Ivan Viola

Professor

Publications

2019

    [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 = "Mörth, 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 = "Mörth, 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 {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"
    }

2017

    [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] [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 {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

    [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] [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

    [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/"
    }
    [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"
    }

2014

    [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"
    }
    [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] [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] [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"
    }
    [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] [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"
    }
    [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"
    }

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]
    @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"
    }
    [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] [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"
    }
    [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 {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] [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"
    }

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] [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"
    }
    [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"
    }
    [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] [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"
    }
    [PDF] [DOI] [YT] [Bibtex]
    @INPROCEEDINGS {Ford-2012-HRV,
    author = "Steven Ford and Ivan Viola and Stefan Bruckner and Hans Torp and Gabriel Kiss",
    title = "HeartPad: Real-Time Visual Guidance for Cardiac Ultrasound",
    booktitle = "Proceedings of WASA 2012",
    year = "2012",
    pages = "169--176",
    month = "nov",
    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/Ford-2012-HRV.pdf",
    images = "images/Ford-2012-HRV.jpg",
    thumbnails = "images/Ford-2012-HRV.png",
    youtube = "https://www.youtube.com/watch?v=2d3G7ig-yiQ",
    affiliation = "tuwien",
    doi = "10.1145/2425296.2425326",
    keywords = "medical visualization, ultrasound",
    url = "http://www.cg.tuwien.ac.at/research/publications/2012/Ford-2012-HRV/"
    }
    [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]
    @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"
    }
    [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]
    @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]
    @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"
    }
    [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]
    @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]
    @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/"
    }
    [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"
    }
    [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]
    @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"
    }
    [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/"
    }

2009

    [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"
    }
    [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"
    }
    [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"
    }

2008

    [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"
    }
    [DOI] [Bibtex]
    @ARTICLE {rautek08illustrative,
    author = "Peter Rautek and Stefan Bruckner and Meister Eduard Gr{\"o}ller and Ivan Viola",
    title = "Illustrative Visualization: New Technology or Useless Tautology?",
    journal = "SIGGRAPH Comput. Graph.",
    year = "2008",
    volume = "42",
    number = "3",
    images = "images/rautek08illustrative.jpg",
    thumbnails = "images/rautek08illustrative_thumb.jpg",
    address = "New York, NY, USA",
    affiliation = "tuwien",
    doi = "http://doi.acm.org/10.1145/1408626.1408633",
    project = "illvis",
    publisher = "ACM",
    url = "http://doi.acm.org/10.1145/1408626.1408633"
    }
    [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"
    }
    [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/"
    }

2007

    [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/"
    }
    [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"
    }
    [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/"
    }