Suchergebnisse

It is expected that virtually all of the world's major producers of colour TV will be manufacturing digital TV by 1990 and that digital TV will gradually displace conventional TV. Information is provided on: the TV industry in Taiwan and other countries, the production process, capital requirements, the cost structure, and demand and price trends. Statistics, 1984-96. (Economische Voorlichtingsdienst)

To assure maximum effectiveness, digital system design parameters must be chosen to optimize human perception. An experimental methodology is described which relates human visual performance and electronic design parameters. These relationships are then used to show how to specify optimal encoder design parameters. To illustrate this experimental procedure, tradeoffs were determined for a digitally encoded television system. These relationships were determined by measuring subjects' minimum perceptible acuities for various length lines and spatial orientations. Visual performance was determined for points along four noise-bandwidth curves representing different information capacities and system costs. Optimum system performance was achieved by maximizing the sampling frequency (bandwidth) of the encoder.

Digital Image Processing in the United States -- Digital Image Processing in Japan -- An Automated Microscope for Digital Image Processing — Part I: Hardware -- An Automated Microscope for Digital Image Processing — Part II: Software -- Clinical Use of Automated Microscopes for Cell Analysis -- Multiband Microscanning Sensor -- Computer Synthesis of High Resolution Electron Micrographs -- Computer Processing of Electron Micrographs of DNA -- Significance Probability Mappings and Automated Interpretation of Complex Pictorial Scenes -- Intracavitary Beta-Ray Scanner and Image Processing for Localization of Early Uterine Cancer -- New Vistas in Medical Reconstruction Imagery -- Digital Image Processing for Medical Diagnoses Using Gamma Radionuclides and Heavy Ions from Cyclotrons -- Processing of RI-Angiocardiographic Images -- Bioimage Synthesis and Analysis from X-Ray, Gamma, Optical and Ultrasound Energy -- A Pap Smear Prescreening System: CYBEST -- Automatic Analysis and Interpretation of Cell Micrographs -- Multi-Layer Tomography Based on Three Stationary X-Ray Images -- Texture Analysis in Diagnostic Radiology -- Automated Diagnosis of the Congenital Dislocation of the Hip-Joint -- Boundary Detection in Medical Radiographs -- Feature Extraction and Quantitative Diagnosis of Gastric Roentgenograms -- Computer Processing of Chest X-Ray Images -- MINISCR-V2 — The Software System for Automated Interpretation of Chest Photofluorograms -- Automatic Recognition of Color Fundus Photographs -- Image Processing in Television Ophthalmoscopy -- Attendees -- Author Index.

Character legibility was measured as a function of facsimile device parameters (pitch and sampling distance, and scan orientation) and of source document parameters (character height and case). The results indicate (I) very slight average difference in legibility (less than 1%) due to scan direction; (2) a more substantial difference (about 9%) between upper and lower case; and (3) legibility directly proportional to pitch and sampling distances, and to character height. For individual characters in standard typescript or similar material, 97.5% legibility apparently requires resolution on the order of 110 × 110 elements to the inch (scanning aperture nine mils square). Two secondary comparisons established the fact that individual character legibility (a) remained virtually unchanged when continuous scanning (one-mil resolution) was substituted for the best (five-mil) sampling distance, and (b) varied less than 2% when extra test documents were generated to check the repeatability of the experiment.

Digital communication systems distort their signals as a consequence of the digitization process. The distortions are related to the code length and sampling frequency of the system. The present study assessed viewers' responses to these variables by using simulated digital television. To do this, 24 subjects rated the quality of pictures distorted by several combinations of the variables. A response surface generated from the ratings showed that the ratings were affected by both variables, but most profoundly by code length. Interpretation of the surface's contours from the perspective of system costs revealed that costs should be considered solely from the standpoint of code length.