随着第4代移动通信技术(4G)的普及以及4核和8核CPU手机的出现,无线网络数据传输能力大幅提升,移动终端性能大为改善.移动用户的广泛参与使得地理信息的采集和上传下载数据巨量,致使有限的带宽传输速率与海量信息传输需求不匹配.针对移动用户对空间数据的高压缩率和高失真度容忍率的需求,提出了一种新的矢量地图数据压缩方法,通过去除冗余点、平移坐标轴和转换数据类型3个步骤,可2次压缩数据.测试结果显示,该方法的综合压缩率接近70%,可有效降低无线网络数据传输负荷,节约移动终端的存储空间.
With the popularization of fourth generation(4G)mobile communication technology and the four/eightcore mobile phones,the data transmission capacity on the wireless network and the performance of mobile terminal are substantially improved.Mobile users are widely involved in making geographic information acquisition,upload and download.However,the requirements of data transmission will reach an unprecedented level,and are incompatible with the limited bandwidth.To meet with the new requirements of the higher compression rate and precision tolerance for spatial data,a vector data compression method is designed independently.Removing redundant points,parallel moving coordinate axis and data type conversion are used as three steps in the method to realize double compression.The tests reveal that the comprehensive compression rate of this method is close to 70%.It has effectively reduced the data transmission pressure in the wireless network,and has saved the memory space of mobile terminal.