Retrieval of building shapes from shadows in high resolution SAR interferometric images

Discontinuous objects, such as buildings, produce shadows in SAR images. Shadows are striking features which greatly help in the image understanding. Because of the high density of buildings in urban areas, shadows cover a large part of the image and provide a major hint to build a map of the city. A straightforward use of the shadows is to determine the building height from the shadow dimensions. We propose another approach here which makes use of the shadow to help in detecting the building itself when a high resolution interferogram is available. Starting from an amplitude image with very high definition and the corresponding interferogram, we model the building detection problem as an energy minimization where the interaction between a building and its shadow is taken into account. The method allows to obtain excellent detections especially for high or isolated building, despite the important noise level.