STORM: Structure-Based Overlap Matching for Partial Point Cloud Registration.

Partial point cloud registration aims to transform partial scans into a common coordinate system. It is an important preprocessing step to generate complete 3D shapes. Although previous registration methods have made great progress in recent decades, traditional registration methods, such as Iterative Closest Point (ICP) and its variants, all these methods highly depend on the sufficient overlaps between two point clouds, because they cannot distinguish outlier correspondences. Note that the overlap between point clouds could always be small, which limits the application of these methods. To tackle this problem, we present a StrucTure-based OveRlap Matching (STORM) method for partial point cloud registration. In our method, an overlap prediction module with differentiable sampling is designed to detect points in overlap utilizing structure information, and facilitates exact partial correspondence generation, which is based on discriminative pointwise feature similarity. The pointwise features which contain effective structural information are extracted by graph-based methods. Experimental results and comparison with state-of-the-art methods demonstrate that STORM can achieve better performance. Moreover, most registration methods perform worse when the overlap ratio decreases, while STORM can still achieve satisfactory performance when the overlap ratio is small.