Point Cloud Attribute Inpainting in Graph Spectral Domain

Abstract

With the prevalence of depth sensors and 3D scanning devices, point clouds have attracted increasing attention as a format for 3D object representation, with applications in various fields such as tele-presence, navigation for autonomous driving and heritage reconstruction. However, point clouds usually exhibit holes of missing data, mainly due to the limitation of acquisition techniques and complicated structure. Hence, we propose an efficient inpainting method for the attribute (e.g., color) of point clouds, exploiting non-local self-similarity in graph spectral domain. Specifically, we represent irregular point clouds naturally on graphs, and split a point cloud into fixed-sized cubes as the processing unit. We then globally search for the most similar cubes to the target cube with holes inside, and compute the graph Fourier transform (GFT) basis from the similar cubes, which will be leveraged for the GFT representation of the target patch. We then formulate attribute inpainting as a sparse coding problem, imposing sparsity on the GFT representation of the attribute for hole filling. Experimental results demonstrate the superiority of our method.