Application of a watermark schema based on local gain control algorithm for video bitstream
Guoqiang Wei · Journal of Central China Normal University · 2004
In this paper, we advanced a new watermarking method based on local gain control algorithm for MPEG-2 bit-streams according to Hartung's approach of video watermarking. We embeded the DCT of a spatial spread watermark directly into the DCT coefficients of host video. In order to resolve the problem of huge operation quantity of current local watermarking approach, a gain control algorithm, weighted on block-by-block basis, was designed according to decoded motion vector from the bit-streams, activity estimation and weight assignment. Furthermore, this algorithm, adapted to the local image characteristics, can control the robustness of embedded watermark and improve visual quality of the watermarked video. Finally, in the experiment, we proved the efficiency and adaptation of the method.