Digital video watermarking in P-frames with controlled video bit-rate increase

Most video watermarking algorithms embed the watermark in I-frames, but refrain from embedding in P- and B-frames, which are highly compressed by motion compensation. However, P-frames appear more frequently in the compressed video and their watermarking capacity should be exploited, despite the fact that embedding the watemark in P-frames can increase the video bit rate significantly. This paper gives a detailed overview of a common approach for embedding the watermark in I-frames. This common approach is adopted to use P-frames for video watermarking. We show that by limiting the watermark to nonzero-quantized ac residuals in P-frames, the video bit-rate increase can be held to reasonable values. Since the nonzero-quantized ac residuals in P-frames correspond to nonflat areas that are in motion, temporal and texture masking are exploited at the same time. We also propose embedding the watermark in nonzero-quantized ac residuals with spatial masking capacity in I-frames. Since the locations of the nonzero-quantized ac residuals is lost after decoding, we develop a watermark detection algorithm that does not depend on this knowledge. Our video watermark detection algorithm has controllable performance. We demonstrate the robustness of our proposed algorithm to several different attacks.