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The use of liquid-crystal panels from a commercially available Sanyo video projector as spatial light modulators in a standard joint transform correlator system is investigated. It is found that the flatness distortion of the panels disturbs the output correlation signal in general. Since the reported solutions for the flatness corrections are either expensive (liquid gates) or suffer from low light efficiency (holographic techniques), we have investigated a possibility to minimize the influence of these distortions on the correlation output without flatness correction. First, we quantify optical flatness across the transparent panel area, and then we measure the effects of flatness distortion by changing the display location of the input objects and the resulting joint power spectrum. It is found that the correlation peak is 1 order of magnitude more sensitive to phase distortions of the input scene than to the same distortions of the joint power spectrum. Choosing the flattest location on the panel allows the utilization of the panels to be demonstrated through recognition of cuneiform inscription signs. Key words: Liquid-crystal television, joint transform correlator, optical pattern recognition.

Television pictures are not always at their best color saturation settings. We propose an intelligent system that automatically adjusts the color saturation on a field-by-field basis. Incoming pictures are first classified into one of two categories, namely, facial tone and nonracial tone images, then each category is subcategorized. Depending on the membership of the picture to each subcategory, color saturation changes are computed and used to modify the color saturation of the following field. The categorization is done by using neural network classifiers operating on the color difference signals. We describe the principles of the color correction scheme, its implementation using analog hardware and its interface to a television. Performance of the color adjustment technique implemented using real-time hardware in a television is discussed. Oversaturated and undersaturated pictures in both facial and nonfacial tone categories can be detected and corrected. The technique lends itself to low-cost analog implementations.

This paper examines the data from the field test of the Grand Alliance HDTV transmission subsystem conducted in Charlotte, NC in 1994. The field test data provides HDTV system designers and researchers with first-hand information on the performance of digital HDTV terrestrial broadcasting as well as on NTSC performance in the real-world environment. Analyses of the field test data are performed with respect to the system performance of an 8-VSB digital transmission subsystem, the performance of NTSC as reference and the television channel characteristics. Observations and conclusions derived from the analyses are provided.

The cultivation perspective holds that heavy exposure to television's consistent messages leads viewers to be more fearful and mistrustful of others. The widespread adoption and use of new television technologies, however, may alter how television viewing cultivates social reality beliefs by allowing for greater programming diversity and greater viewer control. Two random-digit- dialed telephone surveys of adults in two U.S. cities were conducted to test the impact of cable, VCRs, and remote control devices on fear of crime and interpersonal mistrust. It was found that whereas interpersonal mistrust was linked to greater exposure to cable's broadcast-type channels, both fear of crime and mistrust were negatively related to increased exposure to more specialized and diverse cable channels. Fear of crime was also linked negatively to VCR ownership. The discussion suggests that mass communication researchers continue to explore the impact of new television technologies on traditional media effects.

This work extends multistage implementation of sampling structure conversion to the multidimensional (M-D) case. The issues arising in this task are usefully addressed on the basis of lattice theory. Numerical data supporting the advantages of multistage sampling conversion are presented, and the case of format conversion from 4/3 to 16/9 aspect ratio is examined as a study case. The main indication of this work is that multistage implementation, in the case of systems for sampling structure conversion of video signals, may improve the system characteristics and visual rendition.

The improvement in the quality of TV pictures since colour transmission was introduced some 20 years ago in Europe (35 years in the USA) is impressive, and technological advances already achieved give firm promises of further improvement during the next few years. Over and above this, however, looms the prospect of high definition TV as an even better medium of a different kind. There are, however, major technical and economic obstacles to its widespread introduction.

Studies regarding manual work movements, innovative television and the enhancement of quality control in chicken processing plants have provided important implications. These studies have utilized computer simulation methods, transducers, laminated glass car screens and machine vision systems to determine the needed outcomes. The studies have stressed the use of technological innovations in various applications.

BIG-SCREEN BATTLES Bitter battles over technical standards for new electronic products have been fought between the giants of Japan and Europe -- Sony, JVC, Philips and Thomson -- for two [...]