Showing papers on "Computer graphics published in 1975"
19 May 1975
TL;DR: My approach to computer vision is best characterized as inverse computer graphics, where perceived television pictures are analyzed to compute detailed geometric models to generate synthetic television images.
Abstract: My approach to computer vision is best characterized as inverse computer graphics. In computer graphics, the world is represented in sufficient detail so that the image forming process can be numerically simulated to generate synthetic television images; in the inverse, perceived television pictures (from a real TV camera) are analyzed to compute detailed geometric models.
556 citations
01 Jun 1975
176 citations
01 Jan 1975
156 citations
115 citations
01 Oct 1975
TL;DR: The objective of the system is to provide the human operator a set of both high-level and primitive keyboard operations which, in conjunction with the graphics terminal, provide the tools for the successful acquisition, analysis, and display of these behavioral data.
Abstract: The description of an interactive interpretive on-line computer-television system for studying the behavior of organisms is presented. The movements of organisms in a wet-slide preparation is recorded on video tape with the aid of a microscope and rendered to a computer in outline form by a video-to-digital processor. Parameters relating to the behavior of the organisms, such as velocity and rate of change of direction, are extracted with an interactive graphics system. The objective of the system is to provide the human operator a set of both high-level and primitive keyboard operations which, in conjunction with the graphics terminal, provide the tools for the successful acquisition, analysis, and display of these behavioral data.
34 citations
01 Sep 1975
TL;DR: In this paper, a study was conducted to determine how verbal instruction could be supplemented by visuals, and in particular, how to take pedagogical advantage of the excellent capabilities of the PLATO 4 computer-based instructional system.
Abstract: : A study was conducted to determine how verbal instruction could be supplemented by visuals, and in particular, how to take pedagogical advantage of the excellent capabilities of the PLATO 4 computer-based instructional system. Literature research disclosed little previous information of value on the subject. Three versions of a lesson on the sine-ratio concept were prepared, one with verbal text supplemented with animated graphics, one supplemented with still graphics, and one without graphics (text only). Forty-five students from the Basic Electrivity/Electronics School at the Naval Training Center (NTC), San Diego, were randomly assigned to the three versions. A comparison of the pretest and posttest mean scores for each group revealed learning took place in each group, and a questionnaire administered after the posttest revealed that the students gave positive ratings to the instructional materials and presentations. The groups did not differ in time required for training. On the posttest, the animated graphics group had the highest mean performance, but none of the differences between groups were significant. It was concluded that these results are consistent with previous findings suggesting that graphics are more useful for teaching concepts involving time and motion than for concepts involving space, and more useful for tasks involving stimulus identification than for tasks involving terminology or comprehension.
21 citations
[...]
19 May 1975
TL;DR: The two computer graphic sessions are to a high degree End User oriented and the kinds of people interested in the "Economics of C.G." session are End Users and managers who must understand the areas of costs and productivity improvement measures that result from Operational Computer Graphics.
Abstract: The two computer graphic sessions are to a high degree End User oriented. The kinds of people who will find the "Data Base" session of interest are Application Analysts and End Users who with an Applications Analyst's interest is seeking new methods of data representation of physical models where the volume of data can grow quite large while access must remain rapid even though the access trail cannot be predicted or predetermined. The kinds of people interested in the "Economics of C.G." session are End Users and managers who must understand the areas of costs and productivity improvement measures that result from Operational Computer Graphics, and who want to learn from other Users experiences methods of economic justification and measures to ensure economic success of the necessary capital investment.
20 citations
TL;DR: Fuid dynamics principles and numerical analysis techniques are applied to the study of stress distribution in blood caused by the motion of the occluder in a prosthetic heart valve and resulting graphics displays show the stress distribution and other flow parameters.
18 citations
01 Sep 1975
TL;DR: It was concluded that these results are consistent with previous findings suggesting that graphics are more useful for teaching concepts involving time and motion than for concepts involving space, and more usefulfor tasks involving stimulus identification than for tasks involving terminology or comprehension.
Abstract: Abstract : A study was conducted to determine how verbal instruction could be supplemented by visuals, and in particular, how to take pedagogical advantage of the excellent capabilities of the PLATO 4 computer-based instructional system. Literature research disclosed little previous information of value on the subject. Three versions of a lesson on the sine-ratio concept were prepared, one with verbal text supplemented with animated graphics, one supplemented with still graphics, and one without graphics (text only). Forty-five students from the Basic Electrivity/Electronics School at the Naval Training Center (NTC), San Diego, were randomly assigned to the three versions. A comparison of the pretest and posttest mean scores for each group revealed learning took place in each group, and a questionnaire administered after the posttest revealed that the students gave positive ratings to the instructional materials and presentations. The groups did not differ in time required for training. On the posttest, the animated graphics group had the highest mean performance, but none of the differences between groups were significant. It was concluded that these results are consistent with previous findings suggesting that graphics are more useful for teaching concepts involving time and motion than for concepts involving space, and more useful for tasks involving stimulus identification than for tasks involving terminology or comprehension.
TL;DR: An interactive program which uses computer graphics techniques to reconstruct a three dimensional representation of thalamic anatomy from two dimensional serial secretion has applications in stereotaxic surgery, teaching neuroanatomy and may be used to reconstruct other anatomic structures from serial sections.
[...]
TL;DR: Although each of the following topics are aspects of a real-time animation environment deserving a detailed explanation, they will be dealt with in a way to introduce to the reader basic requirements and problems.
Abstract: A comprehensive 3-D real-time computer animation system is based upon a broad range of research activities in the field of computer graphics. In many ways the requirements for such a system are more challenging and complex than for other graphics systems. This is particularly true if one builds a language and a system which is truly user oriented and which has viable production capabilities for researchers and film makers. Too often systems which are the result of a research experiment in hardware or software design do not go beyond a beautiful demonstration of potentialities. Such experimentation is essential to advance the state of knowledge but if computer animation is to become a new research and production instrument we must, in addition, provide more examples of useable systems.Although each of the following topics are aspects of a real-time animation environment deserving a detailed explanation, they will be dealt with in a way to introduce to the reader basic requirements and problems. The topics are:I. STATE OF THE ART SYSTEMS, AND LANGUAGES• Used as references and as a basis of comparison.II. AN ANIMATION ENVIRONMENT• Several systems and languages are being implemented to run under RSX-11/D on our PDP-11/45 computer.A. VISIBLE SURFACE SYSTEM• Allan Myers' algorithm• VILAN (VIsual LANguage)B. GRAPHICS SUPPORT SYSTEM• Manfred Knemeyer's system for handling hardware devices, data structures, management of transformations and time, and memory management for the graphics buffer.C. ANIMA• A new graphics programming language has been designed and is being implemented.D. DATA GENERATION SYSTEM• Some approaches to problems are briefly discussed.III. DISPLAY HARDWARE AND GRAPHICS ALGORITHMS• The problems presented by the order of transformations in an algorithm are briefly described.IV. HIGH PERFORMANCE GRAPHICS• some speculations
TL;DR: This correspondence comments on the method of circle generation described by Armstrong, and discusses the methods by which satisfactory circles for computer graphics may be obtained with digital differential analyzers (DDA's) using a single-phase Adam's procedure.
Abstract: This correspondence comments on the method of circle generation described by Armstrong [1], and discusses the methods by which satisfactory circles for computer graphics may be obtained with digital differential analyzers (DDA's) using a single-phase Adam's procedure.
TL;DR: A technique is described for the analytical representation of the geometry of radial and mixed flow compressor impellers constructed of radial or non-radial blade elements, enabling the designer to apply established two- and three-dimensional fluid dynamic analysis procedures to a wide range of possible design configurations.
Abstract: A technique is described for the analytical representation of the geometry of radial and mixed flow compressor impellers constructed of radial or non-radial blade elements. A similar analytical expression is used to describe the hub, shroud, and camberline curves; if required, the angle of inclination of the blade elements from the radial direction is also described. These analytical expressions lend themselves to rapid manipulation, enabling the designer to apply established two- and three-dimensional fluid dynamic analysis procedures to a wide range of possible design configurations. The analytical expressions completely specify the impeller passage geometry from which computer graphics output can be obtained to give isometric, plan and side views of the impeller. For manufacturing, the computer graphics subroutine supplies a series of flow passage sections on a large scale at any number of axial stations specified by the designer. These passage sections are used in the construction of templates from which the impeller is manufactured using copy milling techniques. The analytical specification also gives a detailed co-ordinate specification of the impeller for use with numerically controlled machines.
TL;DR: The dynamic and kinematic analysis of planar linkage mechanisms is carried out quickly and conveniently using a program developed in the Department of Mechanical Engineering at the University of Newcastle upon Tyne and allows various options including the optimal balancing of chosen mechanisms.
Abstract: The dynamic and kinematic analysis of planar linkage mechanisms is carried out quickly and conveniently using a program developed in the Department of Mechanical Engineering at the University of Newcastle upon Tyne. The program is interactive, using an IBM 360 computer and a Computek terminal, and allows various options including the optimal balancing of chosen mechanisms. Data for the necessary counterweights are calculated which minimize the moments of inertia of the counterweights so that the resulting force-balanced mechanism will experience minimal increase in shaking moment. Polar plots of individual pin forces may be displayed in addition to driving torque and shaking moment using a general plotting routine which includes an automatic scaling facility. An illustrative example is given.
01 Sep 1975
TL;DR: A brief review of the principles of stereoscopy is given followed by a discussion of candidate methods for providing stereoscopic viewing of display data, and a hybrid system would combine good features of both.
Abstract: A brief review of the principles of stereoscopy is given followed by a discussion of candidate methods for providing stereoscopic viewing of display data. An analog computer implementation of a stereoscopic graphics display system is described. The analog implementation provides real-time display capability but has no data storage capability. Implementation with a small digital computer provides data storage but is significantly slower for displaying dynamic changes in the data. Other points of comparison between the two systems are given with the conclusion that a hybrid system would combine good features of both. Experimental evaluation relative to eye fatigue is given for three specific viewing techniques. Example stereograms are given for both the digital and analog systems. Of particular interest was application of the display system for viewing biomedical data, as illustrated by an example display of a vectorcardiogram.
TL;DR: An interactive pattern recognition system has been developed to facilitate the use of pattern recognition in the chemical laboratory and runs on a time-sharing computer and communicates with the chemist via an intelligent computer graphics terminal.
Abstract: : An interactive pattern recognition system has been developed to facilitate the use of pattern recognition in the chemical laboratory. This system has been designed to be user oriented and runs on a time-sharing computer and communicates with the chemist via an intelligent computer graphics terminal. By using a menu on the display screen, the chemist can select the preprocessing to be done, the supervised learning method to be used, the clustering method to be used, or the type of display to be presented. (Modified author abstract)
01 Apr 1975
TL;DR: The design of a new interactive graphics language 'IMAGE' is presented, developed specifically to satisfy the above criteria, and places particular emphasis on providing a graphics application programmer the ability to program graphical interaction.
Abstract: This paper addresses itself to the problems involved in programming an interactive computer graphics display. A list of graphical programming facilities considered necessary for an interactive graphic programming language is presented. An examination of several application programs, written in a variety of existing languages, revealed that many of these facilities are usually lacking.This paper presents the design of a new interactive graphics language 'IMAGE', developed specifically to satisfy the above criteria. The language places particular emphasis on providing a graphics application programmer the ability to program graphical interaction. The 'IMAGE' language utilizes the better features of several current graphic languages and combines these features with a unique interaction control structure. This OBJECT / ACTION control structure, the display picture description syntax and the hardware independent handling of input devices are the main features of the language, providing excellent graphical input response and drawing facilities. The device independent input / output structure permits the implementation of a portable language syntax, since there are no references to display hardware devices. All display references are performed through a virtual terminal. This paper contains a detailed description of the main features of the language and these features are illustrated in an example 'IMAGE' program.
01 Jan 1975
TL;DR: A report based on an international visit of mapping organizations provides a brief survey of techniques under development for use in the automation of cartographic compilation and which may be employed in computer graphics application, such as computer-aided design.
Abstract: A report based on an international visit of mapping organizations. Provides a brief survey of techniques under development for use in the automation of cartographic compilation and which may be employed in computer graphics application, such as computer-aided design.
Journal Article•
TL;DR: The papers presented here note the potential of interactive graphics for restructuring complex problems and elucidating the interrelationships of innumerable variables in a complex plan and the importance of interactive computers for the exploration of values in conflicts and tradeoffs.
Abstract: The general thrust of the papers presented at the session is examined, and various points that have been offered are underscored. Twelve problem areas related to citizen participation in the transportation field are identified, and data are tabulated which show the areas in which interactive graphics will be useful. These are the areas of methods and tools, complexity, value judgements, geographic distances, and technical assistance. The papers presented here note the potential of interactive graphics for restructuring complex problems and elucidating the interrelationships of innumerable variables in a complex plan. The papers also recognize the importance of interactive computers for the exploration of values in conflicts and tradeoffs. It could also help bridge the gap between group dynamics and technical staff. Caution is urged in the use of interactive graphics in citizen participation because not enough is known about the technology. Interactive graphics could be focused on the problem of inadequate communication. Some planning and participation models that can be used with interactive graphics are described, and different types of question-response modes that can be used in a group forum are outlined in another paper.
TL;DR: This paper attempts to develop the two essential components for a people-oriented computer system—habitability and environment, using the educational media production laboratory known as the Circle Graphics Habitat as the example.
TL;DR: A system for displaying studio-quality television images of objects described by a set of closed polyhedra, which incorporates shading of the surfaces based upon the angle of the normal to the surface to the observer.
TL;DR: Two algorithms that solve the frequently occurring problem in computer graphics, windowing, are described and the algorithm incorporating the extended arithmetic capability executes faster and the PDP‐11 versions are substantially smaller.
Abstract: Two algorithms that solve the frequently occurring problem in computer graphics, windowing, are described. The primary distinction between the two algorithms is the need for multiplication and division in one of them. The algorithms are compared for running time and size on two commonly used minicomputer systems, the Digital Equipment Corporation PDP-9/15 and PDP-11. Not surprisingly the algorithm incorporating the extended arithmetic capability executes faster and the PDP-11 versions are substantially smaller.
TL;DR: The most popular subdivisions of passive graphics—microfilm recorders and plotters—in detail are described in detail and some of the pit-falls of this powerful computing tool are indicated.
01 Jan 1975
TL;DR: A subcritical response damping technique, called the combined randomdec/moving-block method, for use in windtunnel-model flutter testing, that has been implemented on the data-acquisition system is described in some detail.
Abstract: The computer-controlled data-acquisition system recently installed for use with a transonic dynamics tunnel was described This includes a discussion of the hardware/software features of the system A subcritical response damping technique, called the combined randomdec/moving-block method, for use in windtunnel-model flutter testing, that has been implemented on the data-acquisition system, is described in some detail Some results using the method are presented and the importance of using interactive graphics in applying the technique in near real time during wind-tunnel test operations is discussed
01 Jan 1975
TL;DR: In this paper, the concept of a data definition language for defining relational structures is extended for graphical data by assigning "meanings" to domain names, and a picture-building system consists of three parts: a mechanism for creating structures for graphical and non-graphical data, an interactive mechanism for loading data into these structures, and an interface for viewing and manipulating the graphical data via pictures.
Abstract: Publisher Summary This chapter focuses on data structures in computer graphics. A central problem in interactive graphical applications is that of structuring the data. Frequently the graphical data and the non-graphical data are maintained in separate data-bases with different structures. If one attempts to use the graphical medium as a window to the data in the data base and attempts to make changes in the data-base by interactively altering displayed images, then conversions are required between the graphical structures and the primary data files. The picture-building system consists of three parts: (1) a mechanism for creating structures for graphical and non-graphical data, (2) a mechanism for interactively loading data into these structures, and (3) a mechanism for viewing and interactively manipulating the graphical data via pictures. The concept of a data definition language for defining relational structures is extended for graphical data by assigning “meanings” to domain names. Correlation is the identification of a line, entity, or group of entities in the data-base structure by pointing at its representation on the screen.
01 Jul 1975
TL;DR: The MAPS-1 system, operational since September 1974, and the MINIMAPS system now under development achieve high performance at low cost for real-time interactive image processing, dynamic spatial simulation modeling, and spatial data base management.
Abstract: The greatest effective bandwidth of the eye is for changes in color and texture, so why does computer graphics emphasize line-drawings? Questions such as this brought about the MAPS Project in 1971 for the purpose of developing graphics systems suitable for geographic applications. The MAPS-1 system, operational since September 1974, and the MINIMAPS system now under development achieve high performance at low cost for real-time interactive image processing, dynamic spatial simulation modeling, and spatial data base management. Standard color television is the primary output medium, facilitating communication of dynamic results. MINIMAPS employs a memory-centered architecture in which processing is distributed by function among a series of microprocessors. The picture processor encodes data matrices directly into color images. The system is highly interactive, performing most functions in 1/30 second. Its control language, packaging and environment are designed to encourage users to play with images, using the system as a perception amplifier.
TL;DR: The package allows users to build-up and edit a database of directed graph designs, which can be used to represent computational structures, particularly electronic hardware.
Abstract: A computer graphics package is described for use on a fast, analogue, refreshed display system connected locally to a minicomputer. The package allows users to build-up and edit a database of directed graph designs, which can be used to represent computational structures, particularly electronic hardware.