Research On Digital Watermarking Of 3D Models

With the rapid development of internet and multimedia technique, how to protect the multimedia information technique is becoming international hot spot. Digital watermarking technique provides an effective and useful method for the copyright protection of digital products. Digital watermarking is a technique which embeds a series of watermarks into the original information and extracts the embedded watermarks completely. It could result in slight visual distortions without effecting the use of original information. Recent years 3D model as a novel multimedia products is becoming increasingly popular and widely used. The rapid development makes it urgent to search for more copyright protection methods of digital information. As for digital watermarking technique, the embedded watermarks is used for copyright protection, data authentication or adding extra information in the original information. After the watermarked models are transmitted on internet, the owner can completely extract watermarks to prove copyright. In addition, reversible watermarking could recover the original model exactly.At present, most digital watermarking methods are mainly about multimedia data such as 2D pictures, audios, videos and so on. The techniques in these fields are relevantly matured-developed, while the development of digital watermarking about 3D models is not yet mature because of late starting up. With the rapid development of 3D models in many fields on internet, the copyright protection and content authentication about this newly coming multimedia product is becoming more and more urgent to solve. Digital watermarking provides an efficient method for the copyright protection of digital products. This paper mainly deals with:Firstly, in this paper, we first introduce the theory and research method of digital watermarking, including the basic concepts, classification, characteristics and application fields of 3D digital watermarking. And then the usually used 3D digital watermarking methods as well as the disadvantages and advantages are described in detail.Secondly, the key point of this paper is the 3D reversible watermarking method based on ratio expansion which operates on the spatial features of points. Using this method, after the watermarked model is translated, rotated and uniform-scaled, the original model and watermarks could be still extracted completely. With the analysis of performances, the experimental results show that this algorithm is of high invisibility and capacity, also it can resist a part of noises at some extent.Thirdly, we draw a conclusion, look into the distance and sum up the achievements and existing problems of 3D digital watermarking field. In addition, the future tasks and goals are listed.