FALSIFICATION DISCRIMINATION DEVICE AND ITS METHOD

摘要

PROBLEM TO BE SOLVED: To discriminate to which part of an image is falsified by imbedding an electronic watermark to the image. SOLUTION: An imbedding section 30 selects DCT coefficients corresponding to each other from respective DCT blocks of a luminance component Y of an image two each of them formed in pairs and included in each pair by using a random number and processes the DCT coefficients so that the correlation between them represents data according to prescribed rules and imbeds the data to the image. When this image is falsified, the DCT coefficients included in the pairs of the falsified part bend the rules so as to represent a different value from that of the original data. An extract section 40 extracts the data from the image, estimates the data imbedded at first through majority decision and discriminates that the pairs with the data different from the estimated data extracted from them receive falsification and displays the discriminated result.