IEEE VIS Publication Dataset

Gray-scale diagrams, which can present large amounts of quantitative information in a compact format, are considered as a candidate for business charts. Hundreds of data points can easily be represented in one diagram, using small gray-scale squares (or tiles), without visually overloading a viewer. An experiment was done to compare the subjects' responses to questions from three types of charts, traditional column and line charts and gray-scale tile charts. The results showed that questions were answered more correctly and more quickly using gray-scale tile charts than using traditional charts. However, subjects reported they experienced more strain using gray-scale charts

Software tools are traditionally connected using human-readable files, an approach that buys flexibility and understandability at some cost in performance relative to binary file formats. The possibility of using shared-memory functions to retain most of the existing style while leapfrogging the speed of reading binary files, at least in some environments and for some applications, is explored. Results of a benchmarking experiment confirm the benefits of this alternative

This paper looks at the role visualization and visual data analysis play in the technical community. It focuses on the premise that the wide variety of applications of visualization mandate a need for a variety of visualization software packages

Software developed to deal with differing image file formats, mismatched byte order and word sizes, and confusing hardcopy device interfaces is described. The SDSC Image Tool suite provides a simple, extensible, and portable mechanism for the support of a variety of common image formats so that tool-writers can concentrate on the task in hand, rather than on the quirks of a particular image file format. Users of such tools are able to work with images generated from a variety of sources, without being restricted to an arbitrary standard format. The SDSC Visualization Printing suite creates a unified view of hardcopy devices

Blood movement investigated by magnetic resonance (MR) velocity mapping is generally presented in the form of velocity components in one or more chosen velocity encoding directions. By viewing these components separately, it is difficult for MR practitioners to conceptualize and comprehend the underlying flow structures, especially when the image data have strong background noise. A flow visualization technique that adapts the idea of particle tracing used in classical fluid dynamics for visualizing flow is presented. The flow image processing relies on the strong correlation between the principal flow direction estimated from the distribution of the modulus of the velocity field and the direction derived from the raw image data. By correlation calculation, severe background noise can be eliminated. Flow pattern rendering and animation provide an efficient way for representing internal flow structures

The problems and advantages of integrating scientific computations and visualization into one common program system are examined. An important point is the direct feedback of information from the visualization into an ongoing simulation. Some strong and weak points of the varying approaches in different software packages are shown. The visualization component of the authors' program system and the advantages of its integration into the overall system are explained. The weak points in their system and the work remaining to deal with them are described

An experiment in exploratory data visualization using a massively parallel processor is described. In exploratory data visualization, it is typically not known what is being looked for: instead, the data are explored with a variety of visualization techniques that can illuminate its nature by demonstrating patterns in it. With this approach, the authors were able to find new features in some of their oldest datasets and to create more vivid presentations of familiar features in these datasets. Their experience has also led to a better understanding of the nature of the exploratory visualization and has resulted in some formal representations of the interaction process in this environment

Two basic principles for interactive visualization of high-dimensional data-focusing and linking-are discussed. Focusing techniques may involve selecting subsets, dimension reduction, or some more general manipulation of the layout information on the page or screen. A consequent of focusing is that each view only conveys partial information about the data and needs to be linked so that the information contained in individual views can be integrated into a coherent image of the data as a whole. Examples are given of how graphical data analysis methods based on focusing and linking are used in applications including linguistics, geographic information systems, time series analysis, and the analysis of multi-channel images arising in radiology and remote sensing

Effective methods for visualizing several sets of volumetric data simultaneously are presented. The methods involve the composition of multiple volumetric rendering techniques. These techniques include contour curves, color-blended contour regions, projection graphs on surfaces, isovalue surface construction, and hypersurface projection graphs

A low-cost, high-performance visualization tool based on the IBM PC is described. Characteristics of scientific and engineering visualization and requirements for real time analysis are discussed. Application programming without coding by use of flowgraphs is also presented

This paper addresses the question of how the work of the scientist will change in the new multimedia environments. Scenarios for the process of simulating and analyzing data in such environments are constructed, and some of the underlying models used in their construction are examined

An experimental volume visualization system, NetV, that distributes volume imaging tasks to appropriate network resources is described. NetV gives offsite scientists easy access to high-end volume imaging software and hardware. The system allows a user to submit volume imaging jobs to an imaging spooler on a visualization-server. Remote high-power compute engines process rendering tasks, while local workstations run the user-interface. The time required to submit a job, render the job on a mini-supercomputer-class machine, and return the volume imaging to the offsite scientist is far less than the time it would take to create a similar image on a local workstation-class machine

A set of volume visualization tools that are based on the use of recursive ray tracing as the primary vehicle for realistic volume imaging is presented. The tools include shadows, mirrors, specularity, and constructive solid geometry. The underlying representation for the ray tracer is a 3-D raster of voxels that holds the discrete form of the scene. Unlike traditional volume rendering techniques, the discrete recursive ray tracer models many illumination phenomena by traversing discrete rays in voxel space. The approach provides true ray tracing of sampled or computed datasets, as well as ray tracing of hybrid scenes where sampled or computed data are intermixed with geometric models and enhances the understanding of complex biomedical datasets

This paper emphasizes the need for and importance of remote visualization. The potential impact of remote visualization on application algorithms, communication protocols, and underlying networks is assessed. Opportunities for research and development to support remote visualization in the context of the National Research and Education network are outlined

An improvement to visualization systems that provides a graphics window into an application displaying program data at run-time through an easy-to-use graphical interface is discussed. With little or no instrumentation of the application the user will be able to dynamically select data for graphical display as the program executes on a remote computer system. The data to be displayed and the type of display to be used are chosen interactively while the application is executing. Any data display can be enabled and disabled at any time; it is not necessary to specify the data or graphics technique before compilation as with conventional graphics tools. An architecture for such a remote visualization system is proposed, and an implementation, called Vista, is described. Designed primarily for scientific visualization, Vista or offers an environment for more effective debugging and program development

Summary form only given, as follows. Historically, scientific visualization has been carried out in two primary modes: interactive on desktop computers, and batch on high-performance computers. The next decade will see a merging of these two approaches with the advent of high-speed networking. The networking is hierarchical in speed from Ethernet to FDDI to HiPPI. This network effectively unites desktop computers with higher-value remote resources into a single metacomputer. To take advantage of this new hardware configuration, distributed visualization software is being developed which allows the flexibility of the local workstation to be coupled with the computing power of distant supercomputers. Examples are discussed for 2D raster graphics and 3D rendered surface and volumetric graphics. These new capabilities are having a remarkable impact on computational science

The technique of placing directed line segments at grid points, known as hedgehogging, which has been used for visualizing 2D vector fields, is considered. A means of rapidly rendering a slice of a 3D field, suitable for a bilevel display, is provided. Shape and shadowing are used to disambiguate orientation. Liberal use of lookup tables makes the technique very fast

Techniques for displaying 3D isovalues of scalar fields such as stress within a solid finite-element model generally involve examining each element for values of interest. An inexpensive, straightforward method is discussed for reducing the number of elements searched for such isovalues. It takes advantage of one traversal of the element data to yield a compact classification of the model by result values and ranges, with no sorting required. This data structure can then relate any scalar isovalue to a set of element groups which are closely inclusive of the isovalue. This method is intended for applications requiring repeated access to the analysis data, such as animation and interactive rendering of isosurfaces and scalar fields. While applicable to general volume visualization problems, it is particularly well suited to optimizing real-valued continuum field results such as those found in finite-element data

A method for computing isovalue or contour surfaces of a trivariate function is discussed. The input data are values of the trivariate function, Fijk, at the cuberille grid points (xi, yj, zk ), and the output of a collection of triangles representing the surface consisting of all points where F(x,y, z) is a constant value. The method is a modification that is intended to correct a problem with a previous method.

Volumetric rendering is applied to the interpretation of atomic-scale data generated from quantum molecular dynamics computations. In particular, for silicon computations it is found that volumetric visualization of the computed 3D electronic charge density is a valuable tool for identifying defect states in silicon lattices in which oxygen atoms occur as impurities. Rendering of several judiciously selected ranges of charge density in translucent colors provides an effective means of identifying broken or altered molecular bonds and induced charge excesses in the lattice. The resulting 3D images reveal important features missed previously in 2D charge density contour maps. Stereoscopic `blink comparison' of image pairs is an extremely valuable way to study the structural differences among various configurations, and animation provides significant insight into the molecular dynamics