Multiple stumpage breast height diameter passive measurement method based on depth extraction model

Abstract

The invention discloses a multiple stumpage breast height diameter passive measurement method based on a depth extraction model. The multiple stumpage breast height diameter passive measurement methodbased on the depth extraction model comprises the following steps: step 1, calibrating a mobile phone camera, and obtaining camera internal parameters and an image resolution; step 2, establishing adepth extraction model (which is as shown in the specification); step 3, collecting and processing an image of a stumpage to be measured, and calculating a stumpage depth value in a photogrammetric coordinate system; and step 4, measuring multiple stumpage breast height diameter values in a single image (the formula is shown in the specification). The multiple stumpage breast height diameter passive measurement method based on the monocular vision and the depth extraction model disclosed by the invention can be applied to cameras with different parameters such as field of view, focal length, image resolution and the like, which improves range accuracy and measurement efficiency, and provides a support to forestry resource surveys and forestry resource management.

Description

technical field [0001] The invention relates to the field of ground close-range photogrammetry, in particular to a method for passively measuring the diameter at breast height of multiple standing trees based on a single image information under a monocular vision system. Background technique [0002] Breast height diameter, also known as DBH (cm), refers to the diameter of the tree at a distance of 1.3 meters from the ground rhizome. [1] . Standing tree diameter at breast height is an important measurement factor in forest resources investigation and management [2-3] . The measured value of traditional DBH measurement method is usually regarded as the standard value of DBH [4-5] , but the method is time-consuming, labor-intensive and inefficient. With the development of sensing technology, machine vision and laser ranging technology, non-contact surveying and mapping methods have emerged. Non-contact DBH measurement methods are mainly divided into active measurement and...

AI Technical Summary

Problems solved by technology

This method realizes the automatic measurement of the DBH of multiple standing trees in the image, but it needs to take multiple pictures, and the length of any object in the image needs to be measured in advance, and the accuracy of the length has a great influence on the measured value of the DBH of other samples

[0004] The invention application with the application number 201710849961.3 discloses an improved camera calibration model and distortion correction model suitable for smart mobile cameras (hereinafter referred to as: improved calibration model with nonlinear distortion items), which can help correct Calibrate the image of the board to obtain higher-precision camera internal and external parameters. The disadvantage is that this method has not been extended to the nonlinear distortion correction of the image to be tested and the measurement of the target object.

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