Potential problems with using reconstruction in morphological profiles for classification of remote sensing images from urban areas

Meter to sub-meter resolution satellite images have generated new interests in extracting man-made structures in the urban area. However, classification accuracies for such purposes are far from satisfactory. Spectral characteristics of urban land cover classes are so similar that they cannot be separated using only spectral information. As a result, there is an increased interest in incorporating geometrical information. One possible approach is the use of a morphological profile [1]. This profile contains information about the size of objects. In literature this is usually combined with morphological reconstruction to better preserve the shapes of objects. In this paper, we show that when used for remote sensing images this leads to ´over- reconstruction´, with a decreased classification performance as a result. We propose a new method called ´partial reconstruction´ to overcome this problem and still be able to preserve the shape of objects. Classification experiments show a better performance with partial reconstruction.