矢量数据向栅格数据转换的一种改进算法

地理信息系统的发展与空间数据结构的优化密不可分，栅格数据与矢量数据之间的高效转换是GIS的关键技术之一。由于栅格数据十分有利于空间分析中的叠置分析，因而通常需要将矢量数据转换成栅格数据。该文分析对比了地理信息系统的两种基本数据结构，在总结已往矢量数据转换为栅格数据方法的基础上，依据边界代数多边形填充算法的基本原理，结合绘图作业时采用的正负法，提出了一种改进的折线边界(数据串)跟踪方法。该算法原理简单，不需进行复杂的距离比较运算，运算速度快，并且通过简单的角度判断保证了填充的精度。

An Improved Algorithm for Transferring Vector to Raster Data

The development of GIS is closely related to the optimization of spatial data structure. The efficient mutual conversion between vector and raster data is one of the key technologies in GIS.For the sake of the convenience for overlay analysis, the vector data are always transferred to raster data. These two fundamental data structures of GIS were analyzed and compared at the beginning of this paper. Various conventional approaches of converting vector data to raster data were summarized, and then the paper presented an improved boundary-tracing algorithm, which was based on BAF (Boundary Algebra Filling) and Positive-Negative algorithm for drawing graphs. The principle of this algorithm is simple, as the computation and comparison of distance between two points is not necessary. Therefore, it considerably improves the speed of the data conversion, and maintains the filling precision through a simple judgment of the angle as well.