Fusion of multi-spectral bands and DSM from WorldView-2 stereo imagery for building extraction

This paper describes a building extraction approach by fusion panchromatic image, multispectral image and Digital Surface Model (DSM) generated from WorldView-2 stereo imagery. First, the DSM is used to indicate a rough building location, and then Hough-transform is followed to generate 2D segments from panchromatic images. Hough lines in the two main directions of each building are kept. The probability of each segment belonging to a building is calculated from random forest estimations. An automatic training data selection strategy is designed for this supervised classification. Finally, the 2D segments and classification results are combined to get the final building boundaries. This method has been tested in the city center of Munich, Germany.