An Anti-Recompression Video Watermarking Algorithm in Bitstream Domain

Following the popularity of digital video application, video copying and dissemination have become very easy; however, this makes video hacking and piracy a potential threat in video communication. Video watermarking technology can solve the problem of copyright protection, and thus, it has been extensively researched. The robustness of the video watermarking algorithm in the bitstream domain is poor, especially the anti-recompression ability, since the watermarked video may be compressed again before transmitting. Considering this, this paper proposes a video watermarking algorithm in the bitstream domain based on moving object detection. To increase the robustness of the watermarking scheme, the moving macroblocks that belong to the moving object in each P frame can be identified via the moving object detection algorithm. Then, watermark embedding in the moving macroblocks is performed using codeword substitution to ensure the consistency of the bitstream. Moving object detection and watermark embedding are independent and are both carried out in the bitstream domain by partially decoding the bitstream; this avoids the complete decoding and reconstruction of the video, making the method to be highly efficient. The simulation results confirm that the proposed method is robust against recompression and has little impact on the video visual quality and no influence on the bit rate.