DevLan/vispubs huggingface dataset:
Visibility culling using plenoptic opacity functions for large volume visualization
Authors: Jinzhu Gao, Jian Huang 0007, Han-Wei Shen, James Arthur Kohl
Published at Vis, 2003

Visibility culling has the potential to accelerate large data visualization in significant ways. Unfortunately, existing algorithms do not scale well when parallelized, and require full re-computation whenever the opacity transfer function is modified. To address these issues, we have designed a Plenoptic Opacity Function (POF) scheme to encode the view-dependent opacity of a volume block. POFs are computed off-line during a pre-processing stage, only once for each block. We show that using POFs is (i) an efficient, conservative and effective way to encode the opacity variations of a volume block for a range of views, (ii) flexible for re-use by a family of opacity transfer functions without the need for additional off-line processing, and (iii) highly scalable for use in massively parallel implementations. Our results confirm the efficacy of POFs for visibility culling in large-scale parallel volume rendering; we can interactively render the Visible Woman dataset using software ray-casting on 32 processors, with interactive modification of the opacity transfer function on-the-fly.
Visualization experiences and issues in deep space exploration
Authors: John R. Wright, Scott C. Burleigh, Makoto Maruya, Scott Maxwell, René Pischel
Published at Vis, 2003

Visualization tools play a key role in the exploration of outer space. Since it is difficult and expensive to send humans to other planets, immersive visualization of such hostile environments is as close as we will get for some time. Visualization is also used in a variety of supporting roles for deep space missions, from simulation and rehearsal of planned operations to analysis of spacecraft state to analysis of science data returned from a variety of instruments. The panelists will discuss their experiences in collecting data in deep space, transmitting it to Earth, processing and visualizing it here, and using the visualization to drive the continued mission. This closes the loop, making missions more responsive to their environment, particularly in-situ operations on planetary surfaces and within planetary atmospheres.
Visualization of noisy and biased volume data using first and second order derivative techniques
Authors: Marc P. Persoon, Iwo Serlie, Frits H. Post, Roel Truyen, Frans Vos
Published at Vis, 2003

The quality of volume visualization depends strongly on the quality of the underlying data. In virtual colonoscopy, CT data should be acquired at a low radiation dose that results in a low signal-to-noise ratio. Alternatively, MRI data is acquired without ionizing radiation, but suffers from noise and bias (global signal fluctuations). Current volume visualization techniques often do not produce good results with noisy or biased data. This paper describes methods for volume visualization that deal with these imperfections. The techniques are based on specially adapted edge detectors using first and second order derivative filters. The filtering is integrated into the visualization process. The first order derivative method results in good quality images but suffers from localization bias. The second order method has better surface localization, especially in highly curved areas. It guarantees minimal detail smoothing resulting in a better visualization of polyps.
Visualization of steep breaking waves and thin spray sheets around a ship
Authors: Paul Adams, Douglas Dommermuth
Published at Vis, 2003

The simulation of breaking of waves, the formation of thin spray sheets, and the entertainment of air around the next generation of naval surface combatants is an ongoing 3-year Department of Defense (DoD) Challenge Project. The goal of this project is a validated computation capability to model the full hydrodynamics around a surface combatant including all of the processes that affect mission and performance. Visualization of these large-scale simulations is paramount to understanding the complex physics involved. These simulations produce enormous data sets with both surface and volumetric qualities. Wave breaking, spray sheets, and air entertainment can be visualized using isosurfaces of scalar data. Visualization of quantities such as the vorticity field also provides insight into the dynamics of droplet and bubble formation. This paper documents the techniques used, results obtained, and lessons learned from the visualization of the hydrodynamics of naval vessels.
Visualization of volume data with quadratic super splines
Authors: Christian Rössl, Frank Zeilfelder, Günther Nürnberger, Hans-Peter Seidel
Published at Vis, 2003

We develop a new approach to reconstruct non-discrete models from gridded volume samples. As a model, we use quadratic trivariate super splines on a uniform tetrahedral partition /spl Delta/. The approximating splines are determined in a natural and completely symmetric way by averaging local data samples, such that appropriate smoothness conditions are automatically satisfied. On each tetra-hedron of /spl Delta/ , the quasi-interpolating spline is a polynomial of total degree two which provides several advantages including efficient computation, evaluation and visualization of the model. We apply Bernstein-Bezier techniques well-known in CAGD to compute and evaluate the trivariate spline and its gradient. With this approach the volume data can be visualized efficiently e.g., with isosurface ray-casting. Along an arbitrary ray the splines are univariate, piecewise quadratics and thus the exact intersection for a prescribed isovalue can be easily determined in an analytic and exact way. Our results confirm the efficiency of the quasi-interpolating method and demonstrate high visual quality for rendered isosurfaces.
Visualization, optimization, business strategy: a case study
Authors: Donna L. Gresh, Eugene I. Kelton
Published at Vis, 2003

We describe a visualization application intended for operational use in formulating business strategy in the customer service arena. The visualization capability provided in this application implicitly allows the user to better formulate the objective function for large optimization runs which act to minimize costs based on certain input parameters. Visualization is necessary because many of the inputs to the optimization runs are themselves strategic business decisions which are not pre-ordained. Both information visualization presentations and three-dimensional visualizations are included to help users better understand the cost/benefit tradeoffs of these strategic business decisions. Here, visualization explicitly provides value not possible algorithmically, as the perceived benefit of different combinations of service level does not have an a priori mathematical formulation. Thus, we take advantage of the fundamental power of visualization, bringing the user's intuition and pattern recognition skills into the solution, while simultaneously taking advantage of the strength of algorithmic approaches to quickly and accurately find an optimal solution to a well-defined problem.
Visualizing industrial CT volume data for nondestructive testing applications
Authors: Runzhen Huang, Kwan-Liu Ma, Patrick S. McCormick, William Ward
Published at Vis, 2003

This paper describes a set of techniques developed for the visualization of high-resolution volume data generated from industrial computed tomography for nondestructive testing (NDT) applications. Because the data are typically noisy and contain fine features, direct volume rendering methods do not always give us satisfactory results. We have coupled region growing techniques and a 2D histogram interface to facilitate volumetric feature extraction. The new interface allows the user to conveniently identify, separate or composite, and compare features in the data. To lower the cost of segmentation, we show how partial region growing results can suggest a reasonably good classification function for the rendering of the whole volume. The NDT applications that we work on demand visualization tasks including not only feature extraction and visual inspection, but also modeling and measurement of concealed structures in volumetric objects. An efficient filtering and modeling process for generating surface representation of extracted features is also introduced. Four CT data sets for preliminary NDT are used to demonstrate the effectiveness of the new visualization strategy that we have developed.
Visualizing spatial and temporal variability in coastal observatories
Authors: Walter Jiménez, Wagner Toledo Corrêa, Cláudio T. Silva, António M. Baptista
Published at Vis, 2003

In this paper, we describe a set of 3D and 4D visualization tools and techniques for CORIE, a complex environmental observation and forecasting system (EOFS) for the Columbia River. The Columbia River, a complex and highly variable estuary, is the target of numerous cross-disciplinary ecosystem research projects and is at the heart of multiple sustainable development issues with long reaching implications for the Pacific Northwest. However, there has been until recently no comprehensive and objective system available for modeling this environment, and as a consequence, researchers and agencies have had inadequate tools for evaluating the effects of natural resource management decisions. CORIE was designed to address this gap and is a major step towards the vision of a scalable, multi-use, real-time EOFS. Although CORIE already had a rich set of visualization tools, most of them produced 2D visualizations and did not allow for interactive visualization. Our work adds advanced interactive 3D tools to CORIE, which can be used for further inspection of the simulated and measured data.
Visually accurate multi-field weather visualization
Authors: Kirk Riley, David S. Ebert, Charles D. Hansen, Jason J. Levit
Published at Vis, 2003

Weather visualization is a difficult problem because it comprises volumetric multi-field data and traditional surface-based approaches obscure details of the complex three-dimensional structure of cloud dynamics. Therefore, visually accurate volumetric multi-field visualization of storm scale and cloud scale data is needed to effectively and efficiently communicate vital information to weather forecasters, improving storm forecasting, atmospheric dynamics models, and weather spotter training. We have developed a new approach to multi-field visualization that uses field specific, physically-based opacity, transmission, and lighting calculations per-field for the accurate visualization of storm and cloud scale weather data. Our approach extends traditional transfer function approaches to multi-field data and to volumetric illumination and scattering.
Volume tracking using higher dimensional isosurfacing
Authors: Guangfeng Ji, Han-Wei Shen, Rephael Wenger
Published at Vis, 2003

Tracking and visualizing local features from a time-varying volumetric data allows the user to focus on selected regions of interest, both in space and time, which can lead to a better understanding of the underlying dynamics. In this paper, we present an efficient algorithm to track time-varying isosurfaces and interval volumes using isosurfacing in higher dimensions. Instead of extracting the data features such as isosurfaces or interval volumes separately from multiple time steps and computing the spatial correspondence between those features, our algorithm extracts the correspondence directly from the higher dimensional geometry and thus can more efficiently follow the user selected local features in time. In addition, by analyzing the resulting higher dimensional geometry, it becomes easier to detect important topological events and the corresponding critical time steps for the selected features. With our algorithm, the user can interact with the underlying time-varying data more easily. The computation cost for performing time-varying volume tracking is also minimized.
Voxels on fire
Authors: Ye Zhao 0004, Xiaoming Wei, Zhe Fan, Arie E. Kaufman, Hong Qin
Published at Vis, 2003

We introduce a method for the animation of fire propagation and the burning consumption of objects represented as volumetric data sets. Our method uses a volumetric fire propagation model based on an enhanced distance field. It can simulate the spreading of multiple fire fronts over a specified isosurface without actually having to create that isosurface. The distance field is generated from a specific shell volume that rapidly creates narrow spatial bands around the virtual surface of any given isovalue. The complete distance field is then obtained by propagation from the initial bands. At each step multiple fire fronts can evolve simultaneously on the volumetric object. The flames of the fire are constructed from streams of particles whose movement is regulated by a velocity field generated with the hardware-accelerated Lattice Boltzmann Model (LBM). The LBM provides a physically-based simulation of the air flow around the burning object. The object voxels and the splats associated with the flame particles are rendered in the same pipeline so that the volume data with its external and internal structures can be displayed along with the fire.
A model of multi-scale perceptual organization in information graphics
Authors: Martin Wattenberg, Danyel Fisher
Published at InfoVis, 2003

We propose a new method for assessing the perceptual organization of information graphics, based on the premise that the visual structure of an image should match the structure of the data it is intended to convey. The core of our method is a new formal model of one type of perceptual structure, based on classical machine vision techniques for analyzing an image at multiple resolutions. The model takes as input an arbitrary grayscale image and returns a lattice structure describing the visual organization of the image. We show how this model captures several aspects of traditional design aesthetics, and we describe a software tool that implements the model to help designers analyze and refine visual displays. Our emphasis here is on demonstrating the model's potential as a design aid rather than as a description of human perception, but given its initial promise we propose a variety of ways in which the model could be extended and validated.
A virtual workspace for hybrid multidimensional scaling algorithms
Authors: Greg Ross, Matthew Chalmers
Published at InfoVis, 2003

In visualising multidimensional data, it is well known that different types of algorithms to process them. Data sets might be distinguished according to volume, variable types and distribution, and each of these characteristics imposes constraints upon the choice of applicable algorithms for their visualization. Previous work has shown that a hybrid algorithmic approach can be successful in addressing the impact of data volume on the feasibility of multidimensional scaling (MDS). This suggests that hybrid combinations of appropriate algorithms might also successfully address other characteristics of data. This paper presents a system and framework in which a user can easily explore hybrid algorithms and the data flowing through them. Visual programming and a novel algorithmic architecture let the user semi-automatically define data flows and the co-ordination of multiple views.
An experimental evaluation of continuous semantic zooming in program visualization
Authors: Kenneth L. Summers, Timothy E. Goldsmith, Steve Kubica, Thomas P. Caudell
Published at InfoVis, 2003

This paper presents the results of an experiment aimed at investigating how different methods of viewing visual programs affect users' understanding. The first two methods used traditional flat and semantic zooming models of program representation; the third is a new representation that uses semantic zooming combined with blending and proximity. The results of several search tasks performed by approximately 80 participants showed that the new method resulted in both faster and more accurate searches than the other methods.
BARD: A visualization tool for biological sequence analysis
Authors: Rhazes Spell, Rachael Brady, Fred Dietrich
Published at InfoVis, 2003

We present BARD (biological arc diagrams), a visualization tool for biological sequence analysis. The development of BARD began with the application of Wattenberg's arc diagrams (Wattenberg, 2002) to results from sequence analysis programs, such as BLAST (Atschul et al., 1990). In this paper, we extend the initial arc diagram concept in two ways: 1) by separating the visualization method from the underlying matching algorithm and 2) by expanding the types of matches to include inexact matches, complemented palindrome matches, and inter-sequence matches. BARD renders each type of match distinctly, resulting in a powerful tool to quickly understand sequence similarities and differences. We illustrate the power of BARD by applying the technique to a comparative sequence analysis of the human pathogenic fungi Cryptococcus neoformans.
Between aesthetics and utility: designing ambient information visualizations
Authors: Tobias Skog, Sara Ljungblad, Lars Erik Holmquist
Published at InfoVis, 2003

Unlike traditional information visualization, ambient information visualizations reside in the environment of the user rather than on the screen of a desktop computer. Currently, most dynamic information that is displayed in public places consists of text and numbers. We argue that information visualization can be employed to make such dynamic data more useful and appealing. However, visualizations intended for non-desktop spaces will have to both provide valuable information and present an attractive addition to the environment - they must strike a balance between aesthetical appeal and usefulness. To explore this, we designed a real-time visualization of bus departure times and deployed it in a public space, with about 300 potential users. To make the presentation more visually appealing, we took inspiration from a modern abstract artist. The visualization was designed in two passes. First, we did a preliminary version that was presented to and discussed with prospective users. Based on their input, we did a final design. We discuss the lessons learned in designing this and previous ambient information visualizations, including how visual art can be used as a design constraint, and how the choice of information and the placement of the display affect the visualization.
Causality visualization using animated growing polygons
Authors: Niklas Elmqvist, Philippas Tsigas
Published at InfoVis, 2003

We present Growing Polygons, a novel visualization technique for the graphical representation of causal relations and information flow in a system of interacting processes. Using this method, individual processes are displayed as partitioned polygons with color-coded segments showing dependencies to other processes. The entire visualization is also animated to communicate the dynamic execution of the system to the user. The results from a comparative user study of the method show that the Growing Polygons technique is significantly more efficient than the traditional Hasse diagram visualization for analysis tasks related to deducing information flow in a system for both small and large executions. Furthermore, our findings indicate that the correctness when solving causality tasks is significantly improved using our method. In addition, the subjective ratings of the users rank the method as superior in all regards, including usability, efficiency, and enjoyability.
Compound brushing
Authors: Hong Chen
Published at InfoVis, 2003

This paper proposes a conceptual model called compound brushing for modeling the brushing techniques used in dynamic data visualization. In this approach, brushing techniques are modeled as higraphs with five types of basic entities: data, selection, device, renderer, and transformation. Using this model, a flexible visual programming tool is designed not only to configure/control various common types of brushing techniques currently used in dynamic data visualization, but also to investigate new brushing techniques.
Constant density displays using diversity sampling
Authors: Mark Derthick, Michael G. Christel, Alex Hauptmann 0001, Howard D. Wactlar
Published at InfoVis, 2003

The Informedia Digital Video Library user interface summarizes query results with a collage of representative keyframes. We present a user study in which keyframe occlusion caused difficulties. To use the screen space most efficiently to display images, both occlusion and wasted whitespace should be minimized. Thus optimal choices will tend toward constant density displays. However, previous constant density algorithms are based on global density, which leads to occlusion and empty space if the density is not uniform. We introduce an algorithm that considers the layout of individual objects and avoids occlusion altogether. Efficiency concerns are important for dynamic summaries of the Informedia Digital Video Library, which has hundreds of thousands of shots. Posting multiple queries that take into account parameters of the visualization as well as the original query reduces the amount of work required. This greedy algorithm is then compared to an optimal one. The approach is also applicable to visualizations containing complex graphical objects other than images, such as text, icons, or trees.
Conveying shape with texture: an experimental investigation of the impact of texture type on shape categorization judgments
Authors: Sunghee Kim, Haleh Hagh-Shenas, Victoria Interrante
Published at InfoVis, 2003

As visualization researchers, we are interested in gaining a better understanding of how to effectively use texture to facilitate shape perception. If we could design the ideal texture pattern to apply to an arbitrary smoothly curving shape to be most accurately and effectively perceived, what would the characteristics of that texture pattern be? In this paper we describe the results of a comprehensive controlled observer experiment intended to yield insight into that question. Here, we report the results of a new study comparing the relative accuracy of observers' judgments of shape type (elliptical, cylindrical, hyperbolic or flat) and shape orientation (convex, concave, both, or neither) for local views of boundary masked quadric surface patches under six different principal direction texture pattern conditions plus two texture conditions (an isotropic pattern and a non-principal direction oriented anisotropic pattern), under both perspective and orthographic projection conditions and from both head-on and oblique viewpoints. Our results confirm the hypothesis that accurate shape perception is facilitated to a statistically significantly greater extent by some principal direction texture patterns than by others. Specifically, we found that, for both views, under conditions of perspective projection, participants more often correctly identified the shape category and the shape orientation when the surface was textured with the pattern that contained oriented energy along both the first and second principal directions only than in the case of any other texture condition. Patterns containing markings following only one of the principal directions, or containing information along other directions in addition to the principal directions yielded poorer performance overall.