An Integrated Digital Watermark Protective System For GIF Image

GIF image is a very popular image type on current internet. It's very important to protect this type of image, but there does not exist a good arithmetic to realize the function of copyright authentication and integrality protection for GIF image. Considerring of this situation, author has brought forward one kind of thought "one arithmetic, two watermarks", which makes the robust watermark information and fragile watermark information together as just one watermark, and then embeds it into a carrier by using an improved SHUFFLE arithmetic. This new method avoids the disadvantage that it is easy to affect by each other for robust and fragile watermarks in the traditional method. So it realizes the two functions of copyright authentication and integrality protection for GIF image.In this paper, author improves SHUFFLE arthmetic which belongs to the sorting arithmetic for colour pallette. For the new arithmetic, the capacity increases a lot and uniforms to a fixed value. It has an additional fuction of error correction code and the funtion is extended so that it can be applied for all GIF image. The improved arithmetic has following characteristics: strongly robust, totally fragile, high and fixed capacity, high running speed. This system has a broad applied prospect, for example, it can be used for protecting the content of Multimedia Messaging Service(MMS).This paper expounds the new arithmetic's principle and realization first. And then gives the test result, including of the arithmetic's following characteristics: transparence, robusticity, fragility, stand against being detected and the running speed. At the end of the paper, author summarize the strongpoints and shortcomings of the arithmetic.