Edge Direction-based Fast Coding Unit Partition For HEVC Screen Content Coding

High efficiency Video Coding is a new video coding standard that presents numerous advantages over previous video coding standards. However with the significantly encoding performance, the complexity of coding increased rapidly. Therefore, this paper focuses on several technologies of the screen content intra coding. The research includes coding efficiency and complexity. The main research achievement includes:(1) This paper proposed a fast and efficient algorithm based on edge direction to partition coding units (CUs) based on their relationship with edge direction to reduce the coding complexity. The key point of this algorithm is to determine the relationship between the edge direction and CUs. Experimental results show that the proposed edge direction-based CU partition algorithm provides a decrease in the screen content coding processing time up to 39%, with a little increase in bit-rate(1.1% on average) and a negligible reduction in the PSNR value.(2) This paper proposed an improved algorithm for HEVC lossless screen content coding to promote the quality of video. HEVC for lossless screen content coding just do entropy coding for residual directly, there are a lot of redundancy in the residual component, hence our paper proposed an lossless transform to remove redundancies of residuals, and there are no additional information to transfer to the decoder, so this algorithm can remove redundancies of residuals effectively and reduces the bitrate of coding with no increase in coding complexity. The proposed algorithm reduces 0.65% bitrate with no increase in coding complexity.