ELECTRONIC WATERMARK EMBEDDING DEVICE, ELECTRONIC WATERMARK DETECTION DEVICE, METHOD THEREOF, AND PROGRAM

摘要

block division means for dividing an input image into a plurality of pixel blocks; electronic watermark diffusion means for diffusing the input electronic watermark information so as to acquire an embedded sequence of the length corresponding to the number of pixel blocks divided; per-block embedding means for selecting at least one frequency from a predetermined plurality of frequencies according to the term value of the embedding sequence corresponding to the position in the image of one pixel block, amplifying the amplitude of the waveform pattern corresponding to the selected frequency with the embed intensity value, and overlapping the waveform pattern whose amplitude has been amplified, on the one pixel block; and image output means for outputting the image in which the waveform pattern is overlapped for each pixel block by the per-block embedding means.