Algorithm for realizing finding of lake center based on Voronoi graph

Abstract

The invention provides an algorithm for realizing the finding of a lake center based on a Voronoi graph. During the process of researching lake change, not only finding a most stable point as a control point, but also registering multi-phase lake data is required, while finding the center point can be changed to obtain the center of a maximum inner circle (inscribed or internally-tangent) of a polygon. According to the algorithm, Voronoi graph generation algorithms of several simple polygons are analyzed at first, and next an arbitrary polygon is subjected to binary tree recursion till being simplified into several simple polygons; for a complex polygon with an island, Voronoi graphs of outer ring interior and inner ring exterior of the complex polygon are calculated at first, the generation of the Voronoi graph of the complex polygon is realized by analyzing corresponding segment intersection sequences, and finally the center point of the maximum inner circle of the polygon is found by traversing corresponding intersection points; and the algorithm complexity analysis shows that the algorithm as a method of which the complexity is lowest at present can be applied to finding the centers of the maximum inner circles of other similar polygons as well.

Description

technical field [0001] The present invention relates to computational geometry and geographic information system space analysis method, specifically, relates to the generation algorithm of the Voronoi figure of arbitrary complex polygon in computational geometry, and adopts the spatial analysis technology of geographical information system to realize lake central point search on this basis Algorithm, the present invention can be applied to the lake center point search, matching and change analysis of the results of multi-period remote sensing image lake extraction. Background technique [0002] In the process of remote sensing multi-period long-term lake change and analysis, it is necessary to register the multi-period images and lake extraction results. On this basis, lake change analysis and other applications can be carried out. The center point of the lake can be used as the multi-period The corresponding references include Sheng Y, Shal C A, Smith L C.2008.Automated ima...

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Problems solved by technology

Another method for finding the largest inner circle of any polygon is based on the iterative method, but this method has two problems: one is that it can only iterate to the local maximum value instead of the maximum value in some cases, and the other point is that The problem of low efficiency due to iteration, the corresponding references include: Zheng Meisheng, Chen Ning, Song Chao. An algorithm for calculating the largest inner circle of any polygon. Mechanical Design and Manufacturing, 2003, 5: 84-85, Jiang Meiyan, Wenhui's method of solving the largest inner circle of any polygon based on optimization theory, Equipment Manufacturing Technology, 2010, 6: 144-145, etc.

[0005] In terms of searching for the largest inner circle of any polygon, especially the fast search for the largest inner circle of any polygon using mathematical methods, it can be seen that there are not many patents / documents at present, and the corresponding small number of documents cannot solve the maximum inner circle of a large number of lakes. Circle Quick Find Questions

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