iPUNet:Iterative Cross Field Guided Point Cloud Upsampling

TL;DR

iPUNet is a learning-based method for upsampling point clouds that generates dense, uniform points with sharp feature preservation, using cross fields and iterative refinement to improve distribution and detail.

Contribution

The paper introduces cross fields aligned to geometric features and an iterative strategy for improved point cloud upsampling, enabling arbitrary ratio generation and better feature capture.

Findings

Outperforms existing upsampling methods on diverse datasets.

Robust to noisy and non-uniform input point clouds.

Effectively captures sharp geometric features.

Abstract

Point clouds acquired by 3D scanning devices are often sparse, noisy, and non-uniform, causing a loss of geometric features. To facilitate the usability of point clouds in downstream applications, given such input, we present a learning-based point upsampling method, i.e., iPUNet, which generates dense and uniform points at arbitrary ratios and better captures sharp features. To generate feature-aware points, we introduce cross fields that are aligned to sharp geometric features by self-supervision to guide point generation. Given cross field defined frames, we enable arbitrary ratio upsampling by learning at each input point a local parameterized surface. The learned surface consumes the neighboring points and 2D tangent plane coordinates as input, and maps onto a continuous surface in 3D where arbitrary ratios of output points can be sampled. To solve the non-uniformity of input points, on top of the cross field guided upsampling, we further introduce an iterative strategy that refines the point distribution by moving sparse points onto the desired continuous 3D surface in each iteration. Within only a few iterations, the sparse points are evenly distributed and their corresponding dense samples are more uniform and better capture geometric features. Through extensive evaluations on diverse scans of objects and scenes, we demonstrate that iPUNet is robust to handle noisy and non-uniformly distributed inputs, and outperforms state-of-the-art point cloud upsampling methods.