D.Thibault & C. M. Gold Terrain Reconstruction from Contours by Skeleton Retraction

Generating terrain models from contour input is still an important process. Most methods have been unsatisfactory, as they either do not preserve the form of minor ridges and valleys, or else they are poor at modeling slopes. A method is described here, based on curve extraction and generalization techniques, that is guaranteed to preserve the topological relationships between curve segments. Based on this approach, which uses the properties of the Voronoi diagram and Delaunay triangulation, it is possible to make reasonable estimates of slopes for terrain models, and to extract meaningful intermediate points for triangulated irregular networks (TINs).