Research Of Digital Video Watermarking Technology In DCT Domain

With the rapid development of network and information technology, the storage, reproduction and dissemination of digital multimedia information have become extremely convenient. However, as digital music and images are susceptible to edition, modification, reproduction and distribution from the third-party, the copyright and economic interest of the creator as well as the reliability, safety of digital media and subsequent issues such as piracy and copyright disputes are becoming increasingly debatable. Digital watermarking technology, as one of the copyright protection technologies, has its unique advantages. Hidden information is embedded at the premise that it does not affect the availability of the original information, thereby providing an alternative means of copyright identification and detection.This thesis firstly analyzes the characteristics of digital video watermarking technology and the current main techniques employed. Then followed by the analysis of the relevant digital video format and coding, and digital watermarking technology, including the embedding program, coding, expansion frequency technology and DCT transform. Then by using the popular MPEG-2 video as a carrier, the thesis analyzes MPEG-2 profile and level, variable length coding(VLC), combined with MPEG-2 encoding structure based on DCT video watermarking scheme and realizes the coding region in the video watermark embedding and detection algorithms. The paper analyzes the embedded strategy. Embedded point selection strategy and embedding method, meanwhile, are thoroughly discussed. Noticeably, watermark detection in the original video is achieved by blind watermark detection. In order to balance the watermark robustness and the invisibility of the watermark, certain concessions are made.Experimental results show that the methods discussed in this thesis can better ensure the watermark invisibility, robustness and security.