Novel robust zero-watermarking scheme for digital rights management of 3D videos

Digital watermarking is an effective technique for the digital rights management (DRM) of three-dimensional (3D) videos, which is still a crucial issue in the field of 3D televisions. The current watermarking schemes for 3D videos can be classified into two main categories: One embeds watermarks into 2D video frames, and the other embeds watermarks into depth maps. The former causes irreversible distortions to synthesized 3D videos whereas the latter is insufficiently robust against some of normal video attacks. Moreover, because these watermarking schemes only embed watermarks into either 2D video frames or depth maps of 3D videos, none of them can protect the copyrights of these two parts simultaneously and independently. To address those problems, a novel robust zero-watermarking scheme for the DRM of 3D videos is proposed in this study. In the proposed scheme, master shares are first generated by extracting features from temporally informative representative images (TIRIs) of both the 2D video frames and depth maps. Then, ownership shares, which denote the relationships between copyright information and master shares, are generated based on the Visual Secret Sharing (VSS) scheme and stored for copyright identification. Finally, copyright ownerships are identified by stacking master shares and ownership shares. The experiment results demonstrate that the proposed scheme outperforms the current state-of-the-art watermarking schemes because it does not cause any distortion to the synthesized 3D videos, exhibits strong robustness against various video attacks, and protects the copyrights of 2D video frames and depth maps of 3D videos simultaneously and independently.