Skeleton extraction method and device for polygonal image

Abstract

The invention discloses a skeleton extraction method and a device for a polygonal image. The method comprises the following steps: carrying out grid Euclidean distance transformation on the polygonal image to obtain the initial distance values and initial closest edge points of all grid points; calculating an extraction radius according to the initial distance value of one grid point, extracting all boundary points of the polygon which are positioned in the range of a circle as a set of closest edge points of the grid point, wherein the center of the circle is the closest edge point of the grid point and the radius of the circle is the extraction radius; calculating a mean distance value from points in the set of closest edge points to the grid point; taking points, the distance from which to the grid point is closest to the mean distance value, as the actual closest edge points of the grid point, and taking the mean distance value as an actual distance value; selecting an initial seed point as a starting point for generating a skeleton, wherein the actual distance value of the initial seed point is greater than the actual distance values of all adjacent grid points; and selectingskeleton points from the adjacent grid points of the initial seed point.

Description

technical field [0001] The invention relates to the field of earth science computing, in particular to a method and a device for extracting polygonal image skeletons in geographic information science. Background technique [0002] Skeleton (Skeleton), also known as Medial Axis (MA), is an abstraction of regionally connected shapes, which can effectively reduce redundant information and preserve the geometry and topology of spatial shapes. It is the simplest way to describe geometric shapes. , one of the most effective methods. In computer vision and pattern recognition, because the skeleton can accurately express the morphological characteristics of some long and narrow strip images, it is often used for text and fingerprint recognition. In the field of geographic information science, skeletons are used in spatial analysis and cartographic synthesis. For example, the main morphological features of roads and rivers can be obtained through skeleton extraction, which can be us...

AI Technical Summary

Problems solved by technology

The skeleton obtained by the thinning iterative method has good topology invariance, but the skeleton position is not accurate; the method based on distance transformation is easy to implement, the obtained skeleton position is accurate, and can handle complex graphics, but the graphics need to be decomposed in advance to obtain the graphics Parts, it is more difficult to deal with special polygons that cannot be accurately decomposed into parts

In addition, the above discrete-domain based algorithms are easily disturbed by polygon boundary noise, the obtained skeleton is prone to glitches and the connectivity is difficult to be guaranteed

Images