A video watermarking technique based on discrete fractional Fourier transform (DFRFT) is proposed. Each frame of original video is first decomposed into two-dimensional (2-D) multiresolution representations by 2-D discrete wavelet transforms (DWT) along the spatial axis. Then the wavelet coefficient frames in each group of pictures (GOP, each is 16 frames) are transformed into DFRFT coefficient frames by one-dimensional (1-D) DFRFT along the temporal axis. The watermark is embedded into each DFRFT coefficient frame in the GOP, and the angular parameter of the DFRFT can be changed to adapt itself to the original video. Experimental results show that the proposed technique is robust enough against the attacks of frame dropping, averaging and lossy compression.

A method of embedding a digital watermark image in video is proposed in this paper. By two- dimensional and three-dimensional multiresolution signal decomposing, the decomposed watermark images with different resolution are embedded in the corresponding resolution of the decomposed video. To enhance the robustness of watermarking, the watermark information is coded by error correction coding of Hamming code in our algorithm. Experimental results show that the proposed technique is robust enough against the attacks of frame dropping, averaging and lossy compression.

Digital watermarking has been presented in recent literatures as a technique to protect the copyright of multimedia data. But most of these literatures focus on the algorithms of embedding one-dimensional watermarks or two-dimensional binary digital watermarks. In this paper, a method of embedding a gray-level digital watermark into an image is proposed. By stack filter's threshold decomposition technique, a gray-level digital watermark is decompounded into a series of binary digital images for implementing multiple watermarking. The experimental results show that the proposed techniques are successfully tolerant to reasonable image processing operations and the lossy compression techniques such as Joint Photographic Experts Group (JPEG).

A multiresolution watermarking method with grey-level watermarking is presented. Both the watermarking and the original image are decomposed into three-level multiresolution structures using different mechanism. The decomposed watermarking information is further coded by error correction coding. Each level of watermark information is embedded into the corresponding level of the transformed image. Experimental results show that the proposed algorithm is robust against common image manipulations.