New Multipurpose Oriented Stereo Image Watermarking Algorithm for 3D Multimedia

Most of digital watermarking algorithms have been designed for only single purpose. In this paper, a new multipurpose oriented stereo image watermarking algorithm is proposed for three dimensional multimedia, which can be used for copyright protection, content authentication and tamper detection in three dimensional (3D) multimedia. Specifically, host stereo image is divided into non-overlapping blocks, and the chaotic feature watermarks are generated according to the stability of low frequency coefficients and largest singular value. As there are redundancies between the left and right views of stereo image, each block of the two views is classified into matchable or non-matchable block to embed digital watermarks with different purposes. At the receiving side, using stereo marching technique as a bridge, the robust and fragile watermarks can be blindly extracted without access to the host stereo image. Meanwhile, the robustness of stereo image watermarking is improved, and a hierarchical tamper detection scheme is presented to ensure the accuracy of tamper localization. Especially, Level-2 detection is employed to improve previously obtained detection results to enhance authentication accuracy. Experimental results show that the proposed algorithm is quite robust to attacks, such as noise, filtering, JPEG compression, cropping and size scaling. Moreover, the experimental results also show that the proposed algorithm can detect tamper accurately and locate forgery effectively. Key-Words: Stereo image watermarking, copyright protection, authentication, multipurpose, matchable block and non-matchable block, chaotic feature watermark