Fast CU Partition Algorithms Based On The Statistics And Estimation In Screen Content Coding

Compared with H.264,H.265 adds efficient coding tools for screen content coding,such as Palette,ACT,Intra BC,AMVR,and so on.Although these tools can improve the compression performance in Screen Content Coding,they bring the problem of high coding complexity,and it can not be applied to the real-time video scene.In order to improve the redundancy of traditional CU Partition process in Screen Content Coding,a series of researches are carried on fast CU Partition decision scheme under H.265,and two algorithms are proposed.The main result referred as follows:(1)Propose a fast CU partition scheme based on coding cost between child-blocks and mother-block.According to the laws of CU coding cost,design a fast algorithm to accelerate the speed of CU Partition.And the threshold in the scheme is based on the coding cost percentage for child-blocks occupying to the mother-block.The experiment results show that the fast algorithm proposed in this paper can save 24.78%of the encoding time at the cost of reducing the coding performance by only about 0.43%.The conclusion remarkably reduces the coding complexity for screen content coding.(2)Propose an early termination scheme based on the estimation of adjacent CUs coding cost.The part is based on the information of the quad-tree coded unit to predict the information of the un-coded part.And an effective early termination scheme is proposed under different numbers of coded child-blocks.Compared with the later reference model,the scheme can save 37.02%of the encoding time at the cost of reducing the coding performance by about 1.47%.