Extracting objects from digital terrain models

The paper introduces the extraction of objects that are higher than their surroundings, like houses, trees, or bridges, by combining the results of a segmentation of a DTM and a texture analysis of the gray image. We propose a new algorithm (called dual rank) to extract the ground in the DTM, which can be seen as an extension of the gray opening. The extraction of trees in the gray image is done by a texture transformation, which is a fast and stable method, for the distinction between houses/roads and trees. The combination of both results is done region-oriented, i.e., every high object is analyzed if it is a house, a tree, or a combination of both and thus separated and classified.