Topic: Robust Digital Watermarking Group members: Andy Kuo-an Chao Chih-chien Chao Digital watermarks have been proposed in recent literature as a means for copyright protection of multimedia data. In this project we are going to explore and implement 3 algorithms based on different method. The first method is based on the DCT coefficients. By embedding a pseudo-random sequence of real numbers, which is the watermark, in a selected set of DCT coefficients. This sequence can be extracted from the watermarked image without resorting to the original. The second method is also based on the DCT coefficients. By using the zerotree, the DCT coefficients can be rearranged to embed the watermark. The algorithm can also extract the watermark from the image without resorting to the original image. The third method is based on the wavelet transform. The watermark, a pseudo-random sequence of real numbers is added to the multiresolution wavelet coefficients. For the detection, the correlation between the wavelet coefficients and the watermark is compared with a threshold to determine the existence of the watermark. The algorithm is claimed to be robust for JPEG compression. If all the 3 algorithms mentioned above is successfully implemented before the project deadline, we will try to study the general attack algorithm for watermark. Since we don't have any watermarked image at hand, it won't be easy to study the attack algorithm. References: 1. Piva, A. et al. "DCT-based watermark recovering without resorting to the uncorrupted original image" Proceedings of International Conference on Image Processing. Held: Santa Barbara, CA, USA 26-29 Oct. 1997. Proceedings. International Conference on Image Processing (Cat.No.97CB36144) (1997) p. 520-3 vol.1 (Conference Paper) 2. Chuan-Fu Wu et al. "Digital watermarking using zerotree of DCT" IEEE TRANSACTIONS ON CONSUMER ELECTRONICS IEEE, Feb. 2000. vol.46,no.1, p.87-94 (Journal Paper - English) 3. Inoue, H. et al. "An image watermarking method based on the wavelet transform" Proceedings of 6th International Conference on Image Processing (ICIP'99). Held: Kobe, Japan 24-28 Oct. 1999. Proceedings 1999 International Conference on Image Processing (Cat. 99CH36348) (1999) p.296-300 vol.1 (Conference Paper) ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com