ELECTRONIC WATERMARK COMBINING DEVICE, ELECTRONIC WATERMARK COMBINING PROGRAM, AUTHENTICATION INFORMATION DETERMINING DEVICE, AND AUTHENTICATION INFORMATION DETERMININIG PROGRAM

摘要

PROBLEM TO BE SOLVED: To embed an electronic watermark and extract it so that the electronic watermark can be extracted without tracing back procedures used for combining and the combined electronic watermark is hardly removed even if compression processing, filtering or geographic modification is applied. SOLUTION: A device is provided with an independent evaluating section 5, a watermark vector correcting section 6 and a linear coupling vector generating section 7. The device corrects image data in an embedding section 8 using a linear coupling vector obtained by linearly coupling an image vector with a watermark vector which are independent from each other to combine the electronic watermark. With this configuration, in extracting the electronic watermark from the combined image data after a mixed vector is obtained, the watermark vector is separated from the mixed vector by a technique of independent component analysis, and authentication information is determined without tracing back the the procedures used for combining. COPYRIGHT: (C)2005,JPO&NCIPI