Guided Cross-Component Prediction for RGB Video Coding

Statistical dependencies among different color components can be exploited to improve the compression efficiency of video coding. In the Range Extensions (RExt) of High Efficiency Video Coding (HEVC) standard, a cross-component prediction tool is adopted. In each transform unit, it explicitly signals a scaling parameter for residual prediction for the second and third color components respectively from the first color component. This paper presents a guided cross-component residual prediction method for the inter prediction coding. Instead of explicit signaling, the residual prediction parameter is derived by analyzing the statistical correlations among the corresponding color components in the motion compensation prediction signal. Compares with the cross-component prediction tool in the HEVC RExt, the proposed method can have 0.6% and 0.9% averaged bit rate savings in coding RGB video in random access and low delay B configurations, respectively. Compares with cross-component prediction tool off, the bit rate savings are about 14% in both configurations.