Patent ID: 7110599

Claim:
An image data retouching apparatus for determining the characteristic of each picture element in image data which express images in a dot matrix form in multiple tones and retouching each picture element in a way appropriate to its characteristic, said apparatus comprising: an image data acquisition unit which acquires said image data; a picture element characteristic determining unit which determines differences of tone levels between object picture elements, which are the picture elements of the image data acquired by said image data acquisition unit, and neighboring picture elements in a prescribed range around the object picture elements, creates a distribution of said differences and determines the characteristic of each object picture element by comparing the distribution of differences with a model distribution; and an image data retouching unit which executes prescribed image processing according to the characteristic of picture elements determined by said picture element characteristic determining unit, wherein said distribution of differences is created by placing each of said differences, respectively, in one of a plurality of predetermined categories, and wherein said picture element characteristic determining unit utilizes, for determination of the characteristic of each object picture element, the positive or negative polarization of said distribution.