Graphics Monitor Research Articles

Evaluation of uniform CRT display scales with visual threshold data

Luminance, chromatic, and color visual threshold contrast data are found along the heated object scale at two mean luminance levels using a high resolution graphics monitor. Data from ideal stimulus characteristics (no or little noise and sharp contrast edges) and test stimulus sizes of 1.00( degrees ), 0.50( degrees ), and 0.25( degrees ) were obtained along with data for linearly stepwise blurred contrast edge stimuli in a noise pattern with test stimulus sizes of 0.50( degrees ) and 0.25( degrees ). All data were collected using an adaptive staircase with a spatial two alternative forced choice paradigm. The results suggest that uniform CRT display scales that have been perceptually optimized for ideal viewing conditions will remain uniform even though the contrast step sizes of the display scale will no longer be perceptually optimized in nonideal viewing conditions.

Fundamentals of Three-Dimensional Computer Graphics

Watt provides a comprehensive introduction to the techniques needed to produce shaded images of three-dimensional solids on a computer graphics monitor. Strongly based on algorithm understanding.

Apparatus for processing fish detection signals

Disclosed is a signal processor for an ultrasonic fish detector, in which the signal processing circuit is arranged separately from the display unit, whereas conventionally both are configured integrally, within a case with the provision of a composite converting circuit and RGB converting circuit with associated video output terminal and RGB output terminal, thereby allowing the user to configure a fish detection system by merely purchasing the fish detection signal processor made up of the signal processing circuit and a transducer and utilizing a home television set or an RGB graphics monitor oriented to personal computers.

CHOROPLETH MAPS ON HIGH RESOLUTION CRTs / THE EFFECTS OF NUMBER OF CLASSES AND HUE ON COMMUNICATION

The research reported here was designed to determine how quickly and accurately map readers viewing choropleth maps on a high-resolution computer monitor are able to identify to which class an areal unit on the map belongs, when the map has between four and eight classes and is produced in shades of either gray, green or magenta. As expected, accuracy rates decreased and reaction times increased as the number of classes on the map increased. Accuracy rates ranged from 91.9% for four-class maps to 68.2% for eight-class maps (averaged for all three colors used in the study). Hue also affected accuracy rates and reaction times, the best results being obtained with achromatic (gray-shaded) maps: 84.5% correct, averaged over all numbers of classes. Maps shaded with magenta proved to be the least satisfactory with an accuracy rate of 72.8%. The study provides cartographers with empirical guidelines regarding what level of map-reading accuracy might be expected for choropleth maps designed with a given number of map classes, in a specific hue, and displayed on a high-resolution graphics monitor.

Simple microcomputer system for mapping tissue sections with the light microscope

We describe a method for two-dimensional mapping of tissue sections that makes use of a drawing tube, microscope stage encoders and a microcomputer. The drawing tube views the graphics monitor and superimposes the image of the screen cursor and on-screen menus on the specimen image. Thus, the position of every landmark in each microscopic field can be mapped without stage movement while directly viewing the specimen through the microscope. A mouse is used for data entry and program control. Fields mapped in this way are then assembled into a complete map, which can include line drawings as well as up to 20 landmark types. The coordinate values of all landmarks mapped are stored and remain accessible for editing and analysis. High resolution plots are produced. Specialized functions include grain counting, area and perimeter calculations as well as a perimeter limiter that predefines the area to be mapped. The system uses general purpose hardware that is widely available. Many hitherto time-consuming tasks, such as detailed mapping of cell positions, regions of immunocytochemical staining, degenerating fibers, neuronal connections or any other anatomical feature, can be done in a fraction of the time and effort previously involved. These labor savings can be realized while maintaining the highest resolution and enabling statistical analysis since the data are already in digital form.

Microcomputer Program for Simulating Clade Diagrams

We have written a microcomputer program that simulates the pattern of evolution and produces clade diagrams and summary statistics. The user can vary the odds affecting the fate of a species and the initial diversity of the taxonomic group. The program runs on computers using the MS-DOS operating system (IBM PC and compatibles) and requires a color graphics monitor (CGA).

Computer Aided Instruction of Topics in Surveying

ABSTRACT THREE surveying programs have been developed for use on a personal computer with a text and a graphics monitor. The leveling program contains tutorial and practice exercise sections. This program is intended to teach leveling and note keeping principles and provide a practice exercise for reinforcing note keeping procedures. The stadia reduction program contains a graphical representation of each vertical angle reduction to assist the student in visualizing principles. The traverse balancing program develops a graphical plan view of the traverse as the data are entered.

Automatic generation of process flow diagrams

An algorithm which automates the generation of process flow diagrams for distributed programs has been developed. The algorithm maps a graph specification to a graph diagram. The implementation of a graphics monitor uses process flow diagrams to monitor execution of distributed programs on an experimental multiprocessor system. Process states are superimposed onto process flow diagrams to enhance visualization of the execution sequence. Techniques of clustering and unclustering processes are also described.

Quantitative evaluation of materials by scanning electron microscopy

QEM*SEM, or quantitative evaluation of materials by scanning electron microscopy, is a fully automated scanning electron microscope system that was designed and engineered by CSIRO in Australia for applications to the minerals industry. It is an integrated system in which the computer and its associated hardware and software control SEM operations. Minerals can be identified in point, linear or area scans. Depending on the type of scan, information is extracted from the data files and summarized in tables and graphs covering mineral abudances, associations, sizes, free surface area and the degree of liberation. In addition, area scans can be replayed on a graphics monitor to produce QEM*SEM mineral species maps.The QEM*SEM system consists of an International Scientific Instruments SX-40 scanning electron microscope with a specially designed sample chamber that permits 100 mm movement of the stage. The EDS units were designed for rapid collection of x-ray spectra and consist of four lithium drifted silicon detectors each with a separate preamplifier.

Personal Computer Based Image Processing With Halftoning

A versatile and useful personal computer based procedure to generate halftone representation of digitized image data is presented. This feature provides limited interactive image processing capability for a basic personal computer work station without having to acquire a video monitor and a digital-to-analog converter board. The generated halftone images can be displayed on the standard dot-addressable graphics monitor, and/or they can be printed on regular paper via an associated printer. The halftoning procedure is based on an error diffusion technique in which dots are produced randomly, one at a time, based on both the local gray level value and some accumulated measure of the error due to previous assignments. The key elements in halftoning, such as dynamic, spatial, and display medium resolutions, are defined, and the mathematical correspondence among them is established.

Turning your PC into a CAD workstation

Computer-aided design (CAD) packages are now available on some personal computers, and can make a good entry system for design offices. However, it is important to take into account the additional costs that might be incurred e.g. more memory, a graphics monitor, a lightpen etc.

Digital image processing to handle neuroanatomical information and neurophysiological data.

An application of computer graphics technology to functional stereotactic neurosurgery is presented. Neuroanatomical images derived from a stereotactic atlas and information retrieved from a neurophysiological data base are drawn on a graphic monitor. The pictures are oriented and scaled according to appropriate landmarks. The aim of this work is to add confidence in the surgeon's selection of the probe trajectory and to improve the knowledge of sensory and motor organization within the thalamus.

Exploitation of spark source mass spectrometry photoplates by digital image processing.

Digitalization of the 15 exposures all along the useful part of the photoplate is done on a high performance microdensitometer. Exploitation takes place on a high resolution color graphic monitor. Ionic species identification is performed directly on the display by comparison between the analysed spectrum image and a reference spectrum image, which shows all possible simple ionic kinds that the spectrograph may transfer. The software manipulates images very fast, bringing the analyst quickness and flexibility in the exploitation of spectra.

Computer-assisted stereotactic microsurgery for the treatment of intracranial neoplasms.

This paper describes a stereotactic CO2 laser system for the removal of intra-axial, intracranial neoplasms. The volume of the neoplasm is transferred into stereotactic space by computer reconstruction of data derived by computed tomography (CT) performed under stereotactic conditions. The tumor volume is sliced in a plane orthogonal to the surgical approach, and slices at specific distances from the focal point of the stereotactic frame are displayed on a graphics monitor in the operating suite along with a cursor representing the position of the surgical laser. Laser vaporization of sequential slices of the tumor results in a cavity, the formation of which is monitored by anteroposterior and lateral roentgenograms. Fifteen stereotactic laser procedures have been performed on 13 patients, and the results are discussed. By this method, it is theoretically possible to remove all of an intracranial neoplasm detected by CT scanning.

An interactive graphical display monitor in a batch-processing environment with remote entry

A graphic monitor program is described. It was developed at Carnegie-Mellon University for the CDC G21 computer, which is a general purpose, batch-processing system with remote entry. The existing G21 system and the graphics hardware are described. The graphic monitor is a resident auxiliary monitor which provides comprehensive managerial capability over the graphical system in response to commands from the human user. It also will respond to commands from a user program through a similar interface, where routine calls take the place of manual actions. Thus the human and program can interact on a symmetrical and equal basis through the medium of the graphic monitor. The choices made in designing the graphic monitor, given the constraints of the existing hardware and computer system, are discussed. The structure of the monitor program and the human and program interfaces are described. There is also a transient swapping version with a small resident part, and provision for swapped used submonitors.