Offset Compensation Method for Skip Mode in Hybrid Video Coding

The skip mode has been adopted to reduce the bitrate in hybrid video coding such as H.264/MPEG-4 Advanced Video Coding (AVC). To improve the coding performance by reducing the dc distortion in the skip mode, we propose a skip with offset method, which uses offset compensation with the estimated offset only in the skip mode. In the proposed method, no flag bit is used for offset because incorrectly estimated offsets are mostly filtered out through the rate distortion mode decision. Only a semantic change is needed at the skip mode in the proposed method. The existing skip mode can therefore be easily replaced with the proposed method. The proposed method shows better coding performance than previous methods, including the weighted prediction method, in H.264/AVC. Furthermore, the proposed method shows a significant coding gain of -7.60% and -5.81% in its averaged bitrate differences compared, respectively, with baseline and high profiles of H.264/AVC at 720p high definition sequences.