Showing papers on "Graphics published in 1996"

Progressive meshes

Abstract: Highly detailed geometric models are rapidly becoming commonplace in computer graphics. These models, often represented as complex triangle meshes, challenge rendering performance, transmission bandwidth, and storage capacities. This paper introduces the progressive mesh (PM) representation, a new scheme for storing and transmitting arbitrary triangle meshes. This efficient, lossless, continuous-resolution representation addresses several practical problems in graphics: smooth geomorphing of level-of-detail approximations, progressive transmission, mesh compression, and selective refinement. In addition, we present a new mesh simplification procedure for constructing a PM representation from an arbitrary mesh. The goal of this optimization procedure is to preserve not just the geometry of the original mesh, but more importantly its overall appearance as defined by its discrete and scalar appearance attributes such as material identifiers, color values, normals, and texture coordinates. We demonstrate construction of the PM representation and its applications using several practical models

Modeling and rendering architecture from photographs: a hybrid geometry- and image-based approach

Abstract: We present a new approach for modeling and rendering existing architectural scenes from a sparse set of still photographs. Our modeling approach, which combines both geometry-based and imagebased techniques, has two components. The first component is a photogrammetricmodeling method which facilitates the recovery of the basic geometry of the photographed scene. Our photogrammetric modeling approach is effective, convenient, and robust because it exploits the constraints that are characteristic of architectural scenes. The second component is a model-based stereo algorithm, which recovers how the real scene deviates from the basic model. By making use of the model, our stereo technique robustly recovers accurate depth from widely-spaced image pairs. Consequently, our approach can model large architectural environments with far fewer photographs than current image-based modeling approaches. For producing renderings, we present view-dependent texture mapping, a method of compositing multiple views of a scene that better simulates geometric detail on basic models. Our approach can be used to recover models for use in either geometry-based or image-based rendering systems. We present results that demonstrate our approach’s ability to create realistic renderings of architectural scenes from viewpoints far from the original photographs. CR Descriptors: I.2.10 [Artificial Intelligence]: Vision and Scene Understanding Modeling and recovery of physical attributes; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism Color, shading, shadowing, and texture I.4.8 [Image Processing]: Scene Analysis Stereo; J.6 [Computer-Aided Engineering]: Computer-aided design (CAD).

Algorithms for image processing and computer vision

Abstract: A cookbook of algorithms for common image processing applicationsThanks to advances in computer hardware and software, algorithms have been developed that support sophisticated image processing without requiring an extensive background in mathematics This bestselling book has been fully updated with the newest of these, including 2D vision methods in content-based searches and the use of graphics cards as image processing computational aids Its an ideal reference for software engineers and developers, advanced programmers, graphics programmers, scientists, and other specialists who require highly specialized image processingAlgorithms now exist for a wide variety of sophisticated image processing applications required by software engineers and developers, advanced programmers, graphics programmers, scientists, and related specialistsThis bestselling book has been completely updated to include the latest algorithms, including 2D vision methods in content-based searches, details on modern classifier methods, and graphics cards used as image processing computational aidsSaves hours of mathematical calculating by using distributed processing and GPU programming, and gives non-mathematicians the shortcuts needed to program relatively sophisticated applicationsAlgorithms for Image Processing and Computer Vision, 2nd Edition provides the tools to speed development of image processing applications

Interactive computer system for providing an interactive presentation with personalized video, audio and graphics responses for multiple viewers

Abstract: The present invention is an interactive computer system which may operate on a computer network. Subscribers interact with a fully interactive programthrough the use of input devices and a personal computer or a television. The multiple video/audio datastreams may be received from a broadcast transmission source or may be resident in local or external storage. In response to user inputs, a personalized graphics, video and/or audio presentation is provided to the user either immediately or at a later time. If not presented immediately, the interactive computer system utilizes "trigger points" to determine when to enable multiple multimedia segments during the show. The CPU uses embedded or stored authoring commands for integrating the various multimedia elements. The interactive multimedia computer enables seamless flicker-free switching from one signal to another on the same or different channels.

Clustering in an object-oriented environment

Abstract: This paper describes the incorporation of seven stand-alone clustering programs into S-PLUS, where they can now be used in a much more flexible way. The original Fortran programs carried out new cluster analysis algorithms introduced in the book of Kaufman and Rousseeuw (1990). These clustering methods were designed to be robust and to accept dissimilarity data as well as objects-by-variables data. Moreover, they each provide a graphical display and a quality index reflecting the strength of the clustering. The powerful graphics of S-PLUS made it possible to improve these graphical representations considerably. The integration of the clustering algorithms was performed according to the object-oriented principle supported by S-PLUS. The new functions have a uniform interface, and are compatible with existing S-PLUS functions. We will describe the basic idea and the use of each clustering method, together with its graphical features. Each function is briefly illustrated with an example.

Computer Graphics, C Version

Abstract: (NOTE: Each chapter concludes with a Summary, References and Exercises.) 1. A Survey of Computer Graphics. 2. Overview of Graphics Systems. 3. Output Primitives. 4. Attributes of Output Primitives. 5. Two-Dimensional Geometric Transformations. 6. Two-Dimensional Viewing. 7. Structures and Hierarchical Modeling. 8. Graphical User Interfaces and Interactive Input Methods. 9. Three-Dimensional Concepts. 10. Three-Dimensional Object Representations. 11. Three-Dimensional Geometric and Modeling Transformations. 12. Three-Dimensional Viewing. 13. Visible-Surface Detection Methods. 14. Illumination Models and Surface-Rendering Methods. 15. Color Models and Color Applications. 16. Computer Animation. Appendix A: Mathematics for Computer Graphics. Bibliography. Index.

Adding force feedback to graphics systems: issues and solutions

Abstract: Integrating force feedback with a complete real-time virtual environment system presents problems which are more difficult than those encountered in building simpler forcefeedback systems. In particular, lengthy computations for graphics or simulation require a decoupling of the haptic servo loop from the main application loop if high-quality forces are to be produced. We present some approaches to these problems and describe our force-feedback software library which implements these techniques and provides other benefits including haptic-textured surfaces, device independence, distributed operation and easy enhancement.

Graphics for regressions with a binary response

Abstract: Central dimension-reduction subspaces, which characterize the dependence of a response variable on one or more predictors, are developed and then used to guide the construction and interpretation of graphics for regression problems with a binary response variable. Graphical methods requiring neither a link function nor residuals are suggested for both development and criticism of model components implied by the central dimension-reduction subspace.

Interactive visualization of 3D-vector fields using illuminated stream lines

Abstract: A new technique for interactive vector field visualization using large numbers of properly illuminated stream lines is presented. Taking into account ambient, diffuse, and specular reflection terms as well as transparency, we employ a realistic shading model which significantly increases quality and realism of the resulting images. While many graphics workstations offer hardware support for illuminating surface primitives, usually no means for an accurate shading of line primitives are provided. However, we show that proper illumination of lines can be implemented by exploiting the texture mapping capabilities of modern graphics hardware. In this way high rendering performance with interactive frame rates can be achieved. We apply the technique to render large numbers of integral curves in a vector field. The impression of the resulting images can be further improved by making the curves partially transparent. We also describe methods for controlling the distribution of stream lines in space. These methods enable us to use illuminated stream lines within an interactive visualization environment.

Physics-Based Deformable Models: Applications to Computer Vision, Graphics, and Medical Imaging

Abstract: From the Publisher: Physics-Based Deformable Models presents a systematic physics-based framework for modeling rigid, articulated, and deformable objects, their interactions with the physical world, and the estimation of their shape and motion from visual data. This book presents a large variety of methods and associated experiments in computer vision, graphics and medical imaging that help the reader better understand the presented material. In addition, special emphasis has been given to the development of techniques with interactive or close to real-time performance. Physics-Based Deformable Models is suitable as a secondary text for a graduate level course on Computer Graphics, Computational Physics, Computer Vision, Medical Imaging, or Biomedical Engineering. In addition, this book is appropriate as a reference for researchers and practitioners in the above mentioned fields.

The design and implementation of an object-oriented toolkit for 3D graphics and visualization

Abstract: The Visualization Toolkit (vtk) is a freely available C++ class library for 3D graphics and visualization. We describe core characteristics of the toolkit. This includes a description of object oriented models for graphics and visualization; methods for synchronizing system execution; a summary of data representation schemes; the role of C++; issues in portability across PC and Unix systems; and how we automatically wrap the C++ class library with interpreted languages such as Java and Tcl. We also demonstrate the capabilities of the system for scalar, vector, tensor, and other visualization techniques.

Digital customized audio products with user created data and associated distribution and production system

Abstract: A system for creation of user-selected customized audio products, defined as a plurality of songs from different recording artists recorded on a single compact disc (CD) or digital audio tape (DAT) cassette, at record store/distributor locations utilizing a digitized, central database with production hardware at distributor sites Customized products consist of CD ROM or digital audio tapes (DAT) with music or voice content selected from large digital database, and are written at local workstations at distribution centers (such as record stores) which are connected by a high-speed communications network The system records costs of the digitized audio (eg, royalties for individual songs) for billing purposes, as well as producing descriptive material (contents, background information, and graphics for labels, etc) Data transfer and production is faster than real-time, and thus will be a significant improvement and will tend to reduce current analog hardware-to-hardware transfer ("pirating") which violate copyright laws and is unauthorized The system consists of integrated, state-of-the-art digital databases, communications networks, computer workstations, and unique workstation processing software, and provides an innovative product/service (individual customized albums or audio data compilations) which currently do not exist

Computer system supporting portable interactive graphics display tablet and communications systems

Abstract: A portable display tablet is operated in conjunction with a base computer system including a host processor for executing an application program with an operational function that generates graphics data and operates in response to input data. The computer system includes a wireless data transceiver coupled to the processor that is capable of communicating the graphics and input data between the computer and portable display tablet. The portable display tablet includes a graphics display panel for displaying the graphical data, a low power wireless data transceiver providing short range data communication of the graphics and input data between the base computer system and portable display tablet, and a controller, embedded within the portable display tablet and coupled to the low power wireless data transceiver, that executes a control program to process the graphics data to provide the graphical display data to the graphics display panel.

High performance low cost video game system with coprocessor providing high speed efficient 3D graphics and digital audio signal processing

Abstract: A low cost high performance three dimensional (3D) graphics system can model a world in three dimensions and project the model onto a two dimensional viewing plane selected based on a changeable viewpoint. The viewpoint can be changed on an interactive, real time basis by operating user input controls such as game controllers. The system rapidly produces a corresponding changing image (which can include animated cartoon characters or other animation) on the screen of a color television set. The richly featured high performance low cost system gives consumers the chance to interact in real time right inside magnificent virtual 3D worlds to provide a high degree of image realism, excitement and flexibility. An optimum feature set/architecture (including a custom designed graphics/audio coprocessor) provides high quality fast moving 3D images and digital stereo sound for video game play and other graphics applications. Numerous features provide flexibility and capabilities in a system within the cost range of most consumers.

Multi-layered television graphical user interface

Abstract: A TV graphical user interface (GUI) is provided to produce a multi-layered graphical presentation. The TV GUI operates in a channel changer mode to enable a user to tune to a required TV channel, and in a program guide mode to show TV program information. A memory for storing graphics data is capable of storing two graphics planes that represent upper and lower layers of graphics displayable on a TV screen. A graphics accelerator combines the graphics planes to produce various graphical effects on the screen. In the channel changer mode, the right hand side of the upper layer is made transparent to expose graphical buttons produced in the lower layer of graphics. In the program guide mode, the graphical buttons are partially covered by a program guide produced in the upper layer. When the user moves a cursor to the right hand side of the screen, the right hand portion of the program guide is made transparent to fully expose the graphical buttons in the lower layer.

Hotlinks between an annotation window and graphics window for interactive 3D graphics

Abstract: A computer graphics system includes a graphics processing engine for processing and displaying graphics data representing three-dimensional objects in a first portion of a display. A text processing engine displays text in a second portion of the display. Embedded in the text is a command or hotlink for controlling operation of the graphics processing engine. In response to user selection of first data displayed in the second portion of the display, a supervisory controller analyzes the first data to determine if the first data includes at least one hotlink command. Upon determining that the first data includes at least one hotlink command, the supervisory controller identifies the hotlink command included in the first data and controls operation of the graphics processing engine to perform at least one graphics function according to the hotlink command included in the first data. The graphics function may be associated with at least one of the three-dimensional objects, a three-dimensional markup, a predefined view point, or a predefined animation.

Method and apparatus for displaying a page with graphics information on a continuous synchronous raster output device

Abstract: An apparatus and method used to perform image rendering in a manner which is capable of producing complex, high resolution page images where a continuous synchronous raster image output device, such as a laser printer, using a minimum of random access memory. The invented technique decomposes basic graphics functions into a compact series of orders commands suitable for real time processing and then generates the output page image in real time. The graphic content of a page is defined in much less memory then the rendered image would otherwise require, but is in a form that can be processed and deliver to the output device at the speed required by the output device. This is accomplished by the use of graphics functions which are represented as low level primitives which can be converted to bit mapped images in real time. Additionally, the number of commands which need to be processed and delivered is reduced by eliminating redundant or overlapping graphics functions to minimize the memory used by the commands.

Computer-vision-based registration techniques for augmented reality

Abstract: Augmented reality is a term used to describe systems in which computer-generated information is superimposed on top of the real world; for example, through the use of a see-through head-mounted display. A human user of such a system could still see and interact with the real world, but have valuable additional information, such as descriptions of important features or instructions for performing physical tasks, superimposed on the world. For example, the computer could identify objects and overlay them with graphic outlines, labels, and schematics. The graphics are registered to the real-world objects and appear to be “painted” onto those objects. Augmented reality systems can be used to make productivity aids for tasks such as inspection, manufacturing, and navigation. One of the most critical requirements for augmented reality is to recognize and locate real-world objects with respect to the person’s head. Accurate registration is necessary in order to overlay graphics accurately on top of the real-world objects. At the Colorado School of Mines, we have developed a prototype augmented reality system that uses head-mounted cameras and computer vision techniques to accurately register the head to the scene. The current system locates and tracks a set of preplaced passive fiducial targets placed on the real-world objects. The system computes the pose of the objects and displays graphics overlays using a see-through head-mounted display. This paper describes the architecture of the system and outlines the computer vision techniques used.

Portable interactive graphics display tablet and communications system

Abstract: A portable display tablet is operated in conjunction with a base computer system including a host processor for executing an application program with a predetermined operational function that generates predetermined graphics data and operates in response to predetermined input data. The computer system includes a wireless data transceiver coupled to the processor that is capable of communicating the predetermined graphics and input data between the computer and portable display tablet. The portable display tablet comprises a graphics display panel for displaying predetermined graphical data, a low power wireless data transceiver providing short range data communication of the predetermined graphics and input data between the base computer system and portable display tablet, and a controller embedded within the portable display tablet and coupled to the low power wireless data transceiver that executes a control program to process the predetermined graphics data to provide the predetermined graphical display data to the graphics display panel.

System and method for generating graphics charts

Abstract: A computer graphics program executed by a processor (12) for generating a plurality of types of graphics charts on a computer display (26) is provided. The program includes instructions for generating an adjustable grid associated with each type of graphics chart. Each grid provides placements for text and shapes for each type of graphics chart. The present invention further includes instructions for generating snap zones associated with each grid for controlling the orientation of the shapes and text placed within the grid.

The graphics calculator in mathematics education: A critical review of recent research

Abstract: The graphics calculator, sometimes referred to as the “super calculator,” has sparked great interest among mathematics educators. Considered by many to be a tool which has the potential to revolutionise mathematics education, a significant amount of research has been conducted into its effectiveness as a tool for instruction and learning within precalculus and calculus courses, specifically in the study of functions, graphing and modelling. Some results suggest that these devices (a) can facilitate the learning of functions and graphing concepts and the development of spatial visualisation skills; (b) promote mathematical investigation and exploration; and (c) encourage a shift in emphasis from algebraic manipulation and proof to graphical investigation and examination of the relationship between graphical, algebraic and geometric representations. Other studies, however, indicate that there is still a need for manipulative techniques in the learning of function and graphing concepts, that the use of graphics calculators may not facilitate the learning of particular precalculus topics, and that some “de-skilling” may occur, especially among males. It is the contention of this paper, however, that much of the research in this new and important field fails to provide clear guidance or even to inform debate in adequate ways regarding the role of graphics calculators in mathematics teaching and learning. By failing to distinguish the role of the tool from that of the instructional process, many studies reviewed could be more appropriately classified as “program evaluations” rather than as research on the graphics calculator per se. Further, claims regarding the effectiveness of the graphics calculator as a tool for learning frequently fail to recognise that judgments of effectiveness result directly from existing assumptions regarding both assessment practice and student “achievement.”

Method and system for merging pixel fragments in a graphics rendering system

Abstract: A method for merging pixel fragments to reduce memory usage in a graphics rendering system. In rendering a graphics scene, geometric primitives of objects in the scene are rasterized to create pixel data including pixel fragments representing partially covered pixels. Lists of pixel fragments having color, depth, and coverage data are stored in a fragment buffer. When a new fragment is generated, an attempt is made to merge the fragment with the last fragment stored for a corresponding pixel location. Fragments are merged if they are within predefined depth and color tolerances.

Graphics and GUIs with MATLAB

Abstract: From the Publisher: Graphics and GUIs with MATLAB completely examines the MATLAB graphics system, describing the enhancements and added features of MATLAB 5. This second edition provides illustrative example sets to simplify the process of learning and mastering the powerful, flexible, and easy-to-use graphics environment. This book serves technical professionals using MATLAB's plotting capabilities, MATLAB programmers learning about the graphics environment, anyone creating pictures using mathematical expressions.

Hardware assisted volume rendering of unstructured grids by incremental slicing

Abstract: Some of the more important research results in computational science rely on the use of simulation methods that operate on unstructured grids. However, these grids, composed of a set of polyhedra, introduce exceptional problems with respect to data visualization. Volume rendering techniques, originally developed to handle rectangular grids, show significant promise for general use with unstructured grids as well. The main disadvantage of this approach, compared to isosurfaces, particles or other visualization tools is its non-interactive performance. We describe an efficient method for rendering unstructured grids that is based on incremental slicing and hardware polygon rendering. For a given view direction, the grid vertices are transformed to image space using available graphics hardware. We then incrementally compute the 2D polygon-meshes that result from letting a set of planes, parallel to the screen plane, intersect (slice) the transformed grid. Finally, we use the graphics hardware to render (interpolate-fill) the polygon-meshes and composite them in visibility order. We show that, in addition to being faster than existing methods, our approach also provides adaptive control and progressive image generation. The adaptive method provides user control to ensure that the contribution of every cell is included in the final image or to limit the number of cells that are missed.

Network conference system using limited bandwidth to generate locally animated displays

Abstract: Electronic conferencing is provide over a computer network, such as the Internet, by passing streams of text with embedded explicit audio and graphics commands. Text is translated to audible speech at the end-user computers by a text-to-speech processor to reduce the amount of data transferred between computers. Implicit commands are generated from the text at the end-user computers as the audible speech is generated. Implicit command may control, for example, the animation of lips to provide a realistic image of the words of the text being spoken. Explicit commands can be used to control the voice characteristics by the text-to-speech processor or to control animation.

Effect of frame rate and force feedback on virtual object manipulation

Abstract: Research on virtual environments VE produced significant advances in computer hardware graphics boards and i/o tools and software real-time distributed simulations. However, fundamental questions remain about how user performance is affected by such factors as graphics refresh rate, resolution, control latencies, and multimodal feedback. This article reports on two experiments performed to examine dextrous manipulation of virtual objects. The first experiment studies the effect of graphics frame rate and viewing mode monoscopic vs. stereoscopic on the time required to grasp a moving target. The second experiment studies the effect of direct force feedback, pseudoforce feedback, and redundant force feedback on grasping force regulation. The trials were performed using a partially-immersive environment graphics workstation and LCD glasses, a DataGlove, and the Rutgers Master with force feedback. Results of the first experiment indicate that stereoscopic viewing is beneficial for low refresh rates it reduced task completion time by about 50% vs. monoscopic graphics. Results of the second experiment indicate that haptic feedback increases performance and reduces error rates, as compared to the open loop case with no force feedback. The best performance was obtained when both direct haptic and redundant auditory feedback were provided to the user. The large number of subjects participating in these experiments over 160 male and female indicates good statistical significance for the above results.

Method of operating a portable interactive graphics display tablet and communications systems

Abstract: A portable display tablet is operated in conjunction with a base computer system including a host processor for executing an application program with a predetermined operational function that generates predetermined graphics data and operates in response to predetermined input data. The computer system includes a wireless data transceiver coupled to the processor that is capable of communicating the predetermined graphics and input data between the computer and portable display tablet. The portable display tablet comprises a graphics display panel for displaying predetermined graphical data, a low power wireless data transceiver providing short range data communication of the predetermined graphics and input data between the base computer system and portable display tablet, and a controller embedded within the portable display tablet and coupled to the low power wireless data transceiver that executes a control program to process the predetermined graphics data to provide the predetermined graphical display data to the graphics display panel.

Assessing dynamics in computer-based instruction

Abstract: We present an evaluation of a multimedia educational software system that includes text, graphics, animations, and simulations. When compared with an informationally equivalent control environment that used text and carefully selected still images, we found little evidence that the dynamic presentations enhanced student understanding of the declarative information in this lesson. Furthermore, students cannot be relied on to take fllll advantage of exploratory opportunities in computer-based instruction. These results prescribe further investigation of whether and how computer-based multimedia can be used effectively in education and training.

System and method for accelerated occlusion culling

Abstract: An occlusion culling circuit for use in a graphics computer receives graphics primitives data including x and y coordinates for each pixel, a z depth value, and r, g, b, and a or index color data. For each group of primitives, the graphics computer scans the primitive and determines a volume which completely bounds the primitive. The z depth values for the pixels comprising the bounding volume are then compared by the occlusion culling circuit to the depths of the pixels in the already rendered primitives to determine whether any pixels in the incoming primitive are visible. If no pixels are visible, the occlusion culling circuit clears the result register and receives the next graphics primitive. If, on the other hand, one or more pixels is visible, the occlusion culling circuit completely renders the primitives bounded by the bounding volume. Since the graphics primitives which are totally occluded can bypass the more intensive pixel by pixel processing and storage, the speed and efficiency of the graphics computer can be significantly increased.