地图数字化中沙地符号的自动去除算法

Algorithm for automatic removal of the sand symbols in map digitizing

在对沙漠地区地形图进行数字化的过程中,图中的各种沙地类型符号对等高线等地图要素的自动矢量化构成了严重干扰,影响了数字化效率。针对扫描地图图像中沙地符号的去除问题,通过分析不同沙地符号的特点,在对地图图像进行二值化和细化处理的基础上,利用形态学去毛刺的方法去除沙地符号。对于较复杂的沙地符号,采用分级去毛刺的方法进行去除。实验结果表明,提出的算法能够有效地去除多种沙地类型符号,为地图要素的自动矢量化创造条件。

In the process of map-digitizing of desert regions, varieties of sand symbols seriously interfere with the vector processing of the cartographic feature, and the performance of the digitizing is restricted. The problem of the sand symbols removing in the scanned maps is aimed at. Through the analysis of the characteristics of different kinds of sand symbols, the morphology-based spur removing method is used to remove the sand symbols after the process of image binarization and morphology-based thinning. Moreover, the multi-level spur removing method is used for the complex sand symbols. Experiments indicate that the proposed method is able to remove different kinds of sand symbols in the scanned maps, which significantly contributes to automatic vectorization of the cartographic feature.