| 摘要 |
According to a first aspect of the invention, saturation is averaged for each pixel block of a predetermined size and maximum one of the saturation values is obtained. Such a maximum mean saturation value is obtained for each of a predetermined number of block sizes, the sum total of the maximum mean saturation values is obtained and basic chromaticity corresponding to the sum total is determined. According to a second aspect of the invention, the saturation values in the first aspect are each corrected by the hue of the corresponding pixel. According to a third aspect of the invention, a correlation coefficient of X and Y coordinates of the pixel positions where the saturation values are greater than a reference saturation value are obtained for each color, and a slanted stripe pattern factor is determined corresponding to the correlation coefficient. According to a fourth aspect of the invention, the width of a striped pattern is detected for each color, the sum of saturation values within the pattern width, a standard deviation of the pixel positions weighted by saturation and the number of pixels within the pattern width are multiplied, and a border striped pattern is determined corresponding to the multiplied value. According to a fifth aspect of the invention, the width of the striped pattern is similarly detected, the sum of saturation values within the pattern width is obtained and a standard deviation of saturation and a standard deviation of pixel positions are calculated. A center stripe pattern factor is determined corresponding to a value obtained by dividing the product of the sum of saturation values and the deviation of saturation by the standard deviation of pixel positions. According to a sixth aspect of the invention, evaluated values of these color reproduction errors are multiplied by predetermined coefficients, respectively, and their sum total is obtained. The sum total is compared with a reference value to determined the quality of a color image signal. |
