3D Buildings extraction based on aerial stereoscopic images

Extraction of "man-made object'' from stereoscopic aerial images is a problem which is not entirely solved. In this paper we propose an interactive approach to extract such objects. The disparity image is used to roughly delineate buildings. Then, the buildings are extracted according to their shape. An operator clicks inside the roof of the building of interest and chooses between two different algorithms, the rest of the process is entirely automatic. A very robust algorithm based on the Hough transform is used to extract rectangular buildings, whereas, a large spectrum algorithm based on snakes is used to extract more complex shapes. Our method gives good results in extracting buildings on IGN aerial images already rectified in epipolar geometry.