Building detection in Ikonos images from disparity of edges

The availability of very high resolution satellite images has enabled the automatic remote detection of man-made structures for applications such as damage assessment or change detection. In particular, stereo pairs of Ikonos or Quickbird images allow for the estimation of the third dimension so distinctive for buildings. Since the areas to be studied may be quite large we propose a simple, fast and possibly accurate approach for building detection. This approach consists in a three step procedure which first detects linear segments independently in the left and right images, then matches segments according to their mutual coverage, orientation and plausible disparity, and finally identifies building areas thanks to the presence of elevated segments. The solution is fast as only pixels of high gradient connected into linear segments are considered. Modelling object parts with linear segments is valid for the vast majority of man-made objects and allows for rapid segment pairing for disparity computation with possible sub-pixel accuracy. This approach has been applied to an Ikonos pair for the detection of large buildings in the context of risk assessment within GMOSS, a European Network of Excellence.