栅格数据矢量化及其存在问题的解决

Vectorization of Raster Data and Solving of it's Problems

矢量结构和栅格结构是GIS的两种主要数据结构形式,而栅格数据的矢量化在GIS中具有十分重要的意义。本文在总结前人算法的基础上,以拓扑关系的原理为指导,提出了改进的栅格结构数据矢量化方法,即在提取结点和坐标点过程中同时提取水平和垂直的所有线段信息,以便于快速、有效地实现栅格数据的矢量化。此外,还采用动态打断和粗网格法等方法,解决了在栅格数据矢量化过程中经常出现的诸如多边形自交、岛等问题。

Raster and vector are two major types of data format in GIS and converting raster data into vector one is of great importance for GIS. On the basis of summarizing the existed algorithms and following the topological theory, an improved method for converting raster data to vector one is suggested in this paper. In other words, in the process of searching nodes and coordinate points, both vertical and horizontal line segments are picked up at the same time in order to realize the vectorization of raster data quickly and more efficiently. In addition, by use of the methods such as automatically breaking and widening grid size, some common problems in the course of vectorization of raster data such as self-intersected polygon and island were successfully solved.