A framework for robust watermarking of H.264-encoded video with controllable detection performance

As H.264 digital video becomes more prevalent, the need for copyright protection and authentication methods that are appropriate for this standard will emerge. This paper proposes a robust watermarking algorithm for H.264. We employ a human visual model adapted for a 4 x 4 discrete cosine transform block to increase the payload and robustness while limiting visual distortion. A key-dependent algorithm is used to select a subset of the coefficients that have visual watermarking capacity. Furthermore, the watermark is spread over frequencies and within blocks to avoid error pooling. This increases the payload and robustness without noticeably changing the perceptual quality. We embed the watermark in the coded residuals to avoid decompressing the video; however, we detect the watermark from the decoded, video sequence in order to make the algorithm robust to intraprediction mode changes. We build a theoretical framework for watermark detection based on a likelihood ratio test. This framework is used to obtain optimal video watermark detection with controllable detection performance. Our simulation results show that we achieve the desired detection performance in Monte Carlo trials. We demonstrate the robustness of our proposed algorithm to several different attacks.