Multi-directional Mode Reduction Algorithm for Intra Prediction in Video Coding

Abstract

ABSTRACTThe recent digital video-coding standard achieves very high data compression by using several new coding features, such as intra/inter predictions, variable block size motion compensation, multiple motion vectors, quarter pixel for motion compensation and so on. Among all the features, one of the key features is intra prediction, which is based on the rate-distortion optimization (RDO) procedure that requires a true encoding of the intra block by trying all intra prediction modes. In this paper, we propose a multi-directional mode reduction (MDMR) algorithm using the prediction error to reduce the number of coding modes required for the RDO procedure. The proposed MDMR algorithm effectively estimates the prediction error of the block to narrow down the predictive modes to reduce RDO computation. Experimental results show that the proposed algorithm achieves a time reduction of more than 64% with negligible PSNR loss and bitrate increment.