Research On Fast Algorithm For 3D-HEVC

With rapid development of the internet industry,people's needs for Hi-Definition picture and video are growing.How to transmit huge amount of data through limited bandwidth are key issues in multimedia technology.In order to encode 3D video efficiently,the joint collaborative team on video coding proposed a coding standard for 3D video based on traditional 2D video coding standard HEVC,names 3D High Efficiency Video Coding(HEVC).3D-HEVC adopted coding structure and most coding methods in HEVC standard,it also added several new methods to improve coding efficiency.On one hand these new methods reduce the quality loss,on the other hand,it increases computational burden.In this paper,we introduce the encoding structure and the coding process of 3DHEVC standard.We analyse the redundancy in spatial,temporal and inter-view domain,texture complexity are also considered.At last,we proposed two fast algorithms for depth map intra prediction and inter prediction process.For intra coding process,we propose a fast algorithm based on Otsu's method.Firstly,analyze the relationship between texture complexity of depth CUs and quadtree splitting results.Applying Otsu's method to each depth level to get the maximum inter class variance,and detect smooth CUs.Stop further splitting process of smooth CUs and simplify the intra prediction process.We further optimize our algorithm by using rate distortion cost based on the correlation between different layers of CUs.Experimental results show that our proposed algorithm can save about 40.1% of time consumption on average with negligible loss of coding performance.For inter coding process,we proposed a fast algorithm based on background segmentation method.Most of CUs use Merge mode and encode with large sizes,only CUs with complex motion features split into depth level 2 and 3,these CUs are at front regions.Depth value represent the absolute distance between objects and cameras.We classify each CU into background region,non-background region through depth value.Non-background region can be further classified into edge region and smooth region by checking whether it contains edges.The total value of transformed block in texture map are used in our algorithm to simplify quad-tree splitting process for each type of CUs.For fast mode decision process,obtain the motion information of already coded parent CUs to reduce the number of modes need to be checked in inter coding process.Our algorithm is implemented on HTM16.0,it achieves an average time reduction of 35.62%,with bitrate loss of 0.27% for synthesized views.In the end,we summarize the research on 3D-HEVC and propose the research direction in the future.