Method fo embedding hidden digital watermark into subband-decomposed image for identification of copyrighter

Abstract

Disclosed is a method of embedding a hidden digital watermark (also called digital stamp, digital seal, digital signature, etc.) into a produced image which can permanently identify the copyrighter of the produced image to cope with an illegal use or modification thereof by imbedding the hidden digital watermark into the produced image so that the copyrighter can identify his/her authorship when the digital image is first produced by the copyrighter. A color or black-and-white image that only the copyrighter possesses is used as the digital watermark, and the digital watermark is embedded into the produced image in a manner that the human eyes cannot realize the difference between the images before and after imbedding the digital watermark. The method includes repeatedly extending the digital watermark in a symmetric form and adjusting the extended digital watermark image in the same size as an image into which the digital watermark is embedded, subband-decomposing and synthesizing the digital watermark image and the image into which the digital watermark is embedded to produce a final image into which the digital watermark is embedded.

Dependencies are inferred from the claim text.