Research And Implementation Of Watermarking System Based Extensive Frequency For MPEG-4 In Compression Domain

With the rapid development of multimedia technique and computer network, digital media has become a convenient way for information communication . This also causes some serious problems such as piracy and copyright infringement. Digital watermarking technology has been regarded as an effective solution to solve intellectual property rights (IPR) protection.This thesis introduces the research background of digital watermarking technology. We describe the categories of digital watermarking, and then discuss their basic principles, some digital watermarking embedding algorithms as well as several attacking approaches for digital watermarking. According to the feature of Video on Demand (VoD) system based on grid platform, aiming at MPEG-4 standard, we propose an extensive frequency digital watermarking approach. This approach embeds a watermark into the direct current coefficients of the chroma's DCT of IVOP in video stream. The embedment and abstraction of watermark needn't decode fully. As a result, the complexity of computation is decreased and the real-time capability is improved. Furthermore, the watermark is robust while guaranteeing the quality of video stream. Finally, experimental results demonstrate the effectiveness of our approach, and we point out the future work.