Building vector boundary simplification method

Abstract

The present invention relates to the field of the geographic information processing, and discloses a building vector boundary simplification method. The method comprises: obtaining a building vector polygon from a building vector diagram; determining the corner points of the vector polygon; determining a distance screening threshold according to the perimeter of the vector polygon or the distance between the corner points; and traversing all the boundary points of the vector polygon, comparing the distance between the traversed boundary points and the boundary points adjacent to the traversed boundary points with the distance screening threshold, and deleting the adjacent boundary points when the distance is smaller the distance screening threshold and the adjacent boundary points are not the corner points. According to the invention, the distance screening threshold is employed to get rid of the boundary points which do not meet the conditions, and therefore the building vector boundary simplification method is applicable to the building vector boundary simplification process and is simple in related calculating process.

Description

technical field [0001] The invention relates to the field of geographic information processing, in particular to a method for simplifying the vector boundary of buildings. Background technique [0002] With the continuous development of geographic information system (Geographic Information System, GIS) and computer technology, more and more data can be studied and utilized, but computer memory and network bandwidth are limited, how to effectively process and transmit massive data , is also a major problem that plagues experts. Generally speaking, the data studied in the GIS field includes two types: attribute data and spatial data. Compared with attribute data, the storage space occupied by spatial data is often large. With the improvement of data resolution, spatial The amount of data will also continue to increase. For building vector data, it will be used in many aspects such as urban planning, land classification, and disaster assessment. The complexity of polygons oft...

AI Technical Summary

Problems solved by technology

The vertex deletion method is to calculate the angle between the vertex and the adjacent two sides, the length of the adjacent two sides, the correlation degree of the vertex and other parameters, and then judge whether to delete the vertex. The principle of this method is easy to understand, and it is suitable for relatively gentle curve data compression , but the corresponding parameters need to be recalculated and sorted every time a point is deleted, the calculation efficiency is not high, and this method does not consider the whole polygon, and cannot eliminate error information such as the wrong inner ring; the edge contraction method is also called Edge collapse algorithm, the main idea of ​​the method is to shrink an edge into a vertex in one operation, and reciprocate until the number of polygon vertices is reduced to the specified number. The advantage of this method is that it can better maintain the original polygon shape, because its polygon The number of vertices has been artificially specified, so there will be no wrong polygons with the number of vertices less than 3, for example, but for inner rings with too small area, this method cannot remove them

Similar to the vertex deletion method, the calculation efficiency of this method is also not high, and if the edge shrinks too much, it may cause the loss of polygon shape information; the Douglas-Peucker method is an improved version of the vertical distance method, by calculating the connection between the vertex and two points The vertical distance, delete the vertices whose vertical distance is greater than the threshold each time, this method has high computational efficiency and a wide range of applications due to the iterative idea, but its calculation of the vertical distance is more complicated, and how to determine the threshold is relatively difficult. intractable problem

This method also does not consider the problem from the perspective of the polygon as a whole, and it is difficult to solve the situation such as the wrong inner ring

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