One efficient compression method used on WebGIS

The features of mass spatial data and the limit of Internet bandwidth are key issues which restrict the WebGIS application performance. How to implement efficient vector data compression is important during the stage of data transmission. To get high compression ratio, we propose one multilevel vector data compression method which combine lossy compression and lossless compression technology. According to the resolution of the map, we ignore some vector coordinates based on visualization. Moreover, we apply coding technique to geographic coordinates to achieve higher compression ratio. After illustrating the design and implementation of this method, we conduct experiments to compare the performance of traditional compression technique and the proposed method. The result shows the significant compression ratio (about 90%) which enhance the data transmission efficiency to a large extent.