Research On The Digital Watermarking Technique

With the popularization of Internet and the development of multimedia techniques,the digital media,including image,graphics,audio and video etc.,has become a main way for information communication.People can get almost information through the lntemet,but this also gives rise to serious problems including wide spread copyrint violation.illegal copying,easy forging etc.which harm the advantage of the author or the copyright owner most. How to provide copyright protection for multimedia data has became an important issue. As a main application in computer multimedia of information hiding, the digital watermarking technique makes it possible embed an invisible signal(watermark) to the multimedia data such as image.audio and video. The digital watermarking tecnique has been proposed as a valid solution for the need of copyright protection and authentication of multimedia data in a networked environment,since it makes possible to identify the author.owner.distributor or authorized consumer of a multimedia data. So it has drawn extensive attention in recent years. In this paper.the author first makes an introductory review on the the digital watermarking techniques including the definition.charactistics and main application domains of digital watermarking. Then the author analyzes fundamental principles of digital watermarking algorithm in detail such as the general framework, classification and the typical algorithm, puts forward two DCT domain image digital watermarking algorithms based on the principles of JEPG. The algorithm I is a private watermarking algorithm which need the original image in the process of extract the watermark .while the algorithm II don't need because it is a semi-private watermarking algorithm. At last,the author make a discussion on the safe problems in the digital watermarking application, especially the problem of the interpretation attack,and proposes a viable solution using the electronic time-stamping technique.