Method and apparatus for calculating distances and reflection differences between measurement points on printed matter to evaluate image quality

Abstract

Upon observing homogeneity in page image by the human eye, a permissible level associated with color reproduction with respect to an identical color signal changes depending on the distance from an interest point. Since the conventional homogeneity in page image evaluation scheme doesn't take the above characteristics into consideration, the correlation between a finished image and the evaluation result cannot be exploited fully. Hence, image data, which forms an image with identical density within a range to be evaluated in one page, is output to a printer to measure reflection characteristics of the image at points on output of the printer. One point is set as a reference point, and distances between the reference point and the remaining points, and differences of the reflection characteristic between the reference point and the remaining points are calculated. The image quality within the range is evaluated based on the distances and differences.