Improved weighted prediction parameter estimation for advanced video coding systems

Weighted prediction (WP) is an efficient tool for encoding of video with brightness variations, if WP parameters can be estimated accurately. In this paper, an improved estimation method for WP parameters of advanced video coding system (AVS) is proposed. To find a best matching block in reference for current block to be encoded, a motion search scheme is presented. Each block in a searching window in the reference is scrutinized and the WP parameters for the block pair are estimated by least squared. Then the candidate WP parameters of the block to be encoded is select by the WP parameters with minimum sum of absolute difference (SAD) in the search window. Finally, the estimate of WP for current frame is selected by voting of all the candidate WP parameters of all blocks in the frame. The proposed scheme is implemented on the reference model of AVS, and shows that the proposed method can estimate WP parameters more accurate and save more bit rate compared the the realization in reference model (RM) of AVS.