Patent ID: 7159117
Filing Date: 2007-01-02
Classification: G06T,H04N

Abstract:
1. An electronic watermark detection apparatus comprising: insertion information memorizing means for preliminarily memorizing insertion information for designating a type of electronic watermark data to be inserted block by block in one frame divided into a plurality of blocks; data extracting means, supplied with an electronic watermark inserted composite image divided into a plurality of blocks in which individual electronic watermark data are inserted block by block, for extracting, on the basis of said insertion information, the electronic watermark data in said electronic watermark inserted composite image by adding the blocks in which the same electronic watermark data are inserted to produce extracted data; electronic watermark data memorizing means for preliminarily memorizing a plurality of electronic watermark data inserted in the respective blocks; electronic watermark data detecting means for calculating a statistical similarity between said extracted data and the respective electronic watermark data stored in said electronic watermark data memorizing means; electronic watermark data accumulating means for accumulating said statistical similarity for a predetermined time interval to produce an accumulated addition value; and determining means for determining whether or not said electronic watermark data is detected by comparing said accumulated addition value with a predetermined threshold value.