关键词: Douglas-Peucker算法, 矢量数据压缩, 可缩放矢量图形（SVG）, 公共边对象化Douglas-Peucker改进算法

Abstract: The paper analyzes the reason of graphic distortion phenomenon when compressing the non-topology vector graphics by classical Douglas-Peucker algorithm.The reason is that the common boundary is compressed with Douglas-Peucker algorithm more than one time.Based on this，an improvement on Douglas-Peucker named common boundary objected Douglas-Peucker improving algorithm is put forward.To implement it，first this paper designs a new algorithm for extracting common boundary between two polygons.Then it adopts the idea of OOP，packages the common boundary to be a class with other information showed in figure two.Finally，on the basis of the class，it applies classical Douglas-Peucker to the common boundary and non-common boundary of polygons respectively to compress vector graphics.At last，the validity of the new compressing algorithm is proved by experiment with SVG graph.And the advantages in space and time efficiency are analyzed by contrast with the other Douglas-Peucker improving algorithm showed in table one and two.

Key words: Douglas-Peucker algorithm, vector data compressing, Scalable Vector Graphics（SVG）, common boundary objected Douglas-Peucker improving algorithm