APPARATUS FOR DISCRIMINATING CONTAMINATION DEGREE OF PAPER SHEET

摘要

PROBLEM TO BE SOLVED: To obtain an apparatus capable of measuring the characteristic quantity of the same index without relying on a feature quantity measuring area and dispensing with the normalization due to the feature quantity measuring area. SOLUTION: An image input part 103 inputs the image data of a paper sheet P to store the same in an image memory 104. A region extracting part 105 extracts the predetermined rectangular region on the basis of the image data inputted by the image input part 103 and a difference image forming part 107 calculates the brightness difference with a peripheral pixel with respect to the extracted rectangular region to form a difference image and a standard deviation calculating part 108 calculates the standard deviation of a pixel value with respect to the formed difference image to set the same to fold feature quantity. A fold decision part 109 decides the contamination degree of the paper sheet P on the basis of the calculated fold feature quantity.