Contour Lines Extraction from Color Scanned Topographical Maps with Improved Snake Algorithm

摘要

Contour lines are the most important features to characterize three dimensional terrain on color scanned topographical map sheet. Based on the analysis of characteristics of contour lines, a novel snake model for automated tracking is proposed. With the variable force control and gradient vector flow, contour lines can be vectorized automatically. The tracking algorithm is significant for its flexible form and combination of global field information with local tracking. Furthermore, the algorithm has general reference to other kinds of graphical vectorization.