Automated plane detection and extraction from airborne laser scanning data of dense urban areas

Abstract: Popular science Digital 3D city models are nowadays used in many GIS applications. Airborne laser scanning is rapidly developing technology that can efficiently plot the 3D shapes of everything on the earth surface. Today, organizations that are responsible for, e.g. urban planning, railway and power line planning, apply such kind of the laser scanning data. For example they use this technique to evaluate if the designed building matches the surrounding landscape or if the trees are too close to the power line. However, those applications normally require that the raw ‘clouds’ of 3D laser scanning point are classified and modeled accordingly. Manual digitization of 3D buildings is rather tedious. In this study, a computer based method for automated extraction and estimation of building roof facets from urban laser scanning data are devised based on available methods and ideas. The method consists of three steps. In the first step, the ground and non-ground points are automatically classified using a method considering neighboring influence, which can effectively remove the points of cars and low shrubs from building points. In the second step, the roof points are extracted from the non-ground points by removing the points of vegetation and other unwanted points using a plane detection technique. And finally, the 3D polygons (or actual lines) of roof facets can be automatically generated from the roof points. In this method, urban laser scanning data is the only necessary input. It does not need any other auxiliary geographical data. This method can be used as a preliminary step of automatic creating of 3D city models. In this sense, the successive step is the assembly of those facet polygons into the complete buildings. In addition, the method can also provide a human-computer interaction method of manually drawing the digital 3D buildings. For example, users can obtain the roof facet polygon by clicking one of the points on the roof facet.