基于网格模板的栅格与矢量叠加统计算法

Vector-raster Overlay Stat Algorithm Based on Grid Template

为了避免矢量栅格数据叠加统计分析中采用逐像元“扫描”判断法所导致的处理速度缓慢的问题,提出将矢量多边形底图切分成具有一定水平、垂直空间尺度的多行、多列网格模板,保存该模板文件,并在模板的基础上进行快速统计叠加的办法。实质是将矢量栅格数据叠加计算间接转换为计算简便的网格格点与栅格数据之间的叠合,从而提高了计算速度。由于底图格点大小及位置与栅格数据不能有效配准而导致“错位”,该文重点给出了解决此类问题在3种不同匹配方式下的处理算法。

To avoid the inefficiency during the procession of the vector-raster overlay, caused by ＂scanning＂ algorithm, which functions in pixel by pixel way, the paper brings forward a new algorithm based on overlay template, which is composed of rows-cols grids interpolated from polygon map-layer, and it takes the measure form vector-raster overlay to raster-raster overlay, which simplifies the procedure and performs perfectly. Moreover, the authors try to overcome the unmatchable raster-raster overlay, and deal with the three cases of irregular match.