Suppression of luminance signal contamination of chrominance signals in a video signal processing system

摘要

Apparatus in a video signal processing system for improving the quality of a reproduced color image by reducing visible "cross-color" interference caused when high frequency luminance signals occur within the passband of the chrominance component of the video signal. Video signals within the chrominance passband are sensed by a signal multiplier responsive to the video signal and to the video signal delayed by a given amount. The amount of delay corresponds to an interval during which rapid luminance transitions capable of producing the high frequency signals within the chrominance passband can occur. The multiplier generates a control signal indicative of the presence of the luminance transitions, which is then utilized for controlling the chrominance signal processing channel such that objectionable cross-color effects otherwise visible in a reproduced image are reduced or eliminated.