等高线内插在地图自动综合、地图数字化、三维地形重建等过程中都具有重要意义。许多等高线内插算法在等高线急剧变化以及闭合等高线处存在问题。在分析已有等高线内插算法优缺点的基础上,提出了一种等高线内插算法。该算法以等高线上的节点为圆心,建立与相邻等高线之间的内切圆来探测相邻等高线之间的空间关系,并获取等高线间的辅助线,进而内插出等高线,一方面弥补了已有等高线内插方法中的问题,另一方面有效提高了等高线内插的速度和质量。通过与其他内插算法之间的实验对比分析,验证了本方法的科学性和先进性。
Contour interpolation is of great significance in many fields,such as automated map generalization,map digitization,3D-terrain rebuilding.For closed and sharply changing contours,many contour interpolation algorithms cannot yield satisfying interpolation results.A new algorithm of contour interpolation is proposed based on analysis of the advantages and disadvantages of existing algorithms.The new algorithm takes the nodes of the contour as the circle centers,then inscribed circles are built which can be used to detect the spatial relationships of the neighboring contours.The auxiliary lines between two neighbor contours can be obtained by the inscribed circles.Then new contours can be interpolated by auxiliary lines.The algorithm improves the speed and quality of interpolation as well as solving problems associated with the existing methods.The validity of this new algorithm is demonstrated by a comparison with those other methods and analysis of the test results.