Digital Watermarking for Depth-Image-Based Rendering 3D Images and Its Application to Quality Evaluation

Abstract

Due to the rapid development of 3D display market, the protection and authentication of the intellectual property rights of 3D multimedia has become an essential concern. As a consequence, the digital watermarking for 3D image and video is attracting considerable attention. The depth-image-based rendering (DIBR) technique has been playing a critical role in 3D contents representation because of its numerous advantages. A good digital watermarking algorithm should be robust to various possible attacks, including geometric distortions and compressions. And di erent from ordinary 2D digital watermarking, there are more speci c requirements for 3D watermarking, especially for DIBR 3D image watermarking. Not only the center view, but also the virtual left and right views can be illegally distributed. Therefore, the embedded watermark information should be accurately extracted from these three views individually for content authentication, even under attacks. In this thesis, we focus on the research of digital watermarking and watermarking based quality evaluation for DIBR 3D images. We first present a 2D image and video watermarking method based on contourlet transform, which is then extended to a robust contourlet-based watermarking algorithm for DIBR 3D images. The watermark is embedded into the center view by quantizing certain contourlet coe cients. The virtual left and right views are synthesized from the watermarked center view and the corresponding depth map. One advantage of our algorithm is its simplicity and practicality. However, the performance on watermark extraction needs to be further improved. As an improvement, a blind watermarking algorithm for DIBR 3D images based on feature regions and ridgelet transform is proposed. The watermarked view has good perceptual quality under both the objective and subjective image quality measures. Compared with other related and state-of-the-art methods, the proposed algorithm shows superiority in terms of watermark extraction and robustness to various attacks. Furthermore, as one of the most promising techniques for quality evaluation, a watermarking based quality evaluation scheme is developed for DIBR 3D images. The qualities of the watermarked center view and the synthesized left and right views under distortions can be estimated by examining the degradation of corresponding extracted watermarks. The simulation results demonstrate that our scheme has good performance of quality evaluation for DIBR 3D images under the attacks.