An Automatic Method for Contour Interpolation in Map Design

This paper presents a contours interpolation algorithm used in map edition, which is to generate some new contours according to the existing ones. First, the basic algorithm is given. Second, the approaches for distinguishing contour extending direction, handing close contour line, and considering the branching from one contour to multiple contours, are presented. The algorithm is so practical that even those very complex situations appearing in practice can be properly handled. In the process of interpolation, the prior knowledge of contours is used sufficiently, so the process speed is high and the quality of interpolated contours is also satisfactory. The operation is very convenient, only requiring the operator to select two or more neighboring contours without their elevations, then the interpolated contours with high quality can be gained. The algorithm is programmed with Visual C++ 6.0, and has been included in the large software package——Founder Map Publishing and Geographical Information System, which is developed by Founder Research Center, and attained much praises from its users.