基于四叉树的矢量数据变化捕捉方法研究

摘要

对传统的历遍要素变化捕捉方法进行改进，提出了基于四叉树的矢量数据变化捕捉方法。该方法利用四叉树的空间索引原理，对新旧图层进行四叉树分割，计算分割区域内新旧要素的“点-弧段”变化特征，以此确定分割区域的变化情况，并进行迭代运算，从而过滤出不变区域，快速定位至变化区域。实验结果表明：该方法计算速率较高，能够准确快速地识别出变化信息，与传统历遍要素变化捕捉的方法相比，更有助于提高GIS数据库更新的效率。%Incremental updating is one of the most frequently used methods in spatial databases updating and the detection of changed objects is the crucial technology.Change detection is of great significance for improving the efficiency of spatial database updating.This paper refines the object-traversing method and proposes a new change detection method based on quad-tree.Considering the principle of spatial in-dex,this method divides the region of the corresponding layers based on quad-tree.By calculating the vertex-edge changed index of the objects in the region,this method can evaluate the changed situation of the region.The method can filter out the unchanged areas and rapidly locate the change areas in an itera-tive way.The experimental result showed that this method can reach high computational efficiency and properly recognize the change information.Comparing with the traditional change detection algorithm, this method can improve the efficiency of GIS database updating significantly.