Electronic watermark embedding device, electronic watermark detection device, method thereof, and program

摘要

A digital watermark embedding apparatus of the present invention includes: a block dividing unit for dividing an input image into plural pixel blocks; a digital watermark information spreading unit for obtaining an embedding series having a length corresponding to a number of divided pixel blocks; a block-by-block embedding unit for selecting at least a frequency from predetermined plural frequencies according to a term value of the embedding series corresponding to a position of a pixel block in the image, amplifying amplitude of a waveform pattern corresponding to the selected frequency with an embedding strength value, and superimposing the waveform pattern in which the amplitude is amplified on the pixel block; and an image outputting unit for outputting an image on which a corresponding waveform pattern is superimposed on each pixel block by the block-by-block embedding unit.