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This paper develops a computational method for analyzing changes in polygon distributions. Unmovable polygons that change
discontinuously without explicit functional linkage information are discussed. Six types of primitive events are used to describe
the change: 1) generation, 2) disappearance, 3) expansion, 4) shrinkage, 5) union, and 6) division. The change of polygon
distributions is decomposed into a combination of these events. A computational procedure for deducing a set of events from
polygon distributions of two times is proposed. The method is applied to the analysis of the spatial competition between the
major and small chains of convenience stores in Tokyo, Japan. Some empirical findings are shown.
Received: 3 August 2000 / Accepted: 6 February 2001 相似文献
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Conventional algorithms for polygon rasterization are typically designed to maintain non-topological characteristics. Consequently, topological relationships, such as the adjacency between polygons, may also be lost or altered, creating topological errors. This paper proposes a topology-preserving polygon rasterization algorithm to avoid topological errors. Four types of topological error may occur during polygon rasterization. The algorithm starts from an initial polygon rasterization and uses a set of preserving strategies to increase topological accuracy. The count of the four types of error measures the topological errors of the conversion. Topological accuracy is summarized as 1 minus the ratio of actual topological errors to the total number of possible error cases. When applied to a land-use dataset with a data volume of 128 MB, 127,836 polygons, and extending 1352 km2, the algorithm achieves a topological accuracy of more than 99% when raster cell size is 30 m or smaller (100% for 5 and 10 m). The effects of cell size, polygon shape, and number of iterations on topological accuracy are also examined. 相似文献
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针对一些大比例尺面要素数据在没有接边线的情况下无法有效进行接边检查的问题,文中在分析面要素接边原则和接边特点的基础上提出一种面要素接边检查算法,并对算法的关键环节进行详细阐述.利用ArcGIS En-gine相关组件,在Visual Studio开发环境下进行算法实现,形成面要素接边检查工具.将所开发的工具应用于陕西省... 相似文献
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GIS中多边形图拓扑信息生成的数学基础 总被引:19,自引:2,他引:19
本文从GIS应用角度给出了多边形图的定义,简述了多边形图的性质;论述了多边形图拓扑信息自动自下而上的数学原理及拓扑信息正确性的检验准则。 相似文献
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本文在系统介绍遥感图像检索中边缘特征描述方法的基础上,将边缘特征归纳为边缘图和边缘方向两类特征。通过对遥感目标图像库和纹理图像库上所做实验的分析,揭示了不同算法的特性,并指出综合两类特征可进一步提高算法的检索性能。 相似文献
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针对轮廓模糊建筑物多边形的化简问题,提出一种基于特征边重构的建筑物化简方法。该方法定义了建筑物的主方向和控制其整体结构的特征边,以保持建筑物的规则形态。首先利用统计加权方法计算建筑物的主方向,基于主方向对建筑物执行直角化操作。然后按照特征边的定义检测直角化建筑物的特征边,将特征边组合并抽象出几种局部结构,建立重组规则。最后通过判别特征边组合的空间关系,选择合适的结构重组规则来化简建筑物。结合真实数据进行多组试验,结果表明该方法有效还原了建筑物的直角特征,面积和形状保持良好,适用性强。 相似文献
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结合边缘编组的Hough变换直线提取 总被引:3,自引:0,他引:3
针对传统Hough变换用于直线检测存在的问题进行了细致的分析和归纳总结,在此基础上,提出一种结合边缘编组的Hough变换直线提取算法。该算法首先采用基于8邻域的边缘跟踪算法对Canny算子检测得到的边缘点进行编组;然后对每一个边缘组分别进行Hough变换,单独确定Hough变换原点和参数的取值范围。Hough变换过程中,采用迭代的"投票"方式,每次确定单一峰值点并删除对应像素。实验证明,该算法原理简单,能有效解决传统Hough变换存在的精度不高、计算复杂等问题。同时该算法具有较强的鲁棒性,可以有效处理不同类型的影像数据,适用于并行处理。 相似文献
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介绍了分布式WADGPS系统中监测站和用户站的监测方法,讨论了监测站和用户站的粗差探测与分离,最后应用分布式WADGPS99‘陆基长距离试验和南海海上试验进行了数据处理和分析。 相似文献
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