Robust video watermarking based on DC coefficients of selected blocks
This paper presents a novel blind video watermarking method based on the stability of the direct current (DC) coefficient values in blocks transformed by discrete cosine transform (DCT). The frame is randomly selected to embed watermark, and then its luminance is blocked by 8-by-8 and transformed by DCT. The watermark is embedded in the high frequency coefficient of some consecutive DC coefficients which have been transformed by DCT. During the detection process, the correlation between the watermark and the high frequency coefficients of the DC coefficients transformed by DCT is computed to judge whether the frame has been embedded watermark. The experimental results indicate that the correlation curve peaks emerge at the watermarked I frames and P frames which suffered MPEG-4 and H.264 compression. The proposed watermarking method has strong robustness against some attacks such as frame deleting, frame inserting, frame shifting, frame statistical average and collusion attack.