METHOD FOR DETECTING DENSITY NONUNIFORMITY OF IMAGE

PROBLEM TO BE SOLVED: To improve the sensitivity of detection treatment, by dividing an image region in two or more, obtaining the difference between the density average value of each region and that of the entire region, by comparing the difference with a threshold, and by specifying a density nonuniformity region. SOLUTION: In the detection of the density nonuniformity of an image in the inspection of a color filter or the like, for example, the density average value of an entire region is obtained first, and then the region is divided into two portions for obtaining the density average value of each region for the image data of a specimen obtained by an image-photographing means. When the difference between the density average value of the entire region and that of the divided one exceeds a specific threshold, it is judged that a nonuniform region exists. Such treatment is repeated until the region is further divided and a preset discontinuation area is reached, the detection nonuniform region, for example, is released by the specific treatment, and the actual nonuniform region is specified, thus detecting nonuniformity that is superposed on an image signal and is not affected by noise from an image pickup system or the like.