Abstract: Terrain Features include terrain feature points and terrain feature lines. They are important medias to analysis and processes of landscape, and the important contents of the structure generalization of landscape. This paper proposes and implements a new method of contour- based terrain features lines extraction. Firstly, the contour lines are divided into two kinds of feature segments that include concave and convex segments, which corresponds to the valleys and ridges respectively , and using the maximum-angle as the constraint condition and using the edges of feature segments as the constraint edges, Constrained Delaunay Triangulation(referred to CDT) are constructed. Then，the skeletons of the CDT of every feature segment are traced and the local terrain structure line tree are constructed based on the obtained skeletons. And the leaf nodes of the terrain structure line trees are extracted and be treated as the terrain feature points of the corresponding feature segment. Finally, these terrain feature points are tracked and connected into terrain structure lines by applying the connecting criterion. Furthermore, this paper conducts the related experiments, which verifies the effectiveness and advantages of the methods proposed by this paper.

Key words: Feature Segment, Constrained Delaunay Triangulation, Feature Point Extraction, Terrain Structure Line Connection