Digital watermark embedding device and digital watermark detecting device

Abstract

A digital watermark embedding device and a digital watermark detecting device are obtained, which can realize stable digital watermark detection using fewer, and embed and detect a larger amount of digital watermark information with an identical number of pixels used for digital watermark embedding in a conventional technology. The digital watermark embedding device includes: an embedding-information converting unit () for converting inputted information to be embedded into a bit string formed of '0's' and '1's' and embedding respective bits of the converted bit string multiple times to output a digital watermark pattern having N −1's or N+1's as elements; an orthogonal-pattern generating unit () for generating orthogonal patterns each formed of a combination of elements of −1's and +1's and orthogonal to one another; an integrating unit () for integrating each of the orthogonal patterns from the orthogonal-pattern generating unit with each of the elements of the digital watermark pattern from the embedding-information converting unit to generate an embedding pattern; and a digital-watermark embedding unit () for embedding embedding pattern from the integrating unit in an input image and outputting an image after embedding information.