We propose a registration algorithm based on neighborhood similarity for 3D point clouds collected by optical measurement and without prior information. The algorithm first applies the improved minimum spanning tree (Prim algorithm) to classify the point cloud in order to obtain the topology information of the data. Specifically, vectors among root nodes and child nodes are processed, and the points on nodes are classified into different levels according to their scanning angle to simplify data and preserve the most representative points. Then, through the perspective conversion between 2D and 3D and according to the corresponding point set obtained by previous classification, the fast normalized cross-correlation (a 2D matching criterion) is applied to determine the relationship between initial characteristic points. Finally, distance constraints remove the errors between point pairs and allow calculating the registration parameters. Experimental results show that the algorithm has high registration accuracy and is suitable for point cloud data obtained by laser and structured light acquisition.
INDEX TERMSMinimum spanning tree, normalized cross-correlation, optical measurement, point cloud classification, point cloud registration. YUAN HUANG received the B.Sc. degree from Nanchang University, in 2010, and the master's degree from the Galway-Mayo Institute of Technology, in 2012. He is currently pursuing the Ph.D. degree with the School of Automation, Southeast University. His main research interests include 3D measurement and image processing.FEIPENG DA received the Ph.D. degree, in 1998. He is currently a Professor and a Ph.D. Supervisor with the School of Automation, Southeast University. His research interests include surface reconstruction, intelligent control, and computer visualization.