EG1982 Proceedings (Technical Papers)
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Item A METHODOLOGY FOR POPULATING DEFAULT COLOR MAPS(The Eurographics Association, 1982) Straayer, David H.; D.S. Greenaway and E.A. WarmanA standard for using colors in computer graphics systems is proposed. A key aspect of this proposed standard is to allow two different levels of access to colors. At the first level, colors are selected from a standard list. To draw a red line, for example, a user would simply issue a command that says, in effect, draw lines in color number two. The association between two and red comes from a standard color map. At the second level, colors can be precisely chosen or mixed from a three-dimensional color model. The first level is a strict subset of the second level. Users can access colors at the level appropriate to their experience or application need and can move from one level to the other as required. The keystone of this proposal is a method for defining a device-independent default colorItem ANALYSIS OF THE DESIGN PROCESS AS BASIS FOR THE DEFINITION OF CAD-FUNCTIONS DISTRIBUTED ON HIERARCHICAL NETWORKS(The Eurographics Association, 1982) Gorny, Peter; D.S. Greenaway and E.A. WarmanIt seems to be no question any more, that intelligent graphics work stations will be integrated as terminals into networks, especially because of the process in hardware and network development. But we do not know yet, which of the graphics and CAD functions will have to be kept local, i.e. on the first processor seen from the user, and which may be placed on more remote processors. The author analyses the designers activities when constructing a new technical object and defines a hierarchy of functions. From this proposal a graphics/CAD system architecture is derived with a functional hierarchy of "pipelined" processors and an outline of a system currently under implementation is given.Item CHITRA - A LOW COST 2-D GRAPHICS PACKAGE FOR THE DESIGN OF DISCRETE SYSTEMS(The Eurographics Association, 1982) Kumar, Ashok; Visweswara, G. H.; Rajaram, S.; Prabhakar, A.; D. S. Greenaway and E. A. WarmanA general purpose 2-D graphics package termed CHITRA has been developed, to aid the design of discrete systems. CHITRA permits the rapid interactive description and design of multiterminal subsystems and links for their interconnection. Attributes can be defined for a subsystem as a whole or for each of its terminals. The package also provides a number of FORTRAN callable access routines to aid the development of application specific post-processors.Item THE IMPORTANCE OF A CORRECT APPROACH TO THE DESIGN OF METAFILES STANDARDS(The Eurographics Association, 1982) Arnold, David B.; D.S. Greenaway and E.A. WarmanItem SAMMIE-3-D GRAPHICS FOR HUMAN FACTORS APPLICATIONS(The Eurographics Association, 1982) Kingsley, Eliot C.; D.S. Greenaway and E.A. WarmanIn the last five years there has become available a wide range of computer aided three dimensional modelling systems, but only one of these has been specifically developed for evaluating human factors aspects of designs, SAMMIE (System for Aiding Man-Machine Interaction Evaluation) is a workplace modelling system that contains a 21 link three dimensional computerised man-model. This paper describes the facilities available in SAMMIE for evaluating the man model's visual field, reach capability and fit in a range of different application examples.Item GENERATING AND PRINTING OF HIGH QUALITY DOCUMENTS IN A DISTRIBUTED OFFICE AUTOMATION NETWORK ENVIRONMENT(The Eurographics Association, 1982) Hersch, R.D.; D.S. Greenaway and E.A. WarmanThis paper analyses the process of creating a printed document, which includes text processing, formatting and printing. Corresponding file formats, soft-copy generation algorithms as well as requirements of high quality graphics displays and printing systems are described. A special architecture for a printer interface system is presented which enables the high-speed generation of a document page on a printer frame-buffer, To limit mass-storage requirements, this architecture supports the generation of characters from an analytical description of their contour. Such a printer interface system has a moderate price, due to the decreasing cost of microprocessor and memory components.Item VISTA VISUAL IMPACT SIMULATION TECHNICAL AID(The Eurographics Association, 1982) Stearn, Donald D; D.S. Greenaway and E.A. WarmanVISTA is a 3-D colour perspective package with hidden surface elimination being developed at the Architecture & Building Aids Computer Unit, Strathclyde (ABACUS). It is an attempt to model the visual reality of both the interior and exterior of buildings. It is designed to handle a range of applications with different levels of detail, from city-scapes where the elements of the model represent complete buildings, to the interior of a room where the elements represent the walls and furnishings. Part of the model consists of a colour rendering procedure which allows the prediction of surface colours and allows for the display of shadows. In fact VISTA can be used to model a wide range of artifacts not restricted to the architectural field.Item COMPUTER GRAPHICS FOR THE REMOTE-SENSING OF THE OCEAN SURFACE BY A HIGH-RESOLUTION RADAR(The Eurographics Association, 1982) Suwais, M.A.; Cooper, D.C.; D.S. Greenaway and E.A. WarmanA high-resolution microwave radar has the ability to resolve the ocean surface large-scale gravity waves or swell and to reveal their various properties (wavelength, velocity and period). Computer analysis and graphics presented in this paper for sea clutter (backscatter), obtained with an I-band high-resolution pulsed radar, illustrate the usefulness of such a radar as an effective tool for the remote sensing of the ocean surface. Such a radar may be mounted on shore, aircraft, ship and other platforms. Also discussed in this paper is how computer graphics can be utilized to support the acceptance of a useful model for the ocean surface.Item GKS in C(The Eurographics Association, 1982) Rosenthal, David S. H.; Hagen, Paul fen; D.S. Greenaway and E.A. WarmanA binding of GKS, the draft ISO standard for 2D graphics software, to the programming language C is presented, together with the principles underlying its design. The binding is compared with the binding to FORTRAN. An implementation of GKS according to this binding is also described, particular attention being paid to the techniques for segment storage, input, and workstations. The implementation is assessed against implementations in FORTRAN.Item INTERACTIVE GENERATION OF 3-DIMENSIONAL COMPUTER GRAPHICS(The Eurographics Association, 1982) Sutty, George J.; D.S. Greenaway and E.A. WarmanA new technology employing a vibrating mirror produces spacefilling images. An observer views a reflection of a CRT in a moving mirror. By displaying a proper sequence of pictures 30 times a second, a space filling three-dimensional image is formed. A computer-driven graphics terminal using this technique has been developed. This paper describes the optical principles behind the display and the components of the terminal. Several new algorithms which are unique to the new system are described. Finally, areas of application for the terminal are listed, and the utility and limitations of the system are discussed.Item A SEMANTIC VIEW ON GEOMETRIC REPRESENTATION OF URBAN LAND INFORMATION(The Eurographics Association, 1982) Eloranta, Kirsi; D.S. Greenaway and E.A. WarmanIn this paper we deal with graphical representation of spatially referenced information. We introduce an approach to geometric representation based on the Entity-Attribute-Relationship (EAR)-model. Our object system is an urban municipality, especially the urban activities which create or utilize land related information. Among those activities we can distinguish certain sequence of information transformations. In this paper we try to describe the various representations of urban land information and the functional connections between then. The purpose of these descriptions is to define the requirements of geodata base structures derived from the semantic contents of information.Item COMPUTER REPRESENTATION OF DEAF SIGN LANGUAGE(The Eurographics Association, 1982) Harrison, R.; D.S. Greenaway and E.A. WarmanA compact system for recording and transmitting messages in Sign will help to alleviate the disadvantages suffered by profoundly deaf children and support an improved cultural environment for deaf adults. This paper proposes that a microprocessor-based system can provide a solution to this need and describes a prototype implementation.Item GRAPHIC DISPLAYS IN THE COMPUTER AIDED DESIGN OF LIFT SYSTEMS(The Eurographics Association, 1982) Barney, G.C.; D.S. Greenaway and E.A. WarmanThe sizing of lift systems to meet passenger demands is normally carried out in a quantitative way by calculation. Nothing is done to determine the quality of service provided. This paper describes how a computer aided design suite using discrete simulation techniques coupled to extensive graphic displays overcomes these deficiencies.Item A BIFOCAL DISPLAY TECHNIQUE FOR DATA PRESENTATION(The Eurographics Association, 1982) Apperley, M. D.; Tzavaras, I.; Spence, R.; D.S. Greenaway and E.A. WarmanA technique for presenting data on a graphics display, while avoiding the inherent windowing problem of conventional v.d.u's is proposed. This technique is centered on the concept of spatial information management. Design principles are presented, together with an example design modifying the display of a conventional microprocessor. The viability of the technique is demonstrated, and a more sophisticated implementation proposed.Item THE APPLICATION OF DATA COMPRESSION TECHNIQUES TO COMPUTER GRAPHICS(The Eurographics Association, 1982) Daskalakis, C.; Hankins, H.C.A.; D.S. Greenaway and E.A. WarmanThe decreasing cost of semiconductor storage combined with inherently low cost of colour television monitors has led to the possibility of an economical interactive graphics terminal. However, although the cost of the frame buffer stores may still limit the range of application of such a combination, the efficient description of display pictures through the use of data compression techniques allows the capacity of the store, and hence the cost, to be significantly reduced. One major disadvantage of this arrangement is the time taken to compile and to change the picture which leads to a slow and unacceptable response time. The authors describe a terminal which makes use of data compression techniques but by the use of picture zoning techniques and algorithms with fast execution, the interaction response time is reduced to a more acceptable level.Item COMPUTER GRAPHICS IN INTERACTIVE DISCRETE-EVENT SIMULATION(The Eurographics Association, 1982) Bennett, B. S.; D.S. Greenaway and E.A. WarmanThe use of computer graphics in the digital simulation of continuous and discrete-event systems has been repeatedly shown to confer many benefits. What is less common is the use of computer graphics to assist the user in setting up simulation models, although for analogue block-orientated systems, the idea is nothing new. This paper concerns a project in which input graphics are applied to a discrete-event simulation language to supplement the conversational-mode input that is already a feature of the package.Item A PACKAGE FOR PROCESSING REMOTE SENSING DATA INTERACTIVELY ON A MINI-COMPUTER SYSTEM(The Eurographics Association, 1982) C.M.C.Jones,; J.P.W.Stark,; F.T.Howell,; D.S. Greenaway and E.A. WarmanA package for the analysis of time sequence remote sensing data is described, which has been designed to run interactively on a mini-computer system utilising colour graphics facilities. The core of the system performs a registration procedure only on a subset of the data to speed system response time. The colour facilities of the system are utilised to direct the user efficiently to the registered image location.Item A FAST ALGORITHM FOR COLOUR REGION SEGMENTATION(The Eurographics Association, 1982) Stark, J.P.W.; Mahdavieh, Y.; Tjahjardi, T.; D.S. Greenaway and E.A. WarmanAn algorithm is described which analyses colour scenes in terms of regions. These regions are defined to have the same 'colour'. In this context the colour of a region is determined by its position in the CIE chromaticity diagram. The procedure outlined reduces the three-dimensional colour cube to a one-dimensional colour grey-scale. This approach significantly reduces the amount of data and also the amount of processing required in colour scene analysis.Item A PRACTICAL STRATEGY FOR CERTIFYING GKS IMPLEMENTATIONS(The Eurographics Association, 1982) Brodlie, K. W.; Maguire, M. C.; Pfaff, G. E.; D.S. Greenaway and E.A. WarmanThe question of how to validate GKS implementations is crucial to the success of GKS as an international standard for computer graphics. This problem has been addressed by a series of certification workshops sponsored by the EEC. A basic strategy for testing GKS implementations is outlined and progress towards the development of a test suite is reported.Item THE EFFECTIVENESS OF HIGH-LEVEL GRAPHICAL LANGUAGES IN DEALING WITH VARIOUS GRAPHICAL DOMAINS(The Eurographics Association, 1982) Ross, R.; Schrack, G.; D.S. Greenaway and E.A. WarmanThere are many domains in which graphical programming languages can be applied. Use of a particular graphical programing language will be limited if the domains in which it can be applied are restricted. High-level graphical languages provide simply expressed constructs for the definition, manipulation, inquiry, and external representation of graphical data. These capabilities permit the application to various domains of high-level graphical languages. Five specific domains are discussed; an example of an application of the graphical language LIG is presented in each domain.