bluuebunny/crossref_metadata_2025_split huggingface dataset:
Continuous anti-aliased rotation and zoom of raster images
Authors: Weiman Carl F. R. 
Published: November 2005

Raster graphics images are difficult to smoothly rotate and zoom because of geometric digitization error. A new algorithm is presented for continuous rotation and zoom, free from the disturbing aliasing artifacts introduced by traditional methods. Applications include smooth animation. No matrix multiplication of pixel coordinates is executed. Instead row and column parallel operations which resemble local digital filters are used. This suggests real time implementation with simple hardware. Anti-aliasing is inherent in the algorithm which operates solely on pixel data, not the underlying geometric structures whose images the pixels may depict. Zoom magnification is achieved without replicating pixels and is easily attained for any rational scale factor including but not restricted to the integer values which most existing commercial raster graphics systems use.
The algorithm is based on a digitized code for lines on rasters, generalized to an interpolation scheme capable of executing all linear geometric transformations. Samples of images which have been rotated and zoomed by a software implementation of the algorithm are presented.
Definition and use of higher-level graphics input tools
Authors: Bos Jan Van den 
Published: November 2005

A proposal is made for the definition of 'tools', high-level graphics input functions based on the six primitive input classes Clock, Pick, Button, Key, Valuator and Locator.
Tools are defined in terms of input expressions, the operands of which are themselves tools, the definition of which may be nested inside this tool. Input expressions are written much like production rules in phrase structure grammars. Determining whether a tool is 'satisfied' can therefore be done most advantageously by an input expression parser.
Tool definitions may occur in-line or stored in a library. They are activated by a 'create' primitive, which creates an instance of the tool and causes the input expression to be made active. The parser then determines whether a tool is actually used. Following a 'read' issued to the tool, the tool body generates the returned information as specified by the tool definition. Tools may be explicitly freed by a 'free' primitive; in the case of nesting, tools are freed implicitly when the surrounding tool is freed.
Using this approach to higher-level input primitives, a programmer does not have to think about graphics input in terms of awaiting events, interrupts and the like. The creation of a defined tool implies a function awaiting action from the tool.
A high performance graphics system for the CRAY-1
Authors: Ewald Robert H. , Maas Lynn D. 
Published: November 2005

This paper describes the design and implementation of a state-of-the-art interactive vector graphics system connected to the CRAY-1 supercomputer. The primary design goal for this graphics system is that it support large hydrodynamic computer programs used in weapons design calculations. The interactive use of these programs requires displays consisting of up to 20,000 vectors, extensive interaction tools, and high-bandwidth communication rates. The major system components selected for this project were an Evans and Sutherland Picture System 2 and a Digital Equipment Corporation (DEC) PDP-11/70 and PDP-11/34 running the UNIX operating system.
This paper presents the system design goals and performance criteria. The hardware/software systems chosen for this project are reviewed, and the integration of this system into the Los Alamos Scientific Laboratory's (LASL) Integrated Computer Network (ICN) is described. This implementation involved most areas of applied computing, including computer graphics, communications, distributed processing, and computer security. The level of effort required for this implementation is described, and the results and benefits are presented. Future plans for this system are also briefly described.
System design and implementation of BGRAF2
Authors: Kaufman Arie A. 
Published: November 2005

BGRAF2 is a real-time interactive 2D graphics language. Its supporting system contends with an unusual combination of features: timing, events, parallelism, image manipulation, user interaction and procedural structures. This combination creates within the system many unpredictable interrelated tasks competing for execution.
A BGRAF2 program is compiled into an object module consisting of a sequence of pure code blocks, tasks, and a set of data blocks. The real-time environment is a hierarchical structure, where the highest level is a Scheduler, and the next level is composed of the object module and five additional processors: Graphics Processor, Control Processor, Input-Output Processor, Real-Time Processor and Memory Manager. The Scheduler is an abstract monitor responsible for scheduling tasks in accordance with a multi-level priority from a multi-queue scheme.
A chip for low-cost raster-scan graphic display
Authors: Matherat Philippe 
Published: November 2005

Lowering the cost of graphic display units for use in personnal computers and as time-sharing consoles suggests the use of TV sets. Display electronics for such a raster-scan unit will include a screen memory containing the state of all displayable points, that is up to 256 Kbits for 512 × 512 B&W display and more for colour applications. Technological advances in NMOS memories make such memory sizes cheaper and cheaper. The control part ensuring screen refresh, memory management, vector and character generation, and computer coupling remains very complex. A microprocessor-oriented Large-Scale-Integrated circuit including all these functions has been designed at the Ecole Normale Supérieure.
Versatility has guided the design, as well for screen memory organization as for microprocessor interface. Display resolution from 64 × 64 to 512 × 512 are possible, with any number of colours or grey levels, depending only upon the memory size. Microprocessor interface is standard: an eight bits bidirectionnal data bus, a four bits address bus, a read-write signal and an interrupt request. These signals control the vector and character generators which execute microprocessor's commands during the idle phasis of the display controller. This permits an always clean diplay and yet a decent average speed of one point every 1.3 μs.
In addition, a light-pen or crosshair circuitry allows interactive graphic use.
Spatial management of information
Authors: Donelson William C. 
Published: November 2005

Methods of spatially managing data are currently under study at the Architecture Machine Group. Management concepts are drawn from everyday examples of paper and document handling. However, the work elaborates data types to include: animation, movies, and sound-sync computer graphics.
Beyond the application of management information systems, the paper portrays a sophisticated surround of keyboardless, interactive, and large scale graphics. Computer graphics, image processing, and broadcast are viewed as one. The system includes three frame buffers, four minicomputers, two touch sensitive displays, an octophonic sound system, and an MCA Optical Videodisc.
Making nested rotations convenient for the user
Authors: Britton Edward G. , Lipscomb James S. , Pique Michael E. 
Published: November 2005

Subimage motion in a three-dimensional computer graphic system is much easier for the user to control if the subimage moves the same direction as his hand while he manipulates the control device. The implementation of such coordinated motion of hand and subimage implies modification of the normal procedure for calculating transformations. The convenience of such manipulation also depends on appropriate selection or design of the input device.
This paper reviews the relevant attributes of locator devices and presents an approach to selection. It presents the mathematics of transformation nesting and “compensation” to preserve motionsynchrony. Finally, it offers a case history of an interactive graphic system whose human factors were improved by these techniques.
Casting curved shadows on curved surfaces
Authors: Williams Lance 
Published: November 2005

Shadowing has historically been used to increase the intelligibility of scenes in electron microscopy and aerial survey. Various methods have been published for the determination of shadows in computer synthesized scenes. The display of shadows may make the shape and relative position of objects in such scenes more comprehensible; it is a technique lending vividness and realism to computer animation.
To date, algorithms for the determination of shadows have been restricted to scenes constructed of planar polygons. A simple algorithm is described which utilizes Z-buffer visible surface computation to display shadows cast by objects modelled of smooth surface patches. The method can be applied to all environments, in fact, for which visible surfaces can be computed. The cost of determining the shadows associated with each light source is roughly twice the cost of rendering the scene without shadows, plus a fixed transformation overhead which depends on the image resolution. No extra entities are added to the scene description in the shadowing process. This comprehensive algorithm, which permits curved shadows to be cast on curved surfaces, is contrasted with a less costly method for casting the shadows of the environment on a single ground plane.
In order to attain good results, the discrete nature of the visible-surface computations must be treated with care. The effects of dither, interpolation, and geometric quantization at different stages of the shadowing algorithm are examined. The special problems posed by self-shadowing surfaces are described.
TIGS
Authors: Heilman Robert L. , Marchant Jean M. 
Published: November 2005

TIGS is a general purpose subroutine package providing display generation and interaction capability for a general class of graphics terminals. The package is computer, operating system, and display device independent. Primary design objectives were transportability, maintainability, and ease of use.
Features supported by TIGS include line, arc, multi-line plot, test and dot primitives with resettable attributes such as line style, character size, intensity, font, color, transformation matrix, etc. The package uses virtual devices such as locators, keyboards, picking devices and function keys which can represent a wide range of physical devices. TIGS supports modelling transformations, 2D and 3D viewing transformations for clipping and window to viewport mapping.
Unlike the GSPC Core System, TIGS uses the interpretive approach which uses a device independent neutral display file. This neutral display file contains information describing all segments, pictures, windows, and viewports in a device independent manner. The file may be saved and used in a later job with a different display device. Additionally, all attributes such as line style, font, character size, etc., can be re-specified without re-defining the contents of a segment.
In planning for expansion for distributed graphics applications, multiple independent user coordinate spaces are used. Each coordinate space is called a picture. This allows for re-specification of a window without re-defining the contents of it. A picture and all the segments contained therein can be manipulated as a group.
Device independence was implemented by dividing TIGS into a device-independent pre-processor invoked by the applications programmer, and internal device drivers, one per display device. Part of the device driver may reside on a separate processor.
An implementation of the ACM/SIGGRAPH proposed graphics standard in a multisystem environment
Authors: Kellner Richard G. , Reed Theodore N. , Solem Ann V. 
Published: November 2005

Los Alamos Scientific Laboratory (LASL) has implemented a graphics system designed to support one user interface for all graphics devices in all operating environments at LASL. The Common Graphics System (CGS) will support Level One of the graphics standard proposed by the ACM/SIGGRAPH Graphic Standards Planning Committee.
CGS is available in six operating environments of two different word lengths and supports four types of graphics devices. It can generate a pseudodevice file that may be postprocessed and edited for a particular graphics device, or it can generate device-specific graphics output directly. Program overlaying and dynamic buffer sharing are also supported.
CGS is structured to isolate operating system dependencies and graphics device dependencies. It is written in the RATFOR (RATional FORtran) language, which supports control flow statements and macro expansion. CGS is maintained as a single source program from which each version can be extracted automatically.
NUDES 2
Authors: Herbison-Evans Don 
Published: November 2005

A system is described for producing 16 mm animated films of moving humanoid figurines and other figures composed of concatenated articulated interpenetrating ellipsoids. For such figures, the hidden line algorithm used consists in solving the quartic equations which result from simultaneous pairs of ellipses viz. (a) the projection of the outline of one being drawn, and (b) that of one potentially obscuring it. This is done in terms of Cohen's parameter, resulting in an ordered list of compacted hidden arcs of each outline. The visible outlines are then generated to the required fidelity separately.
Where two ellipsoids interpenetrate, the outline of each is drawn up to the points where it disappears into the other. These points can be found by the simultaneous solution of the ellipse equations of (a) the projection of the outline being drawn, and (b) the projection of the ellipse of intersection of the obscuring ellipsoid with the plane of the outline of the drawn ellipsoid.
The viewing window is assumed to be an ellipse also. Parts of objects projecting outside this ellipse are not drawn.
The number of quartics to be solved is reduced significantly by testing each pair of ellipsoids for non-intersection of projected outlines by comparing the projected separation of centres with the sum of their maximum semiaxis lengths, and taking advantage of the total obscuration of one ellipsoid by another when discovered.
Graphics standards for three-dimensional modelling
Authors: Sabin Malcolm 
Published: November 2005

Much effort has been spent in defining a standard call interface for a library of routines with display primitives embedded in a three-dimensional space. This paper argues that this is now an inappropriate target. There is too much diversity in the three-dimensional things we want to draw and in the kinds of picture we want to draw of them for any single standard to be both broadly acceptable and specifically useful.
If the decision is made to go for a set of specialized standards for wire frame and for rendered graphics for data presentation, for sculptured surfaces and for object models, it becomes apparent that far more can be gained from a higher level standard, at the data presentation or object modelling level.
In the object modelling community, at least, there is indeed work toward such a standard based on the IGES proposals. This has very few concepts in common with the graphics standard effort, and it is not clear at present what contribution the graphics community has to make in this area.
The suggestion made here is that there may well be a number of paragraphs or sections common to more than one of the graphics-related and higher level standards. One such is the coordinate transformation (the dreaded 4 × 4 matrix). Its definition and its use both for modelling and viewing concepts are suggested which resolve some of the black art associated with transformation in the past. These could become the conceptual basis for a short simple standard in this area.
Presidents' forum
Authors: Feddersen Donald , Linsalata Ralph T. , Preuss Peter , Spann Richard N. , Machover Carl 
Published: November 2005

Computer Graphics has been an integral part of the computer environment since the mid-1950's with origins in military, academic and industrial applications.
Presidents of several leading computer graphics companies will discuss some of the issues they see facing this dynamic industry. One president believes that the 1980's will belong to the systems integrators because of the rapid rate of change in both technology and the competitive environment. Vertical integration will not be a successful strategy for the 1980's.
Another president is concerned that industry research analysts are misusing the term “CAD/CAM” and that, in fact, most of today's CAD/CAM systems are simply productive drafting systems. He is concerned about the confusion between realistic pictures and solid modelling and about the proper mix of functionality and interactivity.
Still another president believes the crucial issues in computer graphics are those that concern users; those that have access to the tools and those of future development of hardware and software to meet their needs. He suggests that only about one to five percent of the potential users have adopted computer graphics. He is concerned about providing increased access to computer graphics facilities and about removing the widespread psychological barrier of “I can't use the computer to do what I want!”.
Other current issues will also be addressed.
The graphics CAD/CAM industry(Panel Session)
Authors: Adler Frederick R. , Kurlack Thomas P. , McNay Joseph C. , Reichenbach Margaret A. , Spann Richard N. 
Published: November 2005

Richard N. Spann
Companies supplying graphics CAD/CAM components and systems form an important high technology business segment. Panelists representing four financial perspectives will discuss market entry, financing, segment performance and shareholder's expectations. Development of the graphics CAD/CAM industry in the 80's will be the unifying theme.
A contour display generation algorithm for VLSI implementation
Authors: Zyda Michael J. 
Published: November 2005

Recent articles have discussed the current trend towards designing raster graphics algorithms into VLSI chips. The purpose of these design efforts is to capture some of the real-time animation capability found in vector graphics systems. Currently, real-time vector graphics animation is limited primarily to operations involving coordinate transformations. In order to enhance this animation capability, frequently encountered vector graphics algorithms that require the high speed, parallel computation capability of VLSI must be identified. Real-time contour display generation from grid data is one such algorithm. This paper describes the specifics of a contour display generation algorithm, the architectural framework of a processor that performs this algorithm and the architectural requirements of such a processor.
The contouring algorithm is based on a data structure, the contouring tree, whose regularity and amenability for parallel computation make it an ideal candidate for VLSI. The architectural framework for a contouring processor chip that performs this algorithm for the real-time environment of interactive graphics is discussed, particularly the issues of memory size and data distribution. A model of the contouring process is created in order to determine the necessary physical parameters of the contouring processor in this architectural framework. Conclusions are drawn concerning the feasibility of producing a VLSI chip that performs this contouring algorithm.
Context-sensitive, graphic presentation of information
Authors: Friedell Mark , Barnett Jane , Kramlich David 
Published: November 2005

We begin by reviewing spatial data management—the technique of accessing and organizing information via its graphical representation in an organized spatial framework.
We describe an operational prototype system that exceeds the capabilities of other spatial data management systems in two ways: (1) the graphical presentation of data is tailored to the user's identity, task, and database query; and (2) the system has the capacity for large databases. These capabilities are possible because the system dynamically generates its graphics environment.
Our technique for dynamically generating the graphics environment relies on modeling of user context, semantic modeling of the underlying database, and direct use of knowledge about design layout and the utility of pictures. We briefly describe our current research efforts to extend this knowledge-based approach to automatic graphics environment synthesis.
A videotape demonstrating the system accompanies this paper.
MAPQUERY
Authors: Frank André 
Published: November 2005

The storage of geographical data is a growing type of application within data processing.
Users want to retrieve parts of the data stored and to have them shown in graphical form. They need an easy and flexible query language to select the data needed and to describe the form of representation. The existing query languages do not suit this purpose without amendments. This paper presents a proposal for adaptation and gives some examples for query formulation. Moreover, it discusses the special problems of graphical input and output.
3D Galatea
Authors: MacKay Steven A. , Sayre Richard E. , Potel Michael J. 
Published: November 2005

We describe an interactive graphics system for the entry of three-dimensional moving points from multiple perspective views. This work represents a major extension of Galatea, our system for graphics-assisted 2D motion analysis. 3D Galatea permits reconstruction of 3D time-dependent positions from 2D entries in two or more perspective views.
The system supports a general approach for calibrating perspective views. This method, based on work of Sutherland, uses a known 3D reference object to calibrate completely arbitrary perspective projections. A somewhat restricted class of perspective views may be calibrated without an explicit calibration object using another approach developed from photogrammety.
In 2D Galatea, we have used an animated graphics overlay onto the source image to give the analyst feedback regarding current and previous data entries. This capability is extended in 3D Galatea by overlaying auxiliary lines, which are the backprojections of previous 2D entries from one view into other views. This concept amounts to a fourth interpretation of the well-known Roberts homogeneous matrix equation describing perspective projections of 3D space into a 2D image. The auxiliary line is useful in locating a point which is obscured in one of the images, or in determining the correspondence of projected points as seen in different views, which may be ambiguous or easily confused.
Business graphics(Panel Session)
Authors: Jarett Irwin , Russell Jack , Johnson Howard , Thompson John , Luther David 
Published: November 2005

Much has been written about the explosive growth occurring and forecast for business graphics. Users and vendors alike are excited by these prospects. But, what is business graphics? Is it narrowly confined to slide making? Some with a broad view have suggested it is an extension of a management information system. Users search through journals and marketing literature eager to prove a salesman's claim that “a pretty color picture is really worth a thousand words” or at least several pages of numbers in a computer printout. Vendors seek the clues to developing a product strategy that will allow them to cash in on the forecasted shipments. One study [1] indicated 58,000 graphic terminals will be used in business graphics applications in 1986 sales, including computer graphics—capable personal computers, and dedicated computer graphics systems.
This panel will present the thoughts and views of four business graphics practitioners—one associated with a large computer company, another a user from a large industrial concern, the third associated with an independent software company and the last, an industry consultant.