360-degree videos have become increasingly popular with the application of virtual reality (VR) technology. To encode such kind of videos with ultra-high resolution, an efficient and real-time video encoder becomes a key requirement. The Versatile Video Coding (VVC) standard has good coding performance. However, it has pretty high computational complexity which increasing the application cost of 360-degree videos. Among them, the decision of the quadtree with nested multi-type tree (QTMT) partitioning structure is one of the time-consuming procedures. In this paper, based on the characteristics of 360-degree video with Equirectangular projection (ERP) format, the empirical variogram combined with Mahalanobis distance is introduced to measure the difference between the horizontal and vertical directions of the CU, and a fast partition algorithm is proposed. The experimental results show that the algorithm saves 32.13% of the coding time with only an increase of 0.66% in BDBR.

随着虚拟现实（VR）技术的应用，360度视频越来越受欢迎。要对此类具有超高分辨率的视频进行编码，高效实时的视频编码器成为关键要求。通用视频编码(VVC)标准具有良好的编码性能。然而，它具有相当高的计算复杂度，增加了360度视频的应用成本。其中，具有嵌套多类型树（QTMT）分区结构的四叉树的决策是耗时的过程之一。本文基于等距柱状投影（ERP）格式的360度视频的特点，引入经验变差函数结合马氏距离来衡量CU水平和垂直方向的差异，并提出了一种快速分区算法。实验结果表明，该算法节省了32.13%的编码时间，而BDBR仅增加了0.66%。