Automatic building extraction from oblique aerial images

Abstract

In this paper we propose an automatic urban building extraction method for oblique aerial images. Five steps are included in this method: point cloud generation, grid partition, feature extraction, building detection and building reconstruction. Taking advantages of recent progress in large-scale Structure from Motion (SfM) and Multiple View Stereo (MVS), dense point cloud is generated first. Then, we project the point cloud into a regularly spaced grid in XY plan, and convert the building extraction problem into an image segmentation problem. By combining the strength of the geometric attribute and spectral attribute, three complementary features are extracted and a MRF based graph model along with an energy function is created. Points belonging to buildings are recognized by minimizing this function, and prismatic 3D building models are reconstructed accordingly.