EXTRACTION OF FLOW DESCRIPTORS FOR RIVERS IN SATELLITE IMAGES

摘要

This paper proposes an approach that extracts water bodies, e.g. rivers and ca-nals, in satellite images, and describes their occurrence in vector form. The advantage of this special way of representation is the data independency, I.e. aspects like different spatial resolu-tions and rotational invariance can be overcome. The main problem is to be insensitive to noise whereby noise in this context incorporates features that aggravate the extraction of the actual feature under consideration. Most prominent are bridges and jetties, which interfere with the water body. For example they prohibit the estimation of the flow direction in rivers and the exact definition of riverbanks. The extracted features can be used as input for geographical information systems or for the characterisation of the corresponding image data in content-based retrieval systems.