While we visualize the 2D data and time as 3D volumes, the temporal dimension is not intuitively communicated. Therefore, we introduce a concept of temporal outlines. Our system is a result of an interdisciplinary collaboration between visualization and marine scientists. The application of our system was evaluated by independent domain experts who were not involved in the design process in order to determine real life applicability.",
pdf = "pdfs/Solteszova12Stylized.pdf",
vid = "vids/Solteszova12Stylized.mp4",
images = "images/Solteszova12Stylized01.png, images/Solteszova12Stylized02.png, images/Solteszova12Stylized03.png",
thumbnails = "images/Solteszova12Stylized01_thumb.png, images/Solteszova12Stylized02_thumb.png, images/Solteszova12Stylized03_thumb.png",
note = "Second best paper and second best presentation awards",
location = "Smolenice castle, Slovakia",
project = "illustrasound,medviz,illvis"
}
    [DOI] [Bibtex] 
    @ARTICLE {Doleish12Interactive,
author = "Helmut Doleisch and Helwig Hauser",
title = "Interactive Visual Exploration and Analysis of Multivariate Simulation Data",
journal = "Computing in Science Engineering",
year = "2012",
volume = "14",
number = "2",
pages = "70--77",
month = "March-April",
abstract = "The interactive visual exploration of large and complex simulation datasets has become an important methodology that improves data analysis for scientists and professional practitioners.",
images = "images/Doleish12Interactive01.png, images/Doleish12Interactive02.png",
thumbnails = "images/Doleish12Interactive01_thumb.png, images/Doleish12Interactive02_thumb.png",
keywords = "complex simulation datasets;data analysis;important methodology; interactive visual exploration;multivariate simulation data;data analysis; data visualisation;geophysics computing;",
doi = "10.1109/MCSE.2012.27",
issn = "1521-9615",
url = "http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6159200"
}
    [Bibtex] 
    @MISC {Viola12Physiological,
author = "Ivan Viola",
title = "Illustrative Visualization of Physiological Models and Imaging",
howpublished = "Talk in the MedViz Conference 2012",
month = "January",
year = "2012",
abstract = "Physiological processes are of multi-scale and multi-system nature. In general they are very difficult to comprehend. This talk discusses challenges of an upcoming research project that aims at proposing an entirely novel research agenda within the data visualization research field to enable understanding, communication, and evaluation of physiology through interactive and easy-to-understand visualization. The visualization metaphors investigated are inspired by textbook illustrations and handcrafted animated illustrations. The primary focus is on development of novel graphics data representations, visual representations, occlusion handling, visual guidance and storytelling, zooming, interaction and integration of physiological models and medical imaging. The visualization technology will be developed and evaluated on multiple scale levels, from molecular machines, up to the organ level. The physiological context for the technological development and evaluation will be primarily the muscular system. The outcome of the discussed project is new visualization technology in form of algorithms, concepts, and proof of concept implementations. The utilization of the outcome can lead to advances in the field of physiology by providing intuitive visual representation, which the user can observe and interact with.",
images = "images/no_thumb.png",
thumbnails = "images/no_thumb.png",
location = "Bergen, Norway",
project = "physioillustration, medviz"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Brambilla12Illustrative,
author = "Andrea Brambilla and Robert Carnecky and Ronald Peikert and Ivan Viola and Helwig Hauser",
title = "Illustrative Flow Visualization: State of the Art, Trends and Challenges",
booktitle = "EuroGraphics 2012 State of the Art Reports (STARs)",
year = "2012",
pages = "75--94",
abstract = "Flow visualization is a well established branch of scientific visualization and it currently represents an invaluable resource to many fields, like automotive design, meteorology and medical imaging. Thanks to the capabilities of modern hardware, flow datasets are increasing in size and complexity, and traditional flow visualization techniques need to be updated and improved in order to deal with the upcoming challenges. A fairly recent trend to enhance the expressiveness of scientific visualization is to produce depictions of physical phenomena taking inspiration from traditional handcrafted illustrations: this approach is known as illustrative visualization, and it is getting a foothold in flow visualization as well. In this state of the art report we give an overview of the existing illustrative techniques for flow visualization, we highlight which problems have been solved and which issues still need further investigation, and, finally, we provide remarks and insights on the current trends in illustrative flow visualization.",
pdf = "pdfs/Brambilla12Illustrative.pdf",
images = "images/Brambilla12Illustrative.png",
thumbnails = "images/Brambilla12Illustrative_thumb.png",
url = "http://diglib.eg.org/EG/DL/conf/EG2012/stars/075-094.pdf",
doi = "10.2312/conf/EG2012/stars/075-094",
location = "Cagliari, Italy",
pres = "pdfs/Brambilla12Illustrative.pptx",
project = "semseg"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {Parulek12Implicit,
author = "Julius Parulek and Cagatay Turkay and Natalie Reuter and Ivan Viola",
title = "Implicit Surfaces for Interactive Graph Based Cavity Analysis of Molecular Simulations",
booktitle = "2nd IEEE Symposium on Biological Data Visualization",
year = "2012",
series = "BioVis 2012",
abstract = "Molecular surfaces provide a suitable way to analyze and to study the evolution and interaction of molecules. The analysis is often concerned with visual identification of binding sites of ligands to a host macromolecule. We present a novel technique that is based on implicit representation, which extracts all potential binding sites and allows an advanced 3D visualization of these sites in the con- text of the molecule. We utilize implicit function sampling strategy to obtain potential cavity samples and graph algorithms to extract arbitrary cavity components defined by simple graphs. Moreover, we propose how to interactively visualize these graphs in the con- text of the molecular surface. We also introduce a system of linked views depicting various graph parameters that are used to perform a more elaborative study on created graphs.",
pdf = "pdfs/Parulek12Implicit.pdf",
images = "images/Parulek12Implicit01.png, images/Parulek12Implicit02.png",
thumbnails = "images/Parulek12Implicit01_thumb.png, images/Parulek12Implicit02_thumb.png",
location = "Seattle (WA), US",
project = "physioillustration"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {Ford12HeartPad,
author = "Steven Ford and Gabriel Kiss and Ivan Viola and Stefan Brukner and Hans Torp",
title = "HeartPad: Real-Time Visual Guidance for Cardiac Ultrasound",
booktitle = "Proceedings of Workshop at SIGGRAPH ASIA 2012",
year = "2012",
series = "WASA 2012",
address = "Fusionopolis, Singapore",
month = "November",
abstract = "Medical ultrasound is a challenging modality when it comes to image interpretation. The goal we address in this work is to assist the ultrasound examiner and partially alleviate the burden of interpretation. We propose to address this goal with visualization that provides clear cues on the orientation and the correspondence between anatomy and the data being imaged. Our system analyzes the stream of 3D ultrasound data and in real-time identifies distinct features that are basis for a dynamically deformed mesh model of the heart. The heart mesh is composited with the original ultrasound data to create the data-to-anatomy correspondence. The visualization is broadcasted over the internet allowing, among other opportunities, a direct visualization on the patient on a tablet computer. The examiner interacts with the transducer and with the visualization parameters on the tablet. Our system has been characterized by domain specialist as useful in medical training and for navigating occasional ultrasound users.",
pdf = "pdfs/Ford12HeartPad.pdf",
images = "images/Ford12HeartPad01.png, images/Ford12HeartPad02.png",
thumbnails = "images/Ford12HeartPad01_thumb.png, images/Ford12HeartPad02_thumb.png",
project = "illustrasound,medviz, illvis"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Pobitzer12Filtering,
author = "Armin Pobitzer and Ronald Peikert and Raphael Fuchs and Holger Theisel and Helwig Hauser",
title = "Filtering of FTLE for Visualizing Spatial Separation in Unsteady 3D Flow",
booktitle = "Topological Methods in Data Analysis and Visualization II",
year = "2012",
editor = "R. Peikert and H. Hauser and H. Carr and R. Fuchs",
pages = "237--253",
publisher = "Springer",
abstract = "Texture mapping is a common method for combining surface geometry with image data, with the resulting photorealistic 3D models being suitable not only for visualisation purposes but also for interpretation and spatial measurement, in many application fields, such as cultural heritage and the earth sciences. When acquiring images for creation of photorealistic models, it is usual to collect more data than is finally necessary for the texturing process. Images may be collected from multiple locations, sometimes with different cameras or lens configurations and large amounts of overlap may exist. Consequently, much redundancy may be present, requiring sorting to choose the most suitable images to texture the model triangles. This paper presents a framework for visualization and analysis of the geometric relations between triangles of the terrain model and covering image sets. The application provides decision support for selection of an image subset optimized for 3D model texturing purposes, for non-specialists. It aims to improve the communication of geometrical dependencies between model triangles and the available digital images, through the use of static and interactive information visualisation methods. The tool was used for computer-aided selection of image subsets optimized for texturing of 3D geological outcrop models. The resulting textured models were of high quality and with a minimum of missing texture, and the time spent in time-consuming reprocessing was reduced. Anecdotal evidence indicated that an increased user confidence in the final textured model quality and completeness makes the framework highly beneficial. ",
pdf = "pdfs/Pobitzer12Filtering.pdf",
images = "images/Pobitzer12Filtering01.png, images/Pobitzer12Filtering02.png",
thumbnails = "images/Pobitzer12Filtering01_thumb.png, images/Pobitzer12Filtering02_thumb.png",
doi = "http://dx.doi.org/10.1007/978-3-642-23175-9_16",
url = "http://dx.doi.org/10.1007/978-3-642-23175-9_16",
project = "semseg"
}
    [DOI] [Bibtex] 
    @INPROCEEDINGS {Natali12Rapid,
author = "Mattia Natali and Ivan Viola and Daniel Patel",
title = "Rapid Visualization of Geological Concepts",
booktitle = "SIBGRAPI 2012 (XXV Conference on Graphics, Patterns and Images)",
year = "2012",
editor = "C. Freitas, L. Silva, R. Scopigno, and S. Sarkar",
address = "Ouro Preto, MG, Brazil",
month = "August",
abstract = "We describe a sketch-based system for constructing an illustrative visualization of the subsurface. An intuitive and rapid modelling tool is defined, which takes as input user's strokes and creates a 3D layer-cake model of the earth. Our tool enables users to quickly express and communicate their ideas directly using a 3D model. For sketching, we have created geometric operators that capture the domain specific modelling requirements.We have devised sketching operators for expressing folding and faulting processes. This makes it possible to produce a large span of scenarios. Moreover, for communicating layer properties such as rock type and grain size, our system allows for associating user defined texture to each layer which can be deformed with a few sketch strokes.",
images = "images/Natali12Rapid01.png, images/Natali12Rapid02.png",
thumbnails = "images/Natali12Rapid01_thumb.png, images/Natali12Rapid02_thumb.png",
url = "http://www.decom.ufop.br/sibgrapi2012/",
doi = "10.1109/SIBGRAPI.2012.29",
project = "geoillustrator"
}
    [PDF] [Bibtex] 
    @MISC {Brambilla12Geilo,
author = "Andrea Brambilla and Armin Pobitzer and Helwig Hauser",
title = "Flow Visualization and the SemSeg project",
howpublished = "Poster presented at the Sintef winter school 2012",
month = "January",
year = "2012",
pdf = "pdfs/Brambilla12Geilo.pdf",
images = "images/Brambilla12Geilo01.png",
thumbnails = "images/Brambilla12Geilo01_thumb.png",
location = "Geilo, Norway",
url = "http://www.sintef.no/Projectweb/eVITA/Winter-Schools/2012/"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {Turkay2012DualDNA,
author = "Cagatay Turkay and Julius Parulek and Helwig Hauser",
title = "Dual analysis of DNA microarrays",
booktitle = "Proceedings of the 12th International Conference on Knowledge Management and Knowledge Technologies",
year = "2012",
series = "i-KNOW '12",
pages = "26:1--26:8",
abstract = "Microarray data represents the expression levels of genes for different samples and for different conditions. It has been a central topic in bioinformatics research for a long time already. Researchers try to discover groups of genes that are responsible for specific biological processes. Statistical analysis tools and visualizations have been widely used in the analysis of microarray data. Researchers try to build hypotheses on both the genes and the samples. Therefore, such analyses require the joint exploration of the genes and the samples. However, current methods in interactive visual analysis fail to provide the necessary mechanisms for this joint analysis. In this paper, we propose an interactive visual analysis framework that enables the dual analysis of the samples and the genes through the use of integrated statistical tools. We introduce a set of specialized views and a detailed analysis procedure to describe the utilization of our framework.",
pdf = "pdfs/Turkay2012DualDNA.pdf",
images = "images/Turkay2012DualDNA01.png, images/Turkay2012DualDNA02.png",
thumbnails = "images/Turkay2012DualDNA01_thumb.png, images/Turkay2012DualDNA02_thumb.png",
location = "Graz, Austria",
articleno = "26",
numpages = "8",
keywords = "interactive visual analysis, microarray data, visual analytics"
}
    [Bibtex] 
    @MISC {Pobitzer12Exploiting,
author = "Armin Pobitzer",
title = "Exploiting the Turbulence Energy Cascade for Flow Visualization",
howpublished = "Invited talk at the weekly seminar of Laboratoire de M\'{e}canique de Lille",
month = "February",
year = "2012",
abstract = "Even though modern technology and tools, together with available computer power, theoretically enable us to visualise large vector fields directly, it often is neither interesting nor necessary to visualise every detail of them. Usually, interesting features of the investigated field can be visualized more efficiently using dedicated feature detectors, e.g. the $\lambda_2$ criterion [2] for vertical structures. In settings with highly complex flow patterns, such as fully developed turbulence, feature detectors may, however, mark almost the whole flow domain as a feature. In these cases visualisations based on these detectors become hard to interpret due to occlusion and visual cluttering. This problem is well known in visualisation, and has been addressed by previous work. Many of these methods have in common that they extract all features at first, and discard some of them afterwards. Criteria for this discarding are often of geometrical character, such as size (volume, length, area ...) or distance to next feature. While the visual output of such strategies satisfies the need to reduce occlusion and visual clutter, the interpretability of the results remains an open question. The immediate relation between the velocity field and the output of the feature detector is lost, since the simplication is made on the `image-level' only. In this talk we discuss how the internal structure of flow fields can be exploited, in particular the turbulence energy cascade. Based on proper orthogonal decomposition [3], we present a general simplification scheme for feature extraction that preserves the 1-to-1 relation between visual output of the method and the flow pattern it is extracted from. We apply the simplification scheme on both Eulerian and Lagrangian feature detectors and discuss the results. In particular the impact of the simplification scheme on the detection and visualization of Lagrangian Coherent Structures based on Finite-time Lyapunov exponents is addressed. The results presented in this talk are published in the article `Energy-scale Aware Feature Extraction for Flow Visualization [4]. [1] L. Hesselink, J. Helman, and P. Ning, Quantitative image processing in fluid mechanics, Experimental Thermal and Fluid Science, 5 (1992), pp. 605-616. Special Issue on Experimental Methods in Thermal and Fluid Science. [2] J. Jeong and F. Hussain, On the identification of a vortex, Journal of Fluid Mechanics, 285 (1995), pp. 69-84. [3] J. L. Lumley, The structure of inhomogeneous turbulent flows, in Atmospheric Turbulence and Radio Wave Propagation, Elsevier, 1967, pp. 166-178. [4] A. Pobitzer, M. Tutkun, O Andreassen, R. Fuchs, R. Peikert, and H. Hauser, Energy-scale aware feature extraction for flow visualization, Computer Graphics Forum, 30 (2011), pp. 771-780. [5] F. Sadlo and R. Peikert, Visualizing Lagrangian coherent structures: A comparison to vector field topology, in Topology-Based Methods in Visualization II: Proc. of the 2nd TopoInVis Workshop (TopoInVis 2007), H.-C. Hege, K. Polthier, and G. Scheuermann, eds, 2009, pp. 15-29.",
images = "images/no_thumb.png",
thumbnails = "images/no_thumb.png",
location = "Lille, France",
url = "http://lml.univ-lille1.fr/lml/?page=33\&seminID=172"
}
    [DOI] [Bibtex] 
    @INPROCEEDINGS {Konyha12Interactive,
author = "Zoltan Konyha and Alan Lez and Kresimir Matkovic and Mario Jelovic and Helwig Hauser",
title = "Interactive visual analysis of families of curves using data aggregation and derivation",
booktitle = "Proceedings of the 12th International Conference on Knowledge Management and Knowledge Technologies",
year = "2012",
series = "i-KNOW '12",
pages = "24:1--24:8",
address = "New York, NY, USA",
publisher = "ACM",
abstract = "Time-series data are regularly collected and analyzed in a wide range of domains. Multiple simulation runs or multiple measurements of the same physical quantity result in ensembles of curves which we call families of curves. The analysis of time-series data is extensively studied in mathematics, statistics, and visualization; but less research is focused on the analysis of families of curves. Interactive visual analysis in combination with a complex data model, which supports families of curves in addition to scalar parameters, represents a premium methodology for such an analysis. In this paper we describe the three levels of complexity of interactive visual analysis we identified during several case studies. The first two levels represent the current state of the art. The newly introduced third level makes extracting deeply hidden implicit information from complex data sets possible by adding data derivation and advanced interaction. We seamlessly integrate data derivation and advanced interaction into the visual exploration to facilitate an in-depth interactive visual analysis of families of curves. We illustrate the proposed approach with typical analysis patterns identified in two case studies from automotive industry.",
images = "images/Konyha12Interactive01.png, images/Konyha12Interactive02.png",
thumbnails = "images/Konyha12Interactive01_thumb.png, images/Konyha12Interactive02_thumb.png",
isbn = "978-1-4503-1242-4",
location = "Graz, Austria",
articleno = "24",
numpages = "8",
url = "http://doi.acm.org/10.1145/2362456.2362487",
doi = "10.1145/2362456.2362487",
acmid = "2362487",
keywords = "attribute derivation, families of curves, interactive visual analysis, knowledge generations"
}
    [Bibtex] 
    @MISC {Hauser12Dagstuhl,
author = "Helwig Hauser",
title = "Automated Methods in Information Visualization",
howpublished = "Invited talk at the Dagstuhl seminar 12081",
month = "February",
year = "2012",
abstract = "Visualization and Machine Learning have related goals in terms of helping analysts to understand characteristic aspects of data. While visualization aims at involving the user through interactive depictions of data, machine learning is generally represented by automatic methods that yield optimal results with respect to certain initially specified tasks. Not at the least within the research direction of visual analytics it seems promising to think about opportunities to integrate both methodologies in order to exploit the strengths of both sides. Up to now, examples of integration very often encompass the visualization of results from automatic methods as well as attempts to make originally automated methods partially interactive. A vision for the future would be to integrate interactive and automatic methods in order to solve problems. A possible realization could be an iterative process where the one or other approach is chosen on demand at each step. ",
images = "images/Hauser12Dagstuhl.png",
thumbnails = "images/Hauser12Dagstuhl_thumb.png",
location = "Wadern, Germany",
url = "http://www.dagstuhl.de/en/program/calendar/semhp/?semnr=12081",
pres = "pdfs/Hauser12Dagstuhl-pres.pdf"
}
    [Bibtex] 
    @MISC {Hauser12TAVA,
author = "Helwig Hauser",
title = "Compromises and Added Value in Visual Analytics",
howpublished = "Keynote talk at the TAVA 2012 workshop",
month = "September",
year = "2012",
images = "images/Hauser12TAVA.png",
thumbnails = "images/Hauser12TAVA_thumb.png",
location = "Graz, Austria",
pres = "pdfs/Hauser12TAVA-slides.pdf"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {Ma12ScientificStorytelling,
author = "Kwan-Liu Ma and I. Liao and J. Frazier and H. Hauser and H.-N. Kostis",
title = "Scientific Storytelling Using Visualization",
journal = "Computer Graphics and Applications, IEEE",
year = "2012",
volume = "32",
number = "1",
pages = "12 -19",
month = "Jan.--Feb.",
abstract = "Scientists frequently tell stories using visualizations of scientific data, in the process of disseminating findings to peers and the general public. However, techniques and methods for effective scientific storytelling have received little attention so far. This article explores how literary and theatrical narrative conventions can inform the design and presentation of visualizations, and discusses the challenges of adapting scientific visualizations for broader audiences. It also summarizes recent workshops' findings on the role of storytelling in visualizations, and presents several examples of successful scientific-storytelling production teams. The conclusion is that scientific storytelling deserves greater support and recognition by the visualization community.",
pdf = "pdfs/Ma12ScientificStorytelling.pdf",
images = "images/Ma12ScientificStorytelling01.jpg, images/Ma12ScientificStorytelling02.jpg , images/Ma12ScientificStorytelling03.jpg, ../../../_images/CGA--2012-01--Cover.png",
thumbnails = "images/Ma12ScientificStorytelling01_thumb.jpg, images/Ma12ScientificStorytelling02_thumb.jpg , images/Ma12ScientificStorytelling03_thumb.jpg, ../../../_images/CGA--2012-01--Cover_thumb.png",
keywords = "literary narrative convention;scientific data visualization; scientific storytelling;theatrical narrative convention;data visualisation; natural sciences computing;",
doi = "10.1109/MCG.2012.24",
url = "http://dx.doi.org/10.1109/MCG.2012.24",
issn = "0272-1716"
}
    [Bibtex] 
    @MISC {Hauser12EuroVA,
author = "Helwig Hauser",
title = "The Iterative Process of Interactive Visual Analysis",
howpublished = "Keynote talk at the EuroVA 2012 workshop",
month = "June",
year = "2012",
abstract = "One central characteristic of our information age is that increasingly often we should exploit the wealth of available data for the sake of learning, decision making, as well as other tasks. A promising approach - not at the least also targeted by visual analytics - is to integrate the strengths of computers (fast computation, efficient handling of large datasets, comparably low costs, etc.) with the strengths of the users (perceptual capabilities, considering domain knowledge, detecting the unexpected, etc.). In this talk, we look at one possible solution, i.e., the concept of interactive visual analysis, and describe it as an iterative process, enabling the integration of computational and interactive means for data exploration and analysis. We consider a data scenario that opposes dependent and independent data dimensions (like in a table), general enough to match many different application cases. We focus on the case of multivariate data, but also address the case of high-dimensional data and opportunities for exploring and analyzing such data. After all, we think of interactive visual analysis as an iterative process, where each step is performed on the basis of a toolbox with computational and interactive visual solutions.",
images = "images/Hauser12EuroVA.jpg",
thumbnails = "images/Hauser12EuroVA_thumb.jpg",
location = "Vienna, Austria",
url = "http://www.eurova.org/previous-events/eurova-2012",
pres = "pdfs/Hauser12EuroVA-pres.pdf"
}
    [Bibtex] 
    @BOOK {peikert12topological,
author = "Ronald Peikert and Helwig Hauser and Hamish Carr and Raphael Fuchs",
title = "Topological Methods in Data Analysis and Visualization II: Theory, Algorithms, and Applications",
publisher = "Springer",
year = "2012",
series = "Mathematics and Visualization",
abstract = "When scientists analyze datasets in a search for underlying phenomena, patterns or causal factors, their first step is often an automatic or semi-automatic search for structures in the data. Of these feature-extraction methods, topological ones stand out due to their solid mathematical foundation. Topologically defined structures -as found in scalar, vector and tensor fields- have proven their merit in a wide range of scientific domains, and scientists have found them to be revealing in subjects such as physics, engineering, and medicine. Full of state-of-the-art research and contemporary hot topics in the subject, this volume is a selection of peer-reviewed papers originally presented at the fourth Workshop on Topology-Based Methods in Data Analysis and Visualization, TopoInVis 2011, held in Zurich, Switzerland. The workshop brought together many of the leading lights in the field for a mixture of formal presentations and discussion. One topic currently generating a great deal of interest, and explored in several chapters here, is the search for topological structures in time-dependent flows, and their relationship with Lagrangian coherent structures. Contributors also focus on discrete topologies of scalar and vector fields, and on persistence-based simplification, among other issues of note. The new research results included in this volume relate to all three key areas in data analysis-theory, algorithms and applications.",
images = "images/peikert12topological.png",
thumbnails = "images/peikert12topological_thumb.png",
isbn = "978-3-642-23175-9",
url = "http://www.springer.com/mathematics/computational+science+%26+engineering/book/978-3-642-23174-2"
}
    [PDF] [Bibtex] 
    @MISC {Pobitzer12Physics,
author = "Armin Pobitzer",
title = "Physics-based Velocity Field Simplification for Flow Visualization",
howpublished = "Invited talk at Minisymposium on Analysis and Representation of Large Data Sets",
month = "February",
year = "2012",
abstract = "With the availability of more computing power, simulations of increasingly complex fluid flows have become possible. In the attempt to make sense of data, visualization has greatly gained importance in everyday scientific computing. Many visualization techniques do, however, suffer from a tendency to overly rich response in complex scenarios. Hence, filtering of the visual output is an important topic. In this talk we discuss how such filtering can be achieved in a physically meaningful way, giving examples from the extraction of vortices and Lagrangian coherent structures.",
pdf = "pdfs/Pobitzer12Physics.pdf",
images = "images/Pobitzer12Physics.png",
thumbnails = "images/Pobitzer12Physics_thumb.png",
location = "Madrid, Spain"
}
    [PDF] [Bibtex] 
    @PHDTHESIS {solteszova12thesis,
author = "Veronika \v{S}olt{\'e}szov{\'a}",
title = "Perception-Augmenting Illumination",
school = "Department of Informatics, University of Bergen, Norway",
year = "2012",
month = "Aug",
abstract = "At each stage of the visualization pipeline, the information is impeded by loss or by noise because of imprecise acquisition, storage limitations, and processing. Furthermore, it passes through the complex and not yet well understood pathways in the human visual system and finally to result into a mental image. Due to the noise that impedes the information in the visualization pipeline and the processes in the human visual system, the mental image and the real-world phenomenon do not match. From the aspect of physics, the input of the visual system is confined only to patterns of light. Illumination is therefore essential in 3D visualization for perception of visualized objects. In this thesis, several advancements for advanced volumetric lighting are presented. First, a novel lighting model that supports interactive light source placement and yields a high-quality soft shadowing effect, is proposed. The light transport is represented by conical functions and approximated with an incremental blurring operation of the opacity buffer during front-to-back slicing of the volume. Furthermore, a new perceptuallyfounded model for expressing shadows that gives a full control over the appearance of shadows in terms of color and opacity, is presented. Third, a systematic error in perception of surface slant is modeled. This knowledge is then applied to adjust an existing shading model in a manner that compensates for the error in perception. These new visualization methodologies are linked to the knowledge of perceptual psychology and the craft of illustrators, who experimented with visual-presentation techniques for centuries. The new methodologies are showcased on challenging acoustic modalities such as 3D medical ultrasound and sonar imaging.",
pdf = "pdfs/solteszova12thesis.pdf",
images = "images/solteszova12thesis.png",
thumbnails = "images/solteszova12thesis_thumb.png",
isbn = "978-82-308-2118-3"
}
    [Bibtex] 
    @MISC {Hauser12PaVis,
author = "Helwig Hauser and Stephen G. Kobourov and Huamin Qu",
title = "Proceedings of the 2012 IEEE Pacific Visualization Symposium",
howpublished = "Conference proceedings",
month = "February-March",
year = "2012",
images = "images/Helwig12PaVis01.png",
thumbnails = "images/Helwig12PaVis01.png",
location = "Songdo, Korea",
url = "http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=6178307"
}
    [DOI] [Bibtex] 
    @ARTICLE {Schindler12Lagrangian,
author = "Benjamin Schindler and Raphael Fuchs and Stefan Barp and Jurgen Waser and Armin Pobitzer and Robert Carnecky and Kresimir Matkovic and Ronald Peikert",
title = "Lagrangian Coherent Structures for Design Analysis of Revolving Doors",
journal = "Visualization and Computer Graphics, IEEE Transactions on",
year = "2012",
volume = "18",
number = "12",
pages = "2159--2168",
month = "December",
abstract = "Room air flow and air exchange are important aspects for the design of energy-efficient buildings. As a result, simulations are increasingly used prior to construction to achieve an energy-efficient design. We present a visual analysis of air flow generated at building entrances, which uses a combination of revolving doors and air curtains. The resulting flow pattern is challenging because of two interacting flow patterns: On the one hand, the revolving door acts as a pump, on the other hand, the air curtain creates a layer of uniformly moving warm air between the interior of the building and the revolving door. Lagrangian coherent structures (LCS), which by definition are flow barriers, are the method of choice for visualizing the separation and recirculation behavior of warm and cold air flow. The extraction of LCS is based on the finite-time Lyapunov exponent (FTLE) and makes use of a ridge definition which is consistent with the concept of weak LCS. Both FTLE computation and ridge extraction are done in a robust and efficient way by making use of the fast Fourier transform for computing scale-space derivatives.",
images = "images/Schindler12Lagrangian01.png",
thumbnails = "images/Schindler12Lagrangian01_thumb.png",
doi = "10.1109/TVCG.2012.243",
issn = "1077-2626",
url = "http://visdom.at/person/5/"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {Solteszova12APerceptual,
author = "Veronika \v{S}olt{\'e}szov{\'a} and Cagatay Turkay and Mark Price and Ivan Viola",
title = "A Perceptual-Statistics Shading Model",
journal = "Visualization and Computer Graphics, IEEE Transaction on",
year = "2012",
volume = "18",
number = "12",
pages = "2265 -2274",
month = "Dec",
abstract = "The process of surface perception is complex and based on several influencing factors, e.g., shading, silhouettes, occluding contours, and top down cognition. The accuracy of surface perception can be measured and the influencing factors can be modified in order to decrease the error in perception. This paper presents a novel concept of how a perceptual evaluation of a visualization technique can contribute to its redesign with the aim of improving the match between the distal and the proximal stimulus. During analysis of data from previous perceptual studies, we observed that the slant of 3D surfaces visualized on 2D screens is systematically underestimated. The visible trends in the error allowed us to create a statistical model of the perceived surface slant. Based on this statistical model we obtained from user experiments, we derived a new shading model that uses adjusted surface normals and aims to reduce the error in slant perception. The result is a shape-enhancement of visualization which is driven by an experimentally-founded statistical model. To assess the efficiency of the statistical shading model, we repeated the evaluation experiment and confirmed that the error in perception was decreased. Results of both user experiments are publicly-available datasets.",
pdf = "pdfs/Solteszova12APerceptual.pdf",
images = "images/Solteszova12APerceptual01.png, images/Solteszova12APerceptual02.png, images/Solteszova12APerceptual03.png",
thumbnails = "images/Solteszova12APerceptual01_thumb.png, images/Solteszova12APerceptual02_thumb.png, images/Solteszova12APerceptual03_thumb.png",
event = "IEEE Scientific Visualization Conference 2012",
location = "Seattle, WA, USA",
doi = "10.1109/TVCG.2012.188",
issn = "1077--2626",
extra = "extra/Solteszova12APerceptual.zip",
project = "illustrasound,medviz,illvis"
}
    [Bibtex] 
    @MISC {Hauser12VisTutorial,
author = "Steffen Oeltze and Helmut Doleisch and Helwig Hauser and Gunther Weber",
title = "Interactive Visual Analysis of Scientific Data",
howpublished = "Tutorial at the IEEE VisWeek 2012",
month = "October",
year = "2012",
abstract = "In a growing number of application areas, a subject or phenomenon is investigated by means of multiple datasets being acquired over time (spatiotemporal), comprising several attributes per data point (multi-variate), stemming from different data sources (multi-modal) or multiple simulation runs (multirun/ensemble). Interactive visual analysis (IVA) comprises concepts and techniques for a user-guided knowledge discovery in such complex data. Through a tight feedback loop of computation, visualization and user interaction, it provides new insight into the data and serves as a vehicle for hypotheses generation or validation. It is often implemented via a multiple coordinated view framework where each view is equipped with interactive drill-down operations for focusing on data features. Two classes of views are integrated: physical views show information in the context of the spatiotemporal observation space while attribute views show relationships between multiple data attributes. The user may drill-down the data by selecting interesting regions of the observation space or attribute ranges leading to a consistent highlighting of this selection in all other views (brushing-and-linking). In this tutorial, we discuss examples for successful applications of IVA to scientific data from various fields: automotive engineering, climate research, biology, and medicine. We base our discussions on a theoretical foundation of IVA which helps the tutorial attendees in transferring the subject matter to their own data and application area. This universally applicable knowledge is complemented in a tutorial part on IVA of very large data which accounts for the tera- and petabytes being generated by simulations and experiments in many areas of science, e.g., physics, astronomy, and climate research. The tutorial further provides an overview of off-the-shelf IVA solutions. It is concluded by a summary of the gained knowledge and a discussion of open problems in IVA of scientific data.",
images = "images/Hauser12VisTutorial.png",
thumbnails = "images/Hauser12VisTutorial_thumb.png",
location = "Seattle (WA), USA",
url = "http://visweek.org/visweek/2012/tutorial/interactive-visual-analysis-scientific-data",
pres = "pdfs/Hauser12VisTutorialPres01.pdf"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {Lidal12Design,
author = "Endre M. Lidal and Helwig Hauser and Ivan Viola",
title = "Design Principles for Cutaway Visualization of Geological Models",
booktitle = "Proceedings of Spring Conference on Computer Graphics (SCCG 2012)",
year = "2012",
pages = "53--60",
month = "May",
abstract = "In this paper, we present design principles for cutaway visualizations that emphasize shape and depth communication of the focus features and their relation to the context. First, to eliminate cutaway-flatness we argue that the cutaway axis should have an angular offset from the view direction. Second, we recommend creating a box-shaped cutaway. Such a simple cutaway shape allows for easier context extrapolation in the cutaway volume. Third, to improve the relationship between the focus features and the context, we propose to selectively align the cutaway shape to familiar structures in the context. Fourth, we emphasize that the illumination model should effectively communicate the shape and spatial ordering inside the cutaway, through shadowing as well as contouring and other stylized shading models. Finally, we recommend relaxing the view-dependency constraint of the cutaway to improve the depth perception through the motion parallax. We have identified these design principles while developing interactive cutaway visualizations of 3D geological models, inspired by geological illustrations and discussions with the domain illustrators and experts.",
pdf = "pdfs/Lidal12Design.pdf",
images = "images/Lidal12Design01.jpg, images/Lidal12Design02.jpg",
thumbnails = "images/Lidal12Design01_thumb.jpg, images/Lidal12Design02_thumb.jpg",
location = "Smolenice castle, Slovakia",
project = "geoillustrator"
}
    [PDF] [Bibtex] 
    @PHDTHESIS {pobitzer12thesis,
author = "Armin Pobitzer",
title = "Interactive Visual Analysis of Time-dependent Flows: Physics- and Statistics-based Semantics",
school = "Department of Informatics, University of Bergen, Norway",
year = "2012",
month = "Apr",
abstract = "With the increasing use of numerical simulations in the fluid mechanics community in recent years flow visualization increasingly gains importance as an advanced analysis tool for the simulation output. Up to now, flow visualization has mainly focused on the extraction and visualization of structures that are defined by their semantic meaning. Examples for such structures are vortices or separation structures between different groups of particles that travel together. In order to deepen our understanding of structures linked to certain flow phenomena, e.g., how and why they appear, evolve, and finally are destroyed, also linking structures to semantic meaning that is not attributed to them by their very definition, is a highly promising research direction to pursue. In this thesis we provide several approaches on how to augment structures stemming from classical flow visualization techniques by additional semantic information originating from new methods based on physics and statistics. In particular, we target separation structures, the linking of structures with a local semantics to global flow phenomena, and minimal representation of particle dynamics in the context of path line attributes.",
pdf = "pdfs/pobitzer12thesis.pdf",
images = "images/Pobitzer12Physics.png",
thumbnails = "images/Pobitzer12Physics_thumb.png",
isbn = "978-82-308-2063-6",
url = "https://bora.uib.no/handle/1956/5856"
}
    [PDF] [Bibtex] 
    @MISC {Pobitzer12NceSubsea,
author = "Armin Pobitzer",
title = "The State of the Art in Flow Visualization",
howpublished = "Invited talk at NCS Subsea Theme Meeting - Visualization for Industrial Applications",
month = "February",
year = "2012",
pdf = "pdfs/Pobitzer12NceSubsea.pdf",
images = "images/no_thumb.png",
thumbnails = "images/no_thumb.png",
location = "Bergen, Norway",
url = "http://eng.ncesubsea.no/page/389/activity/1029/theme-meeting-visualization-for-industrial-applications"
}
    [PDF] [Bibtex] 
    @ARTICLE {Brambilla12AHierarchical,
author = "Andrea Brambilla and Ivan Viola and Helwig Hauser",
title = "A Hierarchical Splitting Scheme to Reveal Insight into Highly Self-Occluded Integral Surfaces",
journal = "Journal of WSCG",
year = "2012",
volume = "20",
number = "1",
pages = "57--64",
month = "July",
abstract = "In flow visualization, integral surfaces are of particular interest for their ability to describe trajectories of massless particles. In areas of swirling motion, integral surfaces can become very complex and difficult to understand. Taking inspiration from traditional illustration techniques, such as cut-aways and exploded views, we propose a surface analysis tool based on surface splitting and focus+context visualization. Our surface splitting scheme is hierarchical and at every level of the hierarchy the best cut is chosen according to a surface complexity metric. In order to make the interpretation of the resulting pieces straightforward, cuts are always made along isocurves of specific flow attributes. Moreover, a degree of interest can be specified, so that the splitting procedure attempts to unveil the occluded interesting areas. Through practical examples, we show that our approach is able to overcome the lack of understanding originating from structural occlusion.",
pdf = "pdfs/Brambilla12AHierarchical.pdf",
images = "images/Brambilla12AHierarchical01.png, images/Brambilla12AHierarchical02.png, images/Brambilla12AHierarchical03.png",
thumbnails = "images/Brambilla12AHierarchical01_thumb.png, images/Brambilla12AHierarchical02_thumb.png, images/Brambilla12AHierarchical03_thumb.png",
issn = "1213-6972",
publisher = "Union Agency",
url = "http://wscg.zcu.cz/JWSCG/",
event = "WSCG 2012 - 20th International Conference on Computer Graphics, Visualization and Computer Vision",
location = "Pilsen, Czech Republic",
pres = "pdfs/Brambilla12AHierarchical.pptx",
project = "semseg"
}
    [Bibtex] 
    @MISC {Pobitzer12PacificVisTutorial,
author = "Helwig Hauser and Alexander Kuhn and Armin Pobitzer and Maik Schulze",
title = "Time-Dependent Flow Visualization",
howpublished = "Tutorial at 5th IEEE PacificVis Symposium",
month = "February",
year = "2012",
abstract = "Vector fields are a common representation of many kinds of dynamic phenomena in a large variety of application fields. A particularly interesting class of vector fields represent time-dependent flows, i.e., flows where the vectors change over time themselves. A lot of good and relevant research work has been done on the question of how to visualize such unsteady vector fields and an overview is presented in this tutorial. In particularly, we emphasize Lagrangian methods, space-time domain approaches, and interactive visual analysis as three interesting and promising types of methodology. The tutorial is also introduced with some general remarks, in particular also on the question of why it often is not straight forward to extend methods that originally were developed for steady flows to the domain of unsteady flows. A number of examples illustrate the overview.",
images = "images/Pobitzer12PacificVisTutorial.png",
thumbnails = "images/Pobitzer12PacificVisTutorial_thumb.png",
location = "Songdo, South Korea",
url = "http://www.semseg.eu/download/2012-02-28--TimeDepFlowVizTutorial--materials/"
}
    [Bibtex] 
    @MISC {Brambilla12SemSegWorkshop,
author = "Andrea Brambilla and Robert Carnecky",
title = "Introduction to Illustrative Flow Visualization",
howpublished = "Presentation at the 3rd SemSeg User Forum Workshop",
month = "February",
year = "2012",
images = "images/Brambilla12Illustrative.png",
thumbnails = "images/Brambilla12Illustrative_thumb.png",
location = "Magdeburg, Germany",
url = "http://vc.cs.ovgu.de/index.php?article_id=232",
pres = "pdfs/Brambilla12SemSegWorkshop.pdf",
project = "semseg"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {Pobitzer12AStatistics,
author = "Armin Pobitzer and Alan Lez and Kresimir Matkovic and Helwig Hauser",
title = "A Statistics-based Dimension Reduction of the Space of Path Line Attributes for Interactive Visual Flow Analysis",
booktitle = "Proceedings of the IEEE Pacific Visualization Symposium (PacificVis 2012)",
year = "2012",
pages = "113--120",
month = "March",
abstract = "Recent work has shown the great potential of interactive flow analysis by the analysis of path lines. The choice of suitable attributes, describing the path lines, is, however, still an open question. This paper addresses this question performing a statistical analysis of the path line attribute space. In this way we are able to balance the usage of computing power and storage with the necessity to not loose relevant information. We demonstrate how a carefully chosen attribute set can improve the benefits of state-of-the art interactive flow analysis. The results obtained are compared to previously published work.",
pdf = "pdfs/Pobitzer12AStatistics.pdf",
images = "images/Pobitzer12AStatistics.png",
thumbnails = "images/Pobitzer12AStatistics_thumb.png",
location = "Songdo, Korea"
}
    [Bibtex] 
    @MISC {Hauser12VCF,
author = "Helwig Hauser",
title = "The Iterative Process of Interactive Visual Analysis",
howpublished = "Talk in the Visual Computing Forum (VCF) at UiB",
month = "September",
year = "2012",
abstract = "One central characteristic of our information age is that increasingly often we should exploit the wealth of available data for the sake of learning, decision making, as well as other tasks. A promising approach - not at the least also targeted by visual analytics - is to integrate the strengths of computers (fast computation, efficient handling of large datasets, comparably low costs, etc.) with the strengths of the users (perceptual capabilities, considering domain knowledge, detecting the unexpected, etc.). In this talk, we look at one possible solution, i.e., the concept of interactive visual analysis, and describe it as an iterative process, enabling the integration of computational and interactive means for data exploration and analysis. We consider a data scenario that opposes dependent and independent data dimensions (like in a table), general enough to match many different application cases. We focus on the case of multivariate data, but also address the case of high-dimensional data and opportunities for exploring and analyzing such data. After all, we think of interactive visual analysis as an iterative process, where each step is performed on the basis of a toolbox with computational and interactive visual solutions.",
images = "images/Hauser12VCF.jpg",
thumbnails = "images/Hauser12VCF_thumb.jpg",
location = "Bergen, Norway",
url = "http://www.ii.uib.no/vis/vcf/"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {Parulek12ImplicitRepresentation,
author = "Julius Parulek and Ivan Viola",
title = "Implicit Representation of Molecular Surfaces",
booktitle = "Proceedings of the IEEE Pacific Visualization Symposium (PacificVis 2012)",
year = "2012",
pages = "217--224",
month = "March",
abstract = "Molecular surfaces are an established tool to analyze and to study the evolution and interaction of molecules. One of the most advanced representations of molecular surfaces is called the solvent excluded surface. We present a novel and a simple method for representing the solvent excluded surfaces (SES). Our method requires no precomputation and therefore allows us to vary SES parameters outright. We utilize the theory of implicit surfaces and their CSG operations to compose the implicit function representing the molecular surface locally. This function returns a minimal distance to the SES representation. Additionally, negative values of the implicit function determine that the point lies outside SES whereas positive ones that the point lies inside. We describe how to build this implicit function composed of three types of patches constituting the SES representation. Finally, we propose a method to visualize the iso-surface of the implicit function by means of ray-casting and the set of rendering parameters affecting the overall performance.",
pdf = "pdfs/Parulek12ImplicitRepresentation.pdf",
images = "images/Parulek12ImplicitRepresentation.png",
thumbnails = "images/Parulek12ImplicitRepresentation_thumb.png",
location = "Songdo, Korea",
project = "physioillustration"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Solteszova12Lowest,
author = "Veronika \v{S}olt{\'e}szov{\'a} and Linn Emilie S{\ae}vil Helljesen and Wolfgang Wein and Odd Helge Gilja and Ivan Viola",
title = "Lowest-Variance Streamlines for Filtering of 3D Ultrasound",
booktitle = "Eurographics Workshop on Visual Computing for Biology and Medicine (VCBM 2012)",
year = "2012",
pages = "41--48",
month = "Sep",
abstract = "Ultrasound as an acoustic imaging modality suffers from various kinds of noise. The presence of noise especially hinders the 3D visualization of ultrasound data, both in terms of resolving the spatial occlusion of the signal by surrounding noise, and mental decoupling of the signal from noise. This paper presents a novel type of structurepreserving filter that has been specifically designed to eliminate the presence of speckle and random noise in 3D ultrasound datasets. This filter is based on a local distribution of variance for a given voxel. The lowest variance direction is assumed to be aligned with the direction of the structure. A streamline integration over the lowest-variance vector field defines the filtered output value. The new filter is compared to other popular filtering approaches and its superiority is documented on several use cases. A case study where a clinician was delineating vascular structures of the liver from 3D visualizations further demonstrates the benefits of our approach compared to the state of the art.",
pdf = "pdfs/Solteszova12Lowest.pdf",
images = "images/Solteszova12Lowest01.png, images/Solteszova12Lowest02.png",
thumbnails = "images/Solteszova12Lowest01_thumb.png, images/Solteszova12Lowest02_thumb.png",
location = "Norrk{\"o}ping, Sweden",
url = "http://diglib.eg.org/EG/DL/WS/VCBM/VCBM12",
doi = "10.2312/VCBM/VCBM12/041-048",
project = "illustrasound,medviz,illvis"
}
    [Bibtex] 
    @MISC {Hauser12SemSegWorkshop,
author = "Helwig Hauser and Kresimir Matkovic",
title = "Interactive Visual Analysis of Time-Dependent Flows",
howpublished = "Presentation at the 3rd SemSeg User Forum Workshop",
month = "February",
year = "2012",
images = "images/Hauser12SemSegWorkshop.png",
thumbnails = "images/Hauser12SemSegWorkshop_thumb.png",
location = "Magdeburg, Germany",
url = "http://vc.cs.ovgu.de/index.php?article_id=232",
pres = "pdfs/Hauser12SemSegWorkshop-pres.pdf",
project = "semseg"
}
    [Bibtex] 
    @INPROCEEDINGS {Oye12Real,
author = "Ola Kristoffer {\O }ye and Wolfgang Wein and Dag Magne Ulvang and Knut Matre and Ivan Viola",
title = "Real Time Image-based Tracking of 4D Ultrasound Data",
booktitle = "Lecture Notes in Computer Science (LNCS)",
year = "2012",
address = "Nice, France",
month = "October",
abstract = "We propose a methodology to perform real time image-based tracking on streaming 4D ultrasound data, using image registration to deduce the positioning of each ultrasound frame in a global coordinate system. Our method provides an alternative approach to traditional external tracking devices used for tracking probe movements. We compare the performance of our method against magnetic tracking on phantom and liver data, and show that our method is able to provide results in agreement with magnetic tracking.",
images = "images/Oye12Real01.png, images/Oye12Real02.png",
thumbnails = "images/Oye12Real01_thumb.png, images/Oye12Real02_thumb.png",
url = "https://link.springer.com/chapter/10.1007/978-3-642-33415-3_55",
event = "15th International Conference on Medical Image Computing and Computer Assisted Invervention (MICCAI)",
extra = "https://www.youtube.com/watch?v=iH6BhJruPRY",
project = "illustrasound,medviz"
}

2011

    [Bibtex] 
    @INCOLLECTION {oye11illustrativeCouinaud,
author = "Ola Kristoffer {\O }ye and Dag Magne Ulvang and Odd Helge Gilja and Helwig Hauser and Ivan Viola",
title = "Illustrative Couinaud Segmentation for Ultrasound Liver Examinations",
booktitle = "Smart Graphics",
publisher = "Springer Berlin / Heidelberg",
year = "2011",
volume = "6815",
series = "Lecture Notes in Computer Science",
pages = "60--77",
abstract = "Couinaud segmentation is a widely used liver partitioning scheme for describing the spatial relation between diagnostically relevant anatomical and pathological features in the liver. In this paper, we propose a new methodologyfor effectively conveying these spatial relations during the ultrasound examinations. We visualize the two-dimensional ultrasound slice in the context of a three-dimensional Couinaud partitioning of the liver. The partitioning is described by planes in 3D reflecting the vascular tree anatomy, specified in the patient by the examiner using her natural interaction tool, i.e., the ultrasound transducer with positional tracking. A pre-defined generic liver model is adapted to the specified partitioning in order to provide a representation of the patients liver parenchyma. The specified Couinaud partitioning and parenchyma model approximation is then used to enhance the examination by providing visual aids to convey the relationships between the placement of the ultrasound plane and the partitioned liver. The 2D ultrasound slice is augmented with Couinaud partitioning intersection information and dynamic label placement. A linked 3D view shows the ultrasound slice, cutting the liver and displayed using fast exploded view rendering. The described visual augmentation has been characterized by the clinical personnel as very supportive during the examination procedure, and also as a good basis for pre-operative case discussions.",
images = "images/oye11illustrativeCouinaud1.jpg, images/oye11illustrativeCouinaud2.jpg, images/oye11illustrativeCouinaud3.jpg",
thumbnails = "images/oye11illustrativeCouinaud1_thumb.jpg, images/oye11illustrativeCouinaud2_thumb.jpg, images/oye11illustrativeCouinaud3_thumb.jpg",
isbn = "978-3-642-22570-3",
url = "http://dx.doi.org/10.1007/978-3-642-22571-0_6",
project = "illustrasound,medviz,illvis"
}
    [Bibtex] 
    @INPROCEEDINGS {solteszova11chromatic,
author = "Veronika \v{S}olt{\'e}szov{\'a} and Daniel Patel and Ivan Viola",
title = "Chromatic Shadows for Improved Perception",
booktitle = "Proc. Non-photorealistic Animation and Rendering (NPAR 2011)",
year = "2011",
pages = "105--115",
abstract = "Soft shadows are effective depth and shape cues. However, traditional shadowing algorithms decrease the luminance in shadowareas. The features in shadow become dark and thus shadowing causesinformation hiding. For this reason, in shadowed areas, medical illustrators decrease the luminance less and compensate the lower luminance range by adding color, i.e., by introducing a chromatic component. This paper presents a novel technique which enables an interactive setup of an illustrative shadow representation for preventing overdarkening of important structures. We introduce a scalar attribute for every voxel denoted as shadowiness and propose a shadow transfer function that maps the shadowiness to a color and a blend factor. Typically, the blend factor increases linearly with the shadowiness. We then let the original object color blend with the shadow color according to the blend factor. We suggest a specific shadow transfer function, designed together with a medical illustrator which shifts the shadow color towards blue. This shadow transfer function is quantitatively evaluated with respect to relative depth and surface perception.",
images = "images/solteszova11chromatic3.jpg, images/solteszova11chromatic2.jpg, images/solteszova11chromatic.jpg, images/solteszova11chromatic4.jpg",
thumbnails = "images/solteszova11chromatic3_thumb.jpg, images/solteszova11chromatic2_thumb.jpg, images/solteszova11chromatic_thumb.jpg, images/solteszova11chromatic4_thumb.jpg",
location = "Vancouver, Canada",
url = "http://dx.doi.org/10.1145/2024676.2024694",
project = "illustrasound,medviz,illvis"
}
    [Bibtex] 
    @ARTICLE {pobitzer11topology,
author = "Armin Pobitzer and Ronald Peikert and Raphael Fuchs and Benjamin Schindler and Alexander Kuhn and Holger Theisel and Kresimir Matkovic and Helwig Hauser",
title = "The State of the Art in Topology-based Visualization of Unsteady Flow",
journal = "Computer Graphics Forum",
year = "2011",
volume = "30",
number = "6",
pages = "1789--1811",
month = "September",
abstract = "Vector fields are a common concept for the representation of many different kinds of flow phenomena in science and engineering. Methods based on vector field topology are known for their convenience for visualizing and analyzing steady flows, but a counterpart for unsteady flows is still missing. However, a lot of good and relevant work aiming at such a solution is available.We give an overview of previous research leading towards topology-based and topology-inspired visualization of unsteady flow, pointing out the different approaches and methodologies involved as well as their relation to each other, taking classical (i.e., steady) vector field topology as our starting point. Particularly, we focus on Lagrangian methods, space-time domain approaches, local methods, and stochastic and multi-field approaches. Furthermore, we illustrate our review with practical examples for the different approaches.",
images = "images/pobitzer10topology.jpg,",
thumbnails = "images/pobitzer10topology_thumb.jpg",
project = "semseg",
url = "http://dx.doi.org/10.1111/j.1467-8659.2011.01901.x"
}
    [Bibtex] 
    @INPROCEEDINGS {florekHauser11modeTree,
author = "Martin Florek and Helwig Hauser",
title = "Interactive Bivariate Mode Trees for Visual Structure Analysis",
booktitle = "Proceedings of the Spring Conference on Computer Graphics (SCCG 2011)",
year = "2011",
pages = "??--??",
abstract = "The number of modes in a kernel density estimation of a certaindata distribution is strongly dependent on the chosen scale parameter.In this paper, we present an interactive mode tree visualizationthat allows to visually analyze the modality structure of a datadistribution. Due to the branched structure of the bivariate modetree, composed of many curved arcs in 3D, we need to utilize advancedtechniques, including clutter removal through transparency,on demand outlier suppression or preservation, and best views, toimprove the legibility of the visualization mapping.",
images = "images/florekHauser11modeTree.jpg, images/florekHauser11modeTree2.jpg",
thumbnails = "images/florekHauser11modeTree_thumb.jpg, images/florekHauser11modeTree2_thumb.jpg",
location = "Budmerice, Slovakia"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {turkay11cluster,
author = "Cagatay Turkay and Julius Parulek and Nathalie Reuter and Helwig Hauser",
title = "Integrating Cluster Formation and Cluster Evaluation in Interactive Visual Analysis",
booktitle = "Proc. Spring Conference on Computer Graphics (SCCG 2011) -- second best paper",
year = "2011",
pages = "??--??",
abstract = "Cluster analysis is a popular method for data investigation wheredata items are structured into groups called clusters. This analysisinvolves two sequential steps, namely cluster formation and clusterevaluation. In this paper, we propose the tight integration of clusterformation and cluster evaluation in interactive visual analysis in orderto overcome the challenges that relate to the black-box nature ofclustering algorithms. We present our conceptual framework in theform of an interactive visual environment. In this realization of ourframework, we build upon general concepts such as cluster comparison,clustering tendency, cluster stability and cluster coherence.Additionally, we showcase our framework on the cluster analysis ofmixed lipid bilayers.",
pdf = "pdfs/turkay11cluster.pdf",
images = "images/turkay11cluster2.jpg, images/turkay11cluster1.jpg, images/turkay11cluster3.jpg",
thumbnails = "images/turkay11cluster2_thumb.jpg, images/turkay11cluster1_thumb.jpg, images/turkay11cluster3_thumb.jpg",
location = "Budmerice, Slovakia"
}
    [Bibtex] 
    @ARTICLE {turkay11brushingDimensions,
author = "Cagatay Turkay and Peter Filzmoser and Helwig Hauser",
title = "Brushing Dimensions -- A Dual Visual Analysis Model for High-dimensional Data",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2011",
volume = "17",
number = "12",
pages = "2591--2599",
abstract = "In many application fields, data analysts have to deal with datasets that contain many expressions per item. The effective analysisof such multivariate datasets is dependent on the users ability to understand both the intrinsic dimensionality of the dataset as well as the distribution of the dependent values with respect to the dimensions. In this paper, we propose a visualization model that enables the joint interactive visual analysis of multivariate datasets with respect to their dimensions as well as with respect to the actual data values. We describe a dual setting of visualization and interaction in items space and in dimensions space. The visualization of items is linked to the visualization of dimensions with brushing and focus+context visualization. With this approach, the user is able to jointly study the structure of the dimensions space as well as the distribution of data items with respect to the dimensions. Even though the proposed visualization model is general, we demonstrate its application in the context of a DNA microarray data analysis.",
images = "images/turkay11dimensions.png, images/turkay11dimensions3.png, images/turkay11dimensions2.png",
thumbnails = "images/turkay11dimensions_thumb.png, images/turkay11dimensions3_thumb.png, images/turkay11dimensions2_thumb.png",
event = "IEEE Information Visualization Conference 2011",
location = "Providence, RI, USA",
url = "http://dx.doi.org/10.1109/TVCG.2011.178"
}
    [PDF] [Bibtex] 
    @MISC {Hauser2011Dagstuhl,
author = "Helwig Hauser",
title = "Helwig Hauser on Interactive Visual Analysis of Multi-Dimensional Scientific Data",
howpublished = "Invited talk at the Dagstuhl Seminar on Scientific Visualization in Dagstuhl, Germany.",
month = "June",
year = "2011",
abstract = "Invited talk at the Dagstuhl Seminar on Scientific Visualization in Dagstuhl, Germany.",
pdf = "pdfs/2011-06-06-Dagstuhl-MultiDimSciDataIVA-print-new-2up.pdf",
images = "images/2011-06-06-Dagstuhl-MultiDimSciDataIVA-print-new-2up_Image_0001.jpg, images/2011-06-06-Dagstuhl-MultiDimSciDataIVA-print-new--2up_Image_0002.jpg, images/2011-06-06-Dagstuhl-MultiDimSciDataIVA-print-new-2up_Image_0002(2).jpg, images/2011-06-06-Dagstuhl-MultiDimSciDataIVA-print-new-2up_Image_0004.jpg",
thumbnails = "images/2011-06-06-Dagstuhl-MultiDimSciDataIVA-print-new-2up_Image_0001(2).jpg"
}
    [Bibtex] 
    @ARTICLE {pobitzer11energyScale,
author = "Armin Pobitzer and Murat Tutkun and {\O }yvind Andreassen and Raphael Fuchs and Ronald Peikert and Helwig Hauser",
title = "Energy-scale Aware Feature Extraction for Flow Visualization",
journal = "Computer Graphics Forum",
year = "2011",
volume = "30",
number = "3",
pages = "771--780",
abstract = "In the visualization of flow simulation data, feature detectors often tend to result in overly rich response, making some sort of filtering or simplification necessary to convey meaningful images. In this paper we present an approach that builds upon a decomposition of the flow field according to dynamical importance of different scales of motion energy. Focusing on the high-energy scales leads to a reduction of the flow field while retaining the underlying physical process. The presented method acknowledges the intrinsic structures of the flow according to its energy and therefore allows to focus on the energetically most interesting aspects of the flow. Our analysis shows that this approach can be used for methods based on both local feature extraction and particle integration and we provide a discussion of the error caused by the approximation. Finally, we illustrate the use of the proposed approach for both a local and a global feature detector and in the context of numerical flow simulations.",
images = "images/pobitzer11energyScale1.jpg, images/pobitzer11energyScale3.jpg, images/pobitzer11energyScale2.jpg",
thumbnails = "images/pobitzer11energyScale1_thumb.jpg, images/pobitzer11energyScale3_thumb.jpg, images/pobitzer11energyScale2_thumb.jpg",
url = "http://dx.doi.org/10.1111/j.1467-8659.2011.01926.x",
event = "EuroVis 2011",
location = "Bergen, Norway",
project = "semseg"
}
    [DOI] [Bibtex] 
    @ARTICLE {Matkovic11CurrentTrends,
author = "Kresimir Matkovic and Alan Lez and Helwig Hauser and Armin Pobitzer and Holger Theisel and Alexander Kuhn and Mathias Otto and Ronald Peikert and Benjamin Schindler and Raphael Fuchs",
title = "Current Trends for 4D Space-Time Topology for Semantic Flow Segmentation",
journal = "Procedia Computer Science",
year = "2011",
volume = "7",
number = "0",
pages = "253--255",
abstract = "Recent advances in computing and simulation technology promote the simulation of time-dependent flows, i.e., flows where the velocity field changes over time. The simulation of time-dependent flow is a more realistic approximation of natural phenomena and it represents an invaluable tool for scientists and practitioners in multiple disciplines, including meteorology, vehicle design, and medicine. Flow visualization, a subfield of scientific visualization, is one of several research areas which deal with the analysis of flows. There are many methods for the analysis of steady flows, but the extension to the time-dependent case is not straight forward. The SemSeg project, a FET-Open project in the 7th Framework programme, attempts to provide a solution for the semantic segmentation of time-dependent flows. It aims at the formulation of a sound theoretical mechanism to describe structural features in time-dependent flow. In this paper, we briefly summarize recent research results from the SemSeg project. Several different approaches are pursued in the project, including methods based on the finite-time Lyapunov exponent (FTLE), methods based on vector field topology (VFT), and interactive visual analysis (IVA) methods. Uncertainty visualization and the interactive evaluation of methods are helping in evaluating the results.",
images = "images/Matkovic11CurrentTrends.png",
thumbnails = "images/Matkovic11CurrentTrends_thumb.png",
note = "Proceedings of the 2nd European Future Technologies Conference and Exhibition 2011 (FET 11)",
issn = "1877-0509",
doi = "10.1016/j.procs.2011.09.013",
url = "http://www.sciencedirect.com/science/article/pii/S1877050911005734"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {lampe11modelbuilding,
author = "Ove Daae Lampe and Helwig Hauser ",
title = "Model Building in Visualization Space ",
booktitle = "Proceedings of Sigrad 2011 ",
year = "2011",
abstract = "Researching formal models that explain selected natural phenomena of interest is a central aspect of most scientific work. A tested and confirmed model can be the key to classification, knowledge crystallization, and prediction.With this paper we propose a new approach to rapidly draft, fit and quantify model prototypes in visualization space. We also show that these models can provide important insights and accurate metrics about the original data. Using our technique, which is similar to the statistical concept of de-trending, data that behaves according to the model is de-emphasized, leaving only outliers and potential model flaws for further inspection. Moreover, we provide several techniques to assist the user in the process of prototyping such models. We demonstrate the usability of this approach in the context of the analysis of streaming process data from the Norwegian oil and gas industry, and on weather data, investigating the distribution of temperatures over the course of a year.",
pdf = "pdfs/lampe11sigrad.pdf",
images = "images/lampe11sigrad.jpg",
thumbnails = "images/lampe11sigrad_thumb.jpg",
location = "Stockholm, Sweeden",
url = "http://www.ep.liu.se/ecp_article/index.en.aspx?issue=065;article=007",
pres = "http://folk.uib.no/ola062/sigrad2011/",
project = "elad"
}
    [PDF] [Bibtex] 
    @PHDTHESIS {lampe11thesis,
author = "Ove Daae Lampe",
title = "Interactive Visual Analysis of Process Data",
school = "Department of Informatics, University of Bergen, Norway",
year = "2011",
month = "Sep",
abstract = "Data gathered from processes, or process data, contains many different aspectsthat a visualization system should also convey. Aspects such as, temporalcoherence, spatial connectivity, streaming data, and the need for in-situvisualizations, which all come with their independent challenges. Additionally,as sensors get more affordable, and the benefits of measurements get clearer weare faced with a deluge of data, of which sizes are rapidly growing. With allthe aspects that should be supported and the vast increase in the amount ofdata, the traditional techniques of dashboards showing the recent data becomesinsufficient for practical use. In this thesis we investigate how to extend the traditionalprocess visualization techniques by bringing the streaming process datainto an interactive visual analysis setting. The augmentation of process visualizationwith interactivity enables the users to go beyond the mere observation,pose questions about observed phenomena and delve into the data to mine forthe answers. Furthermore, this thesis investigates how to utilize frequency based,as opposed to item based, techniques to show such large amounts of data. Byutilizing Kernel Density Estimates (KDE) we show how the display of streamingdata benefit by the non-parametric automatic aggregation to interpret incomingdata put in context to historic data.",
pdf = "pdfs/lampe11thesis.pdf",
images = "images/lampe11thesis.png",
thumbnails = "images/lampe11thesis_thumb.png",
isbn = "978-82-308-1910-4"
}
    [Bibtex] 
    @INPROCEEDINGS {palmerius11ultrasoundPalpation,
author = "Karljohan Lundin Palmerius and Roald Flesland Havre and Odd Helge Gilja and Ivan Viola",
title = "Ultrasound palpation by haptic elastography",
booktitle = "Proc. International Symposium on Computer-Based Medical Systems (CBMS)",
year = "2011",
month = "june",
abstract = "Palpation is an important method in the medical physical examination.Surface palpation alone, however, cannot be used in many situations due to the anatomical positions. Elastography images are therefore in many cases a complement to other imaging modalities. In this article we present a method for providing haptic feedback from elastography imaging data, allowing palpation of the hardness data. A prototype implementation was used in a demonstration session with domain experts providing feedback on the presented algorithm and also on the basic principle of palpating data from elastography imaging.",
images = "images/palmerius11ultrasoundPalpation.jpg",
thumbnails = "images/palmerius11ultrasoundPalpation_thumb.jpg",
location = "Bristol, UK",
url = "http://dx.doi.org/10.1109/CBMS.2011.5999154",
project = "illustrasound,medviz,illvis"
}
    [PDF] [VID] [Bibtex] 
    @ARTICLE {angelelli11straightening,
author = "Paolo Angelelli and Helwig Hauser",
title = "Straightening Tubular Flow for Side-by-Side Visualization",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2011",
volume = "17",
number = "12",
pages = "2063--2070",
abstract = "Flows through tubular structures are common in many fields, including blood flow in medicine and tubular fluid flows in engineering.The analysis of such flows is often done with a strong reference to the main flow direction along the tubular boundary. In this paper we present an approach for straightening the visualization of tubular flow. By aligning the main reference direction of the flow, i.e., the center lineof the bounding tubular structure, with one axis of the screen, we are able to natively juxtapose (1.) different visualizations of the same flow,either utilizing different flow visualization techniques, or by varying parameters of a chosen approach such as the choice of seeding locationsfor integration-based flow visualization, (2.) the different time steps of a time-dependent flow, (3.) different projections around the center line, and (4.) quantitative flow visualizations in immediate spatial relation to the more qualitative classical flow visualization. We describe how to utilize this approach for an informative interactive visual analysis. We demonstrate the potential of our approach by visualizing two datasets from two different fields: an arterial blood flow measurement and a tubular gas flow simulation from the automotive industry.",
pdf = "pdfs/angelelli11straightening.pdf",
vid = "vids/angelelli11TubularFlowStraightening.wmv",
images = "images/angelelli11straightening1.jpg, images/angelelli11straightening2.jpg",
thumbnails = "images/angelelli11straightening1_thumb.jpg, images/angelelli11straightening2_thumb.jpg",
event = "IEEE Visualization Conference 2011",
location = "Providence, RI, USA",
url = "http://dx.doi.org/10.1109/TVCG.2011.235"
}
    [PDF] [VID] [Bibtex] 
    @ARTICLE {kehrer11heterogeneous,
author = "Johannes Kehrer and Philipp Muigg and Helmut Doleisch and Helwig Hauser",
title = "Interactive Visual Analysis of Heterogeneous Scientific Data across an Interface",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2011",
volume = "17",
number = "7",
pages = "934--946",
abstract = "We present a systematic approach to the interactive visual analysis of heterogeneous scientific data. The data consists of two interrelated parts given on spatial grids over time (e.g., atmosphere and ocean part from a coupled climate model). By integrating both data parts in a framework of coordinated multiple views (with linking and brushing), the joint investigation of features across the data parts is enabled. An interface is constructed between the data parts that specifies (a) which grid cells in one part are related to grid cells in the other part, and vice versa, (b) how selections (in terms of feature extraction via brushing) are transferred between the two parts, and (c) how an update mechanism keeps the feature specification in both data parts consistentduring the analysis. We also propose strategies for visual analysis that result in an iterative refinement of features specified across both data parts. Our approach is demonstrated in the context of a complex simulation of fluid--structure interaction and a multi-run climate simulation.",
pdf = "pdfs/kehrer11heterogeneous.pdf",
vid = "vids/kehrer11heterogeneous.html",
images = "images/kehrer11heterogeneous2.jpg, images/kehrer11heterogeneous3.jpg, images/kehrer11heterogeneous0.jpg, images/kehrer11heterogeneous1.jpg",
thumbnails = "images/kehrer11heterogeneous2_thumb.jpg, images/kehrer11heterogeneous3_thumb.jpg, images/kehrer11heterogeneous0_thumb.jpg, images/kehrer11heterogeneous1_thumb.jpg",
event = "IEEE VisWeek 2011",
location = "Providence, RI, USA",
url = "http://dx.doi.org/10.1109/TVCG.2010.111"
}
    [PDF] [VID] [Bibtex] 
    @INPROCEEDINGS {lampe11kde,
author = "Ove Daae Lampe and Helwig Hauser",
title = "Interactive Visualization of Streaming Data with Kernel Density Estimation",
booktitle = "Proceedings of the IEEE Pacific Visualization Symposium (PacificVis 2011)",
year = "2011",
pages = "171--178",
month = "March",
abstract = "In this paper, we discuss the extension and integration of the statistical concept of Kernel Density Estimation (KDE) in a scatterplot-like visualization for dynamic data at interactive rates. We present a line kernel for representing streaming data, we discuss how the concept of KDE can be adapted to enable a continuous representation of the distribution of a dependent variable of a 2D domain. We propose to automatically adapt the kernel bandwith of KDE to the viewport settings, in an interactive visualization environment that allows zooming and panning. We also present a GPU-based realization of KDE that leads to interactive frame rates, even for comparably large datasets. Finally, we demonstrate the usefulness of our approach in the context of three application scenarios -- one studying streaming ship traffic data, another one from the oil and gas domain, where process data from the operation of an oil rig is streaming in to an on-shore operational center, and a third one studying commercial air traffic in the US spanning 1987 to 2008.",
pdf = "pdfs/lampe11kde.pdf",
vid = "vids/lampe11kde.mp4",
images = "images/lampe11kde1.jpg, images/lampe11kde2.jpg",
thumbnails = "images/lampe11kde1_thumb.jpg, images/lampe11kde2_thumb.jpg",
location = "Hong Kong",
url = "http://dx.doi.org/10.1109/PACIFICVIS.2011.5742387"
}
    [VID] [Bibtex] 
    @MISC {viola11passingThrough,
author = "Ivan Viola",
title = "Passing Through the Trough of Disillusionment of Illustrative Visualization",
howpublished = "Keynote at EG-UK Theory and Practice of Computer Graphics Conference (TP.CG.2011)",
month = "September",
year = "2011",
abstract = "Efficient illustration craft is a vast source of inspiration for development of new visual abstractions in data visualization. Many new illustration-inspired techniques have emerged up to now, primarily arguing their validity with a statement like: 'The illustrators have been using this technique for centuries and therefore we adapt their technique for interactive data display...' Argumentation of such kind was stimulating in the initial phase of illustrative visualization research, but nowadays this reasoning is no longer satisfactory. It is becoming apparent that ad-hoc adaptation can have arbitrary outcome. A systematic adaptation requires a vivid dialog with illustrators and a well-founded reasoning by means of the vision and cognitive sciences. This talk will assess the efficiency of selected visual abstractions, adapted for interactive visualization, in terms of their consistency with established perceptual principles.",
vid = "https://picasaweb.google.com/viola.ivan/Talks#5651394119519056546",
images = "images/viola11passingThrough.jpg",
thumbnails = "images/viola11passingThrough_thumb.jpg",
location = "Warwick, UK",
pres = "pdfs/viola11passingThrough.pdf"
}
    [Bibtex] 
    @INPROCEEDINGS {lez11pathlines,
author = "Alan Lez and Andreas Zajic and Kresimir Matkovic and Armin Pobitzer and Michael Mayer and Helwig Hauser",
title = "Interactive Exploration and Analysis of Pathlines in Flow Data",
booktitle = "Proc. International Conference in Central Europe on ComputerGraphics, Visualization and Computer Vision (WSCG 2011)",
year = "2011",
pages = "17--24",
abstract = "The rapid development of large-scale scientific computing nowadays allows to inherently respect the unsteady character of natural phenomena in computational flow simulation. With this new trend to more regularly consider time-dependent flow scenarios, an according new need for advanced exploration and analysis solutions emerges. In this paper, we now present three new concepts in pathline analysis which further improve the abilities of analysis: a multi-step analysis which helps to save time and space needed for computation, direct pathline brushing, and usage of pre-configured view arrangements. We have found that clever combining of these three concepts with already existing methods creates very powerful tool for pathline analysis. The coordinated multiple views (CMV) tool used supports iterative composite brushing which enables a quick information drill-down. We illustrate the usefulness using an example from the automotive industry. We have analyzed an exhaust manifoldtime-dependent simulation data set.",
images = "images/lez11pathlines1.jpg, images/lez11pathlines2.jpg",
thumbnails = "images/lez11pathlines1_thumb.jpg, images/lez11pathlines2_thumb.jpg",
location = "Plzen, Czech Republic",
project = "semseg"
}
    [Bibtex] 
    @ARTICLE {Matkovic11InteractiveVisual,
author = "Kresimir Matkovic and Denis Gracanin and Mario Jelovic and Helwig Hauser",
title = "Interactive Visual Analysis Supporting Design, Tuning, and Optimization of Diesel Engine Injection",
journal = "Proceedings of IEEE Visualization 2011 (Discovery Exhibition)",
year = "2011",
abstract = "Design and optimization of modern, complex systems is unimaginable without simulation. Although the design goals are known in advance, finding an optimal combination of input parameters is a long and tedious task. Simulation of car engine injection systems is a relatively short process. It is possible to run many simulations and then to explore the parameter space. Efficient tools and techniques for parameter space exploration and optimization are needed. We have developed an interactive visual analysis tool, ComVis, and related techniques. We illustrate how ComVis is used to explore the parameter space and to tune and optimize car engine injection systems. The collaboration between domain experts and visualization experts resulted in a new workflow for injection system design, and in development of new, commercially available tools.",
images = "images/Matkovic11InteractiveVisual01.png, Matkovic11InteractiveVisual02.png, Matkovic11InteractiveVisual03.png",
thumbnails = "images/Matkovic11InteractiveVisual_thumb.png",
url = "http://www.discoveryexhibition.org/pmwiki.php/Entries/2011Matkovic"
}
    [PDF] [VID] [Bibtex] 
    @ARTICLE {angelelli11ultrasoundStatistics,
author = "Paolo Angelelli and Kim Nylund and Odd Helge Gilja and Helwig Hauser",
title = "Interactive Visual Analysis of Contrast-enhanced Ultrasound Databased on Small Neighborhood Statistics",
journal = "Computers \& Graphics - Special Issue on Visual Computing in Biology and Medicine",
year = "2011",
volume = "35",
number = "2",
pages = "218--226",
abstract = "Contrast-enhanced ultrasound (CEUS) has recently become an important technology for lesion detection and characterization in cancer diagnosis. CEUS is used to investigate the perfusion kinetics in tissue over time, which relates to tissue vascularization. In this paper we present a pipeline that enables interactive visual exploration and semi-automatic segmentation and classification of CEUS data.For the visual analysis of this challenging data, with characteristic noise patterns and residual movements, we propose a robust method to derive expressive enhancement measures from small spatio-temporal neighborhoods. We use this information in a stagedvisual analysis pipeline that leads from a more local investigation to global results such as the delineation of anatomic regions according to their perfusion properties. To make the visual exploration interactive, we have developed an accelerated frameworkbased on the OpenCL library, that exploits modern many-cores hardware. Using our application, we were able to analyze datasets from CEUS liver examinations, being able to identify several focal liver lesions, segment and analyze them quickly and precisely, and eventually characterize them.",
pdf = "pdfs/angelelli11CEUSIVA.pdf",
vid = "vids/angelelli11CEUSSegmentation.wmv",
images = "images/angelelli11ultrasoundStatistics2.jpg, images/angelelli11ultrasoundStatistics1.jpg",
thumbnails = "images/angelelli11ultrasoundStatistics2_thumb.jpg, images/angelelli11ultrasoundStatistics1_thumb.jpg",
url = "http://dx.doi.org/10.1016/j.cag.2010.12.005",
project = "illustrasound,medviz,illvis"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {Patel-2011-PEA,
author = "Daniel Patel and Meister Eduard Gr{\"o}ller and Stefan Bruckner",
title = "PhD Education Through Apprenticeship",
booktitle = "Proceedings of Eurographics 2011 (Education Papers)",
year = "2011",
editor = "S. Maddock, J. Jorge",
pages = "23--28",
month = "apr",
abstract = "We describe and analyze the PhD education in the visualization group  at the Vienna University of Technology and set the education in a  larger perspective. Four central mechanisms drive the PhD education  in Vienna. They are: to require an article-based PhD; to give the  student freedom to choose research direction; to let students work  in shared offices towards joint deadlines; and to involve students  in reviewing articles. This paper describes these mechanisms in detail  and illustrates their effect.",
pdf = "pdfs/Patel-2011-PEA.pdf",
images = "images/Patel-2011-PEA.jpg",
thumbnails = "images/Patel-2011-PEA.png",
keywords = "M., education, visualization, apprenticeship",
location = "Llandudno, United Kingdom",
url = "http://www.cg.tuwien.ac.at/research/publications/2011/patel-2011-PEA/"
}
    [PDF] [Bibtex] 
    @PHDTHESIS {kehrer11thesis,
author = "Johannes Kehrer",
title = "Interactive Visual Analysis of Multi-faceted Scientific Data",
school = "Department of Informatics, University of Bergen, Norway",
year = "2011",
month = "Mar",
abstract = "Visualization plays an important role in exploring, analyzingand presenting large and heterogeneous scientific data that arise in many disciplines of medicine, research, engineering, and others. We can see that model and data scenarios are becoming increasingly multi-faceted: data are often multi-variate and time-dependent, they stem from different data sources (multi-modal data), from multiple simulation runs (multi-run data), or from multi-physics simulations of interacting phenomena that consist of coupled simulation models (multi-model data). The different data characteristics result in special challenges for visualization research and interactive visual analysis. The data are usually large and come on various types of grids with different resolution that need to be fused in the visual analysis.This thesis deals with different aspects of the interactive visual analysis of multi-faceted scientific data. The main contributions of this thesis are: 1) a number of novel approaches and strategies for the interactive visual analysis of multi-run data; 2) a concept that enables the feature-based visual analysis across an interface between interrelated parts of heterogeneous scientific data (including data from multi-run and multi-physics simulations); 3) a model for visual analysis that is based on the computation of traditionaland robust estimates of statistical moments from higher-dimensional multi-run data; 4) procedures for visual exploration of time-dependent climate data that support the rapid generation of promising hypotheses, which are subsequently evaluated with statistics; and 5) structured design guidelines for glyph-based 3D visualization of multi-variate data together with a novel glyph. All these approaches are incorporated in a single framework for interactive visual analysis that uses powerful concepts such as coordinated multiple views, feature specification via brushing, and focus+context visualization. Especially the data derivation mechanism of the framework has proven to be very useful for analyzing different aspects of the data at different stages of the visual analysis. The proposed concepts and methods are demonstrated in a number of case studies that are based on multi-run climate data and data from a multi-physics simulation.",
pdf = "pdfs/kehrer11thesis.pdf",
images = "images/kehrer11thesis.jpg, images/kehrer11heterogeneous1.jpg, images/kehrer08vis01.jpg, images/kehrer11thesis1.png",
thumbnails = "images/kehrer11thesis_thumb.jpg, images/kehrer11heterogeneous1_thumb.jpg, images/kehrer08vis01_thumb.jpg, images/kehrer11thesis1_thumb.png",
url = "http://www.ii.UiB.no/vis/team/kehrer/thesis/",
isbn = "978-82-308-1733-9"
}
    [Bibtex] 
    @ARTICLE {lampe11curveDensity,
author = "Ove Daae Lampe and Helwig Hauser",
title = "Curve Density Estimates",
journal = "Computer Graphics Forum",
year = "2011",
volume = "30",
number = "3",
pages = "633--642",
abstract = "In this work, we present a technique based on kernel density estimation for rendering smooth curves. With this approach, we produce uncluttered and expressive pictures, revealing frequency information about one, or, multiple curves, independent of the level of detail in the data, the zoom level, and the screen resolution. With this technique the visual representation scales seamlessly from an exact line drawing, (for low-frequency/low-complexity curves) to a probability density estimate for more intricate situations. This scale-independence facilitates displays based on non-linear time, enabling high-resolution accuracy of recent values, accompanied by long historical series forcontext. We demonstrate the functionality of this approach in the context of prediction scenarios and in the context of streaming data.",
images = "images/lampe11curveDensity3.jpg, images/lampe11curveDensity1.jpg, images/lampe11curveDensity2.jpg",
thumbnails = "images/lampe11curveDensity3_thumb.jpg, images/lampe11curveDensity1_thumb.jpg, images/lampe11curveDensity2_thumb.jpg",
url = "http://dx.doi.org/10.1111/j.1467-8659.2011.01912.x",
event = "EuroVis 2011",
location = "Bergen, Norway",
project = "elad"
}
    [Bibtex] 
    @ARTICLE {turkay11temporalCluster,
author = "Cagatay Turkay and Julius Parulek and Nathalie Reuter and Helwig Hauser",
title = "Interactive Visual Analysis of Temporal Cluster Structures",
journal = "Computer Graphics Forum",
year = "2011",
volume = "30",
number = "3",
pages = "711--720",
abstract = "Cluster analysis is a useful method which reveals underlying structures and relations of items after grouping them into clusters. In the case of temporal data, clusters are defined over time intervals where they usually exhibit structural changes. Conventional cluster analysis does not provide sufficient methods to analyze these structural changes, which are, however, crucial in the interpretation and evaluation of temporal clusters. In this paper, we present two novel and interactive visualization techniques that enable users to explore and interpret the structural changes of temporal clusters. We introduce the temporal cluster view, which visualizes the structural quality of a number of temporal clusters, and temporal signatures, which represents the structure of clusters over time. We discuss how these views are utilized to understand the temporal evolution of clusters. We evaluate the proposedtechniques in the cluster analysis of mixed lipid bilayers.",
images = "images/turkay11temporal1.jpg, images/turkay11temporal2.jpg, images/turkay11temporal3.jpg",
thumbnails = "images/turkay11temporal1_thumb.jpg, images/turkay11temporal2_thumb.jpg, images/turkay11temporal3_thumb.jpg",
url = "http://dx.doi.org/10.1111/j.1467-8659.2011.01920.x",
event = "EuroVis 2011",
location = "Bergen, Norway"
}
    [Bibtex] 
    @INPROCEEDINGS {pobitzer11semseg,
author = "Armin Pobitzer and Helwig Hauser",
title = "The {SemSeg} project and recent developments in flow visualization",
booktitle = "Proc. Sixth National Conference on Computational Mechanics (MekIT'11)",
year = "2011",
pages = "281--292",
address = "Trondheim, Norway",
month = "May",
publisher = "Tapir Academic Press",
abstract = "The present paper discusses recent efforts to develop semantic segmentation of spacetime flow domains for visualization purposes, taking thework of the SemSeg project as a starting point. In particular we address separation structures based on Finite-time Lyapunov exponents and their extraction, the incorporation of uncertainty, and the application of Interactive Visual Analysis in the context of flow visualization.",
images = "images/pobitzer11semseg.jpg",
thumbnails = "images/pobitzer11semseg_thumb.jpg",
editors = "B. Skallerud and H.I. Andersson",
project = "semseg"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {schaefer11registration,
author = "Sebastian Sch{\"a}fer and Paolo Angelelli and Kim Nylund and Odd Helge Gilja and Klaus T{\"o}nnies",
title = "Registration of ultrasonography sequences based on temporal regions",
booktitle = "Proc. Intl. Symp. Image and Signal Processing and Analysis (ISPA)",
year = "2011",
pages = "749--754",
abstract = "2D Ultrasonography images with parallel contrast enhanced sequences for analysis constitute a rapid and inexpensive imaging technique with high temporal resolution to assess perfusion of tissue. However, motion from various influences corrupts the inter-pixel correspondences between different time frames and therefore hampers computer-assisted analysis of perfusion parameters. We present a user-supported method applying a temporal similarity matrix to remove frames with uncorrectable out-of-plane motion. For the remaining regions of frames, motion influence can be compensated for by image registration. Subsequently B-Spline based registration is applied using the temporal regions with automatic determination of a suitable reference frame image. Evaluation with ground truth data of six datasets comparing a medical expert frame analysis to the proposed technique yields 85.1% sensitivity and 81.7% specificity in average. On average 6% of the frames have been erroneously included in temporal regions, although they contain out-of-plane motion.",
pdf = "pdfs/schaefer11Registration.pdf",
images = "images/schaefer11registration.jpg",
thumbnails = "images/schaefer11registration_thumb.jpg",
location = "Dubrovnik, Croatia",
url = "http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6046702"
}
    [Bibtex] 
    @ARTICLE {ruiz11automaticTFs,
author = "Marc Ruiz and Anton Bardera and Imma Boada and Ivan Viola and Miquel Feixas and Mateu Sbert",
title = "Automatic Transfer Functions based on Informational Divergence",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2011",
volume = "17",
number = "12",
pages = "1932--1941",
abstract = "In this paper we present a framework to define transfer functions from a target distribution provided by the user. A targetdistribution can reflect the data importance, or highly relevant data value interval, or spatial segmentation. Our approach is basedon a communication channel between a set of viewpoints and a set of bins of a volume data set, and it supports 1D as well as 2D transfer functions including the gradient information. The transfer functions are obtained by minimizing the informational divergence or Kullback-Leibler distance between the visibility distribution captured by the viewpoints and a target distribution selected by the user. The use of the derivative of the informational divergence allows for a fast optimization process. Different target distributions for 1D and 2D transfer functions are analyzed together with importance-driven and view-based techniques.",
images = "images/ruiz11automaticTFs1.jpg, images/ruiz11automaticTFs2.jpg, images/ruiz11automaticTFs3.jpg, images/ruiz11automaticTFs4.jpg",
thumbnails = "images/ruiz11automaticTFs1_thumb.jpg, images/ruiz11automaticTFs2_thumb.jpg, images/ruiz11automaticTFs3_thumb.jpg, images/ruiz11automaticTFs4_thumb.jpg",
event = "IEEE Visualization Conference 2011",
location = "Providence, RI, USA",
project = "illustrasound"
}
    [YT] [Bibtex] 
    @MISC {Lueks11Spatially,
author = "Wouter Lueks and Ivan Viola and Matthew van der Zwan and Henk Bekker and Tobias Isenberg",
title = "Spatially Continuous Change of Abstraction in Molecular Visualization",
howpublished = "BioVis 2011 - Abstract track",
year = "2011",
abstract = "Based on an approach for the temporal change of abstraction in molecular visualization we describe how to achieve a spatially explicit control of abstraction. This allows us to depict different abstraction stages of a single molecule in a single still-image visualization. This approach works best for long, linear molecules with repeating substructures that allow viewers to visually compare the continuous representational changes of these parts.",
images = "images/Lueks11Spatially01.jpg, images/Lueks11Spatially02.jpg, images/Lueks11Spatially03.jpg",
thumbnails = "images/Lueks11Spatially01_thumb.jpg, images/Lueks11Spatially02_thumb.jpg, images/Lueks11Spatially03_thumb.jpg",
youtube = "https://www.youtube.com/watch?v=1ANKp9mMFvo",
location = "Providence, RI",
url = "http://www.cs.rug.nl/~isenberg/VideosAndDemos/Zwan2011IMV",
notes = "Best Abstract award"
}

2010

    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Bruckner-2010-HVC,
author = "Stefan Bruckner and Peter Rautek and Ivan Viola and Mike Roberts and Mario Costa Sousa and Meister Eduard Gr{\"o}ller",
title = "Hybrid Visibility Compositing and Masking for Illustrative Rendering",
journal = "Computers \& Graphics",
year = "2010",
volume = "34",
number = "4",
pages = "361--369",
month = "aug",
abstract = "In this paper, we introduce a novel framework for the compositing  of interactively rendered 3D layers tailored to the needs of scientific  illustration. Currently, traditional scientific illustrations are  produced in a series of composition stages, combining different pictorial  elements using 2D digital layering. Our approach extends the layer  metaphor into 3D without giving up the advantages of 2D methods.  The new compositing approach allows for effects such as selective  transparency, occlusion overrides, and soft depth buffering. Furthermore,  we show how common manipulation techniques such as masking can be  integrated into this concept. These tools behave just like in 2D,  but their influence extends beyond a single viewpoint. Since the  presented approach makes no assumptions about the underlying rendering  algorithms, layers can be generated based on polygonal geometry,  volumetric data, pointbased representations, or others. Our implementation  exploits current graphics hardware and permits real-time interaction  and rendering.",
pdf = "pdfs/Bruckner-2010-HVC.pdf",
images = "images/Bruckner-2010-HVC.jpg",
thumbnails = "images/Bruckner-2010-HVC.png",
youtube = "https://www.youtube.com/watch?v=V-Jbgpd9OjU,https://www.youtube.com/watch?v=Tsc30U4x3ic,https://www.youtube.com/watch?v=I4x5QtG25Tc",
doi = "10.1016/j.cag.2010.04.003",
keywords = "compositing, masking, illustration",
project = "illustrasound,medviz,illvis",
url = "http://www.cg.tuwien.ac.at/research/publications/2010/bruckner-2010-HVC/"
}
    [Bibtex] 
    @ARTICLE {matkovic10modelView,
author = "Kresimir Matkovic and Denis Gracanin and Mario Jelovic and Andreas Ammer and Alan Lez and Helwig Hauser",
title = "Interactive Visual Analysis of Multiple Simulation Runs using the Simulation Model View:  Understanding and Tuning of an Electronic Unit Injector",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2010",
volume = "16",
number = "6",
pages = "1449--1457 ",
abstract = "Multiple simulation runs using the same simulation model with different values of control parameters usually generate large data sets that capture the variational aspects of the behavior of the modeled and simulated phenomenon. We have identified a conceptual and visual gap between the simulation model behavior and the data set that makes data analysis more difficult thannecessary. We propose a simulation model view that helps to bridge that gap by visually combining the simulation model description and the generated data. The simulation model view provides a visual outline of the simulation process and the corresponding simulation model. The view is integrated in a Coordinated Multiple Views (CMV) system. We use three levels of details to efficiently use the display area provided by the simulation model view. We collaborated with a domain expert and used the simulation model view on a problem in the automotive application domain, i.e., meeting the emission requirements for Diesel engines. One of the key components is a fuel injector unit so our goal was to understand and tune an electronic unit injector (EUI). We were mainly interested in understanding the model and how to tune it for three different operation modes: low emission, low consumption, and high power. Very positive feedback from the domain expert shows that the use of the simulation model view and the corresponding analysis procedures within a CMV system amount to an effective technique for interactive visual analysis of multiple simulation runs. We also developed new analysis procedures based on these results.",
images = "images/matkovic10model1.jpg, images/matkovic10model2.jpg, images/matkovic10model3.jpg",
thumbnails = "images/matkovic10model1_thumb.jpg, images/matkovic10model2_thumb.jpg, images/matkovic10model3_thumb.jpg",
event = "IEEE Visualization 2010",
location = "Salt Lake City, US",
url = "http://dx.doi.org/10.1109/TVCG.2010.171"
}
    [Bibtex] 
    @MISC {hauser10levelsOfComplexity,
author = "Helwig Hauser",
title = "Interactive Visual Analysis with different levels of complexity",
howpublished = "Invited talk at TU Delft",
month = "June 24",
year = "2010",
abstract = "Interactive visual data exploration and analysis is a powerful methodology for enabling insight into complex and also large data. The iterative process of visualization and interaction (and back to visualization, aso.) can be seen as a visual dialog between the user and the data. Thereby, powerful data analysis schemes are enabled such as a step-by-step information drill-down, steered by the users perception, cognition, and knowledge. In this talk, we look at different levels of this methodology (in the sense of levels of complexity), starting at the first level of ``show \& brush'' continuing then via ``relational analysis'' to a third level that we call ``complex analysis.'' The hypothesis is stated that it indeed is useful to have these different levels of complexity for interactive visual data analysis: a large share of all addressed problems can be satisfyingly solved with the ``simple'' level of ``show \& brush,'' while the more complex levels of this methodology are only paying off in special cases. Along with a characterization of these levels, we also take a look at a number of illustrative examples.",
images = "images/hauser10levelsOfComplexity.jpg",
thumbnails = "images/hauser10levelsOfComplexity_thumb.png",
location = "Delft, The Netherlands",
pres = "pdfs/hauser10levelsOfComplexity-pres.pdf"
}
    [Bibtex] 
    @MISC {kehrer10edaVis,
author = "Johannes Kehrer",
title = "Selected Opportunities for Integrating Statistics and Visualization in Multi-dimensional Data Exploration",
howpublished = "Talk at EDAVis: Workshop on Exploratory Data Analysis and Visualisation",
month = "May 27",
year = "2010",
abstract = "Visualization and statistics both facilitate the understanding of complex data characteristics, and there is a long history of relations between the two fields. Traditional approaches for data analysis often consider passive visualizations of statistical data properties. Interactive visual analysis, however, as addressed in this talk, allows the iterative exploration and analysis of data in a guided human computer dialog. Graphical representations of the data and well-proven interaction mechanisms are used to concurrently show, explore, and analyze complex (i.e., time-dependent, multi-variate, and/or multi-dimensional) data. Interesting subsets of the data are interactively selected (brushed) directly on the screen, the relations are investigated in other linked views (including 2D scatterplots, histograms, function graph views, parallel coordinates, but also 3D views of volumetric data).In recent work, we have studied the integration of large amounts of locally aggregated statistical data properties as well as measures of outlyingnessin an interactive visual analysis process. The approach is demonstrated on the visual analysis of multi-dimensional climate data. A discussion of possibilities explains how a further combination of interactive statisticalplots and proven interaction schemes from visualization research shows greatpotential for future research.",
images = "images/kehrer10edavis.jpg",
thumbnails = "images/kehrer10edavis_thumb.jpg",
location = "Vienna, Austria"
}
    [Bibtex] 
    @INPROCEEDINGS {birkeland10USpainting,
author = "{\AA}smund Birkeland and Ivan Viola",
title = "Ultrasound Painting of Vascular Tree",
booktitle = "Proceedings of Vision, Modeling, and Visualization (VMV 2010)",
year = "2010",
pages = "163--170",
abstract = "In treatment planning and surgical interventions, physicians and surgeons need information about the spatial extent of specific features and the surrounding structures. Previous techniques for extracting features, based onmagnetic resonance imaging and computed tomography scans, can be slow and cumbersome and are rarely used by doctors. In this paper we will present a novel approach to extract features from tracked 2D ultrasound, in particular hypo-echoic regions such as blood vessels. Features are extracted during live examinations, removing the need for slow and cumbersome post-scan processes and interaction is based on the natural interaction techniques used by doctors during the examination.The ultrasound probe is utilized as a 3D brush, painting features in a 3D environment. The painting occurs during a regular examination, producing little hypo-echoic regions from an ultrasound image and track the regions from frame to frame. 3D models are then generated by storing the outline of the region as a 3D point cloud. Automatically detecting branching, this technique can handle complex structures, such as liver vessel trees, and track multiple regions simultaneously. During the examination, the point cloud is triangulated in real-time, enabling the doctor to examine the results live and discard areas which are unsatisfactory. Toenable modifications of the extracted 3D models, we present how the ultrasound probecan be used as a interaction tool for fast point cloud editing.",
images = "images/birkeland10USpainting2.jpg,images/birkeland10USpainting1.jpg,images/birkeland10USpainting3.jpg",
thumbnails = "images/birkeland10USpainting_thumb.jpg",
proceedings = "Proceedings of Vision, Modeling, and Visualization",
location = "Siegen, Germany"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @INPROCEEDINGS {Patel-2010-SVV,
author = "Daniel Patel and Stefan Bruckner and Ivan Viola and Meister Eduard Gr{\"o}ller",
title = "Seismic Volume Visualization for Horizon Extraction",
booktitle = "Proceedings of IEEE Pacific Visualization 2010",
year = "2010",
pages = "73--80",
month = "mar",
abstract = "Seismic horizons indicate change in rock properties and are central  in geoscience interpretation. Traditional interpretation systems  involve time consuming and repetitive manual volumetric seeding for  horizon growing. We present a novel system for rapidly interpreting  and visualizing seismic volumetric data. First we extract horizon  surface-parts by preprocessing the seismic data. Then during interaction  the user can assemble in realtime the horizon parts into horizons.  Traditional interpretation systems use gradient-based illumination  models in the rendering of the seismic volume and polygon rendering  of horizon surfaces. We employ realtime gradientfree forward-scattering  in the rendering of seismic volumes yielding results similar to high-quality  global illumination. We use an implicit surface representation of  horizons allowing for a seamless integration of horizon rendering  and volume rendering. We present a collection of novel techniques  constituting an interpretation and visualization system highly tailored  to seismic data interpretation.",
pdf = "pdfs/Patel-2010-SVV.pdf",
images = "images/Patel-2010-SVV.jpg",
thumbnails = "images/Patel-2010-SVV.png",
youtube = "https://www.youtube.com/watch?v=YXg4LZsTQdc",
doi = "10.1109/PACIFICVIS.2010.5429605",
keywords = "volume visualization, horizon extraction, seismic data",
location = "Taipei, Taiwan",
project = "geoillustrator,illvis",
url = "http://www.cg.tuwien.ac.at/research/publications/2010/patel-2010-SVV/"
}
    [Bibtex] 
    @INPROCEEDINGS {balabanian10a,
author = "Jean-Paul Balabanian and Meister Eduard Gr{\"o}ller",
title = "A",
booktitle = "Scientific Visualization (Proc. Dagstuhl Seminar)",
year = "2010",
series = "Dagstuhl Seminar Proceedings",
pages = "xx--xx",
abstract = "This paper describes the concept of A-space. A-space is thespace where visualization algorithms reside. Every visualization algorithmis a unique point in A-space. Integrated visualizations can be interpretedas an interpolation between known algorithms. The void between algorithmscan be considered as a visualization opportunity where a new point in A-spacecan be reconstructed and new integrated visualizations can be created.",
images = "images/balabanian10a.jpg, images/balabanian10a2.jpg",
thumbnails = "images/balabanian10a_thumb.jpg, images/balabanian10a2_thumb.jpg",
issn = "1862-4405",
location = "Dagstuhl, Germany",
url = "http://www.cg.tuwien.ac.at/research/publications/2010/Balabanian-2010-PSDSV/"
}
    [Bibtex] 
    @INPROCEEDINGS {pobitzer10topology,
author = "Armin Pobitzer and Ronald Peikert and Raphael Fuchs and Benjamin Schindler and Alexander Kuhn and Holger Theisel and Kresimir Matkovic and Helwig Hauser",
title = "On the Way Towards Topology-Based Visualization of Unsteady Flow - the State of the Art",
booktitle = "EuroGraphics 2010 State of the Art Reports (STARs)",
year = "2010",
pages = "137--154",
abstract = "Vector fields are a common concept for the representation of many different kinds of flow phenomena in science and engineering. Topology-based methods have shown their convenience for visualizing and analyzing steady flow but a counterpart for unsteady flow is still missing. However, a lot of good and relevant work has been done aiming at such a solution.We give an overview of the research done on the way towards topology-based visualization of unsteady flow, pointing out the different approaches and methodologies involved as well as their relation to each other, takingclassical (i.e. steady) vector field topology as our starting point. Particularly, we focus on Lagrangian Methods, Space-Time Domain Approaches, Local Methods, and Stochastic and Multi-Field Approaches. Furthermore, weillustrated our review with practical examples for the different approaches.",
images = "images/pobitzer10topology.jpg,",
thumbnails = "images/pobitzer10topology_thumb.jpg",
event = "EuroGraphics 2010",
location = "Norrk{\"o}ping, Sweden",
pres = "pdfs/pobitzer10topology-presentation.pdf",
project = "semseg"
}
    [VID] [Bibtex] 
    @ARTICLE {kehrer10moments,
author = "Johannes Kehrer and Peter Filzmoser and Helwig Hauser",
title = "Brushing Moments in Interactive Visual Analysis",
journal = "Computer Graphics Forum",
year = "2010",
volume = "29",
number = "3",
pages = "813--822",
month = "june",
abstract = "We present a systematic study of opportunities for the interactive visual analysis of multi-dimensional scientific data. This is based on the integration of statistical aggregations along selected data dimensions in a framework of coordinated multiple views (with linking and brushing). Traditional and robust estimates of the four statistical moments (mean, variance, skewness, and kurtosis) as well as measures of outlyingness are integrated in an iterative visual analysis process. Brushing particular statistics, the analyst can investigate data characteristics such as trends and outliers. We present a categorization of beneficial combinations of attributes in 2D scatterplots: (a) k-th vs. (k+1)-th statistical moment of a traditional or robust estimate, (b) traditional vs. robust version of the same moment, (c) two different robust estimates of the same moment. We propose selected view transformations to iteratively construct this multitude of informative views as well as to enhance the depiction of the statistical properties in the scatterplots. In the framework, we interrelate the original distributional data and the aggregated statistics, which allows the analyst to work with both data representations simultaneously. We demonstrate our approach in the context of two visual analysis scenarios of multi-run climate simulations.",
vid = "vids/kehrer10moments.html",
images = "images/kehrer10moments.jpg, images/kehrer10moments1.jpg, images/kehrer10moments2.jpg",
thumbnails = "images/kehrer10moments_thumb.jpg, images/kehrer10moments1_thumb.jpg, images/kehrer10moments2_thumb.jpg",
event = "EuroVis 2010",
location = "Bordeaux, France",
pres = "pdfs/kehrer10moments-presentation.pdf",
url = "http://dx.doi.org/10.1111/j.1467-8659.2009.01697.x"
}
    [PDF] [VID] [Bibtex] 
    @INPROCEEDINGS {angelelli10guided,
author = "Paolo Angelelli and Ivan Viola and Kim Nylund and Odd Helge Gilja and Helwig Hauser",
title = "Guided Visualization of Ultrasound Image Sequences",
booktitle = "Proceedings of Eurographics Workshop on Visual Computing for Biology and Medicine (VCBM)",
year = "2010",
pages = "125--132",
abstract = "Ultrasonography allows informative and expressive real time examinations of patients. Findings are usually reported as printouts, screen shots and video sequences. However, in certain scenarios, the amount of imaged ultrasound data is considerable or it is challenging to detect the anatomical features of interest. Post-examination access to the information present in the data is, therefore, cumbersome. The examiner must, in fact, review entire videosequences or risk to lose relevant information by reducing the examination to single screen shot and printouts. In this paper we propose a novel post-processing pipeline for guided visual exploration of ultrasound video sequences, to allow easier and richer exploration and analysis of the data. We demonstrate the usefulness of this approach by applying it to a liver examination case, showing easier and quicker ultrasound image selection and data exploration.",
pdf = "pdfs/angelelli2010usvideovis.pdf",
vid = "vids/angelelli10DOISound.mp4",
images = "images/angelelli10guided0.jpg, images/angelelli10guided3.jpg, images/angelelli10guided2.jpg, images/angelelli10guided4.jpg",
thumbnails = "images/angelelli10guided0_thumb.jpg, images/angelelli10guided3_thumb.jpg, images/angelelli10guided2_thumb.jpg, images/angelelli10guided4_thumb.jpg",
location = "Leipzig, Germany",
project = "illustrasound,medviz,illvis"
}
    [Bibtex] 
    @ARTICLE {ladstaedter10explorationClimateData,
author = "Florian Ladst{\"a}dter and Andrea K. Steiner and Bettina C. Lackner and Barbara Pirscher and Gottfried Kirchengast and Johannes Kehrer and Helwig Hauser and Philipp Muigg and Helmut Doleisch",
title = "Exploration of Climate Data Using Interactive Visualization",
journal = "Journal of Atmospheric and Oceanic Technology",
year = "2010",
volume = "27",
number = "4",
pages = "667--679",
month = "April",
abstract = "In atmospheric and climate research, the increasing amount of data available from climate models and observations provides new challenges for data analysis. We present interactive visual exploration as an innovative approach to handle large datasets. Visual exploration does not require any previous knowledge about the data as is usually the case with classical statistics. It facilitatesiterative and interactive browsing of the parameter space in order to quickly understand the data characteristics, to identify deficiencies, to easily focus on interesting features, and to come up with new hypotheses about the data. These properties extend the common statistical treatment of data, and provide a fundamentally different approach. We demonstrate the potential of this technology by exploring atmospheric climate data from different sources including reanalysis datasets, climate models, and radio occultation satellite data. Results are compared to those from classical statistics revealing the complementary advantages of visual exploration. Combining both, the analytical precision of classical statistics and the holistic power of interactive visual exploration, the usual work flow of studying climate data can be enhanced.",
images = "images/ladstaedter10exploration.jpg, images/ladstaedter10exploration1.jpg, images/ladstaedter10exploration3.jpg, images/ladstaedter10exploration2.jpg",
thumbnails = "images/ladstaedter10exploration_thumb.jpg, images/ladstaedter10exploration1_thumb.jpg, images/ladstaedter10exploration3_thumb.jpg, images/ladstaedter10exploration2_thumb.jpg",
url = "http://dx.doi.org/10.1175/2009JTECHA1374.1"
}
    [Bibtex] 
    @MISC {hauser10interactiveStoryTelling,
author = "Helwig Hauser",
title = "Interactive Story Telling for Presentation with Visualization",
howpublished = "Talk at CMR Forum",
month = "December 17",
year = "2010",
images = "images/hauser10interactiveStoryTelling.png",
thumbnails = "images/hauser10interactiveStoryTelling_thumb.jpg",
location = "Christian Michelsen Research, Bergen, www.CMR.no",
pres = "pdfs/hauser10interactiveStoryTelling.pdf"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @INPROCEEDINGS {Haidacher-2010-VVS,
author = "Martin Haidacher and Daniel Patel and Stefan Bruckner and Armin Kanitsar and Meister Eduard Gr{\"o}ller",
title = "Volume Visualization based on Statistical Transfer-Function Spaces",
booktitle = "Proceedings of IEEE Pacific Visualization 2010",
year = "2010",
pages = "17--24",
month = "mar",
abstract = "It is a difficult task to design transfer functions for noisy data.  In traditional transfer-function spaces, data values of different  materials overlap. In this paper we introduce a novel statistical  transfer-function space which in the presence of noise, separates  different materials in volume data sets. Our method adaptively estimates  statistical properties, i.e. the mean value and the standard deviation,  of the data values in the neighborhood of each sample point. These  properties are used to define a transfer-function space which enables  the distinction of different materials. Additionally, we present  a novel approach for interacting with our new transfer-function space  which enables the design of transfer functions based on statistical  properties. Furthermore, we demonstrate that statistical information  can be applied to enhance visual appearance in the rendering process.  We compare the new method with 1D, 2D, and LH transfer functions  to demonstrate its usefulness.",
pdf = "pdfs/Haidacher-2010-VVS.pdf",
images = "images/Haidacher-2010-VVS.jpg",
thumbnails = "images/Haidacher-2010-VVS.png",
youtube = "https://www.youtube.com/watch?v=firkkbHdZ5o",
doi = "10.1109/PACIFICVIS.2010.5429615",
keywords = "transfer function, statistics, shading, noisy data, classification",
location = "Taipei, Taiwan",
url = "http://www.cg.tuwien.ac.at/research/publications/2010/haidacher_2010_statTF/"
}
    [VID] [Bibtex] 
    @INPROCEEDINGS {balabanian10hierarchical,
author = "Jean-Paul Balabanian and Ivan Viola and Meister Eduard Gr{\"o}ller",
title = "Interactive Illustrative Visualization of Hierarchical Volume Data",
booktitle = "Proceedings of Graphics Interface (best student paper award)",
year = "2010",
pages = "xx--xx",
abstract = "In scientific visualization the underlying data often has an inherent abstract and hierarchical structure. Therefore, the same datasetcan simultaneously be studied with respect to its characteristics inthe three-dimensional space and in the hierarchy space. Often bothcharacteristics are equally important to convey. For such scenarioswe explore the combination of hierarchy visualization and scientificvisualization, where both data spaces are effectively integrated. We have been inspired by illustrations of species evolutions where hierarchical information is often present. Motivated by these traditionalillustrations, we introduce integrated visualizations for hierarchicallyorganized volumetric datasets. The hierarchy data is displayed as a graph, whose nodes are visually augmented to depict the corresponding 3D information. These augmentations include images due to volume raycasting, slicing of 3D structures, and indicators of structure visibility from occlusion testing. New interaction metaphors are presented that extend visualizations and interactions, typical for one visualization space, to control visualization parameters of the other space. Interaction on a node in the hierarchy influences visual representations of 3D structures and vice versa. Weintegrate both the abstract and the scientific visualizations into oneview which avoids frequent refocusing typical for interaction withlinked-view layouts. We demonstrate our approach on different volumetricdatasets enhanced with hierarchical information.",
vid = "vids/balabanian10hierarchical.mp4",
images = "images/balabanian09thesis1.jpg, images/balabanian10hierarchical2.jpg, images/balabanian10hierarchical1.jpg, images/balabanian10hierarchical3.jpg",
thumbnails = "images/balabanian09thesis1_thumb.jpg, images/balabanian10hierarchical2_thumb.jpg, images/balabanian10hierarchical1_thumb.jpg, images/balabanian10hierarchical3_thumb.jpg",
location = "Ottawa, Canada",
url = "http://www.cg.tuwien.ac.at/research/publications/2010/Balabanian-2010-IIV/",
project = "medviz,illvis"
}
    [Bibtex] 
    @INPROCEEDINGS {florek10kde,
author = "Martin Florek and Helwig Hauser",
title = "Quantitative data visualization with interactive KDE surfaces",
booktitle = "Proceedings of the Spring Conference on Computer Graphics (SCCG 2010)",
year = "2010",
pages = "--",
month = "May",
abstract = "Kernel density estimation (KDE) is an established statistical concept for assessing the distributional characteristics of data that also has proven its usefulness for data visualization. In this work,we present several enhancements to such a KDE-based visualization that aim (a) at an improved specificity of the visualization with respect to the communication of quantitative information about the data and its distribution and (b) at an improved integration of such a KDE-based visualization in an interactive visualization setting, where, for example, linking and brushing is easily possible both from and to such a visualization. With our enhancements to KDE-based visualization, we can extend the utilization of this great statistical concept in the context of interactive visualization.",
images = "images/florek10kde.jpg",
thumbnails = "images/florek10kde_thumb.jpg",
location = "Budmerice, Slovakia",
url = "http://dx.doi.org/10.1145/1925059.1925068"
}
    [Bibtex] 
    @MISC {hauser10brainPerfusion,
author = "Helwig Hauser and Sylvia Gla\ßer",
title = "Visualizing Statistics of Brain Perfusion Data",
howpublished = "Talk in the MedViz Seminar Series",
month = "October 8",
year = "2010",
abstract = "Following up earlier cooperative research work with the University of Magdeburg in Germany (with Steffen Oeltze et al.), we are pursuing a new study of perfusion data (this time with Sylvia Glasser et al.) based on statistical tools (such as correlation analysis and principal component analysis) and interactive visual analysis. Shape parameters of concentration time curves are investigated (as well as other quantities that we derived from them) to analyze brain regions that are affected by tumors. Low and high grade tumors are compared. In this talk, a short update on the current state of this research is presented, more results are expected during the weeks and months to come.",
images = "images/hauser10brainPerf.png",
thumbnails = "images/hauser10brainPerf_thumb.jpg",
location = "Bergen, Norway",
pres = "pdfs/hauser10brainPerfusion-pres.pdf"
}
    [Bibtex] 
    @ARTICLE {fuchs10lagrangian,
author = "Raphael Fuchs and Jan Kemmler and Benjamin Schindler and Jrgen Waser and Filip Sadlo and Helwig Hauser and Ronald Peikert",
title = "Toward a Lagrangian Vector Field Topology",
journal = "Computer Graphics Forum",
year = "2010",
volume = "29",
number = "3",
pages = "1163--1172",
month = "june",
abstract = "In this paper we present an extended critical point concept which allows us to apply vector field topology in the case of unsteady flow. We propose a measure for unsteadiness which describes the rate of change of the velocities ina fluid element over time. This measure allows us to select particles for which topological properties remain intact inside a finite spatio-temporal neighborhood. One benefit of this approach is that the classification of critical points based on the eigenvalues of the Jacobian remains meaningful. In the steady case the proposed criterion reduces to the classical definition of critical points. As a first step we show that finding an optimal Galilean frame of reference can be obtained implicitly by analyzing the acceleration field. In a second step we show that this can be extended by switching to the Lagrangian frame of reference. This way the criterion can detect critical points moving along intricate trajectories. We analyze the behavior of the proposed criterion based on two analytical vector fields for which a correct solution is defined by their inherent symmetries and present results for numerical vector fields.",
images = "images/fuchs10lagrangian2.jpg, images/fuchs10lagrangian.jpg",
thumbnails = "images/fuchs10lagrangian2_thumb.jpg, images/fuchs10lagrangian_thumb.jpg",
event = "EuroVis 2010",
location = "Bordeaux, France",
url = "http://dx.doi.org/10.1111/j.1467-8659.2009.01686.x",
project = "semseg"
}
    [Bibtex] 
    @ARTICLE {viola10editorial,
author = "Ivan Viola and Helwig Hauser and David Ebert",
title = "Editorial note for special section on illustrative visualization",
journal = "Computers \& Graphics",
year = "2010",
volume = "34",
number = "4",
pages = "335--336",
images = "images/viola10editorial.jpg",
thumbnails = "images/viola10editorial_thumb.jpg",
url = "http://dx.doi.org/10.1016/j.cag.2010.05.011",
project = "illvis"
}
    [Bibtex] 
    @MISC {hauser10visualDialog,
author = "Helwig Hauser",
title = "Interactive Visualization as a Visual Dialog for Data Investigation",
howpublished = "Talk at Visualiseringsdag Stockholm",
month = "April 13",
year = "2010",
images = "images/hauser10visualDialog.png",
thumbnails = "images/hauser10visualDialog_thumb.jpg",
location = "Stockholm, Sweden",
pres = "pdfs/hauser10visualDialog.pdf"
}
    [PDF] [DOI] [YT] [Bibtex] 
    @ARTICLE {Solteszova-2010-MOS,
author = "Veronika \v{S}olt{\'e}szov{\'a} and Daniel Patel and Stefan Bruckner and Ivan Viola",
title = "A Multidirectional Occlusion Shading Model for Direct Volume Rendering",
journal = "Computer Graphics Forum",
year = "2010",
volume = "29",
number = "3",
pages = "883--891",
month = "jun",
abstract = "In this paper, we present a novel technique which simulates directional  light scattering for more realistic interactive visualization of  volume data. Our method extends the recent directional occlusion  shading model by enabling light source positioning with practically  no performance penalty. Light transport is approximated using a tilted  cone-shaped function which leaves elliptic footprints in the opacity  buffer during slice-based volume rendering. We perform an incremental  blurring operation on the opacity buffer for each slice in front-to-back  order. This buffer is then used to define the degree of occlusion  for the subsequent slice. Our method is capable of generating high-quality  soft shadowing effects, allows interactive modification of all illumination  and rendering parameters, and requires no pre-computation.",
pdf = "pdfs/Solteszova-2010-MOS.pdf",
images = "images/Solteszova-2010-MOS.jpg",
thumbnails = "images/Solteszova-2010-MOS.png",
youtube = "https://www.youtube.com/watch?v=V4y0BVKV_bw",
doi = "10.1111/j.1467-8659.2009.01695.x",
event = "EuroVis 2010",
keywords = "global illumination, volume rendering, shadows, optical model",
location = "Bordeaux, France",
project = "illustrasound,medviz,illvis",
url = "http://www.cg.tuwien.ac.at/research/publications/2010/solteszova-2010-MOS/"
}
    [PDF] [VID] [Bibtex] 
    @INPROCEEDINGS {lampe10differenceViews,
author = "Ove Daae Lampe and Johannes Kehrer and Helwig Hauser",
title = "Visual Analysis of Multivariate Movement Data Using Interactive Difference Views",
booktitle = "Proceedings of Vision, Modeling, and Visualization (VMV 2010)",
year = "2010",
pages = "315--322",
abstract = "Movement data consisting of a large number of spatio-temporal agent trajectories is challenging to visualize, especially when all trajectories are attributed with multiple variates. In this paper, we demonstrate the visualexploration of such movement data through the concept of interactive difference views. By reconfiguring the difference views in a fast and flexible way, we enable temporal trend discovery. We are able to analyze large amounts of such movement data through the use of a frequency-based visualization based on kernel density estimates (KDE), where it is also possible to quantify differences in terms of the units of the visualized data. Using the proposed techniques, we show how the user can produce quantifiable movement differences and compare different categorical attributes (such as weekdays, ship-type, or the general wind direction), or a range of a quantitative attribute (such as how two hours traffic compares to the average). We present results from the exploration of vessel movement data from the Norwegian Coastal Administration, collected by the Automatic Identification System (AIS) coastaltracking. There are many interacting patterns in such movement data, both temporal and other more intricate, such as weather conditions, wave heights, or sunlight. In this work we study these movement patterns, answering specific questions posed by Norwegian Coastal Administration on potential shipping lane optimizations.",
pdf = "pdfs/lampe10difference.pdf",
vid = "vids/lampe10difference.mp4",
images = "images/lampe10difference1.jpg,images/lampe10difference3.jpg,images/lampe10difference2.jpg",
thumbnails = "images/lampe10difference1_thumb.jpg,images/lampe10difference3_thumb.jpg,images/lampe10difference2_thumb.jpg",
location = "Siegen, Germany",
pres = "pdfs/lampe10difference-presentation.pdf"
}
    [Bibtex] 
    @MISC {hauser10storyTelling,
author = "Helwig Hauser",
title = "Story Telling for Visualization",
howpublished = "Talk at Story Telling workshop 2010, UC Davis",
month = "November 1",
year = "2010",
images = "images/hauser10storyTelling.png",
thumbnails = "images/hauser10storyTelling_thumb.jpg",
location = "Davis, CA",
pres = "pdfs/hauser10storyTelling.pdf"
}
    [Bibtex] 
    @INPROCEEDINGS {matkovic10car,
author = "Kresimir Matkovic and Denis Gracanin and R. Splechtna and Helwig Hauser",
title = "Interactive Visual Analysis of Families of Surfaces: An Application to Car Race and Car Setup",
booktitle = "Proceedings of the Internat. Symp. on Visual Analytics Science and Technology (EuroVAST 2010)",
year = "2010",
pages = "--",
abstract = "Modern simulations often produce time series, or even functions of two variables as outputs for single attributes. Such complex data require carefully chosen and designed analysis procedures and the corresponding data model. The use of previously developed curve and surface views provides strong support for visual exploration and analysis of complex data. In this paper we describe how interactive visual analysis can support users in getting insightinto complex data. The case study, based on TORCS 3D racing cars simulator, illustrates our approach and its successful application to a real world problem. The analysis of the car parameters and driving performances during races provides an insight and explanation for race results. That insight is then used to fine-tune car parameters to achieve better driving performance.",
images = "images/matkovic10car.jpg, images/matkovic10car2.jpg",
thumbnails = "images/matkovic10car_thumb.jpg, images/matkovic10car2_thumb.jpg",
location = "Bordeaux, France"
}

2009

    [Bibtex] 
    @ARTICLE {matkovic09surfaces,
author = "Kresimir Matkovic and Denis Gracanin and Borislav Klarin and Helwig Hauser",
title = "Interactive Visual Analysis of Complex Scientific Data as Families of Data Surfaces",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2009",
volume = "15",
number = "6",
pages = "1351--1358",
abstract = "The widespread use of computational simulation in science and engineering provides challenging research opportunities. Multiple independent variables are considered and large and complex data are computed, especially in the case of multi-run simulation. Classical visualization techniques deal well with 2D or 3D data and also with time-dependent data. Additional independent dimensions, however, provide interesting new challenges. We present an advanced visual analysis approach that enables a thorough investigation of families of data surfaces, i.e., datasets, with respect to pairs of independent dimensions. While it is almost trivial to visualize one such data surface, the visual exploration and analysis of many such data surfaces is a grand challenge, stressing the users perception and cognition. We propose an approach that integrates projections and aggregations of the data surfaces at different levels (one scalar aggregate per surface, a 1D profile per surface, or the surface as such). We demonstrate the necessity for a flexible visual analysis system that integrates many different (linked) views for making sense of this highly complex data. To demonstrate its usefulness, we exemplify our approach in the context of a meteorological multi-run simulation data case and in the context of the engineering domain, where our collaborators are working with the simulation of elastohydrodynamic (EHD) lubrication bearing in the automotive industry.",
images = "images/matkovic09surfaces.jpg, images/matkovic09surfaces2.jpg",
thumbnails = "images/matkovic09surfaces_thumb.jpg, images/matkovic09surfaces2_thumb.jpg",
event = "IEEE Visualization 2009",
url = "http://dx.doi.org/10.1109/TVCG.2009.155"
}
    [Bibtex] 
    @ARTICLE {patel09knowledge,
author = "Daniel Patel and {\O }yvind Sture and Helwig Hauser and Christopher Giertsen and Meister Eduard Gr{\"o}ller",
title = "Knowledge-assisted visualization of seismic data",
journal = "Computers \& Graphics",
year = "2009",
volume = "33",
number = "5",
pages = "585--596",
abstract = "We present novel techniques for knowledge-assisted annotation and computer-assisted interpretation of seismic data for oil and gas exploration. We describe the existing procedure for oil and gas search which consists of manually extracting information from seismic data and then aggregating it into knowledge in a detail-oriented bottom-up approach. We then point out the weaknesses of this approach and propose how to improve on it by introducing a holistic computer-assisted top-down approach intended as a preparation step enabling a quicker, more focused and accurate bottom-up interpretation. The top-down approach also enables early representations of hypotheses and knowledge using domain-specific textures for annotating the data. Finally we discuss how these annotations can be extended to 3D for volumetric annotations.",
images = "images/patel09knowledge2.jpg, images/patel09knowledge1.jpg, images/patel09knowledge3.jpg, images/patel09knowledge4.jpg",
thumbnails = "images/patel09knowledge2_thumb.jpg, images/patel09knowledge1_thumb.jpg, images/patel09knowledge3_thumb.jpg, images/patel09knowledge4_thumb.jpg",
url = "http://dx.doi.org/10.1016/j.cag.2009.06.005"
}
    [Bibtex] 
    @INPROCEEDINGS {matkovic09imagecollection,
author = "Kresimir Matkovic and Denis Gra\v{c}anin and Wolfgang Freiler and Jana Banova and Helwig Hauser",
title = "Large Image Collections---Comprehension and Familiarization by Interactive Visual Analysis",
booktitle = "Proceedings of the 10th International Symposium on Smart Graphics (SG'09)",
year = "2009",
pages = "15--26",
publisher = "Springer-Verlag",
abstract = "Large size and complex multi-dimensional characteristics of image collections demand a multifaceted approach to exploration and analysis providing better comprehension and appreciation. We explore large and complex data-sets composed of images and parameters describing the images. We describe a novel approach providing new and exciting opportunities for the exploration and understanding of such data-sets. We utilize coordinated, multiple views for interactive visual analysis of all parameters. Besides iterative refinement and drill-down in the image parameters space, exploring such data-sets requiresa different approach since visual content cannot be completely parameterized. We simultaneously brush the visual content and the image parameter values. The user provides a visual hint (using an image) for brushing in addition to providing a complete image parameters specification. We illustrate our approach on a data-set of more than 26,000 images from Flickr. The developed approach can be used in many application areas, including sociology, marketing, or everyday use.",
images = "images/matkovic09image1.jpg, images/matkovic09image.jpg",
thumbnails = "images/matkovic09image1_thumb.jpg, images/matkovic09image_thumb.jpg",
url = "http://dx.doi.org/10.1007/978-3-642-02115-2_2"
}
    [Bibtex] 
    @PHDTHESIS {patel09thesis,
author = "Daniel Patel",
title = "Expressive Visualization and Rapid Interpretation of Seismic Volumes",
school = "Department of Informatics, University of Bergen, Norway",
year = "2009",
month = "oct",
abstract = "One of the most important resources in the world today is energy. Oil and gas provide two thirds of the world energy consumption, making the world completely dependent on it. Locating and recovering the remaining oil and gas reserves will be of high focus in society until competitive energy sources are found. The search for hydrocarbons is broadly speaking the topic of this thesis. Seismic measurements of the subsurface are collected to discover oil and gas trapped in the ground. Identifying oil and gas in the seismic measurements requires visualization and interpretation. Visualization is needed to present the data for further analysis. Interpretation is performed to identify important structures. Visualization is again required for presenting these structures to the user. This thesis investigates how computer assistance in producing high-quality visualizations and in interpretation can result in expressive visualization and rapid interpretation of seismic volumes. Expressive visualizations represent the seismic data in an easily digestible, intuitive and pedagogic form. This enables rapid interpretation which accelerates the finding of important structures.",
images = "images/patel09thesis.jpg, images/patel09thesis1.jpg, images/patel09thesis3.jpg, images/patel09thesis2.jpg",
thumbnails = "images/patel09thesis_thumb.jpg, images/patel09thesis1_thumb.jpg, images/patel09thesis3_thumb.jpg, images/patel09thesis2_thumb.jpg",
url = "http://www.cg.tuwien.ac.at/research/publications/2009/patel-2009-evr/",
project = "illvis"
}
    [Bibtex] 
    @INPROCEEDINGS {shi09path,
author = "Kuangyu Shi and Holger Theisel and Helwig Hauser and Tino Weinkauf and Kresimir Matkovic and Hans-Christian Hege and Hans-Peter Seidel",
title = "Path Line Attributes -- an Information Visualization Approach to Analyzing the Dynamic Behavior of 3D Time-Dependent Flow Fields",
booktitle = "Topology-Based Methods in Visualization II",
year = "2009",
pages = "75--88",
abstract = "We describe an approach to visually analyzing the dynamic behavior of 3D time-dependent flow fields by considering the behavior of the path lines. At selectedpositions in the 4D space-time domain, we compute a number of local and global properties of path lines describing relevant features of them. The resulting multivariate data set is analyzed by applying state-of-the-art information visualization approaches in the sense of a set of linked views (scatter plots, parallel coordinates, etc.) with interactive brushing and focus+context visualization. The selected path lines with certain properties are integrated and visualized as colored 3D curves. This approach allows an interactive exploration of intricate 4D flow structures. We apply our method to a number of flow data sets and describe how path line attributes are used for describing characteristic features of these flows.",
images = "images/shi09path1.jpg, images/shi09path2.jpg",
thumbnails = "images/shi09path1_thumb.jpg, images/shi09path2_thumb.jpg",
url = "http://dx.doi.org/10.1007/978-3-540-88606-8_6"
}
    [Bibtex] 
    @BOOK {sbert09informationTheory,
author = "Mateu Sbert and Miquel Feixas and Jaume Rigau and Miguel Chover and Ivan Viola",
title = "Information Theory Tools for Computer Graphics",
publisher = "Morgan and Claypool Publishers Colorado",
year = "2009",
series = "Synthesis Lectures on Computer Graphics and Animation",
abstract = "Information theory (IT) tools, widely used in scientific fields such as engineering, physics, genetics, neuroscience, and many others,are also emerging as useful transversal tools in computer graphics. In this book, we present the basic concepts of IT and how they have been applied to the graphics areas of radiosity, adaptive ray-tracing, shape descriptors, viewpoint selection and saliency, scientific visualization, and geometry simplification. Some of the approaches presented, such as the viewpoint techniques, are now the state of the art in visualization. Almost all of the techniques presented in this book have been previously published in peer-reviewed conference proceedings or international journals. Here, we have stressed their common aspects and presented them in an unified way, so the reader can clearly see which problems IT tools can help solve, which specific tools to use, and how to apply them. A basic level of knowledge in computer graphics is required but basic concepts in IT are presented. The intended audiences are both students and practitioners of the fields above and related areas in computer graphics. In addition, IT practitioners will learn about these applications.",
images = "images/viola09hand.jpg",
thumbnails = "images/viola09hand_thumb.jpg",
isbn = "1598299298",
url = "http://dx.doi.org/10.2200/S00208ED1V01Y200909CGR012",
project = "illustrasound,illvis"
}
    [Bibtex] 
    @INPROCEEDINGS {patel09momentCurves,
author = "Daniel Patel and Martin Haidacher and Jean-Paul Balabanian and Meister Eduard Gr{\"o}ller",
title = "Moment Curves",
booktitle = "Proceedings of the IEEE Pacific Visualization Symposium 2009",
year = "2009",
pages = "201--208",
month = "April",
abstract = "We define a transfer function based on the first and second statistical  moments. We consider the evolution of the mean and variance with  respect to a growing neighborhood around a voxel. This evolution  defines a curve in 3D for which we identify important trends and  project it back to 2D. The resulting 2D projection can be brushed  for easy and robust classification of materials and material borders.  The transfer function is applied to both CT and MR data.",
images = "images/patel09momentCurves1.jpg, images/patel09momentCurves2.jpg",
thumbnails = "images/patel09momentCurves1_thumb.jpg, images/patel09momentCurves2_thumb.jpg",
location = "Beijing, China",
url = "http://www.cg.tuwien.ac.at/research/publications/2009/patel_2009_MC/"
}
    [Bibtex] 
    @INPROCEEDINGS {konyha09iva,
author = "Zoltan Konyha and Kresimir Matkovic and Helwig Hauser",
title = "Interactive Visual Analysis in Engineering: A Survey",
booktitle = "Proceedings of the Spring Conference on Computer Graphics (SCCG 2009)",
year = "2009",
pages = "31--38",
month = "apr",
abstract = "Interactive visual analysis has become a very popular research field. There is a significant body of literature on making sense of massive data sets, on visualization and interaction techniques as well as on analysis concepts. However, surveying how those results can be applied to actual engineering problems, including both product and manufacturing design as well as evaluation of simulation and measurement data, has not been discussed sufficiently to date. In this paper we provide a selection of demonstration cases that document the potential benefits of using interactive visual analysis in a wide range of engineering domains, including the investigation of flow and particle dynamics, automotive engine design tasks and change management in the product design process. We attempt to identify some of the proven technological details such as the linking of space-time and attribute views through an application-wide coherent selection mechanism. This paper might be an interesting survey for readers with a relation to the engineering sector, both reflecting on available technological building blocks for interactive visual data analysis as well as exemplifying the potential benefits on behalf of the application side.",
images = "images/konyha09iva.jpg",
thumbnails = "images/konyha09iva_thumb.jpg",
location = "Budmerice, Slovakia",
url = "http://www.cg.tuwien.ac.at/research/publications/2009/Konyha_2009_survey/"
}
    [Bibtex] 
    @INCOLLECTION {hauserSchumann09pipeline,
author = "Helwig Hauser and Heidrun Schumann",
title = "Visualization Pipeline",
booktitle = "Encyclopedia of Database Systems",
publisher = "Springer US",
year = "2009",
editor = "Ling Liu and M. Tamer {\"O}zsu",
pages = "3414--3416",
abstract = "Without Abstract",
images = "images/hauserSchumann09pipeline.jpg, images/hauserSchumann09pipeline2.jpg",
thumbnails = "images/hauserSchumann09pipeline_thumb.jpg, images/hauserSchumann09pipeline2_thumb.jpg",
url = "http://dx.doi.org/10.1007/978-0-387-39940-9_1133"
}
    [Bibtex] 
    @MISC {kehrer09wegener,
author = "Helmut Doleisch and Johannes Kehrer",
title = "SimVis \– eine neue Technologie zur interaktiven visuellen Analyse: Konzepte und Anwendungen im Umfeld der Klimaforschung",
howpublished = "Invited talk at Wegener Center for Climate and Global Change",
month = "December",
year = "2009",
images = "images/ladstaedter10exploration.jpg",
thumbnails = "images/ladstaedter10exploration_thumb.jpg",
location = "Graz, Austria"
}
    [Bibtex] 
    @ARTICLE {fuchs09star,
author = "Raphael Fuchs and Helwig Hauser",
title = "Visualization of Multi-Variate Scientific Data",
journal = "Computer Graphics Forum",
year = "2009",
volume = "28",
number = "6",
pages = "1670--1690",
abstract = "In this state-of-the-art report we discuss relevant research worksrelated to the visualization of complex, multi-variate data. We discuss how different techniques take effect at specific stages of the visualization pipeline and how they apply to multi-variate data sets being composed of scalars, vectors and tensors. We also provide a categorization of these techniques with the aim for a better overview of related approaches. Based on this classification we highlight combinable and hybrid approaches and focus on techniques that potentially lead towards new directions in visualization research. In the second part of this paper we take a look at recent techniques that are useful for the visualization of complex data sets either because they are general purpose or because they can be adapted to specific problems.",
images = "images/buerger07star1.png, images/buerger07star2.png",
thumbnails = "images/buerger07star1_thumb.png, images/buerger07star2_thumb.png",
url = "http://dx.doi.org/10.1111/j.1467-8659.2009.01429.x"
}
    [Bibtex] 
    @ARTICLE {lampe09cuvicentric,
author = "Ove Daae Lampe and Carlos Correa and Kwan-Liu Ma and Helwig Hauser",
title = "Curve-Centric Volume Reformation for Comparative Visualization",
journal = "IEEE Transactions on Visualization and Computer Graphics",
year = "2009",
volume = "15",
number = "6",
pages = "1235--1242",
abstract = "We present two visualization techniques for curve-centric volume reformation with the aim to create compelling comparative visualizations. A curve-centric volume reformation deforms a volume, with regards to a curve in space, to create a new space in which the curve evaluates to zero in two dimensions and spans its arc-length in the third. The volume surrounding the curve is deformed such that spatial neighborhood to the curve is preserved. The result of the curve-centric reformation produces images where one axis is aligned to arc-length, and thus allows researchers and practitioners to apply their arc-length parameterized data visualizations in parallel for comparison. Furthermore we show that when visualizing dense data, our technique provides an inside out projection, from the curve and out into the volume, which allows for inspection what is around the curve. Finally we demonstrate  the usefulness of our techniques in the context of two application cases. We show that existing data visualizations of arc-length parameterized data can be enhanced by using our techniques, in addition to creating a new view and perspective on volumetric data around curves. Additionally we show how volumetric data can be brought into plotting environments that allow precise readouts. In the first case we inspect streamlines in a flow field around a car, and in the second we inspect seismic volumes and well logs from drilling.",
images = "images/lampe09cuvicentric4.jpg, images/lampe09cuvicentric5.jpg, images/lampe09cuvicentric2.jpg, images/lampe09cuvicentric3.jpg",
thumbnails = "images/lampe09cuvicentric4_thumb.jpg, images/lampe09cuvicentric5_thumb.jpg, images/lampe09cuvicentric2_thumb.jpg, images/lampe09cuvicentric3_thumb.jpg",
event = "IEEE Visualization 2009",
url = "http://dx.doi.org/10.1109/TVCG.2009.136"
}
    [Bibtex] 
    @MISC {kehrer09potsdam,
author = "Johannes Kehrer",
title = "Interactive Visual Analysis of Multi-run Climate Data",
howpublished = "Invited talk at Potsdam Institute for Climate Impact Research (PIK)",
month = "December",
year = "2009",
abstract = "The increasing complexity of data stemming from climate models and observations creates new challenges for data analysis. Traditional approaches are often based on computing statistical data properties. Interactive visual analysis, on the other hand, allows the stepwise exploration of the data in a guided human-computer dialog. It uses graphical representations of the data to interactively explore the data in multiple linked views. This allows the analyst to rapidly generate and analyze hypotheses, to identify data deficiencies, and to explore data trends and outliers.In an ongoing cooperation between the University of Bergen, Norway, the Potsdam Institute for Climate Impact Research (PIK), and the SimVis GmbH, Vienna, we used and extended our visual analysis framework to also work with multi-run climate data. In the framework, we relate the original multi-run data and derived statistical properties to each other. This allows the analyst to work in parallel with both, the aggregated data representation and the original multi-run data. We demonstrate this in a visual sensitivity analysis of the multi-run data.",
images = "images/kehrer11heterogeneous2.jpg",
thumbnails = "images/kehrer09potsdam_thumb.jpg",
location = "Potsdam, Germany"
}
    [PDF] [Bibtex] 
    @PHDTHESIS {balabanian09thesis,
author = "Jean-Paul Balabanian",
title = "Multi-Aspect Visualization: Going from Linked Views to Integrated Views",
school = "Department of Informatics, University of Bergen, Norway",
year = "2009",
month = "oct",
abstract = "This thesis is a delve into the matter of visualization integration. There are many approaches to visualizing volume data and often several of these approaches can appropriately be used at the same time to visualize dirent aspects. The usual way is to visualize these aspects separately in dirent views, but integrating the visualizations into the same view can often be the superior approach. We describe the two most used approaches to visualizing several aspects at the same time; linked views and integrated views. We describe some approaches to create integrated visualizations by showing where in the visualization pipeline the integration takes place. We present work produced by the author describing the integrated visualizations developed.",
pdf = "pdfs/balabanian09mav.pdf",
images = "images/balabanian09thesis.jpg, images/balabanian09thesis1.jpg, images/balabanian10hierarchical2.jpg, images/balabanian10hierarchical3.jpg,",
thumbnails = "images/balabanian09thesis_thumb.jpg, images/balabanian09thesis1_thumb.jpg, images/balabanian10hierarchical2_thumb.jpg, images/balabanian10hierarchical3_thumb.jpg,",
project = "illvis"
}
    [Bibtex] 
    @INPROCEEDINGS {oeltze09perfusion,
author = "Steffen Oeltze and Bernhard Preim and Helwig Hauser and Jarle R{\O }rvik and Arvid Lundervold",
title = "Visual analysis of cerebral perfusion data -- four interactive approaches and a comparison",
booktitle = "Proceedings of the 6th Intern. Symp. on Image and Signal Processing and Analysis (ISPA 2009)",
year = "2009",
pages = "582--589",
month = "Sept.",
abstract = "Cerebral perfusion data are acquired to characterize the regional blood supply of brain tissue. One of their major diagnostic applications is ischemicstroke assessment. We present a comparison of four interactive approaches to analyzingcerebral perfusion data from ischemic stroke patients which are based on (1) concentration-time curves (CTC) derived from the original data, (2) parameters describing the CTC shape, (3) enhancement trends computed in a statistical analysis, and (4) semi-quantitative perfusion parameters derived via parametric modelling and deconvolution. The comparison is carried out with regard to the involved data pre-processing, the complexity of the interactive analysis and the resulting tissue selections. It is supported by a visual analysis framework that integrates the different approaches. The rich information content in time-dependent 3D perfusion data is both an opportunity for improved diagnosis and a challenge how to optimize the assessment of such rich data. With our comparison we contribute to a discussion between data-near and model-near assessment strategies and their respective opportunities.",
images = "images/oeltze09perfusion1.jpg, images/oeltze09perfusion2.jpg",
thumbnails = "images/oeltze09perfusion1_thumb.jpg, images/oeltze09perfusion2_thumb.jpg"
}
    [PDF] [VID] [Bibtex] 
    @INPROCEEDINGS {birkeland09peeling,
author = "{\AA}smund Birkeland and Ivan Viola",
title = "View-Dependent Peel-Away Visualization for Volumetric Data",
booktitle = "Proceedings of the Spring Conference on Computer Graphics (SCCG 2009)",
year = "2009",
pages = "133--139",
month = "April",
abstract = "In this paper a novel approach for peel-away visualizations is presented. The newly developed algorithm extends existing illustrative deformation approaches which are based on deformation templates and adds a new component of view-dependency of the peel region. The view-dependent property guarantees the viewer an unobstructed view on the inspected feature of interest. This is realized by rotating the deformation template so that the peeled-away segment always faces away from the viewer. Furthermore the new algorithm computes the underlying peel template on-the-fly, which allows animating the level of peeling. When structures of interest are tagged with segmentation masks, an automatic scaling and positioning of peel deformation templates allows guided navigation and clear view on structures in focus as well as feature-aligned peeling. The overall performance allows smooth interaction with reasonably sized datasets and peel templates as the implementation maximizes the utilization of computation power of modern GPUs.",
pdf = "pdfs/birkeland09peeling.pdf",
vid = "vids/birkeland09peeling.mp4",
images = "images/birkeland09peeling.jpg, images/birkeland09peeling2.jpg, images/birkeland09peeling1.jpg",
thumbnails = "images/birkeland09peeling_thumb.jpg, images/birkeland09peeling2_thumb.jpg, images/birkeland09peeling1_thumb.jpg",
location = "Budmerice, Slovakia",
url = "http://dx.doi.org/10.1145/1980462.1980487",
project = "illvis"
}
    [PDF] [VID] [Bibtex] 
    @INPROCEEDINGS {lie09glyphBased3Dvisualization,
author = "Andreas E. Lie and Johannes Kehrer and Helwig Hauser",
title = "Critical Design and Realization Aspects of Glyph-based 3D Data Visualization",
booktitle = "Proceedings of the Spring Conference on Computer Graphics (SCCG 2009)",
year = "2009",
pages = "27--34",
month = "April",
abstract = "Glyphs are useful for the effective visualization of multi-variate  data. They allow for easily relating multiple data attributes to each  other in a coherent visualization approach. While the basic principle  of glyph-based visualization has been known for a long time,  scientific interest has recently increased focus on the question of  how to achieve a clever and successful glyph design. Along this  newer trend, we present a structured discussion of several critical  design aspects of glyph-based visualization with a special focus on  3D data. For three consecutive steps of data mapping, glyph instantiation,  and rendering, we identify a number of design considerations.  We illustrate our discussion with a new glyph-based visualization  of time-dependent 3D simulation data and demonstrate how  effective results are achieved.",
pdf = "pdfs/lie09glyphBased3Dvisualization.pdf",
vid = "vids/lie09glyphBased3Dvisualization.mp4",
images = "images/lie09glyphs.png, images/lie09dpf.jpg, images/lie09hurricane2.jpg, images/lie09hurricane.jpg",
thumbnails = "images/lie09glyphs_thumb.png, images/lie09dpf_thumb.jpg, images/lie09hurricane2_thumb.jpg, images/lie09hurricane_thumb.jpg",
location = "Budmerice, Slovakia",
url = "http://dx.doi.org/10.1145/1980462.1980470"
}
    [Bibtex] 
    @ARTICLE {nylund2009sonography,
author = "Kim Nylund and Svein {\O }degaard and Trygve Hausken and Geir Folvik and Golen Arslan Lied and Ivan Viola and Helwig Hauser and Odd Helge Gilja",
title = "Sonography of the small intestine",
journal = "World Journal of Gastroenterology",
year = "2009",
volume = "15",
number = "11",
pages = "1319--1330",
month = "March",
abstract = "In the last two decades, there has been substantial development in the diagnostic possibilities for examining the small intestine. Compared with computerized tomography, magnetic resonance imaging, capsule endoscopy and double-balloon endoscopy, ultrasonography has the advantage of being cheap, portable, flexible and user- and patient-friendly, while at the same time providing the clinician with image data of high temporal and spatial resolution. The method has limitations with penetration in obesity and with intestinal air impairing image quality. The flexibility ultrasonography offers the examiner also implies that a systematic approach during scanning is needed. This paper reviews the basic scanning techniques and new modalities such as contrast-enhanced ultrasound, elastography, strain rate imaging, hydrosonography, allergosonography, endoscopic sonography and nutritional imaging, and the literature on disease-specific findings in the small intestine. Some of these methods have shown clinical benefit, while others are under research and development to establish their role in the diagnostic repertoire. However, along with improved overall image quality of new ultrasound scanners, these methods have enabled more anatomical and physiological changes in the small intestine to be observed. Accordingly, ultrasound of the small intestine is an attractive clinical tool to study patients with a range of diseases.",
images = "images/nylund09sonosmall.jpg",
thumbnails = "images/nylund09sonosmall_thumb.jpg",
url = "http://www.wjgnet.com/1007-9327/15/1319.pdf",
project = "medviz"
}
    [Bibtex] 
    @INPROCEEDINGS {ropinski09closeups,
author = "Timo Ropinski and Ivan Viola and Martin Biermann and Helwig Hauser and Klaus Hinrichs",
title = "Multimodal Visualization with Interactive Closeups",
booktitle = "EGUK Theory and Practice of Computer Graphics",
year = "2009",
month = "June",
abstract = "Closeups are used in illustrations to provide detailed views on regions of interest. They are integrated into the rendering of the whole structure in order to reveal their spatial context. In this paper we present the concept of interactive closeups for medical reporting. Each closeup is associated with a region of interest and may show a single modality or a desired combination of the available modalities using different visualization styles. Thus it becomes possible to visualize multiple modalities simultaneously and to support doctor-to-doctor communication on the basis of interactive multimodal closeup visualizations. We discuss how to compute a layout for 2D and 3D closeups, and how to edit a closeup configuration to prepare a presentation or a subsequent doctor-to-doctor communication. Furthermore, we introduce a GPU-based rendering algorithm, which allows to render multiple closeups at interactive frame rates. We demonstrate the application of the introduced concepts to multimodal PET/CT data sets additionally co-registered with MRI.",
images = "http://viscg.uni-muenster.de/publications/2009/RVBHH09/bc-case_closeups.png, http://viscg.uni-muenster.de/publications/2009/RVBHH09/3dcloseup.jpg, http://viscg.uni-muenster.de/publications/2009/RVBHH09/closeup0.jpg, http://viscg.uni-muenster.de/publications/2009/RVBHH09/interaction2.jpg",
thumbnails = "images/ropinski09closeup_thumb.jpg, http://viscg.uni-muenster.de/publications/2009/RVBHH09/.thumbs/3dcloseup.jpg.jpg, http://viscg.uni-muenster.de/publications/2009/RVBHH09/.thumbs/closeup0.jpg.jpg, http://viscg.uni-muenster.de/publications/2009/RVBHH09/.thumbs/interaction2.jpg.jpg",
url = "http://viscg.uni-muenster.de/publications/2009/RVBHH09/",
project = "illvis,medviz"
}
    [Bibtex] 
    @INPROCEEDINGS {piringer09hds,
author = "Harald Piringer and Matthias Buchetics and Helwig Hauser and Meister Eduard Gr{\"o}ller",
title = "Hierarchical Difference Scatterplots - Interactive Visual Analysis of Data Cubes",
booktitle = "Proceedings of the ACM SIGKDD Workshop on Visual Analytics and Knowledge Discovery (VAKD)",
year = "2009",
pages = "56--65",
month = "jun",
abstract = "Data cubes as employed by On-Line Analytical Processing(OLAP) play a key role in many application domains. The analysis typically involves to compare categories of different hierarchy levels with respect to size and pivoted values. Most existing visualization methods for pivotedvalues, however, are limited to single hierarchy levels. Themain contribution of this paper is an approach calledHierarchical Difference Scatterplot (HDS). A HDS allows forrelating multiple hierarchy levels and explicitly visualizesdifferences between them in the context of the absoluteposition of pivoted values. We discuss concepts of tightlycoupling HDS to other types of tree visualizations andpropose the integration in a setup of multiple views, whichare linked by interactive queries on the data. We evaluateour approaches by analyzing social survey data incollaboration with a domain expert.",
images = "images/piringer09hds.jpg, images/piringer09hds2.jpg",
thumbnails = "images/piringer09hds_thumb.jpg, images/piringer09hds2_thumb.jpg",
location = "Paris, France",
url = "http://www.cg.tuwien.ac.at/research/publications/2009/piringer-2009-hds/"
}
    [Bibtex] 
    @INCOLLECTION {ladstaedter09opac,
author = "Florian Ladst{\"a}dter and Andrea K. Steiner and Bettina C. Lackner and Gottfried Kirchengast and Philipp Muigg and Johannes Kehrer and Helmut Doleisch",
title = "SimVis: An Interactive Visual Field Exploration Tool Applied to Climate Research",
booktitle = "New Horizons in Occultation Research",
publisher = "Springer",
year = "2009",
editor = "A. Steiner and B. Pirscher and U. Foelsche and G. Kirchengast",
pages = "235--245",
abstract = "Climate research often deals with large multi-dimensional fields describing the state of the atmosphere. A novel approach to gain information about these large data sets has become feasible only recently using 4D visualization techniques. The Simulation Visualization (SimVis) software tool, developed by the VRVis Research Center (Vienna, Austria), uses such techniques to provide access to the data interactively and to explore and analyze large three-dimensional time-dependent fields. Non-trivial visualization approaches are applied to provide a responsive and useful interactive experience for the user. In this study we used SimVis for the investigation of climate research data sets. An ECHAM5 climate model run and the ERA-40 reanalysis data sets were explored, with the ultimate goal to identify parameters and regions reacting most sensitive to climate change, representing robust indicators. The focus lies on the upper troposphere-lower stratosphere (UTLS) region, in view of future applications of the findings to radio occultation (RO) climatologies. First results showing the capability of SimVis to deal with climate data, including trend time series and spatial distributions of RO parameters are presented.",
images = "images/ladstaedter09opac.jpg",
thumbnails = "images/ladstaedter09opac_thumb.jpg",
isbn = "978-3-642-00321-9",
url = "http://dx.doi.org/10.1007/978-3-642-00321-9_19"
}

2008

    [VID] [Bibtex] 
    @ARTICLE {kehrer08hypothesisGeneration,
author = "Johannes Kehrer and Florian Ladst{\"a}dter and Philipp Muigg and Helmut Doleisch and Andrea Steiner and Helwig Hauser",
title = "Hypothesis Generation in Climate Research with Interactive Visual Data Exploration",
journal = "IEEE Transactions on Visualization and Computer Graphics (IEEE TVCG)",
year = "2008",
volume = "14",
number = "6",
pages = "1579--1586",
month = "Oct",
abstract = "One of the most prominent topics in climate research is the investigation, detection, and allocation of climate change. In this paper, we aim at identifying regions in the atmosphere (e.g., certain height layers) which can act as sensitive and robust indicators for climate change. We demonstrate how interactive visual data exploration of large amounts of multi-variate and time-dependent climate data enables the steered generation of promising hypotheses for subsequent statistical evaluation. The use of new visualization and interaction technology -- in the context of a coordinated multiple views framework -- allows not only to identify these promising hypotheses, but also to efficiently narrow down parameters that are required in the process of computational data analysis. Two datasets, namely an ECHAM5 climate model run and the ERA-40 reanalysis incorporating observational data, are investigated. Higher-order information such as linear trends or signal-to-noise ratio is derived and interactively explored in order to detect and explore those regions which react most sensitively to climate change. As one conclusion from this study, we identify an excellent potential for usefully generalizing our approach to other, similar application cases, as well.",
vid = "vids/kehrer08hypothesis.html",
images = "images/kehrer08vis01.jpg, images/kehrer08vis03.jpg, images/kehrer08vis04.png",
thumbnails = "images/kehrer08vis01_thumb.jpg, images/kehrer08vis03_thumb.jpg, images/kehrer08vis04_thumb.png",
event = "IEEE Visualization 2008",
location = "Columbus, Ohio, USA",
url = "http://dx.doi.org/10.1109/TVCG.2008.139",
pres = "pdfs/kehrer08vis-presentation.pdf"
}
    [Bibtex] 
    @ARTICLE {freiler08setTyped,
author = "Wolfgang Freiler and Kresimir Matkovic and Helwig Hauser",
title = "Interactive Visual Analysis of Set-Typed Data",
journal = "IEEE Transactions on Visualization and Computer Graphics (IEEE TVCG)",
year = "2008",
volume = "14",
number = "6",
pages = "1340--1347",
month = "Oct",
abstract = "While it is quite typical to deal with attributes of different data types in the visualization of heterogeneous and multivariate  datasets, most existing techniques still focus on the most usual data types such as numerical attributes or strings. In this paper we present a new approach to the interactive visual exploration and analysis of data that contains attributes which are of set type. A set-typed attribute of a data item -- like one cell in a table -- has a list of n>=0 elements as its value.  We present the setogram as a new visualization approach to represent data of set type and to enable interactive visual exploration and analysis. We also demonstrate how this approach is capable to help in dealing with datasets that have a larger number of dimensions (more than a dozen or more),  especially also in the context of categorical data. To illustrate the effectiveness of our approach, we present the interactive visual analysis of a CRM dataset with data from a questionnaire on the education and shopping habits of about 90000 people.",
images = "images/freiler08setTyped.png, images/freiler08setTyped1.png, images/freiler08setTyped2.png",
thumbnails = "images/freiler08setTyped_thumb.png, images/freiler08setTyped1_thumb.png, images/freiler08setTyped2_thumb.png",
event = "IEEE Information Visualization 2008",
location = "Columbus, Ohio, USA",
url = "http://dx.doi.org/10.1109/TVCG.2008.144"
}
    [VID] [Bibtex] 
    @INPROCEEDINGS {viola08illustrasound,
author = "Ivan Viola and Kim Nylund and Ola Kristoffer {\O }ye and Dag Magne Ulvang and Odd Helge Gilja and Helwig Hauser",
title = "Illustrated Ultrasound for Multimodal Data Interpretation of Liver Examinations",
booktitle = "Proceedings of Eurographics Workshop on Visual Computing in Biomedicine",
year = "2008",
pages = "125--133",
month = "Oct",
abstract = "Traditional visualization of real-time 2D ultrasound data is difficult to interpret, even for experienced medical personnel. To make the interpretation during the education phase easier, we enhance the visualization during liver examinations with an abstracted depiction of relevant anatomical structures, here denoted as illustrated ultrasound. The specifics of enhancing structures are available through an interactively co-registered computed tomography, which has been enhanced by semantic information. To assist the orientation in the liver, we partition the liver into Couinaud segments. They are defined in a rapid segmentation process based on linked 2D slice views and 3D exploded views. The semantics are interactively related from the co-registered modality to the real-time ultrasound via co-registration. During the illustrated ultrasound examination training we provide visual enhancements that depict which liver segments are intersected by the ultrasound slice.",
vid = "vids/viola08illustrasound.mp4",
images = "images/viola08illustrasound.jpg, images/viola08illustrasound1.jpg, images/viola08illustrasound2.jpg, images/viola08illustrasound3.jpg",
thumbnails = "images/viola08illustrasound_thumb.jpg, images/viola08illustrasound1_thumb.jpg, images/viola08illustrasound2_thumb.jpg, images/viola08illustrasound3_thumb.jpg",
location = "Delft, The Netherlands",
url = "http://www.ii.uib.no/vis/team/viola/_pdfs/viola_2008_vcbm.pdf",
project = "illvis,illustrasound,medviz"
}
    [PDF] [Bibtex] 
    @ARTICLE {fuchs08parallel,
author = "Raphael Fuchs and Ronald Peikert and Helwig Hauser and Filip Sadlo and Philipp Muigg",
title = "Parallel Vectors Criteria for Unsteady Flow Vortices",
journal = "IEEE Transactions on Visualization and Computer Graphics (IEEE TVCG)",
year = "2008",
volume = "14",
number = "3",
pages = "615--626",
month = "May",
abstract = "Feature-based flow visualization is naturally dependent on feature extraction. To extract flow features, often higher-order properties of the flow data are used such as the Jacobian or curvature properties, implicitly describing the flow features in terms of their inherent flow characteristics (e.g., collinear flow and vorticity vectors). In this paper we present recent research which leads to the (not really surprising) conclusion that feature extraction algorithms need to be extended to a time-dependent analysis framework (in terms of time derivatives) when dealing with unsteady flow data. Accordingly, we present two extensions of the parallel vectors based vortex extraction criteria to the time-dependent domain and show the improvements of feature-based flow visualization in comparison to the steady versions of this extraction algorithm both in the context of a high-resolution dataset, i.e., a simulation specifically designed to evaluate our new approach, as well as for a real-world dataset from a concrete application.",
pdf = "http://dx.doi.org10.1109/TVCG.2007.70633",
images = "images/fuchs08parallel.jpg, images/fuchs08parallel1.jpg",
thumbnails = "images/fuchs08parallel_thumb.jpg, images/fuchs08parallel1_thumb.jpg",
keywords = "Time-Varying Data Visualization, Vortex Feature Detection",
url = "http://www.cg.tuwien.ac.at/research/publications/2008/fuchs_raphael_2007_par/"
}
    [VID] [Bibtex] 
    @ARTICLE {patel08seismicAnalyzer,
author = "Daniel Patel and Christopher Giertsen and John Thurmond and John Gjelberg and Meister Eduard Gr{\"o}ller",
title = "The Seismic Analyzer: Interpreting and Illustrating 2D Seismic Data",
journal = "IEEE Transactions on Visualization and Computer Graphics (IEEE TVCG)",
year = "2008",
volume = "14",
number = "6",
pages = "1571--1578",
month = "Oct",
abstract = "We present a toolbox for quickly interpreting and illustrating 2D slices of seismic volumetric reflection data. Searching for oil and gas involves creating a structural overview of seismic reflection data to identify hydrocarbon reservoirs. We improve the search of seismic structures by precalculating the horizon structures of the seismic data prior to interpretation. We improve the annotation of seismic structures by applying novel illustrative rendering algorithms tailored to seismic data, such as deformed texturing and line and texture transfer functions. The illustrative rendering results in multi-attribute and scale invariant visualizations where features are represented clearly in both highly zoomed in and zoomed out views. Thumbnail views in combination with interactive appearance control allows for a quick overview of the data before detailed interpretation takes place. These techniques help reduce the work of seismic illustrators and interpreters.",
vid = "vids/patel08vis.html",
images = "images/patel08seismic.png, images/patel08seismic4.jpg, images/patel08seismic3.jpg, images/patel08seismic1.png",
thumbnails = "images/patel08seismic_thumb.png, images/patel08seismic4_thumb.jpg, images/patel08seismic3_thumb.jpg, images/patel08seismic1_thumb.png",
event = "IEEE Visualization 2008",
location = "Columbus, Ohio, USA",
url = "http://dx.doi.org/10.1109/TVCG.2008.170",
pres = "pdfs/patel08vis-presentation.pdf"
}
    [Bibtex] 
    @ARTICLE {Muigg08four,
author = "Philipp Muigg and Johannes Kehrer and Steffen Oeltze and Harald Piringer and Helmut Doleisch and Bernhard Preim and Helwig Hauser",
title = "A Four-level Focus+Context Approach to Interactive Visual Analysis of Temporal Features in Large Scientific Data",
journal = "Computer Graphics Forum",
year = "2008",
volume = "27",
number = "3",
pages = "775--782",
month = "may",
abstract = "In this paper we present a new approach to the interactive visual analysis of time-dependent scientific data both from measurements as well as from computational simulation by visualizing a scalar function over time  for each of tenthousands or even millions of sample points. In order to cope  with overdrawing and cluttering, we introduce a new four-level method of focus+context visualization. Based on a setting of coordinated, multiple views (with linking and brushing), we integrate three different kinds of focus and also the context in every single view. Per data item we use three values (from  the unit interval each) to represent to which degree the data item is part of  the respective focus level. We present a color compositing scheme which is capable of expressing all three values in a meaningful way, taking semantics  and their relations amongst each other (in the context of our multiple linked  view setup) into account. Furthermore, we present additional image-based postprocessing methods to enhance the visualization of large sets of function graphs, including a texture-based technique based on line integral convolution  (LIC). We also propose advanced brushing techniques which are specific to the timedependent nature of the data (in order to brush patterns over time more efficiently). We demonstrate the usefulness of the new approach in the context of medical perfusion data.",
images = "images/muigg08_eurovis3.jpg, images/muigg08_eurovis1.jpg, images/muigg08_eurovis2.jpg",
thumbnails = "images/muigg08_eurovis3_thumb.jpg, images/muigg08_eurovis1_thumb.jpg, images/muigg08_eurovis2_thumb.jpg",
event = "EuroVis 2008",
location = "Eindhooven, Netherlands",
url = "http://dx.doi.org/10.1111/j.1467-8659.2008.01207.x"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Ruiz-2008-SEV,
author = "Marc Ruiz and Ivan Viola and Imma Boada and Stefan Bruckner and Miquel Feixas and Mateu Sbert",
title = "Similarity-based Exploded Views",
booktitle = "Proceedings of Smart Graphics 2008",
year = "2008",
pages = "154--165",
month = "aug",
abstract = "Exploded views are often used in illustration to overcome the problem  of occlusion when depicting complex structures. In this paper, we  propose a volume visualization technique inspired by exploded views  that partitions the volume into a number of parallel slabs and shows  them apart from each other. The thickness of slabs is driven by the  similarity between partitions. We use an information-theoretic technique  for the generation of exploded views. First, the algorithm identifies  the viewpoint from which the structure is the highest. Then, the  partition of the volume into the most informative slabs for exploding  is obtained using two complementary similarity-based strategies.  The number of slabs and the similarity parameter are freely adjustable  by the user.",
pdf = "pdfs/Ruiz-2008-SEV.pdf",
images = "images/Ruiz-2008-SEV.jpg",
thumbnails = "images/Ruiz-2008-SEV.png",
doi = "10.1007/978-3-540-85412-8_14",
keywords = "volume visualization, illustrative visualization, exploded views",
location = "Rennes, France",
project = "illvis,medviz",
url = "http://www.cg.tuwien.ac.at/research/publications/2008/ruiz-2008-SEV/"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {Balabanian20083DPVT,
author = "Jean-Paul Balabanian and Ivan Viola and Torsten M{\"o}ller  and Meister Eduard Gr{\"o}ller",
title = "Temporal Styles for Time-Varying Volume Data",
booktitle = "Proceedings of 3DPVT'08 - the Fourth International  Symposium on 3D Data Processing, Visualization and Transmission",
year = "2008",
editor = "Stephan Gumhold and Jana Kosecka and Oliver Staadt",
pages = "81--89",
month = "June",
abstract = "This paper introduces interaction mechanisms for conveying  temporal characteristics of time-varying volume  data based on temporal styles. We demonstrate the flexibility  of the new concept through different temporal style  transfer function types and we define a set of temporal compositors  as operators on them. The data is rendered by a  multi-volume GPU raycaster that does not require any grid  alignment over the individual time-steps of our data nor a  rectilinear grid structure. The paper presents the applicability  of the new concept on different data sets from partial to full voxel alignment with rectilinear and curvilinear grid layout.",
pdf = "pdfs/Balabanian2008_3DPVT.pdf",
images = "images/balabanian2008_3dpvt_isabel.jpg, images/balabanian2008_3dpvt_overview.jpg, images/balabanian2008_3dpvt_poster.jpg",
thumbnails = "images/balabanian2008_3dpvt_isabel_thumb.jpg, images/balabanian2008_3dpvt_overview_thumb.jpg, images/balabanian2008_3dpvt_poster_thumb.jpg",
location = "Atlanta, USA",
event = "3D Data Processing, Visualization and Transmission 2008",
url = "http://www.cc.gatech.edu/research/reports/GT-IC-08-05",
project = "illvis"
}
    [PDF] [DOI] [Bibtex] 
    @ARTICLE {Rautek-2008-IVN,
author = "Peter Rautek and Stefan Bruckner and Ivan Viola and Meister Eduard Gr{\"o}ller",
title = "Illustrative visualization: new technology or useless tautology?",
journal = "ACM SIGGRAPH Computer Graphics",
year = "2008",
volume = "42",
number = "3",
month = "aug",
abstract = "The computer graphics group at TU Vienna has created some of most  beautiful and effective illustrative visualizations. In this article,  they share with us their unique perspective on illustrative visualization.",
pdf = "pdfs/Rautek-2008-IVN.pdf",
images = "images/Rautek-2008-IVN.jpg",
thumbnails = "images/Rautek-2008-IVN.png",
doi = "10.1145/1408626.1408633",
url = "http://www.cg.tuwien.ac.at/research/publications/2008/Rautek-2008-VF/"
}
    [VID] [Bibtex] 
    @INPROCEEDINGS {balabanian08hierarchical,
author = "Jean-Paul Balabanian and Martin Ystad and Ivan Viola and Arvid Lundervold and Helwig Hauser and Meister Eduard Gr{\"o}ller",
title = "Hierarchical Volume Visualization of Brain Anatomy",
booktitle = "Proceeding of Vision, Modeling and Visualization (VMV 2008)",
year = "2008",
pages = "313--322",
month = "oct",
abstract = "Scientific data-sets often come with an inherent hierarchical  structure such as functional substructures within organs. In this work we propose a new  visualization approach for volume data which is  augmented by the explicit representation of hierarchically structured data. The volumetric structures are organized in an interactive hierarchy view. Seamless zooming between data visualization, with volume rendering, and map viewing, for orientation and navigation within the hierarchy, facilitates deeper insight on multiple levels. The map shows all structures, organized in multiple hierarchy levels. Focusing on a selected node allows a visual analysis of a substructure as well as identifying its location in the hierarchy. The visual style of the  node in focus, its parent and child nodes are automatically  adapted during interaction to emphasize the embedding in the hierarchy. The hierarchy view is linked to a traditional  tree view. The value of this new visualization approach is demonstrated on segmented  MRI brain data consisting of hundreds of cortical and sub-cortical structures.",
vid = "vids/balabanian08hierarchical.mp4",
images = "images/balabanian08hierarchical1.jpg, images/balabanian08hierarchical2.jpg, images/balabanian08hierarchical3.jpg",
thumbnails = "images/balabanian08hierarchical1_thumb.jpg, images/balabanian08hierarchical2_thumb.jpg, images/balabanian08hierarchical3_thumb.jpg, images/wmv_thumb.png",
isbn = "978-3-89838-609-8",
location = "Konstanz, Germany",
url = "http://www.cg.tuwien.ac.at/research/publications/2008/balabanian-2008-hvv/",
project = "illvis,medviz"
}
    [Bibtex] 
    @INPROCEEDINGS {piringer08comparing,
author = "Harald Piringer and Wolfgang Berger and Helwig Hauser",
title = "Quantifying and Comparing Features in High-Dimensional Datasets",
booktitle = "Proceedings of the International Conference on Information Visualisation (IV 2008)",
year = "2008",
pages = "240--245",
address = "Washington, DC, USA",
month = "7",
publisher = "IEEE Computer Society",
abstract = "Linking and brushing is a proven approach to analyzing multi-dimensional datasets in the context of multiple coordinated views. Nevertheless, most of the respective visualization techniques only offer qualitative visual results. Many user tasks, however, also require precise quantitative results as, for example, offered by statistical analysis.  In succession of the useful Rank-by-Feature Framework, this paper describes a joint visual and statistical approach for guiding the user through a high-dimensional dataset by ranking  dimensions (1D case) and pairs of dimensions (2D case) according to statistical summaries. While the original Rank-by-Feature Framework is limited to global features, the most important novelty here is the concept to consider local features, i.e., data subsets defined by brushing in linked views. The ability to compare subsets to other subsets and subsets to the whole dataset in the context of a large number of dimensions significantly extends the benefits of the approach especially in later stages of an exploratory data analysis. A case study illustrates the workflow by analyzing counts of keywords for classifying e-mails as spam or no-spam.",
images = "images/piringer08comparing1.png, images/piringer08comparing2.png, images/piringer08comparing3.png",
thumbnails = "images/piringer08comparing1_thumb.png, images/piringer08comparing2_thumb.jpg, images/piringer08comparing3_thumb.png",
location = "London, UK",
url = "http://dx.doi.org/10.1109/IV.2008.17"
}
    [PDF] [DOI] [Bibtex] 
    @INPROCEEDINGS {Ruiz-2008-OVR,
author = "Marc Ruiz and Imma Boada and Ivan Viola and Stefan Bruckner and Miquel Feixas and Mateu Sbert",
title = "Obscurance-based Volume Rendering Framework",
booktitle = "Proceedings of Volume Graphics 2008",
year = "2008",
pages = "113--120",
month = "aug",
abstract = "Obscurances, from which ambient occlusion is a particular case, is  a technology that produces natural-looking lighting effects in a  faster way than global illumination. Its application in volume visualization  is of special interest since it permits us to generate a high quality  rendering at a low cost. In this paper, we propose an obscurance-based  framework that allows us to obtain realistic and illustrative volume  visualizations in an interactive manner. Obscurances can include  color bleeding effects without additional cost. Moreover, we obtain  a saliency map from the gradient of obscurances and we show its application  to enhance volume visualization and to select the most salient views.",
pdf = "pdfs/Ruiz-2008-OVR.pdf",
images = "images/Ruiz-2008-OVR.jpg",
thumbnails = "images/Ruiz-2008-OVR.png",
doi = "10.2312/VG/VG-PBG08/113-120",
keywords = "volume rendering, illustrative visualization, ambient occlusion",
location = "Los Angeles, CA, USA",
project = "illvis,medviz",
url = "http://www.cg.tuwien.ac.at/research/publications/2008/ruiz-2008-OVR/"
}
    [Bibtex] 
    @INPROCEEDINGS {matkovic08comVis,
author = "Kresimir Matkovic and Wolfgang Freiler and Denis Gracanin and Helwig Hauser",
title = "ComVis: a Coordinated Multiple Views System for Prototyping New Visualization Technology",
booktitle = "Proceedings of the International Conference on Information Visualisation (IV 2008)",
year = "2008",
pages = "215--220",
address = "Washington, DC, USA",
month = "7",
publisher = "IEEE Computer Society",
abstract = "There is a large number of interactive visualization tools, however no universal tool exists that covers all relevant aspects for all possible application domains. We have developed a tool, ComVIs, which was intended to be used as a research prototype for new visualization techniques. We have identified some interesting aspects from developers and users point of view during tool development. In this paper we describe lessons learned during the process, and share our findings with visualization research community. Examples at the end prove the usefulness of the developed tool. One particular example, the concept of families of function graphs and application to analysis of fuel injection concludes the paper.",
images = "images/matkovic08comvis.jpg",
thumbnails = "images/matkovic08comvis_thumb.jpg",
url = "http://dx.doi.org/10.1109/IV.2008.87",
location = "London, UK"
}
    [Bibtex] 
    @ARTICLE {matkovic08visualSteering,
author = "Kresimir Matkovic and Denis Gracanin and Mario Jelovic and Helwig Hauser",
title = "Interactive Visual Steering - Rapid Visual Prototyping of a Common Rail Injection System",
journal = "IEEE Transactions on Visualization and Computer Graphics (IEEE TVCG)",
year = "2008",
volume = "14",
number = "6",
pages = "1699--1706",
month = "Oct",
abstract = "Interactive steering with visualization has been a common goal of the visualization research community for twenty years, but it is rarely ever realized in practice. In this paper we describe a successful realization of a tightly coupled steering loop, integrating new simulation technology and interactive visual analysis in a prototyping environment for automotive industry system design. Due to increasing pressure on car manufacturers to meet new emission regulations, to improve efficiency, and to reduce noise, both simulation  and visualization are pushed to their limits. Automotive system components, such as the powertrain system or the injection system, have an increasing number of parameters, and new design approaches are required. It is no longer possible to optimize such a system solely based on experience or forward optimization. By coupling interactive visualization with the simulation back-end (computational steering), it is now possible to quickly prototype a new system, starting from a non-optimized initial prototype and the corresponding simulation model. The prototyping continues through the refinement of the simulation model, of the simulation parameters and through trial-and-error attempts to an optimized solution. The ability to early see the first results from a multidimensional simulation space -- thousands of simulations are run for a multidimensional variety of input parameters --  and to quickly go back into the simulation and request more runs in particular parameter regions of interest significantly improves the prototyping process and provides a deeper understanding of the system behavior. The excellent results which we achieved for the common rail injection system strongly suggest that our approach has a great potential of being generalized to other, similar scenarios.",
images = "images/matkovic08vis.png, images/matkovic08vis1.png, images/matkovic08vis3.png, images/matkovic08vis4.png",
thumbnails = "images/matkovic08vis_thumb.png, images/matkovic08vis1_thumb.png, images/matkovic08vis3_thumb.png, images/matkovic08vis4_thumb.png",
event = "IEEE Visualization 2008",
location = "Columbus, Ohio, USA",
url = "http://dx.doi.org/10.1109/TVCG.2008.145"
}

2007

    [Bibtex] 
    @ARTICLE {muigg07hybrid,
author = "Philipp Muigg and Markus Hadwiger and Helmut Doleisch and Helwig Hauser",
title = "Scalable Hybrid Unstructured and Structured Grid Raycasting",
journal = "IEEE Transactions on Visualization and Computer Graphics (IEEE TVCG)",
year = "2007",
volume = "13",
number = "6",
pages = "1592--1599",
month = "nov",
abstract = "This paper presents a scalable framework for real-time raycasting of large unstructured volumes that employs a hybrid bricking approach. It adaptively combines original unstructured bricks in important (focus) regions, with structured bricks that are resampled on demand in less important (context) regions. The basis of this focus+context approach is interactive specification of a scalar degree-of-interest (DOI) function. Thus, rendering always considers two volumes simultaneously: a scalar data volume, and the current DOI volume. The crucial problem of visibility sorting is solved by raycasting individual bricks and compositing in visibility order from front to back. In order to minimize visual errors at the grid boundary, it is always rendered accurately, even for resampled bricks. A variety of different rendering modes can be combined, including contour enhancement. A very important property of our approach is that it supports a variety of cell types natively, i.e., it is not constrained to tetrahedral grids, even when interpolation within cells is used. Moreover, our framework can handle multi-variate data, e.g., multiple scalar channels such as temperature or pressure, as well as time-dependent data. The combination of unstructured and structured bricks with different quality characteristics such as the type of interpolation or resampling resolution in conjunction with custom texture memory management yields a very scalable system.",
images = "images/muigg07hybrid.png, images/muigg07hybrid1.png, images/muigg07hybrid2.png",
thumbnails = "images/muigg07hybrid_thumb.png, images/muigg07hybrid1_thumb.png, images/muigg07hybrid2_thumb.png",
issn = "1077-2626",
location = "Sacramento, California, USA",
event = "IEEE Visualization 2007",
url = "http://dx.doi.org/10.1109/TVCG.2007.70588",
publisher = "IEEE Computer Society"
}
    [Bibtex] 
    @INPROCEEDINGS {toth2007ndd,
author = "Zsolt Toth and Ivan Viola and Andrej Ferko and Meister Eduard Gr{\"o}ller",
title = "N-dimensional Data-Dependent Reconstruction Using Topological Changes",
booktitle = "Topology-based Methods in Visualization (Proc. of TopoInVis 2005)",
year = "2007",
editor = "H. Hauser, H. Hagen, H. Theisel",
pages = "183--198",
month = "sep",
publisher = "Springer",
abstract = "We introduce a new concept for a geometrically based feature preserving reconstruction technique of n-dimensional scattered data. Our goal is to generate an n-dimensional triangulation, which preserves the high frequency regions via local topology changes. It is the generalization of a 2D reconstruction approach based on data-dependent triangulation and Lawson's optimization procedure. The definition of the mathematic optimum of the reconstruction is given. We discuss an original cost function and a generalization of known functions for the n-dimensional case.",
images = "images/toth07ndd.jpg",
thumbnails = "images/toth07ndd_thumb.jpg",
location = "Budmerice, Slovakia",
url = "http://www.cg.tuwien.ac.at/research/publications/2007/toth-2007-ndd/"
}
    [Bibtex] 
    @INPROCEEDINGS {viola07ort,
author = "Ivan Viola and Meister Eduard Gr{\"o}ller",
title = "On the Role of Topology in Focus+Context Visualization",
booktitle = "Topology-based Methods in Visualization (Proc. of TopoInVis 2005)",
year = "2007",
editor = "H. Hauser, H. Hagen, H. Theisel",
pages = "171--181",
month = "sep",
publisher = "Springer",
abstract = "In this paper three types of visualization scenarios are discussed, where topology improves the readability of particular visualization results. The first type combines topology information represented by simple graphical primitives with other forms of visual representations. The second type uses the topology information to define the relevance of objects within the data. The relevance is re ected in the visualization by applying the cut-away concept. The third type of visualizations is based on the change of topology of the underlying data to increase visibility of the most interesting information. Every type handles topology in a different way. This illustrates various roles of topology in scientific visualization.",
images = "images/viola07topology.png",
thumbnails = "images/viola07topology_thumb.png",
location = "Budmerice, Slovakia",
url = "http://www.cg.tuwien.ac.at/research/publications/2007/viola-2007-ort/"
}
    [Bibtex] 
    @ARTICLE {oeltze07perfusion,
author = "Steffen Oeltze and Helmut Doleisch and Helwig Hauser and Philipp Muigg and Bernhard Preim",
title = "Interactive Visual Analysis of Perfusion Data",
journal = "IEEE Transactions on Visualization and Computer Graphics (IEEE TVCG)",
year = "2007",
volume = "13",
number = "6",
pages = "1392-1399",
month = "nov",
abstract = "Perfusion data are dynamic medical image data which characterize the regional blood flow in human tissue. These data bear a great potential in medical diagnosis, since diseases can be better distinguished and detected at an earlier stage compared to static image data. The wide-spread use of perfusion data is hampered by the lack of efficient evaluation methods. For each voxel, a time-intensity curve characterizes the enhancement of a contrast agent. Parameters derived from these curves characterize the perfusion and have to be integrated for diagnosis. The diagnostic evaluation of this multi-field data is challenging and time-consuming due to its complexity. For the visual analysis of such datasets, feature-based approaches allow to reduce the amount of data and direct the user to suspicious areas. We present an interactive visual analysis approach for the evaluation of perfusion data. For this purpose, we integrate statistical methods and interactive feature specification. Correlation analysis and Principal Component Analysis (PCA) are applied for dimensionreduction and to achieve a better understanding of the inter-parameter relations. Multiple, linked views facilitate the definition of features by brushing multiple dimensions. The specification result is linked to all views establishing a focus+context style of visualization in 3D. We discuss our approach with respect to clinical datasets from the three major application areas: ischemic stroke diagnosis, breast tumor diagnosis, as well as the diagnosis of the coronary heart disease (CHD). It turns out that the significance of perfusion parameters strongly depends on the individual patient, scanning parameters, and data pre-processing.",
images = "images/oeltze07perfusion.png, images/oeltze07perfusion1.png",
thumbnails = "images/oeltze07perfusion_thumb.png, images/oeltze07perfusion1_thumb.png",
issn = "1077-2626",
publisher = "IEEE Computer Society",
location = "Sacramento, California, USA",
event = "IEEE Visualization 2007",
url = "http://dx.doi.org/10.1109/TVCG.2007.70569"
}
    [PDF] [Bibtex] 
    @ARTICLE {Lampe2007TMV,
author = "Ove Daae Lampe and Ivan Viola and Nathalie Reuter and Helwig Hauser",
title = "Two-Level Approach to Efficient Visualization of Protein Dynamics",
journal = "IEEE Transactions on Visualization and Computer Graphics (IEEE TVCG)",
year = "2007",
volume = "13",
number = "6",
pages = "1616--1623",
month = "nov",
abstract = "Proteins are highly flexible and large amplitude deformations of their structure, also called slow dynamics, are often decisive to their function. We present a two-level rendering approach that enables visualization of slow dynamics of large protein assemblies. Our approach is aligned with a hierarchical model of large scale molecules. Instead of constantly updating positions of large amounts of atoms, we update the position and rotation of residues, i.e., higher level building blocks of a protein. Residues are represented by one vertex only indicating its position and additional information defining the rotation. The atoms in the residues are generated on-the-fly on the GPU, exploiting the new graphics hardware geometry shader capabilities. Moreover, we represent the atoms by billboards instead of tessellated spheres. Our representation is then significantly faster and pixel precise. We demonstrate the usefulness of our new approach in the context of our collaborative bioinformatics project.",
pdf = "pdfs/lampe_2007_tvcg.pdf",
images = "images/moleculevr_single_mol-20070329-0857270.jpeg, images/color_per_chain.jpeg, images/nanoThickWallSleveCHonly_anaglyph.jpeg, images/phi29Contour.jpeg, images/python 2007-06-25 23-07-54-84.jpeg, images/python 2007-06-25 23-31-18-14.jpeg",
thumbnails = "images/moleculevr_single_mol-20070329-0857270_thumb.jpeg, images/color_per_chain_thumb.jpeg, images/nanoThickWallSleveCHonly_anaglyph_thumb.jpeg, images/phi29Contour_thumb.jpeg, images/python 2007-06-25 23-07-54-84_thumb.jpeg, images/python 2007-06-25 23-31-18-14_thumb.jpeg",
event = "IEEE Visualization 2007",
location = "Sacramento, California, USA",
issn = "1077-2626"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {Balabanian2007,
author = "Jean-Paul Balabanian and Ivan Viola and Egil Ona and Ruben Patel  and Meister Eduard Gr{\"o}ller",
title = "Sonar Explorer: A New Tool for Visualization of Fish Schools from  {3D} Sonar Data",
booktitle = "Data Visualization - EuroVis 2007",
year = "2007",
editor = "K. Museth and T. M{\"o}ller and A. Ynnerman",
pages = "155--162",
month = "may",
publisher = "Eurographics Association",
abstract = "We present a novel framework for analysis and visualization of fish  schools in 3D sonar surveys. The 3D sonar technology is new and there  have not been applications to visualize the data in 3D. We have created  an application called Sonar Explorer that satisfies the requirements  of domain scientists. Sonar Explorer provides easy and intuitive  semi-automatic fish school tracking and survey map generation. The  overall pipeline is described and all pipeline stages relevant for  visualization are highlighted. We present techniques to deal with  3D sonar data specifics: highly anisotropic volume data aligned on  a curvilinear grid. Domain scientists provide initial impressions  on interaction and outlook.",
pdf = "pdfs/Balabanian2007.pdf",
images = "images/balabanian_2007_eurovis.png",
thumbnails = "images/balabanian_2007_eurovis_thumb.png",
isbn = "978-3-905673-45-6",
location = "Norrk{\"o}ping, Sweden",
event = "EuroVis 2007"
}
    [PDF] [Bibtex] 
    @ARTICLE {Gilja2007,
author = "Odd Helge Gilja and Trygve Hausken and Jan G. Hatlebakk and Svein {\O }degaard and Arnold Berstad and Ivan Viola and Christopher Giertsen and Hans Gregersen",
title = "Advanced Imaging and Visualization in Gastrointestinal Disorders",
journal = "World Journal of Gastroenterology",
year = "2007",
volume = "13",
number = "9",
pages = "1408--1421",
abstract = "Advanced medical imaging and visualization has a strong impact on research and clinical decision making in gastroenterology. The aim of this paper is to show how imaging and visualization can disclose structural and functional abnormalities of the gastrointestinal (GI) tract. Imaging methods such as ultrasonography, magnetic resonance imaging (MRI), endoscopy, endosonography, and elastography will be outlined and visualization with Virtual Reality and haptic methods. Ultrasonography is a versatile method that can be used to evaluate antral contractility, gastric emptying, transpyloric flow, gastric configuration, intragastric distribution of meals, gastric accommodation and strain measurement of the gastric wall. Advanced methods for endoscopic ultrasound, three-dimensional (3D) ultrasound, and tissue Doppler ( Strain Rate Imaging) provide detailed information of the GI tract. Food hypersensitivity reactions including gastrointestinal reactions due to food allergy can be visualized by ultrasonography and MRI. Development of multi- parametric and multi-modal imaging may increase diagnostic benefits and facilitate fusion of diagnostic and therapeutic imaging in the future.",
pdf = "http://www.wjgnet.com/1007-9327/13/1408.pdf",
images = "images/gilja_2007_wjg.jpg",
thumbnails = "images/gilja_2007_wjg_thumbnail.jpg",
url = "http://www.wjgnet.com/1007-9327/13/1408.asp"
}
    [PDF] [Bibtex] 
    @INPROCEEDINGS {patel_daniel_2007_IRSD,
author = "Daniel Patel and Christopher Giertsen and John Thurmond and Meister Eduard Gr{\"o}ller",
title = "Illustrative Rendering of Seismic Data",
booktitle = "Proceeding of Vision Modeling and Visualization 2007",
year = "2007",
editor = "Hendrik Lensch, Bodo Rosenhahn, H.P. Seidel",
pages = "13--22",
month = "nov",
abstract = "In our work we present techniques for illustrative rendering of interpreted seismic volume data by adopting elements from geology book illustrations. We also introduce combined visualization techniques of interpreted and uninterpreted data for validation, comparison and interdisciplinary communication reasons. We introduce the concept of smooth transitions between these two semantical levels. To achieve this we present transfer functions that map seismic volume attributes to 2D textures that flow according to a deformation volume describing the buckling and discontinuities of the layers of the seismic data.",
pdf = "pdfs/patel_daniel_2007_IRSD-paper.pdf",
images = "images/patel_daniel_2007_IRSD-Illustrative%20rendering.png",
thumbnails = "images/patel_daniel_2007_IRSD-Illustrative%20rendering_thumb.png",
journal = "Vision, Modelling and Visualization",
location = "Saarbr{\"u}cken, Germany",
url = "http://www.cg.tuwien.ac.at/research/publications/2007/patel_daniel_2007_IRSD/"
}
    [Bibtex] 
    @INPROCEEDINGS {buerger2007star,
author = "Raphael B{\"u}rger and Helwig Hauser",
title = "Visualization of Multi-variate Scientific Data",
booktitle = "EuroGraphics 2007 State of the Art Reports (STARs)",
year = "2007",
pages = "117--134",
abstract = "In this state-of-the-art report we discuss relevant research works related to the visualization of complex, multi-variate data. We focus on ''non-classical'' approaches, i.e. approaches which haven't been discussed in previous related reports, and we highlight techniques which potentially lead towards new directions in visualization research. We discuss how different techniques take effect at specific stages of the visualization pipeline and how they apply to multi-variate data sets being composed of scalars, vectors, and tensors. We also provide a categorization of these techniques in the aim for a better overview of related approaches. In the second part of this paper we take a look at recent techniques that are useful for the visualization of complex data sets either because they are general purpose or because they can be adapted to specific problems.",
images = "images/buerger07star1.png, images/buerger07star2.png",
thumbnails = "images/buerger07star1_thumb.png, images/buerger07star2_thumb.png",
isbn = "1017-4656",
keywords = "scientific data, multi-variate data",
event = "EuroGraphics 2007",
location = "Prague, Czech Republic",
url = "http://www.cg.tuwien.ac.at/research/publications/2007/buerger-2007-star/"
}
    [Bibtex] 
    @INPROCEEDINGS {matkovic07color_lines_view,
author = "Kresimir Matkovic and Denis Gracanin and Zoltan Konyha and Helwig Hauser",
title = "Color Lines View: An Approach to Visualization of Families of Function Graphs",
booktitle = "Proceeding of the 11th International Conference on Information Visualization (IV 2007)",
year = "2007",
pages = "59-64",
month = "7",
abstract = "Data sets often include information that can be represented as a mapping that describes how a dependent variable depends on an independent variable. Such a mapping, usually represented as a function graph, can be parameterized to provide a family of function graphs. The challenge is how to efficiently aggregate individual function graph views to represent the whole family and allow visual analysis and search for patterns. We propose a novel view, called the color lines view, which provides a two dimensional, rectangular view where each line represents a single function graph. The points on the line correspond to values of the independent variable. The point colors represent the value of the dependent variable. The lines, placed next to each other in parallel, show a family of function graphs. The color lines view offers sorting and brushing features which support visual analysis procedures that are difficult to perform with previously existing views.",
images = "images/matkovic07color_lines_view1.png, images/matkovic07color_lines_view.png",
thumbnails = "images/matkovic07color_lines_view1_thumb.png, images/matkovic07color_lines_view_thumb.png",
location = "Z{\"u}rich, Switzerland",
url = "http://dx.doi.org/10.1109/IV.2007.35"
}
    [Bibtex] 
    @INPROCEEDINGS {Burns2007,
author = "Michael Burns and Martin Haidacher and Wolfgang Wein and Ivan Viola and Meister Eduard Gr{\"o}ller",
title = "Feature Emphasis and Contextual Cutaways for Multimodal Medical Visualization",
booktitle = "Proceedings of Eurographics / IEEE VGTC Symposium on Visualization (EuroVis 2007)",
year = "2007",
pages = "275--282",
month = "may",
abstract = "Dense clinical data like 3D Computed Tomography (CT) scans can be visualized together with real-time imaging for a number of medical intervention applications. However, it is difficult to provide a fused visualization thatallows sufficient spatial perception of the anatomy of interest, as derived from the rich pre-operative scan, while not occluding the real-time image displayed embedded within the volume. We propose an importance-driven approach that presents the embedded data such that it is clearly visible along with its spatial relation to the surrounding volumetric material. To support this, we present and integrate novel techniques for importance specification, feature emphasis, and contextual cutaway generation. We show results in a clinical context where a pre-operative CT scan is visualized alongside a tracked ultrasound image, such that the important vasculature is depicted between the viewpoint and the ultrasound image, while amore opaque representation of the anatomy is exposed in the surrounding area.",
images = "images/burns07eurovis.jpg, images/burns07eurovis2.jpg",
thumbnails = "images/burns07eurovis_thumb.jpg, images/burns07eurovis2_thumb.jpg",
location = "Norrk{\"o}ping, Sweden",
event = "EuroVis 2007",
url = "http://www.cs.princeton.edu/gfx/pubs/Burns_2007_FEA/"
}
    [Bibtex] 
    @INPROCEEDINGS {konyha07timing_chain,
author = "Zoltan Konyha and Kresimir Matkovix and Denis Graxanin and Mario Duras and Josip Juric and Helwig Hauser",
title = "Interactive Visual Analysis of a Timing Chain Drive Using Segmented Curve View and other Coordinated Views",
booktitle = "Proceeding of the 5th Intern. Conference on Coordinated \& Multiple Views in Exploratory Visualization (CMV 2007)",
year = "2007",
pages = "3-15",
month = "7",
abstract = "A timing chain drive transfers motion from the engine's crankshaft to the camshaft that operates the valves. The design process of timing chain drives involves computer simulation of many design variants in order to find an optimum. Most of the simulation results can be represented as families of function graphs (data series). Previously, the analysis of those results was based on static 2D diagrams and animated 3D visualizations. They were suitable for the detailed analysis of a few simulation variants, but not for the comparison of many cases. In this paper we propose a new approach to the analysis based on coordinated linked views and advanced brushing features. Our proposed method supports the interactive analysis of many design variants. We introduce a novel view, called segmented curve view, which can display distributions in families of function graphs. The segmented curve view combines individual function graphs where for a fixed value of the independent variable, a bar extends from minimum to maximum values across the family of function graphs. Each bar is divided into segments (bins) with a color that represents the number of function graphs with the value in that segment. In the case study, we demonstrate that the new view combined with traditional; views provides a strong support for the interactive visual exploration and analysis of a real world timing chain design problem.",
images = "images/konya07timing_chain2.png, images/konya07timing_chain.png, images/konya07timing_chain1.png",
thumbnails = "images/konya07timing_chain2_thumb.png, images/konya07timing_chain_thumb.png, images/konya07timing_chain1_thumb.png",
location = "Z{\"u}rich, Switzerland",
url = "http://dx.doi.org/10.1109/CMV.2007.13"
}