Map based building reconstruction from laser data and images

Large scale maps are available for many countries. The building ground plans of those maps can be helpful for the reconstruction of 3D building models from laser data and aerial images. This paper presents two studies on 3D building reconstruction. The first study combines data of a laser scanner with a high point density with the ground plans. The reconstruction approach is data driven. The second study is more model driven and utilises the ground plans for the building reconstruction from aerial photographs with known orientations. Results of both approaches are described and the pros and cons of them are analysed. This paper is about the usage of maps for building reconstruction. It presents two different studies. In one the building ground plans support the reconstruction from laser data (Section 3). In the other the maps are used to improve the reconstruction from aerial images (Section 4). The strategies for the incorporation of the ground plans into the reconstruction process differ. In Section 5 the strengths and weaknesses of the different strategies are analysed. Section 2 first briefly describes different approaches for segmenting a building ground plan. 2 PARTITIONING OF GROUND PLANS Many buildings can be modelled by taking the union of multiple building primitives with a simple roof shape on a rectangular area. The ground plans of such buildings often give an indication on how to place these primitive models (Haala et al. 1998). By extending the ground plan lines that intersect in concave corners a building ground plan can be segmented into small rectangles as shown in Figure 1a. The ground surface of a building primitive often corresponds to a group of such segments. Figure 2 shows several building hypotheses generated on the basis of the segmented ground plan and the usage of building primitives with a flat, gable and hip roof.