Probability propagation for faster and efficient point cloud segmentation using a neural network

Abstract

Neural networks (NN) have shown promising performance in point cloud segmentation (PCS). However, the measured points are too numerous to be used as model input at once. It results in a long inference time and high computational cost due to iterative sampling and inference. This study proposes Probability Propagation (PP) as a stochastic upsampling method. PP propagates the predicted probability of a sampled part of a point cloud into the other unpredicted points by considering proximity. By replacing the iterative inference of NN with PP, large point clouds can be dealt with quickly and efficiently. We investigated the effectiveness of PP using the ShapeNet benchmark on various settings: sampling methods (random, farthest point, and Poisson disk sampling) with sampling ratios (5%, 10%, 20%, 39%, and 78%) for NN and the stochastic mapping conditions (uniform, linear, cosine, Gaussian, and exponential distributions) for PP. Using NN with PP achieved higher performance and faster inference speed than when using NN alone. For the farthest point sampling method of 5% sampling ratio, NN+PP improved the instance mIoU by 2.457%p with 102 times faster speed compared to that when using NN alone. The result indicates that PP can significantly contribute to the improvement of performance and efficiency in PCS when used in edge AI systems.