Research For The Digital Watermarking Techniques Of Three-Dimensional Mesh Models

The rapid developments of techniques for Internet make people work cooperatively and publish various kinds of multimedia products such as texts, images, audios, videos and 3D models more conveniently through Internet. But, the convenience of Internet has also prompt unauthorized occupancy, duplication, modification and distribution of valuable contents. Digital watermarking has been widely researched as an effective solution for copyright protection and authentication since 1990s. However, the bulk of the research on digital watermarking has focused on media such as images, texts, audios and videos and fewer have focused on 3D models. This paper researches and discusses the robust watermarking techniques for copyright authentication of 3D mesh models.First, we make a survey of the related knowledge about the digital watermarking including the background, basic idea, applications etc. We present the principle, characteristics, classifications, typical algorithms, attacks and performance measures in detail. Some research directions and key issues in the future are also discussed.Then, a robust spatial private watermarking scheme is proposed embedding watermark into the ratio of distances that is invariant to affine transformation. We describe the steps of watermark embedding and detection including controlling local watermark strength, resample and weighted process for watermark detection.We propose a robust spatial public watermarking scheme that achieves blind detection of watermark by useing the property of the detected model instead of the original model as the comparable parameter.Finally, we introduce the principle of zero watermarking appeared in rescent years and apply it to 3D mesh models. A robust spatial zero watermarking scheme is proposed that makes use of the property of 3D mesh model to construct watermark instead of modifying the original data of 3D mesh model.