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Bridge extraction based on on constrained Delaunay triangulation for panchromatic image

Nowadays, with the rapid increase of spatial resolution in remote sensing, accurate and efficient identification of man-made targets from large-scale high resolution panchromatic images plays a more and more important role in real applications. This paper presents an efficient bridge extraction method based on CDT. it consists of two steps: river segmentation and bridge extraction. First, river region is segmented from complicated background by texture analysis. Second, constrained Delaunay triangulation (CDT) is applied to segment river region into a triangular mesh. The medial axes of river is computed from the skeleton segments of triangles and therefore bridges are easily detected along the end points of river medial axes. Extensive experiments have been performed on panchromatic QuickBird images. The experiment results show that our method achieves detection accuracy and satisfies the speed request in large-scale high resolution panchromatic image.