Abstract:
It is only recently — as a result of rapid advances in semiconductor technology and digital techniques — that television pictures have been created by image generators. For example, NHK (Japan Broadcasting Corp.) regularly uses image generators for tracking results during its live election coverage and for animation in children's programming. Although the images generated are relatively simple, the range of special effects available makes such applications promising for the future. The authors describe a newly developed system that can be used to perform real-time image manipulation using a joystick, light pen, or other control data by converting the computer output into raster scan signals that are fed into the vertical blanking interval. This feature has been made possible by the selection of trapezoidal forms as basic patterns, with images being built up through composite layering. Therefore, the demands placed on the computer have been drastically reduced, allowing even minicomputers and microcomputers with limited capacity to produce real-time moving color imagery.