Verfahren zur Bestimmung von farbigen Bildsignalen

摘要

In a color image signal evaluating apparatus and method, a color image signal corresponding to each pixel position on a display screen is converted by a color signal converter to an I signal and a Q signal, which are stored, as pixel data, in first and second image memories (13A,13B), each at an address corresponding to the pixel position. The I signal and Q signal read out of the first and second image memories (13A,13B) are differentiated by first and second differentiators (14A,14B), respectively, with respect to the directions of pixel arrays to thereby obtain an I-signal differentiated value and a Q-signal differentiated value at each pixel position. A vector-composed value of the I-signal differentiated value and the Q-signal differentiated value at each pixel position is calculated and is stored in a third image memory (16). An evaluation part (17) represents, as a factor of the degree of a color reproduction error, the magnitude of a change in the differentiated vector-composed value stored in the third image memory and compares the factor with a fixed value, thereby determining whether or not the color reproduction error is within a given limit range.