Transition-Aware Point Cloud Completion by a Progressive Refinement Generative Adversarial Network

Three-dimensional reconstruction can help robots and vehicles understand their surroundings for subsequent navigation and manipulation tasks. However, in the case of target occlusion, it is difficult for visual sensors to acquire complete information about objects. In this work, we propose a progressive refinement generative adversarial network (PR-GAN) to recover object shapes guided by transition-awareness. This method directly predicts the missing point cloud from the partial point cloud. Our PR-GAN contains a progressive generation module (PGM) and a discriminator. A self-attention-based encoder is proposed in PGM to capture contextual information between local and global features. To guide encoders in generating accurate point clouds, we further propose a progressive fusion module (PFM) that extracts transition information between point clouds of different scales. Moreover, a part-whole correlation module (PWCM) is designed to extract the transition-awareness between the partial and the whole point clouds to further preserve the details. With the above modules, we enhance the spatial logic perception capability of the network so that PR-GAN can fully extract point cloud features and predict the high-fidelity point cloud. Experimental results show that PR-GAN performs better compared to other methods, evaluated on three public datasets.