Upsampling Algorithm for V-PCC-Coded 3D Point Clouds

Abstract

Point cloud (PC) compression is crucial to immersive visual applications such as autonomous vehicles to classify objects on the roads. The Motion Picture Experts Group (MPEG) standardization group has achieved a notable compression efficiency, called video-based PC compression (V-PCC), which consists of an encoder-decoder. The V-PCC encoder takes original 3D PC data and projects them onto multiple 2D planes to generate several 2D feature images. These images are then compressed using the well-established High-Efficiency Video Coding (HEVC) method. The V-PCC decoder uses compressed information and decoding techniques to reconstruct the 3D PC. However, the PCs produced by V-PCC are often sparse, non-uniform, and contain artifacts. In many practical applications, it is necessary to recover complete PCs from partial ones in real time. This article presents a method for enhancing decoded PCs as a post-processing step in the V-PCC with reduced computational time. Our approach involves a 2D upsampling for the V-PCC occupancy image, which increases the density of the PC, and a 2D high-resolution auxiliary information modification algorithm for the 2D-3D conversion of high-resolution 3D PCs, which improves the uniformity and reduces the noise in the PC. The 3D high-resolution PC has been further enhanced using the developed 3D outlier removal and point regeneration algorithm. Our proposed work can significantly simplify the state-of-the-art super resolution methods for PCs and reduce the time complexity of 61–75% while maintaining a high level of quality in PCs.