Investigation For Watermarking Graphics Data

With the rapid development of the computer networks and communication technology, digital multimedia works, including graphics, image, video, and audio etc, are used widely, along with the problems of property protection and content authentication. These problems would be urgent to be solved. Digital watermarking is a new technology to protect property, authenticate origin and integrity in open networks environment. It has been paid more attention to by people recently, and has become a new research hotspot in multimedia signal processing field.At present time, most research on digital watermarking focus on image watermarking, especially on robust watermark for property protection. However, with people's deeper investigation and wider scope, the research for digital watermarking is not limited to still image. Graphic data, as an important kind of multimedia information, also needs some kinds of method to protect its property and to authenticate its resource and facility. All kinds of designing blueprints,3D models, graphics and cartoons all belong to graphic data. These years watermarking graphics has been gained more importance.This paper first introduces background knowledge of digital watermarking, including its developing history, basic specialty, categorization and its application domain etc. And also gives a general frame for watermarking system and some practical application using this general frame, mostly including the practical work I have done during two projects, Research on Key Technology of Middle Ware and Digital Archaeological Museum of ShanDong University. The main work I have done in this paper is as follows:1. Present a new method of digital watermarking of 2D vector graphics for property protection. The watermark is embedded in the Complex Wavelet Domain of Relative Coordinates Line. Robustness to some common manipulations, such as translation, rotation scaling and local modification, have been proved by preliminary experimental results.2. Point out the significance of another kind format of digital watermarking, that is, annotation watermark. The annotation watermark is some different from robust watermark which is mainly used to property protecting. It is mostly used for watermarking related information and annotation for graphics. So graphics can take its related information conveniently while transferring. And also present an annotation watermarking scheme, analyze existing problems and give some improving ideas.3. Discuss a fragile watermarking scheme for graphics authentication. This scheme can be precise to every point. If choose a logo image as watermark signal, it also can declare copyright on a certain degree. This scheme can easily extend on 3D models and point cloud data, and also make sense on scene authentication which contains image and graphic data at the same time.