Efficient differential prediction error based intra mode decision algorithm for video coding

H.264, MPEG-4 Part 10, is the recent digital video coding standard that achieves very high data compression by using several new coding 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. The computational burden of intra prediction with the RDO procedure is extremely high for real time applications. In this paper, we propose an efficient directional difference prediction algorithm using the prediction error to reduce the number of coding modes required for the RDO procedure. The proposed DDP 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.