SHADING CORRECTION DATA GENERATOR, WHITE SHADING CORRECTION DEVICE, IMAGE READER, IMAGE FORMING DEVICE, SHADING CORRECTION DATA GENERATING METHOD, PROGRAM AND STORAGE MEDIUM

摘要

PROBLEM TO BE SOLVED: To thoroughly eliminate noises from white shading correction data by excluding pixels subjected to the influence of dust, dirt and flaw or the like. SOLUTION: An averaging circuit 32 generates shading correction data used for white shading correction from image data obtained by reading a white reference board. An averaging circuit 29 applies weighted mean processing to data by a plurality of lines at the head of image data of the white reference board (reference data generating area) to generate reference data. A comparator circuit 31 discriminates whether or not a relation of 'image data after the reference data generating area < reference data - a prescribed value NOREF' holds and excludes the image data after the reference data generating area from the object of generating the shading correction data by the averaging circuit 32 for each pixel selectively when the relation holds.