An Adaptive CU Split Method for VVC Intra Encoding

Abstract

In order to reduce the coding complexity and ensure that versatile video coding (H.266/VVC) effectively maintains the equilibrium between coding efficiency and quality in the coding process, an adaptive coding unit (CU) split method for intra encoding is proposed in this paper. First, the coding speed of CU division is accelerated by an iterative algorithm based on the interval relation of texture complexity energy. Then, according to the relationship between texture features and CU segmentation patterns, the Scharr edge gradient operator algorithm is used to describe the texture information and the threshold. Texture uniformity, directionality, and subblock discrepancy are analyzed and discussed, respectively. Finally, the optimal segmentation pattern is determined based on the texture information to adaptively skip unnecessary segmentation modes. The results show that the algorithm can save 45.2% of the overall coding time on average with an average cost of 0.51% Bjontegaard delta bit rate (BDBR). The algorithm ensures the coding quality while reducing the computational complexity.