Digital watermark embedding apparatus, digital watermark embedding method, and digital watermark detection apparatus

A digital watermark embedding apparatus comprising:

• an interface unit which acquires video data and digital watermark information;
• and
• a processing unit which embeds the digital watermark information into the video data, wherein the processing unit implements:
• a watermark pattern position determining function which determines the position of a watermark pattern including a plurality of pixels and to be superimposed on each image contained in the video data so that the watermark pattern moves with time according to the value of a symbol contained in the digital watermark information within a first moving range that contains at least a portion of a reference region defined in a designated position on each image contained in the video data, and so that an average pixel value of the reference region overlapped with the watermark pattern varies in a periodic fashion as the watermark pattern moves;
• and
• a watermark pattern superimposing function which corrects the value of each pixel contained in a region where the reference region and the watermark pattern overlap each other by using the value of a corresponding one of the pixels contained in the watermark pattern.