A Fast Texture-Based 8K Intra-Partitioning Algorithm for Versatile Video Coding (VVC)

Versatile Video Coding (VVC), standardized in 2022 as ITU-T Recommendation H.266, ISO/IEC 23090-3 and MPEG-I Part3, is the latest block-based hybrid video coding standard. It defines many tools to increase compression efficiency while maintaining the same quality level. The tradeoff is the computational complexity. The intra-coding loop of VVC is computationally very complex due to its nature of iteratively trying all possible Quad-Tree Multitype-Tree (QTMT) partitioning alternatives starting from 128x128 Coding Tree Unit (CTU) size and going down to 4x4 min Coding Unit (CU) size. For camera-taken real-world broadcast video, compared to smaller resolutions, the objects in 8K are larger with respect to the fixed CTU size of VVC. As a result, for such 8K video, less detailed coding in the VVC QTMT may be enough for practical purposes. In this paper, we define a new fast intra-partitioning algorithm for 8K video and compare its performance with Common Test Conditions (CTC) All-Intra (AI) configuration based on the compression efficiency (bits), quality (Y-PSNR, SSIM and MS-SSIM metrics), and computational complexity (runtime). We observe 81.61% runtime gain with only 2.99% increase in bitrate, 0.1339 dB decrease in Y-PSNR, 0.0022 decrease in SSIM and 0.0007 decrease in MS-SSIM on average. This is a remarkable gain in complexity with a limited effect on efficiency and quality.