中山大学学报(自然科学版)
中山大學學報(自然科學版)
중산대학학보(자연과학판)
ACTA SCIENTIARUM NATURALIUM UNIVERSITATIS SUNYATSENI
2013年
6期
6-10
,共5页
夏永华%张新长%杜国明%郭泰圣
夏永華%張新長%杜國明%郭泰聖
하영화%장신장%두국명%곽태골
变化捕捉%四叉树%增量式更新
變化捕捉%四扠樹%增量式更新
변화포착%사차수%증량식경신
change detection%quad-tree%incremental updating
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。
對傳統的歷遍要素變化捕捉方法進行改進,提齣瞭基于四扠樹的矢量數據變化捕捉方法。該方法利用四扠樹的空間索引原理,對新舊圖層進行四扠樹分割,計算分割區域內新舊要素的“點-弧段”變化特徵,以此確定分割區域的變化情況,併進行迭代運算,從而過濾齣不變區域,快速定位至變化區域。實驗結果錶明:該方法計算速率較高,能夠準確快速地識彆齣變化信息,與傳統歷遍要素變化捕捉的方法相比,更有助于提高GIS數據庫更新的效率。
대전통적력편요소변화포착방법진행개진,제출료기우사차수적시량수거변화포착방법。해방법이용사차수적공간색인원리,대신구도층진행사차수분할,계산분할구역내신구요소적“점-호단”변화특정,이차학정분할구역적변화정황,병진행질대운산,종이과려출불변구역,쾌속정위지변화구역。실험결과표명:해방법계산속솔교고,능구준학쾌속지식별출변화신식,여전통력편요소변화포착적방법상비,경유조우제고GIS수거고경신적효솔。
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.