Video Digital Watermark Research And Implement Based On MPEG2 Video

The present computer technology makes people more and more easy to create and use digital media works, what's more, the development of Internet promotes the wide-spread of digital media works, one excellent works would be spread all over the world almost one light. However, the copyright of the digital media works is seriously damaged , because one can easily access, duplicate and spread the works at random, as a result the interests of the owner are heavily damaged.To effectively protect the copyright of works, many methods are produced, digital watermarking is one of those methods. As one way of information hiding, digital watermarking can embed secret information (watermark) into original data (carrier data) without having effects on the using of the carrier data, in addition, the watermark can not be removed, only special software can extract it. At present, there have many results in the research about digital watermark, there even have usable products of image digital watermark.In this paper, the character of video digital watermark and the current technical method are discussed, then one way as "digital watermark embedding scheme based on gridding division" is produced, by this way, embedding and extracting watermark in compressed video domain are carried out. In this paper, chroma DC coefficients are selected as the carrier data because chroma DC coefficients are robust. Also, alterable steps are used to select one part of the coefficients, so the watermark is imperceptible; Before watermark embedding, the watermark is divided into many parts, every part is individuallyembedded into one GOP of the video, even if a GOP is destroyed, the watermark can be extracted correctly, this methods promotes the robustness of the watermark; In addition, in order to promote the security of the watermark, the user's ID and password are used to generate chaos sequence by the chaos system which is created in this paper, later, watermark is mixed by the chaos sequence. Also, the embedding position of the watermark bit is modified by one chaos sequence, so, unauthorized person can not extract or remove the watermark, since the embedding position is unknown.Experiments make it clear that the scheme adopted in this paper fully satisfy the requirements for imperceptibility, robustness and security.