矢量行政区划界线数据压缩方法研究

Research on administrative division vector data compression method

针对传统算法对行政区划边界矢量数据进行压缩时不能够满足各级行政区划线在实际应用中的分级表达且容易产生自相交、邻边相交、重合边出现“裂缝”等拓扑异化的问题,该文提出了一种改进的矢量行政区划界线数据压缩算法。以Visvalingam-Whyatt算法为基础,通过压缩时设定限制条件保留特征点以及对不同等级行政区划线进行分级压缩和迭代压缩,获得了不同等级压缩率下的高质量、多层级的行政区划边界矢量数据。实验结果表明,改进算法在对行政区划边界矢量数据进行压缩时能够有效解决拓扑异化的问题,与传统算法相比,在同等级的压缩率下能够更好地保持图形的几何特征以及更高的位置精度,并且能够满足行政区划矢量数据在实际应用的多层级表达。

In view of the problem that the traditional algorithm cannot meet the hierarchical expression of administrative divisions at all levels in practical application when compressing the vector data of administrative divisions boundary,and it is easy to produce topological alienation such as self-intersection,adjacent-edge intersection,and“crack”at the overlap edge,an improved administrative division vector data compression algorithm was proposed in this paper.Based on Visvalingam-Whyatt algorithm,the constraint conditions were set to retain feature points during compression and conduct hierarchical compression and iterative compression of administrative divisions at different levels,which obtained high-quality and multi-level boundary vector data of administrative divisions at different levels of compression rates.Experimental results showed that the improved algorithm could effectively solve the problem of topological alienation when compressing the boundary vector data of administrative divisions.Compared with the traditional algorithm,the improved algorithm could better maintain the geometric characteristics position accuracy of the graphics at the same compression rate and meet the multi-level expression of the administrative division vector data in practical application.