ELECTRONIC WATERMARK EMBEDDING APPARATUS, ELECTRONIC WATERMARK VERIFYING APPARATUS, ELECTRONIC WATERMARK EMBEDDING METHOD, AND ELECTRONIC WATERMARK VERIFYING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an electronic watermark embedding apparatus, electronic watermark verifying apparatus, electronic watermark embedding method and electronic watermark verifying method in which an embedded message can be rightly extracted by rightly decoding additional data in a portion other than an important area even when important area information is added or deleted. SOLUTION: The electronic watermark embedding apparatus comprises an important area information input terminal 2 to which the important area information is inputted in relation to whether each of blocks resulting from dividing inputted image data belongs to an important area or to a non-important area, a signature generating part 101 which generates signature data for the unit of division into blocks, and a signature embedding part 102 for embedding the signature data into the image data according to the important area information. The signature embedding part 102 then does not embeds the signature data for an important area in the important area but embeds the signature data for the important area in the surrounding non-important area and embeds the signature data for the important area in non-important areas in addition to signature data for non-important areas. COPYRIGHT: (C)2005,JPO&NCIPI