空间查询算子的栅格算法与实现-《计算机技术与发展》

文章信息/Info

Title:: Implementation of Spatial Operators Based on Rasterization Approach Algorithm

Author(s):: LIU Yan ; DONG Hui; [1]Binnan Production Plant of Shengli Oil Field,China Petroleum ＆ Chemical[2]Institute of Computing Technology,Chinese Academy of Sciences

摘要:: 地理信息获得了越来越广泛与深入的应用。空间分析是地理信息系统平台最核心的计算之一。矢量方法是面向物体的描述,物体间的几何关系隐含,关系判断需要基于计算几何算法定位、分析和检索,时间与空间复杂度较高。为避免其缺点,提出了基于栅格的空间查询算子算法的实现框架。此算法基于亚像素精度,可以较准确记录边界栅格的覆盖面积,通过判断两个图层相应栅格的覆盖面积,即可得出空间关系。此方法的正确率大大高于四色栅格签名（4CRS）。同时,栅格索引中保存了要素属性信息等,可以为空间查询算子判断提供更有用的结果信息

Abstract:: Geographic information service has gained wider and more advanced application in recent years.The computational geometry algorithm approach to spatial operators,which is one essential feature in GIS,has to utilize spatial access,analysis and query methods to figure out the spatial relation,which is hidden in feature geometry representation,between features.To avoid the disadvantages of computational geometry algorithm approach,propose one improved method,combined with the rendering engine,which can enhance the filter accuracy and avoid drawbacks of four color raster signature（4CRS）.This proposal can record coverage area of border grid cells accurately based on subpixel accuracy,so it can determine whether two polygons overlap through judging coverage area of the corresponding grid cells.As side effects,the rendering engine can preserve feature attribute information（polygon IDs etc.） in the cell structure which offers more useful hints for spatial relation judgment