Depth-Wise Split Unit Coding Order for Video Compression

In this paper, we propose a depth-wise flexible block processing method called split unit coding order (SUCO) for video coding. Conventionally, block-based image and video compression frameworks always apply raster scans to process blocks in order from left to right. Owing to the fixed coding order, the available information for prediction in the coding blocks is limited to adjacent blocks on the left and top. To address the limitations of block-based images and video compression frameworks, the proposed SUCO provides more flexibility in handling coding block sequences than predicted on the left and top, and thus coding blocks can take advantage of adjacent right information, such as reconstructed pixels and motion information. The flexibility is achieved by depth-wise signaling of preferred coding order for the given partitions. The experiment results demonstrate that the proposed SUCO can effectively improve the coding efficiency of both intra and inter prediction in the latest video coding standards.