Watermark Embedding Method

Abstract. The digital watermark technology is now drawing the attention as a new method of protecting copyrights, it is realized by embedding an invisible signal with an imperceptible form for human audio/visual systems, which is statistically undetectable and resistant to lossy compression and common signal processing operations, on the other hand, digital signature is another conventional scheme for image authentication, it is a set of features extracted from a media, and these features are stored as a file, which will be used later for authentication. To avoid the extra bandwidth needed for transmission of the signature in a conventional digital signature scheme, we present in this paper a combined digital signature and digital watermark scheme for image authentication method. The image provider extracts the content-dependent signature from the original image and then embeds it back into the images as a semi-fragile watermark