Morphing Algorithm for Linear Feature Considering Generalization Requirements

A linear feature Morphing method is proposed based on the fact that the spatial characteristic of linear element is represented by bent structure. First, for linear features at different scales, by construction and classification of Constrained Delaunay Triangulation, we can build the multiway trees to express the curves' bend hierarchical structure. Then, by the matching of multiway trees, we can get the bends corresponding relationship between two linear features at different scales. By the importance evaluation of matching bends, we can divide the linear element into different line segments. Last, different strategies are implemented for different type of bends. For the corresponding line segments, linear interpolation operation is adopted to exaggerate the small bend or shrink the big bend; for the no-matching segments, deletion operation is implemented. Experimental results show that the proposed Morphing method for linear features can meet the map generalization requirements, and keep the balance of curvature and quantity of bends, which finally achieving smooth and gradient continuous generalization of linear features.