A New Gradient-Based Mode Selection of Intra Prediction for 4×4 block in H.264/AVC

In this paper, we propose a new gradient-based mode selection of intra prediction for 4times4 block in H.264/AVC video coding standard. In order to achieve rate distortion optimization, H.264/AVC encoder has to code the video by exhaustively trying all the mode combinations, including different intra prediction modes. As a result, the computational complexity of H.264/AVC encoder increases drastically. Based on local edge direction, the proposed method considerably reduces the overall complexity and encoding time by using a few candidate modes instead of all nine modes for intra mode selection of H.264/AVC. The proposed method, which was implemented into JM9.4 provided by Joint Video Team (JVT), can reduce about 58.4% in regard to computation complexity and 51.9% as to encoding time over full search method while maintaining similar PSNR and bite rate