Technical report on automated 3D reconstruction of buildings out of point clouds obtained from panoramic images, funded by Cyclomedia

Team: Ir. J. Chen, Ir. R. Šilerytė, Ir. K. Zhou, P. Nourian, Prof.dr. Dipl. Ing. S. Zlatanova

Key words: Hough Transform, Computational Geometry, Shape Simplification, Voxel-Based Region Growing, Panoramic Photographs, Point Cloud, 3D Reconstruction

CycloMedia is a Dutch company specialized in the large-scale and systematic visualization of environments based on 360°panoramic photographs. The images are captured from public roads at street level, using a car to carry a panoramiccamera system. High resolution spherical panoramas are geometrically correct and thus allow auser to perform photogrammetric 3D measurements anduse imagery for 3D modelling and texture mapping. Drawing 3D point cloud (or rather pixel cloud) is a relatively new approach to use panoramic images. Currently there is no completely steady and consummate method to reconstruct digital building models from point clouds, thus this projectaims topropose an innovativeand practicalframeworkofbuildingreconstructionin particular. The developed method uses segmentation by region growing based on normals and curvature, constructing topology between segments by Voronoi partitioning,shape simplification by segmented least squares and principal component analysis methods. The method proves to have goodresults while tested on Lidar point clouds, however with some modifications is also applicable to pixel clouds obtained from panoramic imagery.