Enhancement of blind watermark retrieval in drift-compensated MPEG video

The concept of drift compensation has been proposed to alleviate the propagation of visual distortions between successive video frames, which exists as a result of embedding watermarks in the compressed domain without re-performing motion prediction. By viewing the drift compensation data as watermark signals with inverse polarity, we propose to enhance the blind watermark retrieval of drift-compensated watermarked MPEG video by appropriately de-spreading the drift compensation data and adding the resultant correlation output to the usual watermark correlation sum. In our experiments, spread spectrum watermarks with additive and multiplicative embedding for MPEG video are used. The results show that the proposed technique is indeed capable of improving the reliability of the estimated watermark for different videos compressed at different bit rates. The proposed idea is expected to be applicable to any image and video compression formats with predictive coding, including MPEG-1, MPEG-2, MPEG-4, H.261, or H.263.