Graphic space superposition analysis drafting method of complex vector polygon

Abstract

The invention relates to a graphic space superposition analysis drafting method of a complex vector polygon, belonging to the technical field of spatial analysis drafting and spatial data mining techniques in a geographic information system. The method comprises the steps of: converting two vector polygon graphs into precision run length coding graphs; carrying out overlying transverse superposition, polygon spanning detection and decomposition on another vector polygon graphic chain segment in an interleaved mode and a mode that one of the precision run length coding graphs is used as a background base graph, so as to obtain resolved and unresolved chain segments; screening a qualified chain segment which conforms to the superposition mode to be used as a constituting chain segment of a superposition achievement vector polygon graph; and constructing the superposition achievement vector polygon graph containing a definite spatial relationship. According to the graphic space superposition analysis drafting method, the intersecting judgment of a great number of chain segments and possible misjudgment and omission which are caused by the direct superposition of vector polygon graphs are avoided, the condition for effectively establishing a new topology relationship is created, the operability, the robustness and the practicability of a vector polygon graphic spatial superposition analysis drafting technique are improved.

Description

technical field [0001] The present invention relates to a complex vector polygon graphics spatial overlay analysis and drawing method, the core technology of which is based on the mixed and overlay processing method of vector polygon graphics and precision run-length coded graphics, belonging to spatial analysis and mapping and spatial data mining in geographic information systems, etc. technology field. Background technique [0002] The spatial overlay analysis of vector polygonal graphics is a spatial overlay operation performed on two irregular surface element sets containing the topological relationship of spatial elements. It superimposes two single-element area layers to generate a new element layer. The new feature layer synthesizes the attributes of the elements of the two original map layers, and establishes the membership relationship between the new feature layer unit and the two overlapping layer units. The spatial overlay analysis of vector polygon graphics no...

AI Technical Summary

Problems solved by technology

In order to detect the possible intersecting chain segments between two polygonal graphics, filter the spatially separated chain segments, and reduce unnecessary intersection calculations, outsourced rectangle detection methods, vector raster methods, and raster-assisted methods have emerged. These methods To a certain extent, the efficiency of analysis and drawing has been improved, but for large-format complex graphics, the additional space and time overhead added by the algorithm are still too large, and may still exceed the acceptable range, which restricts the practicability of the method; It is an indirect method, that is, first convert the polygonal graphics involved in the superposition into raster graphics with a certain precision, then overlay the raster graphics, and finally convert the superimposed raster graphics into vector polygonal graphics, and establish the corresponding topological relationship

Since the conversion between vector polygonal graphics and raster graphics is a graphic format conversion with loss of precision, the accuracy of vector polygonal graphics obtained by overlay analysis depends on the accuracy of the used raster, and high-precision raster analysis usually increases sharply The storage space, the two-way conversion of the format and the processing time of overlaying will also be greatly increased, and the feasibility will be reduced

Therefore, the space and time complexity of the indirect method and algorithm are simultaneously restricted by the complexity of the graph and the accuracy of the grid, and its practicability is affected, making it difficult to become a stable and efficient spatial overlay analysis method.

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