Abstract: Currently, Scalable Vector Graphics（SVG）-based spatial vector data publishing often results in big network transmission delays and high CPU usages. Based on the Window-to-Viewport Transformation principle, this paper proposes a visual-lossless data compression algorithm for SVG-based spatial vector data. The algorithm resets the SVG viewBox, and transforms the spatial data according to the new viewBox. Results of the experiment show that compared to the popular Douglas-Peucker algorithm, the proposed algorithm can achieve better compression ratio and less computation cost.

Key words: Scalable Vector Graphics（SVG）, Web-based Geographic Information System（WebGIS）, spatial vector data compression, visual lossless

摘要： 现有基于可缩放矢量图形SVG的空间矢量数据网络发布往往存在着网络延时大、浏览器资源占用率高等问题。根据窗视变换原理，提出了视觉无损的SVG空间矢量数据压缩算法。该算法通过重新设定SVG的地图范围，根据新的范围对原始空间数据进行变换，从而实现空间数据的约减。实验结果表明，该算法优于常用的Douglas-Peucker算法，在提高压缩率的同时也减少了计算时间。

关键词: 可缩放矢量图形（SVG）, 互联网地理信息系统（WebGIS）, 空间矢量数据压缩, 视觉无损