| As the newest generation of video coding standard, H.264 absorbs the most advanced theory productions and coding algorithms nowadays in video coding domain, which can significantly improve the video compression efficiency. H.264 adopts RDO (Rate Distortion Optimization) which has to select the best coding mode and reference frames for each macroblock. By this way the computational complexity of H.264 is much higher than other video coding standards. Compared to the MPEG-4 simple profile, its coding complexity has increased 10 times at least. In order to meet the requirements of real-time video communication, the compression method has to be optimized to improve the coding efficiency.As a primary method to remove space redundancy, intra prediction makes full use of space correlation in an image to eliminate the redundancy in each frame. Especially in the smooth changing areas, intra prediction achieves excellent performance and improves the coding efficiency greatly. At the same time, highly efficient intra prediction algorithms have greatly increased the computational complexity of the encoder. To reduce complexity associated with intra prediction mode selection, an improved fast mode selection method for intra prediction is proposed. Experiments on different typical video sequences show that, this method can get stable performance gain in encoding time with little lost of PSNR and bit rate. |
