Patent ID: 8509515
Filing Date: 2013-08-13
Classification: G07D

Abstract:
1. A paper sheet identification apparatus comprising a reading unit which reads a watermarked image formed on a paper sheet; a converter which converts the watermarked image read by the reading unit into data for each pixel of a predetermined size as a unit, which contain color information having brightness; a watermarked image correction processing part which calculates an average density value for each pixel array in one direction, an average density value for each pixel array in another direction, and an average density value of an entire watermarked image based on the watermarked image having been converted for each pixel by the converter, and which corrects density values of respective pixels such that respective average density values for each pixel array in said one direction and for each pixel array in said another direction are approximated or matched to the average density value of the entire watermarked image; a storage part which stores a reference watermarked image serving as a reference for comparison and containing color information having brightness for each pixel in the predetermined size as the unit; and an identification processing part which compares an image corrected by the watermarked image correction processing part with the reference watermarked image stored in the storage part and identifies an authenticity of the paper sheet.