Tree height measuring method based on hemisphere image

Abstract

The invention discloses a tree height measuring method based on a hemisphere image. According to the method, a mathematic model is built for measuring the height of the tree according to the fisheye camera imaging principle; a measuring device composed of an intelligent terminal, a fisheye lens matched with the intelligent terminal and a laser range finder is adopted, a black and white checkerboard calibration board is matched with the measuring device to determine a distortion coefficient, the highest point and the lowest point of the measured tree are selected on a screen of the intelligentterminal, and the height of the tree is calculated through a measuring program. The method is wide in measurement range, the amount of information of single collected standing tree is large, the treeheight of a row of trees can be measured and calculated in the hemisphere image, and the measurement workload is effectively reduced; and the cost is low, equipment is portable, operation is easy, andmeasurement can be completed by a single person.

Description

technical field [0001] The invention relates to the field of agriculture and forestry, in particular to a tree height measurement method based on a hemispherical image based on a fisheye camera imaging principle in the national forest resource survey. Background technique [0002] With the continuous improvement of precision forestry requirements, accurate, convenient and efficient measurement of standing tree height has become one of the hot issues in forestry research. In forest resources investigation, the determination of standing tree height is very important, which directly affects the forest stock volume and the accuracy of forest biomass extraction. The currently widely used tree height measuring instruments include the Brewleys altimeter and the ultrasonic altimeter. This commercialized device has the advantages of small size and easy portability, but its measurement principle has clear requirements for horizontal and vertical movement. , but the operator cannot st...

AI Technical Summary

Problems solved by technology

The monocular vision measurement of ordinary cameras has the advantages of simple camera calibration process and fast calculation speed, but because of its small viewing angle, it is required to introduce the angle between the camera projection and the optical axis and the vertical viewing angle of the camera, but this angle information is difficult to measure

Binocular vision measurement can effectively solve the problem of viewing angle. Two cameras are used to extract and match feature points from two images of the measured standing tree, and perform 3D reconstruction of pixels. However, the measurement steps are complicated, feature point matching is difficult, and various algorithms are required. , computational redundancy and other issues

Images