Study Of Digital Video Watermarking Technology Based On Wavelet Transform

With the development of multimedia and Internet technology, the digital information revolution has brought about profound changes in our society and our lives. There are a variety of digital audio-visual products for our entertainment and they can easily be copied and delivered on Internet without any losses in quality. Therefore, more and more pirates strongly hurt the producer and author's interests. It has aroused intense interest in multimedia security and copyright protection. A digital watermark is to embed auxiliary information into a digital signal by making small changes that are not perceptible to its intended recipient.Video watermarking is one of the most difficult and active area in the digital watermarking research. In this paper, a comprehensive approach for protecting and managing video copyright with watermarking techniques is introduced. Based on wavelet transform, we propose a new watermark scheme of combination audio and video. Further more, the retrieval of the embedded watermark dose not need the original image .This is an important property to video watermarking.The proposed algorithm makes use of independent watermarks for different scenes. On the one hand, the watermarks are embedded into both video and audio channel. On the other hand, the watermark to be embedded is divided into several blocks. Different watermark blocks are embedded into all frames of different scenes. Within all frames of the same scene, an identical watermark block is used. In the process of embedding, the watermark block is disposed by Laplacian Pyramid multiresolution decomposition and bit-plane decomposition. At the same time, the frames are transformed to the wavelet domain. And then, the bit-plane information is embedded into corresponding resolution of the decomposed original frames, which makes the watermark be adapted to the original video frames. In additional, Error correcting code of the video watermark can be embedded into audio channel as dual-watermarking, both robust and fragile. With the mechanisms, the proposed scheme is robust against the attacks of frame dropping, averaging, swap, and statistical analysis. With the mechanisms of accessorial dual-watermark in the audio channel, watermarks can resist most distorts. As a result, it is robust against some certain attacks. Finally, we have a relevant test to the scheme and analyze the direction of future research.