Low Complexity Fast Grid-Based Refining Segmentation in the V-PCC encoder

The video-based point cloud compression (V-PCC, ISO/IEC 23090–5) is the state-of-the-art international standard for compressing dynamic dense point cloud. Despite its good rate-distortion (RD) performance, excessive encoding complexity makes real-time V-PCC applications difficult to implement. One of the most computationally intensive modules of the V-PCC encoder is the fast grid-based refine segmentation (FGRS). This paper proposes fast and efficient radius search method for the FGRS. The proposed radius search method works twice as fast as the conventional k-d tree radius search in the FGRS. In addition, overall coding efficiency is slightly improved by applying a coarse-to-fine approach to sorting search results according to geometric priority. Simulation results show that the proposed method reduces the FGRS time by an average of 47% with a slight coding gain.