Electronic watermark embedding device and detection device, detection method, detection program, and intergrated circuit device thereof

摘要

An electronic watermark technique which allows precise detection of electronic watermark information from image having any size is provided. In an electronic watermark embedding device 100, an image size obtaining section 101 obtains an image size. A block size determination section 102 defines an area formed of a plurality of pixels as a block, and calculates a size of the block based on the image size. An embedding section 103 embeds the electronic watermark in units of the block of the calculated size. In an electronic watermark detection device 700, an image size obtaining section 701 obtains an image size of image data in which the electronic watermark is embedded. A detection filter producing section 702 calculates a size of a detection filter based on the image size. A detection section 703 detects the electronic watermark using correlation between the detection filter having the calculated size and the image data.