Exploiting XML Documents to Watermark JPEG Images

Abstract

The rise of the Internet and the advances in multimedia technologies have encouraged users to copy digital contents and ille- gally share them, thus violating the legal rights of content owners. In such a scenario, digital watermarking has become a key technology to support the copyright protection of multimedia digital contents dis- tributed on the Internet. This paper presents a nonblind watermarking procedure for JPEG images based on protected XML documents. The procedure enables the copyright owner to insert a distinct watermark code identifying the buyer into the distributed images. More precisely, the watermark is repeatedly embedded into an image in the DCT do- main at different frequencies and by exploiting both block classifica- tion techniques and perceptual analysis. The watermark is then ex- tracted from an image according to the information contained in a protected XML document associated to the image.