DEVICE, METHOD AND PROGRAM FOR DATA DETECTION

摘要

PROBLEM TO BE SOLVED: To accurately detect an electronic watermark from a DCT (Discrete Cosine Transform) area, even when the area setting of an electronic watermark pattern does not match DCT block configuration. SOLUTION: The electronic watermark detector 10 is provided with a correlation detection section 12, that detects an electronic watermark component detection value WM which is the correlation value between an electronic watermark pattern W to be detected and detection object image data Y by each one a plurality of areas set to the detection object image data Y. The electronic watermark detector 10 uses the correlation detection section 12 for obtaining a correlation value to be extracted from one area not only from the data of that area, but also by performing correlation arithmetic operations between the overall detection object image data Y and an electronic watermark pattern for calculating the correlation value of each area of the same size as that of the detection object image data Y.