AN AUTOMATED PROCESS TO DETECT EDGES IN UNORGANIZED POINT CLOUDS

Abstract. This paper presents an automated and effective method for detecting planes and their intersections as edges in unorganized point clouds. The edges are subsequently extracted as vectors to a CAD environment. The software was developed within the Microsoft Visual Studio and the open source Point Cloud Library (PCL, http://pointclouds.org/) was used. The Point Cloud Library is a standalone, large scale, open project for 2D/3D image and point cloud processing. The code was written in C++. For the detection of the planes in the point cloud the RANSAC algorithm was employed. Subsequently, and according to the standard theory of Analytic Geometry the edges were determined as the intersections of these planes with each other. A straight line in 3D space is defined by one of its points, which was determined with the Lagrangian Multipliers method and a parallel vector, which was determined with the help of the cross product of two vectors on space. Finally, the algorithm and the results of the implementation of the process with real data were evaluated by performing various checks, mainly aiming to determine the accuracy of the edge detection.