IEEE VIS Publication Dataset

In researching the communication mechanisms between cells of the immune system, visualization of proteins in three dimensions can be used to determine which proteins are capable of interacting with one another at a given time by showing their spatial colocality. Volume data sets are created using digital confocal immunofluorescence microscopy. A variety of visualization approaches are then used to examine the interactions. These include volume rendering, isosurface extraction, and virtual reality. Based on our experiences, we have concluded that no single one of these approaches provides a complete solution for visualizing biological data. However, in combination, their respective strengths complement one another to provide an understanding of the data.

The paper describes time management and time critical computing for a near real time interactive unsteady visualization environment. Subtle issues regarding the flow of time are described, formalized and addressed. The resulting system correctly reflects time behavior while allowing the user to control the flow of time. The problem of time critical computation is discussed and a solution is presented. These time critical algorithms provide control over the frame rate of a visualization system, allowing interactive exploration.

We propose to fit triangular NURBS surfaces to noisy, sparse, scattered 3D data while simultaneously localizing and preserving sharp edges. We use a vector voting method to interpolate, from sparse data, three dense potential fields for surfaces, edges, and junctions. The global voting interpolants encode several human perceptual grouping principles such as co-surfacity, proximity, and constancy of curvuture. The inferred potential fields are stored in three volumetric grids, giving each voxel the probability of being a surface point, an edge point, and a junction point. Then we use a new model called “winged B-snakes”, which are deformable triangular NURBS surfaces embedded with active curves, to fit the surfaces and align the edges and junctions. Finally, a smooth CL surface which preserves discontinuity edges and junctions is constructed. Fine-tuning and surface fairing is done by adjusting the weights.

This paper describes a minimally immersive interactive system for visualization of multivariate volumetric data. The system, SFA, uses glyph-based volume rendering which does not suffer the initial costs of isosurface rendering or voxel-based volume rendering, while offering the capability of viewing the entire volume. Glyph rendering also allows the simultaneous display of multiple data values per volume location. Two-handed interaction using three-space magnetic trackers and stereoscopic viewing are combined to produce a minimally immersive volumetric visualization system that enhances the user's three-dimensional perception of the data. We describe the usefulness of this system for visualizing volumetric scalar and vector data. SFA allows the three-dimensional volumetric visualization, manipulation, navigation, and analysis of multivariate, time-varying volumetric data, increasing the quantity and clarity of the information conveyed from the visualization system.

Uncertainty or errors are introduced in fluid flow data as the data is acquired, transformed and rendered. Although researchers are aware of these uncertainties, little has been done to incorporate them in the existing visualization systems for fluid flow. In the absence of integrated presentation of data and its associated uncertainty, the analysis of the visualization is incomplete at best and may lead to inaccurate or incorrect conclusions. The article presents UFLOW-a system for visualizing uncertainty in fluid flow. Although there are several sources of uncertainties in fluid flow data, in this work, we focus on uncertainty arising from the use of different numerical algorithms for computing particle traces in a fluid flow. The techniques that we have employed to visualize uncertainty in fluid flow include uncertainty glyphs, flow envelopes, animations, priority sequences, twirling batons of trace viewpoints, and rakes. These techniques are effective in making the users aware of the effects of different integration methods and their sensitivity, especially near critical points in the flow field.

A method for visualizing unknottedncss of mathematical knots via energy optimization with simulated annealing is presented. In this method a potential field is formed around a tangled rope that causes it to self-repel. By allowing the rope to evolve in this field in search of an energy minimizing configuration we can determine the knot type of the initial configuration. In particular, it is natural to conjecture that if such a “charged rope” was not initially knotted, it will reach its minimal potential in a circular configuration, given a suitable energy functional. Because situations potentially arise in which the functional may not be strictly unimodal, WC suggest it to be advantageous to use a robust stochastic optimization technique (simulated annealing), rather than a deterministic hill climber common in physically-based approaches, to make sure that the evolving rope does not settle in a suboptimal configuration. The same method is applicable to simplifying arbitrary knots and links and for establishing knot equivalence. Aside from its theoretical appeal. the method promises to solve practical problems common in genetic research and polymer design.

We describe an on-going project that is using visualization as an indispensable tool for the restoration of the disintegrated ceiling of a ritual precinct that was discovered during archaeological excavations of a group of pre-Inca temples in Peru. This ceiling is unique-it is the only one ever found that has pictures painted on it, rather than being simply white-washed. The restoration of the ceiling, and the recovery of these iconographic figures will provide an unprecedented opportunity to study the culture of the Moche people who build and used these temples.

The Virtual Workbench (VW) is a non-immersive virtual environment that allows users to view and interact with stereoscopic objects displayed on a workspace similar to a tabletop workspace used in day-to-day life. A VW is an ideal environment for collaborative work where several colleagues can gather around the table to study 3D virtual objects. The Virtual Reality laboratory at the Naval Research Laboratory has implemented the VW using a concept similar to (Froehlich et al., 1994). This paper investigates how the VW can be used as a non-immersive display device for understanding and interpreting complex objects encountered in the scientific visualization field. Different techniques for interacting with 3D visualization objects on the table and using VW as a display device for visualization are evaluated using several cases.

We are investigating methods for simplifying complex models for interactive visualizations using texture-based representations. This paper presents a simplification method which dynamically “caches” distant geometry into textures and trades off accurate rendering of the distant geometry for performance. Smooth transitions and continuous borders are defined between the geometry and textures thus the representations can be switched without sudden jumps (as is the case with many current texturing techniques). Ail the computations for the transitions can be done a priori without the need to change the textures each frame thereafter.

We discuss a visualization system for the comparison of simulated and measured water quality. The system extends SCIRT (Site Characterization Interactive Research Toolkit), an interactive system originally developed at the NSF Engineering Research Center for Computational Field Simulation at Mississippi State University. The ongoing study of the Chesapeake Bay presents research in 3D visualization of model-data comparisons.

Explores the way in which data visualization systems, in particular modular visualization environments, can be used over the World Wide Web. The conventional approach is for the publisher of the data also to be responsible for creating the visualization, and posting it as an image on the Web. This leaves the viewer in a passive role, with no opportunity to analyse the data in any way. We look at different scenarios that occur as we transfer more responsibility for the creation of the visualization to the viewer, allowing visualization to be used for analysis as well as presentation. We have implemented one particular scenario, where the publisher mounts the raw data on the Web, and the viewer accesses this data through a modular visualization environment-in this case, IRIS Explorer. The visualization system is hosted by the publisher, but its fine control is the responsibility of the viewer. The picture is returned to the viewer as VRML, for exploration via a VRML viewer such as Webspace. We have applied this to air quality data which is posted on the Web hourly: through our system, the viewer selects what data to look at (e.g. species of pollutant, location, time period) and how to look at it-at any time and from anywhere on the Web.

An isosurface can be efficiently generated by visiting adjacent intersected cells in order as if the isosurface were propagating itself. We previously proposed an extrema graph model, which generates a graph connecting extremum points. The isosurface propagation starts from some of the intersected cells that are found both by visiting the cells through which arcs of the graph pass and by visiting the cells on the boundary of a volume. In this paper, we propose an efficient method of searching for cells intersected by an isosurface. this method generates a volumetric skeleton consisting of cells, like an extrema graph, by applying a thinning algorithm used in the image recognition area. Since it preserves the topological features of the volume and the connectivity of the extremum points, it necessarily intersects every isosurface. The method is more efficient than the extrema graph method, since it does not require that cells on the boundary be visited.

3D time varying datasets are difficult to visualize and analyze because of the immense amount of data involved. This is especially true when the datasets are turbulent with many evolving amorphous regions, as it is difficult to observe patterns and follow regions of interest. We present our volume based feature tracking algorithm and discuss how it can be used to help visualize and analyze large time varying datasets. We also address efficiency issues in dealing with massive time varying datasets.

A method of lossless compression using wavelets is presented that enables progressive transmission of computational fluid dynamics (CFD) data in PLOT3D format. The floating point data is first converted to double-precision floating point format to maintain adequate precision throughout the transform process. It is then transformed using Haar wavelets-four times in two spatial dimensions, twice in the third spatial dimension, and twice in time for a total compression factor of 64 times. The double precision format will maintain enough precision during the transform to keep the process lossless. Next, the transformed data is compressed using Huffman coding and transmitted progressively using spectral selection. This allows most of the information to be transmitted in the first pass. Details are transmitted in later passes which ultimately provide for lossless reconstruction of the original data.

The explosive growth in world-wide communications, especially the Internet, has highlighted the need for techniques to visualize network traffic. The traditional node and link network displays work well for small datasets but become visually cluttered and uninterpretable for large datasets. A natural 3D metaphor for displaying world-wide network data is to position the nodes on a globe and draw arcs between them coding the traffic. This technique has several advantages of over the traditional 2D displays, it naturally reduces line crossing clutter, provides an intuitive model for navigation and indication of time, and retains the geographic context. Coupling these strengths with some novel interaction techniques involving the globe surface translucency and arc heights illustrates the usefulness for this class of displays.

The use of thumbnails (i.e., miniatures) in the user-interface of image databases allows searching and selection of images without the need for naming policies. Treating parent images prior to reduction with edge-detecting smoothing, lossy image compression, or static codebook compression resulted in thumbnails where the distortion caused by reduction was lessened. An experiment assessing these techniques found resulting thumbnails could be recognised more quickly and accurately than thumbnails of the same parent images that had been reduced without treatment. This pretreatment in thumbnail creation is offered as an improvement.

As the Internet continues to grow, the amount of accessible information becomes increasingly vast. Search tools exist that allow users to find relevant information. However, a search can often produce such a large amount of data that it becomes hard to ferret out the most appropriate and highest quality information. In addition, some search tools lose valuable information when displaying the results to the user. The paper describes a search visualization tool, called FISH, for viewing hierarchically structured information and managing information overload. FISH (Forager for the Information Super Highway) allows users to visualize the results of search requests across large document spaces in a way that preserves the structure of the information space. FISH displays the returned documents as rectangles, using a combination of order, indentation, size, and color to denote document hierarchy, the score of the documents with respect to the search, and other data attributes. In addition, the user can navigate through the document space for in-depth probing and refinement.

The goal is to improve the ability of people from all walks of life and interests to access, search, and use the information distributed in Internet resources. The process of interacting with information resources starts with browsing, continues with digesting and assimilating pieces of information, terminates with generation of new information, and begins anew with analysis of pre-existing and new information. Our approach is user-centric-taking users needs into account by allowing them to interact with the information contained in large arrays of documents. The visualization process is an integral part of the overall process. We have covered three related categories in this methodology. The first one is browsing through the World-Wide Web (WWW) hyperspace without becoming lost, based on a visual representation of the hyperspace hierarchical structure (hyperspace view). The second category is overcoming the rigidity of the WWW by allowing the user to construct interactively and visually a personal hyperspace of information, linking the documents according to the application or problem domain, or to the user's own perception, experience, culture, or way of thinking. The third category includes discovery and analysis of new information and relationships in retrieved documents by aggregating relevant information and representing it visually.

The paper examines how to provide scientific visualization capabilities to environmental scientists, policy analysts and decision makers with personal computers (PCs) on their desktops. An approach for using the World Wide Web (WWW) for disseminating knowledge on scientific visualization and for intelligent access to visualization capabilities on high performance (UNIX) workstations is outlined.

It is becoming increasingly important that support is provided for users who are dealing with complex information spaces. The need is driven by the growing number of domains where there is a requirement for users to understand, navigate and manipulate large sets of computer based data; by the increasing size and complexity of this information and by the pressures to use this information efficiently. The paradigmatic example is the World Wide Web, but other domains include software systems, information systems and concurrent engineering. One approach to providing this support is to provide sophisticated visualisation tools which lead the users to form an intuitive understanding of the structure and behaviour of their domain and which provide mechanisms which allow them to manipulate objects within their system. The paper describes such a tool and a number of visualisation techniques that it implements.