Video watermark embedding in the compressed domain
Shekhar Verma, Rohini Chandra, Hyoung-Joong Kim, Geetam Singh Tomar · 2006
Watermark can be embedded in raw video streams or in different stages of the compression process. Real time constraints entail embedding to be done in the compressed domain prior to or after entropy coding. In this paper, a robust watermarking technique to embed directly in the VLC domain has been proposed. A content dependent bipolar sequence watermark derived from DC co-efficients of macroblocks is used as the watermark. The watermark sequence is transparent and is embedded into macroblocks by modification of the level values in the run level pairs of the MBs. The content dependence renders the watermark robust and VLC domain operations allow embedding and retrieval in real time. Experimental results verify the effectiveness of the technique against compression, noise, frame dropping etc. at the cost of little loss in quality and with almost no appreciable change in the bit rate such that the technique is able to address the robustness against intentional and unintentional attacks.