Adaptive weighted prediction in video coding

An adaptive weighted prediction algorithm is proposed to improve the coding efficiency for video scenes that contain global brightness variations caused by fade in/out or local brightness variations caused by camera flashes. A two brightness-variation parameters model is used, which represent multiplier and offset components of the brightness variation. Brightness variations at frame and macroblock level, respectively, are detected; if there are brightness variations, we use weighted prediction to compensate these brightness variations; otherwise the conventional prediction method is used. Simulation results show that the proposed algorithm can improve the coding efficiency sufficiently when the coded scenes contain brightness variations. This technology is adopted by AVS.