Conference stringclasses 6 values | Year int64 1.99k 2.03k | Title stringlengths 8 187 | DOI stringlengths 16 32 | Abstract stringlengths 128 7.15k ⌀ | Accessible bool 2 classes | Early bool 2 classes | AuthorNames-Deduped listlengths 1 24 | Award listlengths 0 2 | Resources listlengths 0 5 | ResourceLinks listlengths 0 10 |
|---|---|---|---|---|---|---|---|---|---|---|
EuroVis | 2,005 | Tiled Parallel Coordinates for the Visualization of Time-Varying Multichannel EEG Data | 10.2312/VisSym/EuroVis05/061-068 | The field of visualization assists data interpretation in many areas, but some types of data are not manageable by existing visualization techniques. This holds in particular for time-varying multichannel EEG data. No existing technique can simultaneously visualize information from all channels in use and all time steps. To address this problem, a new visualization technique is presented, based on the parallel coordinate method and making use of a tiled organization. This tiled organization employs a two-dimensional row-column representation, rather than a one-dimensional arrangement in columns as used for the classical parallel coordinates. The usefulness of the new method, referred to as tiled parallel coordinates, is demonstrated by one particular type of EEG data. It can be applied to an arbitrary number of time steps, for the maximum number of channels currently in use. The general setup of the method makes it widely applicable to other time-varying multivariate data types. | false | false | [
"Michael ten Caat",
"Natasha M. Maurits",
"Jos B. T. M. Roerdink"
] | [] | [] | [] |
EuroVis | 2,005 | Transfer Functions for Imaging Spectroscopy Data using Principal Component Analysis | 10.2312/VisSym/EuroVis05/117-123 | In this paper we present a new application of the principal component analysis (PCA) to generate multidimensional transfer functions. These transfer functions are needed in the volumetric visualization of spectral data to isolate regions that contain interesting peak-shaped features. Both large and small peaks can be equally important and represent the presence of different chemical elements in a dataset. Principal component analysis separates these peaks in different uncorrelated components and can simultaneously identify spatial patterns. This approach is characterized by the direct linkage between the resulting spectral and spatial components. Our method enables us to create an opacity map from these components. One or more mappings can be selected to highlight features in three-dimensional volume visualization. | false | false | [
"Alexander Broersen",
"Robert van Liere"
] | [] | [] | [] |
EuroVis | 2,005 | Vector Field Analysis and Visualization through Variational Clustering | 10.2312/VisSym/EuroVis05/029-035 | Scientific computing is an increasingly crucial component of research in various disciplines. Despite its potential, exploration of the results is an often laborious task, owing to excessively large and verbose datasets output by typical simulation runs. Several approaches have been proposed to analyze, classify, and simplify such data to facilitate an informative visualization and deeper understanding of the underlying system. However, traditional methods leave much room for improvement.
In this article we investigate the visualization of large vector fields, departing from accustomed processing algorithms by casting vector field simplification as a variational partitioning problem. Adopting an iterative strategy, we introduce the notion of vector "proxies" to minimize the distortion error of our simplification by clustering the dataset into multiple best-fitting characteristic regions. This error driven approach can be performed with respect to various similarity metrics, offering a convenient set of tools to design clear and succinct representations of high dimensional datasets. We illustrate the bene fits of such tools through visualization experiments of three-dimensional vector fields. | false | false | [
"Alexander McKenzie",
"Santiago V. Lombeyda",
"Mathieu Desbrun"
] | [] | [] | [] |
EuroVis | 2,005 | Version-Centric Visualization of Code Evolution | 10.2312/VisSym/EuroVis05/223-230 | The source code of software systems changes many times during the system lifecycle. We study how developers can get insight in these changes in order to understand the project context and the product artifacts. For this we propose new techniques for code evolution representation and visualization interaction from a version-centric perspective. Central to our approach is a line-based display of the changing code, where each file version is shown as a column and the horizontal axis shows time. We propose a version centric layout of line representations and a constrained interaction scheme that makes it easy to navigate. Additionally, we describe a cushion based technique to enhance visualization with information about stable evolution areas. We demonstrate the usefulness of our approach on real- life data sets. | false | false | [
"Lucian Voinea",
"Alexandru C. Telea",
"Michel R. V. Chaudron"
] | [] | [] | [] |
EuroVis | 2,005 | VIS-a-VE: Visual Augmentation for Virtual Environments in Surgical Training | 10.2312/VisSym/EuroVis05/101-108 | Photo-realistic rendering combined with vision techniques is an important trend in developing next generation surgical simulation devices. Training with simulator is generally low in cost and more efficient than traditional methods that involve supervised learning on actual patients. Incorporating genuine patient data in the simulation can significantly improve the efficacy of training and skills assessment. In this paper, a photo-realistic simulation architecture is described that utilises patient-specific models for training in minimally invasive surgery. The datasets are constructed by combining computer tomographic images with bronchoscopy video of the same patient so that the three dimensional structures and visual appearance are accurately matched. Using simulators enriched by a library of datasets with sufficient patient variability, trainees can experience a wide range of realistic scenarios, including rare pathologies, with correct visual information. In this paper, the matching of CT and video data is accomplished by using a newly developed 2D/3D registration method that exploits a shape from shading similarity measure. Additionally, a method has been devised to allow shading parameter estimation by modelling the bidirectional reflectance distribution function (BRDF) of the visible surfaces. The derived BRDF is then used to predict the expected shading intensity such that a texture map independent of lighting conditions can be extracted. Thus new views can be generated that were not captured in the original bronchoscopy video, thus allowing free navigation of the acquired 3D model with enhanced photo-realism. | false | false | [
"Adrian James Chung",
"Fani Deligianni",
"Pallav L. Shah",
"Athol Wells",
"Guang-Zhong Yang"
] | [] | [] | [] |
EuroVis | 2,005 | VisBiz: A Business Process Visualization Case Study | 10.2312/VisSym/EuroVis05/109-116 | Business process management involves many parameters and relationships and is modeled as complex business process workflows. A common way to analyze the process data is by using flowcharts. Visual analysis of a largescale chart, however, is too complex. In this case study, we employ a novel visualization technique, called VisBiz. VisBiz reduces data complexity by automatically analyzing operational data and abstracting the most critical parameters that influence business process. The basic idea is to select the most relevant parameters and layout them on a "triple-attributes" circular graph based on their relationships and user domain knowledge. VizBiz transforms the attributes to nodes and the process flows to lines. VisBiz derives a new process flow matrix to link the process of multiple circular graphs as the analyst introduces more parameters for further analysis. The results of the real-world credit card fraud study show the significant advantages of this technique in finding fraud distribution patterns and root causes of frauds. | false | false | [
"Ming C. Hao",
"Daniel A. Keim",
"Umeshwar Dayal",
"Jörn Schneidewind"
] | [] | [] | [] |
EuroVis | 2,005 | Visualisation and Analysis of Large and Complex Scale-free Networks | 10.2312/VisSym/EuroVis05/239-246 | Scale-free networks appear in many application domains such as social and biological networks [BA99, BB03, BO04]. Roughly speaking, scale-free networks have power-law degree distribution, ultra-short average path length and high clustering coefficient [BA99, BB03, BO04].
This paper presents new methods for visualising scale-free networks in three dimensions. To make effective use of the third dimension and minimise occlusion, we produce graph visulaisations with nodes constrained to lie on parallel planes or on the surface of spheres.
We implement the algorithms using a variation of a fast force-directed graph layout method [QE00]. Results with real world data sets such as IEEE InfoVis citation and collaboration networks and a protein-protein interaction network show that our method can be useful for visual analysis of large and complex scale-free networks. We also discuss the issue of visualisation of evolving networks and network integration. | false | false | [
"Adel Ahmed",
"Tim Dwyer",
"Seok-Hee Hong 0001",
"Colin Murray",
"Le Song",
"Ying Xin Wu"
] | [] | [] | [] |
EuroVis | 2,005 | Visualization for Validation and Improvement of Three-dimensional Segmentation Algorithms | 10.2312/VisSym/EuroVis05/093-100 | The Berkeley Drosophila Transcription Network Project (BDTNP) is developing a suite of methods that will allow a quantitative description and analysis of three dimensional (3D) gene expression patterns in an animal with cellular resolution. An important component of this approach are algorithms that segment 3D images of an organism into individual nuclei and cells and measure relative levels of gene expression. As part of the BDTNP, we are developing tools for interactive visualization, control, and verification of these algorithms. Here we present a volume visualization prototype system that, combined with user interaction tools, supports validation and quantitative determination of the accuracy of nuclear segmentation. Visualizations of nuclei are combined with information obtained from a nuclear segmentation mask, supporting the comparison of raw data and its segmentation. It is possible to select individual nuclei interactively in a volume rendered image and identify incorrectly segmented objects. Integration with segmentation algorithms, implemented in MATLAB, makes it possible to modify a segmentation based on visual examination and obtain additional information about incorrectly segmented objects. This work has already led to significant improvements in segmentation accuracy and opens the way to enhanced analysis of images of complex animal morphologies. | false | false | [
"Gunther H. Weber",
"Cris L. Luengo Hendriks",
"Soile V. E. Keränen",
"Scott E. Dillard",
"Derek Y. Ju",
"Damir Sudar",
"Bernd Hamann"
] | [] | [] | [] |
EuroVis | 2,005 | Visualization of Computer-Modeled Forests for Forest Management | 10.2312/VisSym/EuroVis05/183-190 | Forest management is a costly and time-consuming activity. Remote sensing has the potential to improve the process by making it cheaper and more efficient, but only if appropriate characteristics can be determined from computer-models. This paper describes the implementation of a forest visualization system and a corresponding user study that tests the accuracy of parameter estimation and forest characterization. The study uses data obtained from field-surveys to generate a computer-modeled forest. Five different stands were tested. Based on the quantitative results obtained, generally, there is no statistically significant difference in parameter estimation when comparing field-recorded videos and computer-generated videos. | false | false | [
"Mahnas Jean Mohammadi-Aragh",
"Ikuko Fujisaki",
"Derek Irby",
"David L. Evans",
"Robert J. Moorhead",
"Scott Roberts"
] | [] | [] | [] |
CHI | 2,005 | Feature congestion: a measure of display clutter | 10.1145/1054972.1055078 | Management of clutter is an important factor in the design of user interfaces and information visualizations, allowing improved usability and aesthetics. However, clutter is not a well defined concept. In this paper, we present the Feature Congestion measure of display clutter. This measure is based upon extensive modeling of the saliency of elements of a display, and upon a new operational definition of clutter. The current implementation is based upon two features: color and luminance contrast. We have tested this measure on maps that observers ranked by perceived clutter. Results show good agreement between the observers' rankings and our measure of clutter. Furthermore, our measure can be used to make design suggestions in an automated UI critiquing tool. | false | false | [
"Ruth Rosenholtz",
"Yuanzhen Li",
"Jonathan Mansfield",
"Zhenlan Jin"
] | [] | [] | [] |
CHI | 2,005 | Improving aviation safety with information visualization: a flight simulation study | 10.1145/1054972.1055033 | Many aircraft accidents each year are caused by encounters with invisible airflow hazards. Recent advances in aviation sensor technology offer the potential for aircraft-based sensors that can gather large amounts of airflow velocity data in real-time. With this influx of data comes the need to study how best to present it to the pilot - a cognitively overloaded user focused on a primary task other than that of information visualization.We focus on one particular aviation application, but the results may be relevant to user interfaces in other operationally stressful environments. | false | false | [
"Cecilia R. Aragon",
"Marti A. Hearst"
] | [] | [] | [] |
CHI | 2,005 | prefuse: a toolkit for interactive information visualization | 10.1145/1054972.1055031 | Although information visualization (infovis) technologies have proven indispensable tools for making sense of complex data, wide-spread deployment has yet to take hold, as successful infovis applications are often difficult to author and require domain-specific customization. To address these issues, we have created prefuse, a software framework for creating dynamic visualizations of both structured and unstructured data. prefuse provides theoretically-motivated abstractions for the design of a wide range of visualization applications, enabling programmers to string together desired components quickly to create and customize working visualizations. To evaluate prefuse we have built both existing and novel visualizations testing the toolkit's flexibility and performance, and have run usability studies and usage surveys finding that programmers find the toolkit usable and effective. | false | false | [
"Jeffrey Heer",
"Stuart K. Card",
"James A. Landay"
] | [] | [] | [] |
CHI | 2,005 | Studying the effectiveness of MOVE: a contextually optimized in-vehicle navigation system | 10.1145/1054972.1055051 | In-vehicle navigation has changed substantially in recent years, due to the advent of computer generated maps and directions. However, these maps are still problematic, due to a mismatch between the complexity of the maps and the attentional demands of driving. In response to this problem, we are developing the MOVE (Maps Optimized for Vehicular Environments) system. This system will provide situationally appropriate map information by presenting information that uses appropriate amounts of the driver's attention. In this paper, we describe our findings of studies to help shape the design of the MOVE system, including studies on map reading and in-vehicle navigation, and studies on the effectiveness of a variety of contextually optimized route map visualizations in a simulated driving context.Results show that contextually optimized displays designed for the MOVE system should significantly reduce perceptual load in the context of driving. In our laboratory experiment there was a six-fold decrease in the total map display fixation time and nearly threefold decrease in the number of glances needed to interpret the contextually optimized display compared to a static display. | false | false | [
"Joonhwan Lee",
"Jodi Forlizzi",
"Scott E. Hudson"
] | [] | [] | [] |
CHI | 2,005 | Use of eye movements as feedforward training for a synthetic aircraft inspection task | 10.1145/1054972.1054993 | Aircraft inspection is a vital element in assuring safety and reliability of the air transportation system. The human inspector performing visual inspection of an aircraft is the backbone of this process and training is an effective strategy for improving their inspection performance. Previous studies have shown offline feedback training to be effective in improving subsequent visual inspection performance. Because experienced inspectors are known to adopt a better inspection strategy than novices, providing visualization of experts' cognitive processes a priori can accelerate novices' adoption of the experts' strategy. Using eye tracking equipment, we record the point of regard of an expert inspector performing an inspection task in a virtual reality simulator. Analysis of their eye movements leads to a visualization of their scanpaths and allows us to display the inspector's visual search (hence cognitive) strategy. We show how providing this type of scanpath-based feedforward training of novices leads to improved accuracy performance in the simulator coupled with an observed speed-accuracy tradeoff. We contend that the tradeoff results from trained novices adopting a slower paced strategy through increased fixation durations, suggesting trained novices learn a more deliberate target search/discrimination strategy that requires more time to execute. | false | false | [
"Sajay Sadasivan",
"Joel S. Greenstein",
"Anand K. Gramopadhye",
"Andrew T. Duchowski"
] | [] | [] | [] |
CHI | 2,005 | Visualization of mappings between schemas | 10.1145/1054972.1055032 | In this paper we describe a novel approach to the visualization of the mapping between two schemas. Current approaches to visually defining such a mapping fail when the schemas or maps become large. The new approach uses various information visualization techniques to simplify the view, making it possible for users to effectively deal with much larger schemas and maps. A user study verifies that the new approach is useful, usable, and effective. The primary contribution is a demonstration of novel ways to effectively present highly complex information. | false | false | [
"George G. Robertson",
"Mary Czerwinski",
"John E. Churchill"
] | [] | [] | [] |
CHI | 2,005 | Who gets to know what when: configuring privacy permissions in an awareness application | 10.1145/1054972.1054987 | We report on a study (N=36) of user preferences for balancing awareness with privacy. Participants defined permissions for sharing of location, availability, calendar information and instant messaging (IM) activity within an application called mySpace. MySpace is an interactive visualization of the physical workplace that provides dynamic information about people, places and equipment. We found a significant preference for defining privacy permissions at the group level. While "family" received high levels of awareness sharing, interestingly, "team" was granted comparable levels during business hours at work. Surprisingly, presenting participants with a detailed list of all pieces of personal context to which the system had access, did not result in more conservative privacy settings. Although location was the most sensitive aspect of awareness, participants were comfortable disclosing room-level location information to their team members at work. Our findings suggest utilizing grouping mechanisms to balance privacy control with configuration burden, and argue for increased system transparency to build trust. | false | false | [
"Sameer Patil",
"Jennifer Lai"
] | [] | [] | [] |
Vis | 2,004 | 2D Maps for Visual Analysis and Retrieval in Large Multi-Feature 3D Model Databases | 10.1109/VISUAL.2004.2 | Multimedia objects are often described by high-dimensional feature vectors which can be used for retrieval and clustering tasks. We have built an interactive retrieval system for 3D model databases that implements a variety of different feature transforms. Recently, we have enhanced the functionality of our system by integrating a SOM-based visualization module. In this poster demo, we show how 2D maps can be used to improve the effectiveness of retrieval, clustering, and over-viewing tasks in a 3D multimedia system. | false | false | [
"Benjamin Bustos",
"Daniel A. Keim",
"Christian Panse",
"Tobias Schreck"
] | [] | [] | [] |
Vis | 2,004 | A graphics hardware-based vortex detection and visualization system | 10.1109/VISUAL.2004.3 | Feature detection in flow fields is a well-researched area, but practical application is often difficult due to the numerical complexity of the algorithms preventing interactive use and due to noise in experimental or high-resolution simulation data sets. We present an integrated system that provides interactive denoising, vortex detection, and visualisation of vector data on Cartesian grids. All three major phases are implemented in such a way that the system runs completely on a modern GPU once the vector field is downloaded into graphics memory. The application aspect of our paper is twofold. First, we show how recently presented, prototypical GPU-based algorithms for filtering, numerical computation, and volume rendering can be combined into one productive system by handling all idiosyncrasies of a chosen graphics card. Second, we demonstrate that the significant speedup achieved compared to an optimized software implementation now allows interactive exploration of characteristic structures in turbulent flow fields. | false | false | [
"Simon Stegmaier",
"Thomas Ertl"
] | [] | [] | [] |
Vis | 2,004 | Adaptive 4-8 texture hierarchies | 10.1109/VISUAL.2004.4 | We address the texture level-of-detail problem for extremely large surfaces such as terrain during realtime, view-dependent rendering. A novel texture hierarchy is introduced based on 4-8 refinements of raster tiles, in which the texture grids in effect rotate 45 degrees for each level of refinement. This hierarchy provides twice as many levels of detail as conventional quadtree-style refinement schemes such as mipmaps, and thus provides per-pixel view-dependent filtering that is twice as close to the ideal cutoff frequency for an average pixel. Because of this more gradual change in low-pass filtering, and due to the more precise emulation of the ideal cutoff frequency, we find in practice that the transitions between texture levels of detail are not perceptible. This allows rendering systems to avoid the complexity and performance costs of per-pixel blending between texture levels of detail. The 4-8 texturing scheme is integrated into a variant of the real-time optimally adapting meshes (ROAM) algorithm for view-dependent multiresolution mesh generation. Improvements to ROAM included here are: the diamond data structure as a streamlined replacement for the triangle bintree elements, the use of low-pass-filtered geometry patches in place of individual triangles, integration of 4-8 textures, and a simple out-of-core data access mechanism for texture and geometry tiles. | false | false | [
"Lok M. Hwa",
"Mark A. Duchaineau",
"Kenneth I. Joy"
] | [
"BP"
] | [] | [] |
Vis | 2,004 | Anisotropic volume rendering for extremely dense, thin line data | 10.1109/VISUAL.2004.5 | Many large scale physics-based simulations which take place on PC clusters or supercomputers produce huge amounts of data including vector fields. While these vector data such as electromagnetic fields, fluid flow fields, or particle paths can be represented by lines, the sheer number of the lines overwhelms the memory and computation capability of a high-end PC used for visualization. Further, very dense or intertwined lines, rendered with traditional visualization techniques, can produce unintelligible results with unclear depth relationships between the lines and no sense of global structure. Our approach is to apply a lighting model to the lines and sample them into an anisotropic voxel representation based on spherical harmonics as a preprocessing step. Then we evaluate and render these voxels for a given view using traditional volume rendering. For extremely large line based datasets, conversion to anisotropic voxels reduces the overall storage and rendering for O(n) lines to O(1) with a large constant that is still small enough to allow meaningful visualization of the entire dataset at nearly interactive rates on a single commodity PC. | false | false | [
"Gregory L. Schussman",
"Kwan-Liu Ma"
] | [] | [] | [] |
Vis | 2,004 | Atlas-Aware Laplacian Smoothing | 10.1109/VISUAL.2004.6 | We consider an image, a result of sampling over a finite two dimensional regular grid a vector valued function of two variables. There is a wealth of work in both theory and application of image processing operations. Our approach is to map into the parameter space then perform image processing operations there. Laplacian smoothing is the building block for defining linear filters, which can be described in terms of polynomials of the Laplacian operator. We focus on extending basic Laplacian smoothing to continuous vector valued functions irregularly sampled on multi-chart parameterized surfaces. Our goal is to efficiently perform Laplacian smoothing with out introducing seam artifacts. We present an algorithm for Laplacian smoothing over a texture atlas which takes into account the discontinuities imposed by the charts. Our general approach is based on the finite volume method, and the graph Laplacian used in geometric signal processing. In image processing, the Laplacian of an image is obtained by convolving the image with the following 3×3 kernel: | false | false | [
"Peter G. Sibley",
"Gabriel Taubin"
] | [] | [] | [] |
Vis | 2,004 | Augmented reality with tangible auto-fabricated models for molecular biology applications | 10.1109/VISUAL.2004.7 | The evolving technology of computer auto-fabrication ("3D printing") now makes it possible to produce physical models for complex biological molecules and assemblies. We report on an application that demonstrates the use of auto-fabricated tangible models and augmented reality for research and education in molecular biology, and for enhancing the scientific environment for collaboration and exploration. We have adapted an augmented reality system to allow virtual 3D representations (generated by the Python Molecular Viewer) to be overlaid onto a tangible molecular model. Users can easily change the overlaid information, switching between different representations of the molecule, displays of molecular properties such as electrostatics, or dynamic information. The physical model provides a powerful, intuitive interface for manipulating the computer models, streamlining the interface between human intent, the physical model, and the computational activity. | false | false | [
"Alexandre Gillet",
"Michel F. Sanner",
"Daniel Stoffler",
"David S. Goodsell",
"Arthur J. Olson"
] | [] | [] | [] |
Vis | 2,004 | Automatic Fast Detection of Tumor Suspect Areas on CT Scan | 10.1109/VISUAL.2004.9 | Our research deals with a fully automatic and fast visualization of possible tumoral areas on CT Scan images. To achieve this task, we use the bilateral symmetry of the human body and the asymmetry introduced by the presence of tumors. Our work was initially dedicated to the head and neck area but it should work well for any other body part and even better for more symmetric areas like the brain. | false | false | [
"Matei Mancas",
"Bernard Gosselin",
"Benoît Macq"
] | [] | [] | [] |
Vis | 2,004 | Building an Ontology of Visualization | 10.1109/VISUAL.2004.10 | Recent activity within the UK National e-Science Programme has identified a need to establish an ontology for visualization. Motivation for this includes defining web and grid services for visualization (the ‘semantic grid’), supporting collaborative work, curation, and underpinning visualization research and education. At a preliminary meeting, members of the UK visualization community identified a skeleton for the ontology. We have started to build on this by identifying how existing work might be related and utilized. We believe that the greatest challenge is reaching a consensus within the visualization community itself. This poster is intended as one step in this process, setting out the perceived needs for the ontology, and sketching initial directions. It is hoped that this will lead to debate, feedback and involvement across the community. | false | false | [
"David J. Duke",
"Ken Brodlie",
"David A. Duce"
] | [] | [] | [] |
Vis | 2,004 | Capillary Histology Imagery Visualization and Exploration | 10.1109/VISUAL.2004.11 | In this poster, we describe the Capillary Histology Imagery Visualization and Exploration (CHIVE) project that is developing new tools for studying the vascular system in the mouse brain. Our ultimate goal is to understand the micro-vascular architecture of the brain and its role in development and disease. The size and complexity of brain vasculature demands a new methodology for study. We are developing such a methodology for imaging and examining the micro-vasculature of the mouse brain. To study the vascular system in the brain, we need an imaging modality capable of seeing the capillaries, the smallest vessels that ultimately deliver oxygen and nutrients from the blood. We are interested in the patternings of these vessels throughout the brain. This requires an imaging modality capable of extremely high resolution: we must resolve individual capillaries that are a few microns wide, over the entire brain. At present, the only method capable of this resolution is histology and montage-microscopy: physically sectioning a specimen and imaging it under a light microscope. The histological process produces a unique dataset containing an immense amount of small details over a large volume. To make use of this data, we have needed to develop a new suite of tools for visualization and analysis. The result is a visualization system that allows a scientist to work with the large image sets that result from histology in a way that supports exploration and analysis that is tuned to the unusual features of the image sets. In the poster summarized in this abstract we will outline our protocol for data collection and the types of data it creates. We will describe how the features of the data lead to challenges for visualization and analysis. We will describe our preliminary system for working with the data, CHIVE, and describe how it responds to some of these challenges. We conclude by discussing some of the issues CHIVE does not presently address. | false | false | [
"Michael Gleicher",
"Tom Brunet",
"K. Evan Nowak",
"Liz Osten",
"Matt McElwee",
"Kevin Tanty",
"Adam Gepner",
"Garet Lahvis"
] | [] | [] | [] |
Vis | 2,004 | Centroidal Voronoi tessellation based algorithms for vector fields visualization and segmentation | 10.1109/VISUAL.2004.13 | A new method for the simplification and the visualization of vector fields is presented based on the notion of centroidal Voronoi tessellations (CVT's). A CVT is a special Voronoi tessellation for which the generators of the Voronoi regions in the tessellation are also the centers of mass (or means) with respect to a prescribed density. A distance function in both the spatial and vector spaces is introduced to measure the similarity of the spatially distributed vector fields. Based on such a distance, vector fields are naturally clustered and their simplified representations are obtained. Our method combines simple geometric intuitions with the rigorously established optimality properties of the CVTs. It is simple to describe, easy to understand and implement. Numerical examples are also provided to illustrate the effectiveness and competitiveness of the CVT-based vector simplification and visualization methodology. | false | false | [
"Qiang Du 0001",
"Xiaoqiang Wang 0002"
] | [] | [] | [] |
Vis | 2,004 | Code Checking and Visualization of an Architecture Design | 10.1109/VISUAL.2004.14 | Computer graphics has be successfully applied to architecture design. There is more demand to new applications. One of them, to be addressed in this work, is the code checking and visualization of the checking results. | false | false | [
"Rong Xu",
"Wawan Solihin",
"Zhiyong Huang"
] | [] | [] | [] |
Vis | 2,004 | Compatible triangulations of spatial decompositions | 10.1109/VISUAL.2004.15 | We describe a general algorithm to produce compatible 3D triangulations from spatial decompositions. Such triangulations match edges and faces across spatial cell boundaries, solving several problems in graphics and visualization including the crack problem found in adaptive isosurface generation, triangulation of arbitrary grids (including unstructured grids), clipping, and the interval tetrahedrization problem. The algorithm produces compatible triangulations on a cell-by-cell basis, using a modified Delaunay triangulation with a simple point ordering rule to resolve degenerate cases and produce unique triangulations across cell boundaries. The algorithm is naturally parallel since it requires no neighborhood cell information, only a unique, global point numbering. We show application of this algorithm to adaptive contour generation; tetrahedrization of unstructured meshes; clipping and interval volume mesh generation. | false | false | [
"William J. Schroeder",
"Berk Geveci",
"Mathieu Malaterre"
] | [] | [] | [] |
Vis | 2,004 | Compression, Segmentation, and Modeling of Large-Scale Filamentary Volumetric Data | 10.1109/VISUAL.2004.16 | We describe a method for processing large amounts of volumetric data collected from a Knife Edge Scanning Microscope (KESM). The neuronal data that we acquire consists of thin, branching structures extending over very large regions that prior volumetric representations have difficulty dealing with efficiently. Since the full volume data set can be extremely large, on-the-fly processing of the data is necessary. | false | false | [
"Bruce H. McCormick",
"Purna Doddapaneni",
"David Mayerich",
"Zeki Melek",
"John Keyser"
] | [] | [] | [] |
Vis | 2,004 | Constrained inverse volume rendering for planetary nebulae | 10.1109/VISUAL.2004.18 | Determining the three-dimensional structure of distant astronomical objects is a challenging task, given that terrestrial observations provide only one viewpoint. For this task, bipolar planetary nebulae are interesting objects of study because of their pronounced axial symmetry due to fundamental physical processes. Making use of this symmetry constraint, we present a technique to automatically recover the axisymmetric structure of bipolar planetary nebulae from two-dimensional images. With GPU-based volume rendering driving a nonlinear optimization, we estimate the nebula's local emission density as a function of its radial and axial coordinates, and we recover the orientation of the nebula relative to Earth. The optimization refines the nebula model and its orientation by minimizing the differences between the rendered image and the original astronomical image. The resulting model enables realistic 3D visualizations of planetary nebulae, e.g. for educational purposes in planetarium shows. In addition, the recovered spatial distribution of the emissive gas allows validating computer simulation results of the astrophysical formation processes of planetary nebulae. | false | false | [
"Marcus A. Magnor",
"Gordon L. Kindlmann",
"Neb Duric",
"Charles D. Hansen"
] | [] | [] | [] |
Vis | 2,004 | Context-Adaptive Mobile Visualization and Information Management | 10.1109/VISUAL.2004.19 | This poster abstract presents a scalable information visualization system for mobile devices and desktop systems. It is designed to support the operation and the workflow of wastewater systems. The regarded information data includes general information about buildings and units, process data, occupational safety regulations, work directions and first aid instructions in case of an accident. Technically, the presented framework combines visualization with agent technology in order to automatically scale various visualization types to fit on different platforms like PDAs (Personal Digital Assistants) or Tablet PCs. The implementation is based on but not limited to SQL, JSP, HTML and VRML. | false | false | [
"Jochen Ehret",
"Achim Ebert",
"Lars Schuchardt",
"Heidrun Steinmetz",
"Hans Hagen"
] | [] | [] | [] |
Vis | 2,004 | DaMI - Data Management for Multimedial Information Systems | 10.1109/VISUAL.2004.21 | This paper describes a Data Management System for Multimedial Information Visualization called DaMI. It is possible to create 2D or 3D model based on data out of standard databases and additional metainformation. DaMI is a generic system guaranteeing an optimal reusability and compatibility. | false | false | [
"Hans Hagen",
"Gerhard Steinebach",
"Michael Münchhofen",
"Inga Scheler",
"Maja Ruby",
"Michael Wadlé"
] | [] | [] | [] |
Vis | 2,004 | Depth Enhanced Panoramas | 10.1109/VISUAL.2004.22 | We describe a method for interactive modeling and visualization of room-size indoor scenes that is fast, easy, and inexpensive. We have designed a novel data acquisition device, called a ModelCamera, that consists of a video camera with an attached laser system that generates a 7x7 pattern of depth samples. The operator pans and tilts the ModelCamera around the camera's center of projection and it acquires a sequence of color and depth frames. The frames are registered in world coordinates and are merged into an evolving scene model, called a depth enhanced panorama. The model is visualized continually; the immediate feedback allows the operator to monitor the model quality and to identify missing scene surfaces. Our approach extends color panoramas to support viewpoint translation, while retaining their speed, convenience, and low cost (Figure 1). It is a practical alternative to modeling systems that provide complete models at a high cost. | false | false | [
"Gleb Bahmutov",
"Voicu Popescu",
"Elisha Sacks"
] | [] | [] | [] |
Vis | 2,004 | Detection and visualization of anomalous structures in molecular dynamics simulation data | 10.1109/VISUAL.2004.23 | We explore techniques to detect and visualize features in data from molecular dynamics (MD) simulations. Although the techniques proposed are general, we focus on silicon (Si) atomic systems. The first set of methods use 3D location of atoms. Defects are detected and categorized using local operators and statistical modeling. Our second set of exploratory techniques employ electron density data. This data is visualized to glean the defects. We describe techniques to automatically detect the salient isovalues for isosurface extraction and designing transfer functions. We compare and contrast the results obtained from both sources of data. Essentially, we find that the methods of defect (feature) detection are at least as robust as those based on the exploration of electron density for Si systems. | false | false | [
"Sameep Mehta",
"Kaden Hazzard",
"Raghu Machiraju",
"Srinivasan Parthasarathy 0001",
"John Wilkins"
] | [] | [] | [] |
Vis | 2,004 | Dispersion simulation and visualization for urban security | 10.1109/VISUAL.2004.24 | We present a system for simulating and visualizing the propagation of dispersive contaminants with an application to urban security. In particular, we simulate airborne contaminant propagation in open environments characterised by sky-scrapers and deep urban canyons. Our approach is based on the multiple relaxation time lattice Boltzmann model (MRTLBM), which can efficiently handle complex boundary conditions such as buildings. In addition, we model thermal effects on the flow field using the hybrid thermal MRTLBM. Our approach can also accommodate readings from various sensors distributed in the environment and adapt the simulation accordingly. We accelerate the computation and efficiently render many buildings with small textures on the GPU. We render streamlines and the contaminant smoke with self-shadowing composited with the textured buildings. | false | false | [
"Feng Qiu",
"Ye Zhao 0004",
"Zhe Fan",
"Xiaoming Wei",
"Haik Lorenz",
"Jianning Wang",
"Suzanne Yoakum-Stover",
"Arie E. Kaufman",
"Klaus Mueller 0001"
] | [] | [] | [] |
Vis | 2,004 | Display of vector fields using a reaction-diffusion model | 10.1109/VISUAL.2004.25 | Effective visualization of vector fields relies on the ability to control the size and density of the underlying mapping to visual cues used to represent the field. In this paper we introduce the use of a reaction-diffusion model, already well known for its ability to form irregular spatio-temporal patters, to control the size, density, and placement of the vector field representation. We demonstrate that it is possible to encode vector field information (orientation and magnitude) into the parameters governing a reaction-diffusion model to form a spot pattern with the correct orientation, size, and density, creating an effective visualization. To encode direction we texture the spots using a light to dark fading texture. We also show that it is possible to use the reaction-diffusion model to visualize an additional scalar value, such as the uncertainty in the orientation of the vector field. An additional benefit of the reaction-diffusion visualization technique arises from its automatic density distribution. This benefit suggests using the technique to augment other vector visualization techniques. We demonstrate this utility by augmenting a LIC visualization with a reaction-diffusion visualization. Finally, the reaction-diffusion visualization method provides a technique that can be used for streamline and glyph placement. | false | false | [
"Allen R. Sanderson",
"Christopher R. Johnson 0001",
"Robert M. Kirby"
] | [] | [] | [] |
Vis | 2,004 | DTI Fiber Clustering in the Whole Brain | 10.1109/VISUAL.2004.26 | References [1] Ding et al. Classification and quantification of neuronal fiber pathways using diffusion tensor MRI. Magnetic Resonance in Medicine, 49:716–721, 2003. [2] Corouge et al. Towards a shape model of white matter fiber bundles using diffusion tensor MRI. In International Symposium on Biomedical Imaging, pages 344–347, 2004. [3] Zhang et al. Visualizing diffusion tensor MR images using streamtubes and streamsurfaces. IEEE Transactions on Visualization and Computer Graphics, 9(4):454–462, October 2003. [4] Duda et al. Pattern Classification. Wiley-Interscience Publication, 2000. Introduction | false | false | [
"Song Zhang 0004",
"David H. Laidlaw"
] | [] | [] | [] |
Vis | 2,004 | Dual contouring with topology-preserving simplification using enhanced cell representation | 10.1109/VISUAL.2004.27 | We present a fast, topology-preserving approach for isosurface simplification. The underlying concept behind our approach is to preserve the disconnected surface components in cells during isosurface simplification. We represent isosurface components in a novel representation, called enhanced cell, where each surface component in a cell is represented by a vertex and its connectivity information. A topology-preserving vertex clustering algorithm is applied to build a vertex octree. An enhanced dual contouring algorithm is applied to extract error-bounded multiresolution isosurfaces from the vertex octree while preserving the finest resolution isosurface topology. Cells containing multiple vertices are properly handled during contouring. Our approach demonstrates better results than existing octree-based simplification techniques. | false | false | [
"Nan Zhang 0011",
"Wei Hong 0006",
"Arie E. Kaufman"
] | [] | [] | [] |
Vis | 2,004 | Dual marching cubes | 10.1109/VISUAL.2004.28 | We present the definition and computational algorithms for a new class of surfaces which are dual to the isosurface produced by the widely used marching cubes (MC) algorithm. These new isosurfaces have the same separating properties as the MC surfaces but they are comprised of quad patches that tend to eliminate the common negative aspect of poorly shaped triangles of the MC isosurfaces. Based upon the concept of this new dual operator, we describe a simple, but rather effective iterative scheme for producing smooth separating surfaces for binary, enumerated volumes which are often produced by segmentation algorithms. Both the dual surface algorithm and the iterative smoothing scheme are easily implemented. | false | false | [
"Gregory M. Nielson"
] | [] | [] | [] |
Vis | 2,004 | Efficient point-based isosurface exploration using the span-triangle | 10.1109/VISUAL.2004.29 | We introduce a novel span-triangle data structure, based on the span-space representation for isosurfaces. It stores all necessary cell information for dynamic manipulation of the isovalue in an efficient way. We have found that using our data structure in combination with point-based techniques, implemented on graphics hardware, effects in real-time rendering and exploration. Our extraction algorithm utilizes an incremental and progressive update scheme, enabling smooth interaction without significant latency. Moreover, the corresponding visualization pipeline is capable of processing large data sets by utilizing all three levels of memory: disk, system and graphics. We address practical usability in actual medical applications, achieving a new level of interactivity. | false | false | [
"Bartosz von Rymon-Lipinski",
"Nils Hanssen",
"Thomas Jansen 0005",
"Lutz Ritter",
"Erwin Keeve"
] | [] | [] | [] |
Vis | 2,004 | Exploration of the brain's white matter pathways with dynamic queries | 10.1109/VISUAL.2004.30 | Diffusion tensor imaging (DTI) is a magnetic resonance imaging method that can be used to measure local information about the structure of white matter within the human brain. Combining DTI data with the computational methods of MR tractography, neuroscientists can estimate the locations and sizes of nerve bundles (white matter pathways) that course through the human brain. Neuroscientists have used visualization techniques to better understand tractography data, but they often struggle with the abundance and complexity of the pathways. We describe a novel set of interaction techniques that make it easier to explore and interpret such pathways. Specifically, our application allows neuroscientists to place and interactively manipulate box-shaped regions (or volumes of interest) to selectively display pathways that pass through specific anatomical areas. A simple and flexible query language allows for arbitrary combinations of these queries using Boolean logic operators. Queries can be further restricted by numerical path properties such as length, mean fractional anisotropy, and mean curvature. By precomputing the pathways and their statistical properties, we obtain the speed necessary for interactive question-and-answer sessions with brain researchers. We survey some questions that researchers have been asking about tractography data and show how our system can be used to answer these questions efficiently. | false | false | [
"David Akers",
"Anthony J. Sherbondy",
"Rachel Mackenzie",
"Robert F. Dougherty",
"Brian A. Wandell"
] | [] | [] | [] |
Vis | 2,004 | Fast Rendering of Foveated Volume in the Wavelet Domain | 10.1109/VISUAL.2004.31 | A design issue in remote visualization is on the mapping of the viewer’s intention to the relevant data to be sent. One possible approach is to let the viewer interactively indicate the region of interests (ROI), and objects in the ROI will have higher priority during transmission. For media objects like images and video, foveation has been used to formulate the priority of spatial information. Foveation can be treated as a way to distribute information across the space, in order to have wide coverage and yet high concentration in the interesting location. There are a number of works on image transmission and video encing exploiting the compression rate provided by foveation [Basu et 1993; Basu and Wiebe 1998; Chang et al. 20001. From another perspective, foveation can be viewed as a way to distribute computing resources across space. For example, Levoy et [Levoy and Whitaker propose to use foveation to speed up volume rendering. In this paper, we presented a novel algorithm for fast rendering volumes with special structure: foveated volumes. Our major contribution is to exploit the implicit structure of the foveated volume, different from other types of data, t o accelerate the volume rendering. We render a foveated volume directly in the Wavelet domain, and its running time depends mainly on the number of relevant coefficients. Potentially, foveation can be exploited in remote volume visualization to give a fast rendering that does not depend on the size of the full resolution volume. | false | false | [
"Hang Yu",
"Ee-Chien Chang",
"Zhiyong Huang",
"Zhijian Zheng"
] | [] | [] | [] |
Vis | 2,004 | Flow field clustering via algebraic multigrid | 10.1109/VISUAL.2004.32 | We present a novel multiscale approach for flow visualization. We define a local alignment tensor that encodes a measure for alignment to the direction of a given flow field. This tensor induces an anisotropic differential operator on the flow domain, which is discretized with a standard finite element technique. The entries of the corresponding stiffness matrix represent the anisotropically weighted couplings of adjacent nodes of the domain mesh. We use an algebraic multigrid algorithm to generate a hierarchy of fine to coarse descriptions for the above coupling data. This hierarchy comprises a set of coarse grid nodes, a multiscale of basis functions and their corresponding supports. We use these supports to obtain a multilevel decomposition of the flow structure. Standard streamline icons are used to visualize this decomposition at any user-selected level of detail. The method provides a single framework for vector field decomposition independent on the domain dimension or mesh type. Applications are shown in 2D, for flow fields on curved surfaces, and for 3D volumetric flow fields. | false | false | [
"Michael Griebel",
"Tobias Preußer",
"Martin Rumpf",
"Marc Alexander Schweitzer",
"Alexandru C. Telea"
] | [] | [] | [] |
Vis | 2,004 | Force-Feedback-Enhanced Navigation for Interactive Visualization of Coronary Vessels | 10.1109/VISUAL.2004.33 | Coronary heart disease (CHD) is the number one killer in the United States. Although it is well known that CHD mainly occurs due to blocked arteries, there are contradictory results from studies designed to identify basic causes for this common disease is. To find out more about the true reason for CHD, virtual models can be employed to better understand the way the heart functions. With such a model, scientists and surgeons are able to analyze the effects of different treatment options, and ultimately find more suited ways to prevent coronary heart diseases. To investigate a given model, appropriate navigation methods are required, including suitable input devices. For the visualization, graphics cards originally designed for gaming applications are used; so, it is a just natural transition to adapt gaming input devices to a visualization system for controlling of the navigation. These devices are usually well designed with respect to ergonomics and durability, yielding more degrees of freedom in steering than two-dimensional input devices, such as desktop mice. This poster describes a visualization system that provides the user with advanced control devices for navigation enabling interactive exploration of the model. Force-feedback and sound effects provide additional cues. | false | false | [
"Thomas Wischgoll",
"Elke Moritz",
"Jörg Meyer 0002"
] | [] | [] | [] |
Vis | 2,004 | Generating realistic images from hydrothermal plume data | 10.1109/VISUAL.2004.34 | Most data used in the study of seafloor hydrothermal plumes consists of sonar (acoustic) scans and sensor readings. Visual data captures only a portion of the sonar data range due to the prohibitive cost and physical infeasibility of taking sufficient lighting and video equipment to such extreme depths. However, visual images are available from research dives and from the recent IMAX movie, volcanoes of the deep sea. In this application paper, we apply existing lighting models with forward scattering and light attenuation to the 3D sonar data in order to mimic the visual images available. These generated images are compared to existing visual images. This can help the geoscientists understand the relationship between these different data modalities and elucidate some of the mechanisms used to capture the data. | false | false | [
"Kristina Santilli",
"Karen G. Bemis",
"Deborah Silver",
"Jamshed Dastur",
"Peter A. Rona"
] | [] | [] | [] |
Vis | 2,004 | Generating sub-resolution detail in images and volumes using constrained texture synthesis | 10.1109/VISUAL.2004.35 | A common deficiency of discretized datasets is that detail beyond the resolution of the dataset has been irrecoverably lost. This lack of detail becomes immediately apparent once one attempts to zoom into the dataset and only recovers blur. We describe a method that generates the missing detail from any available and plausible high-resolution data, using texture synthesis. Since the detail generation process is guided by the underlying image or volume data and is designed to fill in plausible detail in accordance with the coarse structure and properties of the zoomed-in neighborhood, we refer to our method as constrained texture synthesis. Regular zooms become "semantic zooms", where each level of detail stems from a data source attuned to that resolution. We demonstrate our approach by a medical application - the visualization of a human liver - but its principles readily apply to any scenario, as long as data at all resolutions are available. We first present a 2D viewing application, called the "virtual microscope", and then extend our technique to 3D volumetric viewing. | false | false | [
"Lujin Wang",
"Klaus Mueller 0001"
] | [] | [] | [] |
Vis | 2,004 | Guaranteed quality triangulation of molecular skin surfaces | 10.1109/VISUAL.2004.36 | We present an efficient algorithm to mesh the macromolecules surface model represented by the skin surface defined by Edelsbrunner. Our algorithm overcomes several challenges residing in current surface meshing methods. First, we guarantee the mesh quality with a provable lower bound of 21/spl deg/ on its minimum angle. Second, we ensure the triangulation is homeomorphic to the original surface. Third, we improve the efficiency of constructing the restricted Delaunay triangulation (RDT) of smooth surfaces. We achieve this by constructing the RDT using the advancing front method without computing the Delaunay tetrahedrization of the sample points on the surfaces. The difficulty of handling the front collision problem is tackled by employing the Morse theory. In particular, we construct the Morse-Smale complex to simplify the topological changes of the front. Our implementation results suggest that the algorithm decrease the time of generating high quality homeomorphic skin mesh from hours to a few minutes. | false | false | [
"Ho-Lun Cheng",
"Xinwei Shi"
] | [] | [] | [] |
Vis | 2,004 | Haptic display of interaction between textured models | 10.1109/VISUAL.2004.37 | Surface texture is among the most salient haptic characteristics of objects; it can induce vibratory contact forces that lead to perception of roughness. We present a new algorithm to display haptic texture information resulting from the interaction between two textured objects. We compute contact forces and torques using low-resolution geometric representations along with texture images that encode surface details. We also introduce a novel force model based on directional penetration depth and describe an efficient implementation on programmable graphics hardware that enables interactive haptic texture rendering of complex models. Our force model takes into account important factors identified by psychophysics studies and is able to haptically display interaction due to fine surface textures that previous algorithms do not capture. | false | false | [
"Miguel A. Otaduy",
"Nitin Jain",
"Avneesh Sud",
"Ming C. Lin"
] | [] | [] | [] |
Vis | 2,004 | Hardware-accelerated adaptive EWA volume splatting | 10.1109/VISUAL.2004.38 | We present a hardware-accelerated adaptive EWA (elliptical weighted average) volume splatting algorithm. EWA splatting combines a Gaussian reconstruction kernel with a low-pass image filter for high image quality without aliasing artifacts or excessive blurring. We introduce a novel adaptive filtering scheme to reduce the computational cost of EWA splatting. We show how this algorithm can be efficiently implemented on modern graphics processing units (GPUs). Our implementation includes interactive classification and fast lighting. To accelerate the rendering we store splat geometry and 3D volume data locally in GPU memory. We present results for several rectilinear volume datasets that demonstrate the high image quality and interactive rendering speed of our method. | false | false | [
"Wei Chen 0001",
"Ren Liu",
"Matthias Zwicker",
"Hanspeter Pfister"
] | [] | [] | [] |
Vis | 2,004 | Hierarchy Based 3D Visualization of Large Software Structures | 10.1109/VISUAL.2004.39 | Modern object-oriented programs are hierarchical systems with many thousands of interrelated subsystems. Visualization helps developers to better comprehend these large and complex systems. This work presents a three-dimensional visualization technique that represents the static structure of object-oriented software using distributions of three-dimensional objects on a two-dimensional plane. The visual complexity is reduced by adjusting the transparency of object surfaces to the distance of the viewpoint. An approach called Hierarchical Net is proposed for a clear representation of the relationships between the subsystems. | false | false | [
"Michael Balzer",
"Oliver Deussen"
] | [] | [] | [] |
Vis | 2,004 | ImageSurfer: a tool for visualizing correlations between two volume scalar fields | 10.1109/VISUAL.2004.46 | ImageSurfer is a tool designed to explore correlations between two 3D scalar fields. Our scientific goal was to determine where a protein is located, and how much its concentration varies along the membrane of a neuronal dendrite. The 3D scalar field data sets fall into two categories: dendritic plasma membranes (defining the structure) and immunofluorescent staining (defining protein concentration along the structure). ImageSurfer enables scientists to analyze relationships between multiple data sets obtained with confocal microscopy by providing 3D surface view, height field, and graphing tools. Each tool reduces the complexity of the problem by extracting a restricted subset of data: finding a region of interest in 3D; getting a sense of relative concentrations in 2D, and getting exact concentration values in 1D. The current design is presented, along with the rationale for each design decision. The tool is already proving useful for data exploration, analysis, and presentation. | false | false | [
"Dennis Jen",
"Peter Parente",
"Jonathan Robbins",
"Chris Weigle",
"Russell M. Taylor II",
"Alain Burette",
"Richard Weinberg"
] | [] | [] | [] |
Vis | 2,004 | Immersive design of DNA molecules with a tangible interface | 10.1109/VISUAL.2004.47 | This work presents an experimental immersive interface for designing DNA components for application in nanotechnology. While much research has been done on immersive visualization, this is one of the first systems to apply advanced interface techniques to a scientific design problem. This system uses tangible 3D input devices (tongs, a raygun, and a multipurpose handle tool) to create and edit a purely digital representation of DNA. The tangible controllers are associated with functions (not data) while a virtual display is used to render the model. This interface was built in collaboration with a research group investigating the design of DNA tiles. A user study shows that scientists find the immersive interface more satisfying than a 2D interface due to the enhanced understanding gained by directly interacting with molecules in 3D space. | false | false | [
"Steven Schkolne",
"Hiroshi Ishii 0001",
"Peter Schröder"
] | [] | [] | [] |
Vis | 2,004 | Importance-driven volume rendering | 10.1109/VISUAL.2004.48 | This work introduces importance-driven volume rendering as a novel technique for automatic focus and context display of volumetric data. Our technique is a generalization of cut-away views, which - depending on the viewpoint - remove or suppress less important parts of a scene to reveal more important underlying information. We automatize and apply this idea to volumetric data. Each part of the volumetric data is assigned an object importance, which encodes visibility priority. This property determines which structures should be readily discernible and which structures are less important. In those image regions, where an object occludes more important structures it is displayed more sparsely than in those areas where no occlusion occurs. Thus the objects of interest are clearly visible. For each object several representations, i.e., levels of sparseness, are specified. The display of an individual object may incorporate different levels of sparseness. The goal is to emphasize important structures and to maximize the information content in the final image. This work also discusses several possible schemes for level of sparseness specification and different ways how object importance can be composited to determine the final appearance of a particular object. | false | false | [
"Ivan Viola",
"Armin Kanitsar",
"M. Eduard Gröller"
] | [] | [] | [] |
Vis | 2,004 | Interactive design of multi-perspective images for visualizing urban landscapes | 10.1109/VISUAL.2004.50 | Multiperspective images are a useful way to visualize extended, roughly planar scenes such as landscapes or city blocks. However, constructing effective multiperspective images is something of an art. We describe an interactive system for creating multiperspective images composed of serially blended cross-slits images. Beginning with a sideways-looking video of the scene as might be captured from a moving vehicle, we allow the user to interactively specify a set of cross-slits cameras, possibly with gaps between them. In each camera, one of the slits is defined to be the camera path, which is typically horizontal, and the user is left to choose the second slit, which is typically vertical. The system then generates intermediate views between these cameras using a novel interpolation scheme, thereby producing a multiperspective image with no seams. The user can also choose the picture surface in space onto which viewing rays are projected, thereby establishing a parameterization for the image. We show how the choice of this surface can be used to create interesting visual effects. We demonstrate our system by constructing multiperspective images that summarize city blocks, including corners, blocks with deep plazas and other challenging urban situations. | false | false | [
"Augusto Román",
"Gaurav Garg",
"Marc Levoy"
] | [] | [] | [] |
Vis | 2,004 | Interactive exploration of large remote micro-CT scans | 10.1109/VISUAL.2004.51 | Datasets of tens of gigabytes are becoming common in computational and experimental science. This development is driven by advances in imaging technology, producing detectors with growing resolutions, as well as availability of cheap processing power and memory capacity in commodity-based computing clusters. We describe the design of a visualization system that allows scientists to interactively explore large remote data sets in an efficient and flexible way. The system is broadly applicable and currently used by medical scientists conducting an osteoporosis research project. Human vertebral bodies are scanned using a high resolution microCT scanner producing scans of roughly 8 GB size each. All participating research groups require access to the centrally stored data. Due to the rich internal bone structure, scientists need to interactively explore the full dataset at coarse levels, as well as visualize subvolumes of interest at the highest resolution. Our solution is based on HDF5 and GridFTP. When accessing data remotely, the HDF5 data processing pipeline is modified to support efficient retrieval of subvolumes. We reduce the overall latency and optimize throughput by executing high-level operations on the remote side. The GridFTP protocol is used to pass the HDF5 requests to a customized server. The approach takes full advantage of local graphics hardware for rendering. Interactive visualization is accomplished using a background thread to access the datasets stored in a multiresolution format. A hierarchical volume tenderer provides seamless integration of high resolution details with low resolution overviews. | false | false | [
"Steffen Prohaska",
"Andrei Hutanu",
"Ralf Kähler",
"Hans-Christian Hege"
] | [] | [] | [] |
Vis | 2,004 | Interactive point-based isosurface extraction | 10.1109/VISUAL.2004.52 | We propose a novel point-based approach to view dependent isosurface extraction. We introduce a fast visibility query system for the view dependent traversal, which exhibits moderate memory requirements. This technique allows for an interactive interrogation of the full visible woman dataset (1GB) at four to fifteen frames per second on a desktop computer. The point-based approach is built on an extraction scheme that classifies different sections of the isosurface into four categories, depending on the size of the geometry when projected onto the screen. In particular, we use points to represent small and subpixel triangles, as well as larger sections of the isosurface whose projection has subpixel size. To assign consistent and robust normals to individual points representing such regions, we propose to compute them during post processing of the extracted isosurface and provide the corresponding hardware implementation. | false | false | [
"Yarden Livnat",
"Xavier Tricoche"
] | [] | [] | [] |
Vis | 2,004 | Interactive Poster: Grid-Enabled Collaborative Scientific Visualization Environment | 10.1109/VISUAL.2004.53 | At its core, the grid is concerned with distributed computing and resource management. In essence, the grid is the federation and virtualization of computing resources to accelerate application processing [Unger-Haynos]. As described by Foster et al, grid computing focuses on large-scale resource sharing between dynamic collections of individuals, institutions, and resources via flexible, secure, and coordinated mechanisms. | false | false | [
"Eric Christopher Wyatt",
"Patrick O'Leary"
] | [] | [] | [] |
Vis | 2,004 | Interactive Poster: Illustrating Different Convection Velocities of Turbulent Flow | 10.1109/VISUAL.2004.54 | The visualization of any vector field is dependent on the relative velocity of the observer. In experimentally generated vector fields, the average value of the streamwise component of the global vector field is typically calculated and subtracted from each vector. We demonstrate that the resulting image, critical points, and vector field features are greatly influenced by the magnitude of the value subtracted from the streamwise velocity. | false | false | [
"Timothy Urness",
"Victoria Interrante",
"Ellen Longmire",
"Ivan Marusic",
"Bharathram Ganapathisubramani"
] | [] | [] | [] |
Vis | 2,004 | Interactive terascale particle visualization | 10.1109/VISUAL.2004.55 | This work describes the methods used to produce an interactive visualization of a 2 TB computational fluid dynamics (CFD) data set using particle tracing (streaklines). We use the method introduced by Bruckschen el al. (2001) that precomputes a large number of particles, stores them on disk using a space-filling curve ordering that minimizes seeks, then retrieves and displays the particles according to the user's command. We describe how the particle computation can be performed using a PC cluster, how the algorithm can be adapted to work with a multiblock curvilinear mesh, how scalars can be extracted and used to color the particles, and how the out-of-core visualization can be scaled to 293 billion particles while still achieving interactive performance on PC hardware. Compared to the earlier work, our data set size and total number of particles are an order of magnitude larger. We also describe a new compression technique that losslessly reduces the amount of particle storage by 41% and speeds the particle retrieval by about 20%. | false | false | [
"David Ellsworth",
"Bryan Green",
"Patrick J. Moran"
] | [] | [] | [] |
Vis | 2,004 | Interactive thickness visualization of articular cartilage | 10.1109/VISUAL.2004.56 | This work describes a method to visualize the thickness of curved thin objects. Given the MRI volume data of articular cartilage, medical doctors investigate pathological changes of the thickness. Since the tissue is very thin, it is impossible to reliably map the thickness information by direct volume rendering. Our idea is based on unfolding of such structures preserving their thickness. This allows to perform anisotropic geometrical operations (e.g., scaling the thickness). However, flattening of a curved structure implies a distortion of its surface. The distortion problem is alleviated through a focus-and-context minimization approach. Distortion is smallest close to a focal point which can be interactively selected by the user. | false | false | [
"Matej Mlejnek",
"Anna Vilanova",
"M. Eduard Gröller"
] | [] | [] | [] |
Vis | 2,004 | Introducing Topological Attributes for Objective-Based Visualization | 10.1109/VISUAL.2004.57 | Direct volume rendering is a standard technique for projecting all the optically-encoded samples onto the screen at once to allow us to peer into the inner structures involved in a volume data. Datacentric approaches to the design of transfer functions (TFs) have recently been well-established, which perform mathematical analysis of the data prior to pertinent rendering. The advent of multidimensional TFs is one of the latest major achievements in the volume visualization research. As opposed to the traditional onedimensional TFs that only consider a voxel’s scalar field value, the multi-dimensional TFs assign auxiliary attributes to the voxels to construct their sophisticated parametric domains. For example, when visualizing volumes obtained by scientific simulations, the observers can utilize their own knowledge about the simulation settings to extract the global characteristics of the volumes and to locate regions of particular interest. If they are allowed to design multi-dimensional TFs using staff attributes so as to encapsulate such advance knowledge, they can readily yield visualization results to fulfill their purposes. Nevertheless, nearly all attributes for the conventional multi-dimensional TFs are based on local features, such as differentials and curvatures, and are difficult to capture the global structure of the volume contrary to the observer’s purposes. This paper therefore introduces a new set of topological attributes to establish a new framework that is intended to realize objective-based assistance. Topological attributes proposed herein are derived from the level-set graph, which delineates the topological evolution of an isosurface with respect to the scalar field. | false | false | [
"Yuriko Takeshima",
"Shigeo Takahashi",
"Issei Fujishiro",
"Gregory M. Nielson"
] | [] | [] | [] |
Vis | 2,004 | Intuitive and interactive modification of large finite element models | 10.1109/VISUAL.2004.58 | Virtual prototyping is increasingly replacing real mock-ups and experiments in industrial product development. Part of this process is the simulation of structural and functional properties, which is in many cases based on finite element analysis (FEA). One prominent example from the automotive industry is the safety improvement resulting from crash worthiness simulations. A simulation model for this purpose usually consists of up to one million finite elements and is assembled from many parts, which are individually meshed out of their CAD representation. In order to accelerate the development cycle, simulation engineers want to be able to modify their FE models without going back to the CAD department. Furthermore, valid CAD models might even not be available in preliminary design stages. However, in contrast to CAD, there is a lack of tools that offer the possibility of modification and processing of finite element components while maintaining the properties relevant to the simulation. In this application paper we present interactive algorithms for intuitive and fast editing of FE models and appropriate visualization techniques to support engineers in understating these models. This includes new kinds of manipulators, feedback mechanisms and facilities for virtual reality and immersion at the workplace, e.g. autostereoscopic displays and haptic devices. | false | false | [
"Dirc Rose",
"Katrin Bidmon",
"Thomas Ertl"
] | [] | [] | [] |
Vis | 2,004 | Investigating swirl and tumble flow with a comparison of visualization techniques | 10.1109/VISUAL.2004.59 | We investigate two important, common fluid flow patterns from computational fluid dynamics (CFD) simulations, namely, swirl and tumble motion typical of automotive engines. We study and visualize swirl and tumble flow using three different flow visualization techniques: direct, geometric, and texture-based. When illustrating these methods side-by-side, we describe the relative strengths and weaknesses of each approach within a specific spatial dimension and across multiple spatial dimensions typical of an engineer's analysis. Our study is focused on steady-state flow. Based on this investigation we offer perspectives on where and when these techniques are best applied in order to visualize the behavior of swirl and tumble motion. | false | false | [
"Robert S. Laramee",
"Daniel Weiskopf",
"Jürgen Schneider",
"Helwig Hauser"
] | [] | [] | [] |
Vis | 2,004 | JointViewer - An Interactive System for Exploring Orthopedic Data | 10.1109/VISUAL.2004.60 | We present JointViewer, a software tool to aid orthopedics researchers in exploring complex, in-vivo joint kinematics. Given bone-geometry data and bone-motion information, JointViewer models and visualizes bone inter-spacing in the joint. Next, it proposes and displays plausible ligament paths which connect bones together. Both types of models are constructed through a distancefield approach. Users can maneuver the bones in a joint for better viewing, see motion relative to a specific bone, or remove bones from a joint. We demonstrate JointViewer’s effectiveness in three applications: examining normal human wrist kinematics, capturing the effect of injury on forearm kinematics, and exploring the kinematic constraints imposed by ligaments in a pigeon shoulder. In all applications, the system effectively highlights subtle yet important relationships among bones and soft-tissue that in previous standard joint visualizations had gone unnoticed. | false | false | [
"G. Elisabeta Marai",
"Çagatay Demiralp",
"Stuart Andrews",
"David H. Laidlaw"
] | [] | [] | [] |
Vis | 2,004 | Light Collages: lighting design for effective visualization | 10.1109/VISUAL.2004.62 | We introduce Light Collages - a lighting design system for effective visualization based on principles of human perception. Artists and illustrators enhance perception of features with lighting that is locally consistent and globally inconsistent. Inspired by these techniques, we design the placement of light sources to convey a greater sense of realism and better perception of shape with globally inconsistent lighting. Our algorithm segments the objects into local surface patches and uses a number of perceptual heuristics, such as highlights, shadows, and silhouettes, to enhance the perception of shape. We show our results on scientific and sculptured datasets. | false | false | [
"Chang Ha Lee",
"Xuejun Hao",
"Amitabh Varshney"
] | [] | [] | [] |
Vis | 2,004 | Light weight space leaping using ray coherence | 10.1109/VISUAL.2004.63 | We present a space leaping technique for accelerating volume rendering with very low space and run-time complexity. Our technique exploits the ray coherence during ray casting by using the distance a ray traverses in empty space to leap its neighboring rays. Our technique works with parallel as well as perspective volume rendering, does not require any preprocessing or 3D data structures, and is independent of the transfer function. Being an image-space technique, it is independent of the complexity of the data being rendered. It can be used to accelerate both time-coherent and noncoherent animation sequences. | false | false | [
"Sarang Lakare",
"Arie E. Kaufman"
] | [] | [] | [] |
Vis | 2,004 | Lighting transfer functions using gradient aligned sampling | 10.1109/VISUAL.2004.64 | An important task in volume rendering is the visualization of boundaries between materials. This is typically accomplished using transfer functions that increase opacity based on a voxel's value and gradient. Lighting also plays a crucial role in illustrating surfaces. In this paper we present a multi-dimensional transfer function method for enhancing surfaces, not through the variation of opacity, but through the modification of surface shading. The technique uses a lighting transfer function that takes into account the distribution of values along a material boundary and features a novel interface for visualizing and specifying these transfer functions. With our method, the user is given a means of visualizing boundaries without modifying opacity, allowing opacity to be used for illustrating the thickness of homogeneous materials through the absorption of light. | false | false | [
"Eric B. Lum",
"Kwan-Liu Ma"
] | [] | [] | [] |
Vis | 2,004 | Linear and cubic box splines for the body centered cubic lattice | 10.1109/VISUAL.2004.65 | We derive piecewise linear and piecewise cubic box spline reconstruction filters for data sampled on the body centered cubic (BCC) lattice. We analytically derive a time domain representation of these reconstruction filters and using the Fourier slice-projection theorem we derive their frequency responses. The quality of these filters, when used in reconstructing BCC sampled volumetric data, is discussed and is demonstrated with a raycaster. Moreover, to demonstrate the superiority of the BCC sampling, the resulting reconstructions are compared with those produced from similar filters applied to data sampled on the Cartesian lattice. | false | false | [
"Alireza Entezari",
"Ramsay Dyer",
"Torsten Möller"
] | [] | [] | [] |
Vis | 2,004 | Linking Representation with Meaning | 10.1109/VISUAL.2004.66 | The purpose of visualization is not just to depict data, but to gain or present insight into the domain represented in data. However in visualization systems, this link between features in the data and the meaning of those features is often missing or implicit. It is assumed that the user, through looking at the output, will close the loop between representation and insight. An alternative is to view visualization tools as interfaces between data and insight, and to enrich this interface with capabilities linked to users’ conceptual models of the data. Preliminary work has been carried out to develop such an interface as a modular component that can be installed in a pipelined architecture. This poster expands the motivation for this work, and describes the initial implementation carried out within the Visualization Toolkit (VTK). | false | false | [
"David J. Duke"
] | [] | [] | [] |
Vis | 2,004 | Live Range Visibility Constraints for Adaptive Terrain Visualization | 10.1109/VISUAL.2004.67 | Although there is a remarkable pace in the advance of computational resources and storage for real-time visualization the immensity of the input data continues to outstrip any advances. The task for interactively visualizing such a massive terrain is to render a triangulated mesh using a view-dependent error tolerance, thus intelligently and perceptually managing the scene’s geometric complexity. At any particular instance in time (i.e. displayed frame), this level-of-detail (LOD) terrain surface consists of a mesh composed of hundreds of thousands of dynamically selected triangles. The triangles are selected using the current time-step’s view parameters and the view-dependent error tolerance. Massive terrain data easily exceeds main memory storage capacity such that out-of-core rendering must be performed. This further complicates the triangle selection and terrain rendering owing to tertiary storage’s relatively poor performance. | false | false | [
"Xiaohong Bao",
"Renato Pajarola",
"Michael Shafae"
] | [] | [] | [] |
Vis | 2,004 | Local and global comparison of continuous functions | 10.1109/VISUAL.2004.68 | We introduce local and global comparison measures for a collection of k /spl les/ d real-valued smooth functions on a common d-dimensional Riemannian manifold. For k = d = 2 we relate the measures to the set of critical points of one function restricted to the level sets of the other. The definition of the measures extends to piecewise linear functions for which they are easy to compute. The computation of the measures forms the centerpiece of a software tool which we use to study scientific datasets. | false | false | [
"Herbert Edelsbrunner",
"John Harer",
"Vijay Natarajan",
"Valerio Pascucci"
] | [] | [] | [] |
Vis | 2,004 | LoD volume rendering of FEA data | 10.1109/VISUAL.2004.69 | A new multiple resolution volume rendering method for finite element analysis (FEA) data is presented. Our method is composed of three stages: in the first stage, the Gauss points of the FEA cells are calculated. The function values, gradients, diffusions, and influence scopes of the Gauss points are computed. By representing the Gauss points as graph vertices and connecting adjacent Gauss points with edges, an adjacency graph is created. The adjacency graph is used to represent the FEA data in the subsequent computation. In the second stage, a hierarchical structure is established upon the adjacency graph. Any two neighboring vertices with similar function values are merged into a new vertex. The similarity is measured by using a user-defined threshold. Consequently, a new adjacency graph is constructed. Then the threshold is increased, and the graph reduction is triggered again to generate another adjacency graph. By repeating the processing, multiple adjacency graphs are computed, and a level of detail (LoD) representation of the FEA data is established. In the third stage, the LoD structure is rendered by using a splatting method. At first, a level of adjacency graph is selected by users. The graph vertices arc sorted based on their visibility orders and projected onto the image plane in back-to-front order. Billboards are used to render the vertices in the projection. The function values, gradients, and influence scopes of the vertices are utilized to decide the colors, opacities, orientations, and shapes of the billboards. The billboards are then modulated with texture maps to generate the footprints of the vertices. Finally, these footprints are composited to produce the volume rendering image. | false | false | [
"Shyh-Kuang Ueng",
"Yan-Jen Su",
"Chi-Tang Chang"
] | [] | [] | [] |
Vis | 2,004 | Methods for efficient, high quality volume resampling in the frequency domain | 10.1109/VISUAL.2004.70 | Resampling is a frequent task in visualization and medical imaging. It occurs whenever images or volumes are magnified, rotated, translated, or warped. Resampling is also an integral procedure in the registration of multimodal datasets, such as CT, PET, and MRI, in the correction of motion artifacts in MRI, and in the alignment of temporal volume sequences in fMRI. It is well known that the quality of the resampling result depends heavily on the quality of the interpolation filter used. However, high-quality filters are rarely employed in practice due to their large spatial extents. We explore a new resampling technique that operates in the frequency-domain where high-quality filtering is feasible. Further, unlike previous methods of this kind, our technique is not limited to integer-ratio scaling factors, but can resample image and volume datasets at any rate. This would usually require the application of slow discrete Fourier transforms (DFT) to return the data to the spatial domain. We studied two methods that successfully avoid these delays: the chirp-z transform and the FFTW package. We also outline techniques to avoid the ringing artifacts that may occur with frequency-domain filtering. Thus, our method can achieve high-quality interpolation at speeds that are usually associated with spatial filters of far lower quality. | false | false | [
"Aili Li",
"Klaus Mueller 0001",
"Thomas Ernst 0001"
] | [] | [] | [] |
Vis | 2,004 | Modeling Decomposing Objects under Combustion | 10.1109/VISUAL.2004.71 | We present a simple yet effective method for modeling of object decomposition under combustion. A separate simulation models the flame production and generates heat from a combustion process, which is used to trigger pyrolysis of the solid object. The decomposition is modeled using level set methods, and can handle complex topological changes. Even with a very simple flame model on a coarse grid, we can achieve a plausible decomposition of the burning object. | false | false | [
"Zeki Melek",
"John Keyser"
] | [] | [] | [] |
Vis | 2,004 | Non-linear model fitting to parameterize diseased blood vessels | 10.1109/VISUAL.2004.72 | Accurate estimation of vessel parameters is a prerequisite for automated visualization and analysis of healthy and diseased blood vessels. The objective of this research is to estimate the dimensions of lower extremity arteries, imaged by computed tomography (CT). These parameters are required to get a good quality visualization of healthy as well as diseased arteries using a visualization technique such as curved planar reformation (CPR). The vessel is modeled using an elliptical or cylindrical structure with specific dimensions, orientation and blood vessel mean density. The model separates two homogeneous regions: its inner side represents a region of density for vessels, and its outer side a region for background. Taking into account the point spread function (PSF) of a CT scanner, a function is modeled with a Gaussian kernel, in order to smooth the vessel boundary in the model. A new strategy for vessel parameter estimation is presented. It stems from vessel model and model parameter optimization by a nonlinear optimization procedure, i.e., the Levenberg-Marquardt technique. The method provides center location, diameter and orientation of the vessel as well as blood and background mean density values. The method is tested on synthetic data and real patient data with encouraging results. | false | false | [
"Alexandra La Cruz",
"Matús Straka",
"Arnold Köchl",
"Milos Srámek",
"M. Eduard Gröller",
"Dominik Fleischmann"
] | [] | [] | [] |
Vis | 2,004 | On the role of color in the perception of motion in animated visualizations | 10.1109/VISUAL.2004.73 | Although luminance contrast plays a predominant role in motion perception, significant additional effects are introduced by chromatic contrasts. In this paper, relevant results from psychophysical and physiological research are described to clarify the role of color in motion detection. Interpreting these psychophysical experiments, we propose guidelines for the design of animated visualizations, and a calibration procedure that improves the reliability of visual motion representation. The guidelines are applied to examples from texture-based flow visualization, as well as graph and tree visualisation. | false | false | [
"Daniel Weiskopf"
] | [] | [] | [] |
Vis | 2,004 | On the Visualization of Time-Varying Structured Grids Using a 3D Warp Texture | 10.1109/VISUAL.2004.74 | We present a novel scheme to interactively visualize time-varying scalar fields defined on a structured grid. The underlying approach is to maximize the use of current graphics hardware by using 3D texture mapping. This approach commonly suffers from an expensive voxelization of each time-step as well as from large size of the voxel array approximating each step. Hence, in our scheme, instead of explicitly voxelizing each scalar field, we directly store each time-step as a three dimensional texture in its native form. We create the function that warps a voxel grid into the given structured grid. At rendering time, we reconstruct the function at each pixel using hardware-based trilinear interpolation. The resulting coordinates allow us to compute the scalar value at this pixel using a second texture lookup. For fixed grids, the function remains constant across time-steps and only the scalar field table needs to be re-loaded as a texture. Our new approach achieves excellent performance with relatively low texture memory requirements and low approximation error. | false | false | [
"Yuan Chen",
"Jonathan D. Cohen 0001",
"Subodh Kumar 0001"
] | [] | [] | [] |
Vis | 2,004 | Optimal global conformal surface parameterization | 10.1109/VISUAL.2004.75 | All orientable metric surfaces are Riemann surfaces and admit global conformal parameterizations. Riemann surface structure is a fundamental structure and governs many natural physical phenomena, such as heat diffusion and electro-magnetic fields on the surface. A good parameterization is crucial for simulation and visualization. This paper provides an explicit method for finding optimal global conformal parameterizations of arbitrary surfaces. It relies on certain holomorphic differential forms and conformal mappings from differential geometry and Riemann surface theories. Algorithms are developed to modify topology, locate zero points, and determine cohomology types of differential forms. The implementation is based on a finite dimensional optimization method. The optimal parameterization is intrinsic to the geometry, preserves angular structure, and can play an important role in various applications including texture mapping, remeshing, morphing and simulation. The method is demonstrated by visualizing the Riemann surface structure of real surfaces represented as triangle meshes. | false | false | [
"Miao Jin",
"Yalin Wang 0001",
"Shing-Tung Yau",
"Xianfeng Gu"
] | [] | [] | [] |
Vis | 2,004 | Panel 1: Can We Determine the Top Unresolved Problems of Visualization? | 10.1109/VISUAL.2004.76 | Many of us working in visualization have our own list of our top 5 or 10 unresolved problems in visualization. We have assembled a group of panelists to debate and perhaps reach concensus on the top problems in visualization that still need to be explored. We include panelists from both the information and scientific visualization domains. After our presentations, we encourage interaction with the audience to see if we can further formulate and perhaps finalize our list of top unresolved problems in visualization. | false | false | [
"Theresa-Marie Rhyne",
"Bill Hibbard",
"Christopher R. Johnson 0001",
"Chaomei Chen",
"Steve Eick"
] | [] | [] | [] |
Vis | 2,004 | Panel 2: In the Eye of the Beholder: The Role of Perception in Scientific Visualization | 10.1109/VISUAL.2004.77 | The evolution of computational science over the last decade has resulted in a dramatic increase in raw problem solving capabilities. This growth has given rise to advances in scientific and engineering simulations that have put a high demand on tools for high-performance large-scale data exploration and analysis. These simulations have the potential to generate large amounts of data. Humans, however are relatively poor at gaining insight from raw numerical data, and as a result, have used visualization as a tool for understanding, interpreting and exploring data of all types and sizes. Allowing for efficient visual explorations of data, however, requires that the ratio of knowledge gained versus the cost of the visualization be maximized. This, in turn, mandates the integration of principles from human perception. Understanding perception as it relates to visualization requires that we understand not only the biology of the human visual system, but principles from vision theory, and perceptual psychology as well. This panel is the result of bringing together practioners and researchers from a broad spectrum of interests relating to the ability to maximize the amount of information that is effectively perceived from a given visualization. Position statements will be given by researchers interested in perceptual psychology and the perception of natural images, integrating art and design principles, non-photorealistic rendering techniques, and the use of global illumination methods to provide benefical perceptual cues. | false | false | [
"Kelly P. Gaither",
"David S. Ebert",
"Bill Geisler",
"David H. Laidlaw"
] | [] | [] | [] |
Vis | 2,004 | Panel 3: The Future Visualization Platform | 10.1109/VISUAL.2004.78 | Advances in graphics hardware and rendering methods are shaping the future of visualization. For example, programmable graphics processors are redefining the traditional visualization cycle. In some cases it is now possible to run the computational simulation and associated visualization side-by-side on the same chip. Moreover, global illumination and non-photorealistic effects promise to deliver imagery which enables greater insight into high resolution, multivariate, and higher-dimensional data. The panelists will offer distinct viewpoints on the direction of future graphics hardware and its potential impact on visualization, and on the nature of advanced visualizationrelated tools and techniques. Presentation of these viewpoints will be followed by audience participation in the form of a question and answer period moderated by the panel organizer. | false | false | [
"Greg Johnson",
"David S. Ebert",
"Charles D. Hansen",
"David Blair Kirk",
"Bill Mark",
"Hanspeter Pfister"
] | [] | [] | [] |
Vis | 2,004 | Panel 4: What Should We Teach in a Scientific Visualization Class? | 10.1109/VISUAL.2004.79 | Scientific Visualization (SciVis) has evolved past the point where one undergraduate course can cover all of the necessary topics. So the question becomes "how do we teach SciVis to this generation of students?" Some examples of current courses are: A graduate Computer Science (CS) course that prepares the next generation of SciVis researchers. An undergraduate CS course that prepares the future software architects/developers of packages such as vtk, vis5D and AVS. A class that teaches students how to do SciVis with existing software packages and how to deal with the lack of interoperability between those packages (via either a CS service course or a supercomputing center training course). An inter-disciplinary course designed to prepare computer scientists to work with the "real" scientists (via either a CS or Computational Science course). In this panel, we will discuss these types of courses and the advantages and disadvantages of each. We will also talk about some issues that you have probably encountered at your university: How do we keep the graphics/vis-oriented students from going to industry? How does SciVis fit in with evolving Computational Science programs? Is SciVis destined to be a service course at most universities? How do we deal with the diverse backgrounds of students that need SciVis? | false | false | [
"Jon D. Genetti",
"Michael J. Bailey",
"David H. Laidlaw",
"Robert J. Moorhead II",
"Ross T. Whitaker"
] | [] | [] | [] |
Vis | 2,004 | Physically based methods for tensor field visualization | 10.1109/VISUAL.2004.80 | The physical interpretation of mathematical features of tensor fields is highly application-specific. Existing visualization methods for tensor fields only cover a fraction of the broad application areas. We present a visualization method tailored specifically to the class of tensor field exhibiting properties similar to stress and strain tensors, which are commonly encountered in geomechanics. Our technique is a global method that represents the physical meaning of these tensor fields with their central features: regions of compression or expansion. The method is based on two steps: first, we define a positive definite metric, with the same topological structure as the tensor field; second, we visualize the resulting metric. The eigenvector fields are represented using a texture-based approach resembling line integral convolution (LIC) methods. The eigenvalues of the metric are encoded in free parameters of the texture definition. Our method supports an intuitive distinction between positive and negative eigenvalues. We have applied our method to synthetic and some standard data sets, and "real" data from earth science and mechanical engineering application. | false | false | [
"Ingrid Hotz",
"Louis Feng",
"Hans Hagen",
"Bernd Hamann",
"Kenneth I. Joy",
"Boris Jeremic"
] | [] | [] | [] |
Vis | 2,004 | Pixel-exact rendering of spacetime finite element solutions | 10.1109/VISUAL.2004.81 | Computational simulation of time-varying physical processes is of fundamental importance for many scientific and engineering applications. Most frequently, time-varying simulations are performed over multiple spatial grids at discrete points in time. We investigate a new approach to time-varying simulation: spacetime discontinuous Galerkin finite element methods. The result of this simulation method is a simplicial tessellation of spacetime with per-element polynomial solutions for physical quantities such as strain, stress, and velocity. To provide accurate visualizations of the resulting solutions, we have developed a method for per-pixel evaluation of solution data on the GPU. We demonstrate the importance of per-pixel rendering versus simple linear interpolation for producing high quality visualizations. We also show that our system can accommodate reasonably large datasets - spacetime meshes containing up to 20 million tetrahedra are not uncommon in this domain. | false | false | [
"Yuan Zhou",
"Michael Garland",
"Robert B. Haber"
] | [] | [] | [] |
Vis | 2,004 | PQuad: visualization of predicted peptides and proteins | 10.1109/VISUAL.2004.82 | New high-throughput proteomic techniques generate data faster than biologists can analyze it. Hidden within this massive and complex data are answers to basic questions about how cells function. The data afford an opportunity to take a global or systems approach studying whole proteomes comprising all the proteins in an organism. However, the tremendous size and complexity of the high-throughput data make it difficult to process and interpret. Existing tools for studying a few proteins at a time are not suitable for global analysis. Visualization provides powerful analysis capabilities for enormous, complex data at multiple resolutions. We developed a novel interactive visualization tool, PQuad, for the visual analysis of proteins and peptides identified from high-throughput data on biological samples. PQuad depicts the peptides in the context of their source protein and DNA, thereby integrating proteomic and genomic information. A wrapped line metaphor is applied across key resolutions of the data, from a compressed view of an entire chromosome to the actual nucleotide sequence. PQuad provides a difference visualization for comparing peptides from samples prepared under different experimental conditions. We describe the requirements for such a visual analysis tool, the design decisions, and the novel aspects of PQuad. | false | false | [
"Susan L. Havre",
"Mudita Singhal",
"Deborah A. Payne",
"Bobbie-Jo M. Webb-Robertson"
] | [] | [] | [] |
Vis | 2,004 | Projecting tetrahedra without rendering artifacts | 10.1109/VISUAL.2004.85 | Hardware-accelerated direct volume rendering of unstructured volumetric meshes is often based on tetrahedral cell projection, in particular, the projected tetrahedra (PT) algorithm and its variants. Unfortunately, even implementations of the most advanced variants of the PT algorithm are very prone to rendering artifacts. In this work, we identify linear interpolation in screen coordinates as a cause for significant rendering artifacts and implement the correct perspective interpolation for the PT algorithm with programmable graphics hardware. We also demonstrate how to use features of modern graphics hardware to improve the accuracy of the coloring of individual tetrahedra and the compositing of the resulting colors, in particular, by employing a logarithmic scale for the preintegrated color lookup table, using textures with high color resolution, rendering to floating-point color buffers, and alpha dithering. Combined with a correct visibility ordering, these techniques result in the first implementation of the PT algorithm without objectionable rendering artifacts. Apart from the important improvement in rendering quality, our approach also provides a test bed for different implementations of the PT algorithm that allows us to study the particular rendering artifacts introduced by these variants. | false | false | [
"Martin Kraus",
"Wei Qiao",
"David S. Ebert"
] | [] | [] | [] |
Vis | 2,004 | Quick-VDR: interactive view-dependent rendering of massive models | 10.1109/VISUAL.2004.86 | We present a novel approach for interactive view-dependent rendering of massive models. Our algorithm combines view-dependent simplification, occlusion culling, and out-of-core rendering. We represent the model as a clustered hierarchy of progressive meshes (CHPM). We use the cluster hierarchy for coarse-grained selective refinement and progressive meshes for fine-grained local refinement. We present an out-of-core algorithm for computation of a CHPM that includes cluster decomposition, hierarchy generation, and simplification. We make use of novel cluster dependencies in preprocess to generate crack-free, drastic simplifications at runtime. The clusters are used for occlusion culling and out-of-core rendering. We add a frame of latency to the rendering pipeline to fetch newly visible clusters from the disk and to avoid stalls. The CHPM reduces the refinement cost for view-dependent rendering by more than an order of magnitude as compared to a vertex hierarchy. We have implemented our algorithm on a desktop PC. We can render massive CAD, isosurface, and scanned models, consisting of tens or a few hundreds of millions of triangles at 10-35 frames per second with little loss in image quality. | false | false | [
"Sung-Eui Yoon",
"Brian Salomon",
"Russell Gayle",
"Dinesh Manocha"
] | [] | [] | [] |
Vis | 2,004 | Radial hermite operators for scattered point cloud data with normal vectors and applications to implicitizing polygon mesh surfaces for generalized CSG operations and smoothing | 10.1109/VISUAL.2004.87 | We describe a new technique for fitting scattered point cloud data. Given a scattered point cloud of 3D data points and associated normal vectors, our new method produces an implicit volume model whose zero level isosurface interpolates the given points and associated normal vectors. We concentrate on certain application of these new volume modeling techniques. We take existing polygon mesh surfaces and use the present methods to construct implicit volume models for these surfaces. Implicit models allow for the application of Boolean operations on these surfaces through the techniques of constructive solid geometry. Also, standard wavelet and filter operators can be applied to the implicit volume model leading to effective smoothing and filtering algorithms, which are simple to implement. | false | false | [
"Gregory M. Nielson"
] | [] | [] | [] |
Vis | 2,004 | Real-time motion estimation and visualization on graphics cards | 10.1109/VISUAL.2004.88 | We present a tool for real-time visualization of motion features in 2D image sequences. The motion is estimated through an eigenvector analysis of the spatio-temporal structure tensor at every pixel location. This approach is computationally demanding but allows reliable velocity estimates as well as quality indicators for the obtained results. We use a 2D color map and a region of interest selector for the visualization of the velocities. On the selected velocities we apply a hierarchical smoothing scheme which allows the choice of the desired scale of the motion field. We demonstrate several examples of test sequences in which some persons are moving with different velocities than others. These persons are visually marked in the real-time display of the image sequence. The tool is also applied to angiography sequences to emphasize the blood flow and its distribution. An efficient processing of the data streams is achieved by mapping the operations onto the stream architecture of standard graphics cards. The card receives the images and performs both the motion estimation and visualization, taking advantage of the parallelism in the graphics processor and the superior memory bandwidth. The integration of data processing and visualization also saves on unnecessary data transfers and thus allows the real-time analysis of 320/spl times/240 images. We expect that on the newest generation of graphics hardware our tool could run in real time for the standard VGA format. | false | false | [
"Robert Strzodka",
"Christoph S. Garbe"
] | [] | [] | [] |
Vis | 2,004 | Real-Time Volume Rendering of Four Channel Data Sets | 10.1109/VISUAL.2004.89 | We present a novel method to encode four data channels in a volumetric data set, and render it at interactive frame rates with maximum intensity projection (MIP) using textured polygons. The first three channels are stored in the volume texture’s red, green, and blue components. The fourth channel is stored in the alpha channel. To achieve real-time rendering speed we are using a pixel shader. | false | false | [
"Jürgen P. Schulze",
"Alexander Rice"
] | [] | [] | [] |
Vis | 2,004 | Rendering implicit flow volumes | 10.1109/VISUAL.2004.90 | Traditional flow volumes construct an explicit geometrical or parametrical representation from the vector field. The geometry is updated interactively and then rendered using an unstructured volume rendering technique. Unless a detailed refinement of the flow volume is specified for the interior, information inside the underlying flow volume is lost in the linear interpolation. These disadvantages can be avoided and/or alleviated using an implicit flow model. An implicit flow is a scalar field constructed such that any point in the field is associated with a termination surface using an advection operator on the flow. We present two techniques, a slice-based three-dimensional texture mapping and an interval volume segmentation coupled with a tetrahedron projection-based renderer, to render implicit stream flows. In the first method, the implicit flow representation is loaded as a 3D texture and manipulated using a dynamic texture operation that allows the flow to be investigated interactively. In our second method, a geometric flow volume is extracted from the implicit flow using a high dimensional isocontouring or interval volume routine. This provides a very detailed flow volume or set of flow volumes that can easily change topology, while retaining accurate characteristics within the flow volume. The advantages and disadvantages of these two techniques are compared with traditional explicit flow volumes. | false | false | [
"Daqing Xue",
"Caixia Zhang",
"Roger Crawfis"
] | [] | [] | [] |
Vis | 2,004 | Rendering planar cuts through quadratic and cubic finite elements | 10.1109/VISUAL.2004.91 | Coloring higher order scientific data is problematic using standard linear methods as found in OpenGL. The visual results are inaccurate when there is a large scalar gradient over an element or when the scalar field is nonlinear. In addition to shading nonlinear data, last and accurate rendering of planar cuts through parametric elements can be implemented using programmable shaders on current graphics hardware. The intersection of a planar cut with geometrically curved volume elements can be rendered using a combination of selective refinement and programmable shaders. This hybrid algorithm also handles curved 2D planar triangles. | false | false | [
"Michael Brasher",
"Robert Haimes"
] | [] | [] | [] |
Vis | 2,004 | Rough interface reconstruction using the level set method | 10.1109/VISUAL.2004.94 | We present a new level set method for reconstructing interfaces from point aggregations. Although level-set-based methods are advantageous because they can handle complicated topologies and noisy data, most tend to smooth the inherent roughness of the original data. Our objective is to enhance the quality of a reconstructed surface by preserving certain roughness-related characteristics of the original dataset. Our formulation employs the total variation of the surface as a roughness measure. The algorithm consists of two steps: a roughness-capturing flow and a roughness-preserving flow. The roughness capturing step attempts to construct a surface for which the original roughness is captured - distance flow is well suited for roughness capturing. Surface reconstruction is enhanced by using a total variation preserving (TVP) scheme for the roughness-preserving flow. The shock filter formulation of Osher and Rudin is exploited to achieve this goal. In practice, we have found that better results arc obtained by balancing the TVP term with a smoothing term based on curvature. The algorithm is applied to both fractal surface growth simulations and scanned data sets to demonstrate the efficacy of our approach. | false | false | [
"Yootai Kim",
"Raghu Machiraju",
"David S. Thompson"
] | [] | [] | [] |
Vis | 2,004 | Scout: a hardware-accelerated system for quantitatively driven visualization and analysis | 10.1109/VISUAL.2004.95 | Quantitative techniques for visualization are critical to the successful analysis of both acquired and simulated scientific data. Many visualization techniques rely on indirect mappings, such as transfer functions, to produce the final imagery. In many situations, it is preferable and more powerful to express these mappings as mathematical expressions, or queries, that can then be directly applied to the data. We present a hardware-accelerated system that provides such capabilities and exploits current graphics hardware for portions of the computational tasks that would otherwise be executed on the CPU. In our approach, the direct programming of the graphics processor using a concise data parallel language, gives scientists the capability to efficiently explore and visualize data sets. | false | false | [
"Patrick S. McCormick",
"Jeff T. Inman",
"James P. Ahrens",
"Charles D. Hansen",
"Greg Roth"
] | [] | [] | [] |
Vis | 2,004 | Self-illustrating phenomena | 10.1109/VISUAL.2004.12 | Summary form only given. A self-illustrating phenomenon is an image which exposes the science behind it. Some famous examples are pictures of iron filings aligned along magnetic lines of force, sand particles collecting at the stationary points of the standing waves of a violin, stress in a mechanical part revealed through birefringence, and particle tracks in a bubble chamber. Such images brilliantly combine experimental design, analysis, and visualization. Quoting J. Tukey, "the general purposes of conducting experiments and analyzing data match, point by point". We argue in this talk that computer tools for visual analysis should normally be conceived of as aids in constructing computational visual experiments; and that the resulting visualizations be consciously designed to help validate or invalidate the hypothesis being tested by the experiment. | false | false | [
"Pat Hanrahan"
] | [] | [] | [] |
Vis | 2,004 | Simplifying flexible isosurfaces using local geometric measures | 10.1109/VISUAL.2004.96 | The contour tree, an abstraction of a scalar field that encodes the nesting relationships of isosurfaces, can be used to accelerate isosurface extraction, to identify important isovalues for volume-rendering transfer functions, and to guide exploratory visualization through a flexible isosurface interface. Many real-world data sets produce unmanageably large contour trees which require meaningful simplification. We define local geometric measures for individual contours, such as surface area and contained volume, and provide an algorithm to compute these measures in a contour tree. We then use these geometric measures to simplify the contour trees, suppressing minor topological features of the data. We combine this with a flexible isosurface interface to allow users to explore individual contours of a dataset interactively. | false | false | [
"Hamish A. Carr",
"Jack Snoeyink",
"Michiel van de Panne"
] | [
"TT"
] | [] | [] |
Vis | 2,004 | STEPS - an application for simulation of transsphenoidal endonasal pituitary surgery | 10.1109/VISUAL.2004.98 | Endonasal transsphenoidal pituitary surgery is a minimally invasive endoscopic procedure, applied to remove various kinds of pituitary tumors. To reduce the risk associated with this treatment, the surgeon must be skilled and well-prepared. Virtual endoscopy can be beneficial as a tool for training, preoperative planning and intraoperative support. This work introduces STEPS, a virtual endoscopy system designed to aid surgeons in getting acquainted with the endoscopic view, the handling of instruments, the transsphenoidal approach and challenges associated with the procedure. STEPS also assists experienced surgeons in planning a real endoscopic intervention by getting familiar with the individual patient anatomy, identifying landmarks, planning the approach and deciding upon the ideal target position of the actual surgical activity. Besides interactive visualization using two different first-hit ray casting techniques, the application provides navigation and perception aids and the possibility to simulate the procedure, including haptic feedback and simulation of surgical instruments. | false | false | [
"André Neubauer 0002",
"Stefan Wolfsberger",
"Marie-Thérèse Forster",
"Lukas Mroz",
"Rainer Wegenkittl",
"Katja Bühler"
] | [
"BA"
] | [] | [] |
Vis | 2,004 | Stream line and path line oriented topology for 2D time-dependent vector fields | 10.1109/VISUAL.2004.99 | Topological methods aim at the segmentation of a vector field into areas of different flow behavior. For 2D time-dependent vector fields, two such segmentations are possible: either concerning the behavior of stream lines, or of path lines. While stream line oriented topology is well established, we introduce path line oriented topology as a new visualization approach in this paper. As a contribution to stream line oriented topology we introduce new methods to detect global bifurcations like saddle connections and cyclic fold bifurcations. To get the path line oriented topology we segment the vector field into areas of attracting, repelling and saddle-like behavior of the path lines. We compare both kinds of topologies and apply them to a number of data sets. | false | false | [
"Holger Theisel",
"Tino Weinkauf",
"Hans-Christian Hege",
"Hans-Peter Seidel"
] | [] | [] | [] |
Vis | 2,004 | Surface reconstruction of noisy and defective data sets | 10.1109/VISUAL.2004.101 | We present a novel surface reconstruction algorithm that can recover high-quality surfaces from noisy and defective data sets without any normal or orientation information. A set of new techniques is introduced to afford extra noise tolerability, robust orientation alignment, reliable outlier removal, and satisfactory feature recovery. In our algorithm, sample points are first organized by an octree. The points are then clustered into a set of monolithically singly-oriented groups. The inside/outside orientation of each group is determined through a robust voting algorithm. We locally fit an implicit quadric surface in each octree cell. The locally fitted implicit surfaces are then blended to produce a signed distance field using the modified Shepard's method. We develop sophisticated iterative fitting algorithms to afford improved noise tolerance both in topology recognition and geometry accuracy. Furthermore, this iterative fitting algorithm, coupled with a local model selection scheme, provides a reliable sharp feature recovery mechanism even in the presence of bad input. | false | false | [
"Hui Xie 0001",
"Kevin T. McDonnell",
"Hong Qin"
] | [] | [] | [] |
Vis | 2,004 | TetSplat: real-time rendering and volume clipping of large unstructured tetrahedral meshes | 10.1109/VISUAL.2004.102 | We present a novel approach to interactive visualization and exploration of large unstructured tetrahedral meshes. These massive 3D meshes are used in mission-critical CFD and structural mechanics simulations, and typically sample multiple field values on several millions of unstructured grid points. Our method relies on the preprocessing of the tetrahedral mesh to partition it into nonconvex boundaries and internal fragments that are subsequently encoded into compressed multiresolution data representations. These compact hierarchical data structures are then adaptively rendered and probed in real-time on a commodity PC. Our point-based rendering algorithm, which is inspired by QSplat, employs a simple but highly efficient splatting technique that guarantees interactive frame-rates regardless of the size of the input mesh and the available rendering hardware. It furthermore allows for real-time probing of the volumetric data-set through constructive solid geometry operations as well as interactive editing of color transfer functions for an arbitrary number of field values. Thus, the presented visualization technique allows end-users for the first time to interactively render and explore very large unstructured tetrahedral meshes on relatively inexpensive hardware. | false | false | [
"Ken Museth",
"Santiago V. Lombeyda"
] | [] | [] | [] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.