Contour Lines and DEM: Generation and Extraction

Contour lines are, as Digital Elevation Models (DEM), 3D information describing the terrain topography. The aim of this work is to demonstrate how the use of a powerful DEM modeling structure, taking into account both representation characteristics, eases their collaboration for topography representation. After regarding the link between contour lines and DEM, we introduce a new type of triangular representation for surface modeling: The Delaunay Constrained Triangulation developed to maintain the Delaunay nature of the final triangulation. This efficient structure is used for 2.5D DEM design and contour lines management.We present the main properties and interest for DEM modeling with this structure before focusing on the contour lines management. The bilateral relationship between contour lines and DEM is studied in two Processing chains. First, the use isolines as input data for DEM design. Second, the extraction from triangulated DEM. We propose for both aspects automatic and easy to use processing chains exploiting the Delaunay structure properties.