Fast CU Partition for VVC Intra-Frame Coding via Texture Complexity

In versatile video coding (VVC), the quadtree with nested multi-type tree (QTMT) partition module significantly improves encoding performance compared to other coding tools. However, it also introduces notable computational complexity in intra-frame coding, occupying over 90% of the encoding time. This letter presents a fast coding unit (CU) partition method based on texture complexity to achieve a balance between compression efficiency and computational complexity for VVC intra-frame coding. In particular, the texture complexity of CUs is quantitatively measured by the ratio of horizontal to vertical gradient and that of sub-block variances. Firstly, directions with higher texture complexity are identified as unlikely coding modes and eliminated from the candidate set. Next, the sub-block variances of binary and ternary partitions are compared to determine a fine-grained CU partition pattern, avoiding unlikely partition modes. Experimental results show that our method is simple but efficient, and achieves higher computation efficiency compared to recent machine learning-based and handcrafted-based methods.