A stumpage height extraction method under a plane constraint

Abstract

The invention discloses a stumpage height extraction method under a plane constraint, which is characterized in that the method comprises the following steps of step 1 selecting a reference object; 2obtaining a standing wood image of that height to be measured; 3 identifying that outline of the reference object; 4 detecting that coordinates of the extinction point; 5 constructing cross ratio information, setting MN as a reference object of a known height, so that that height of the object to be measure MQ can be calculated through the ratio of the two, the height of the tree to be measured isset as T2, and the height of the tree to be measured can be obtain according to the proportional relationship between pixels when the height of the tree to be measured is known T2=MQ. The method of the invention can complete the height measurement of the standing timber without obtaining the internal and external parameters of the camera, simplifies the tedious process in the computer operation process, reduces the error of the straight line detection result, improves the flexibility of the line segment calculation in the plane, and is particularly suitable for the geometric information extraction of the standing timber scene object under the structured condition.

Description

technical field [0001] The invention relates to a method for measuring tree heights, in particular to a method for extracting standing tree heights under plane constraints. Background technique [0002] Determining the height of trees has become a must in forest resource surveys [1] . At present, in addition to the traditional visual method, simple methods such as manual contact surveying and mapping methods [2] In addition, the sensor-based laser dendrometer [3] , telescopic dendrometer [4] Measurement methods such as tools are also widely used. Traditional surveying and mapping methods are labor-intensive, labor-intensive, and inefficient, while professional precision measuring equipment has problems such as complicated operation, difficult portability, and high cost [5-6] . With the development of science and technology, machine vision technology for tree height measurement has the advantages of accurate image information, simple equipment operation, and low cost. ...

AI Technical Summary

Problems solved by technology

Wang Meizhen [11] The camera plane and the three-dimensional scene are used to calculate the line segment distance through the parameters obtained by linear transformation; but the accuracy of the algorithm is affected by the selection of the reference length in the three-dimensional scene, and the measurement results of the length of the line segment to be measured in different directions have different accuracy, resulting in measurement The accuracy of the result is unstable

The above methods require more constraints on the acquisition of the input image, including the fixed aspect ratio of the camera screen, the main point is located in the center of the image, etc., and a large number of matrix operations are required, and the geometric requirements in the scene are also high.

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