Color misregistration easing system which corrects on a pixel or block

Abstract

An encoder decomposes an input color image signal into a luminance signal and color signals, places the color signals in image memories, then fetches color signals of a given screen before and after. A detector calculates differences between the color signals to detect color misregistration either on a pixel basis or a block basis. On the other hand, color signals of a last image acquired before occurrence of color misregistration are stored in frame memories. When color misregistration is detected, a corrector reads the color signals of the last image from the frame memories, and produces correction signals. A counter carries out counting for each difference between color signals of given screens before and after, then detects a distribution of color misregistration of a screen. A selector checks the distribution of color misregistration of a screen to identify the cause of color misregistration, then selectively outputs either the input color image signal or a correction signal sent from the corrector. Thereby, color misregistration is corrected either on a pixel basis or a block basis. This prevents deterioration of image quality due to unnecessary correction.