Method and apparatus for generating video signal representing

Abstract

A matte synthesizer and method generates baseband video signal information from user inputs for selecting levels of luminance, saturation and hue. The synthesizer includes continuously variable controls for inputting user selections over respective ranges of adjustment, a processor programmed to calculate directly a plurality of discrete amplitude samples in a chroma cycle of a video signal corresponding to a periodic wave at a baseband frequency of the video signal with a DC level determined by the luminance, a peak-to-peak amplitude determined by the saturation, and a phase shift relative to a reference burst determined by the hue, and a multiplexing method operable to read out the discrete amplitude samples to an output, during each cycle of the chroma baseband frequency. The discrete amplitude samples are calculated for a vertical field of the composite video signal and displayed during the next field. The signal thus obtained is filtered and superimposed with a synchronizing signal. The resulting matte signal can be displayed on a standard color television monitor. The repetitive output can be provided by sequentially and repetitively routing calculated amplitude values through a digital to analog converter and summing the output with synchronizing information.