A Method for Measurement of Fruit Tree Canopy Volume Based on Image Analysis

Abstract

The invention discloses an image analysis-based fruit tree crown volume measurement method. The method includes the following steps that: the images of five fruit trees are acquired, and tree crown volume is measured manually; tree crown area is obtained by using an image processing technology; based on the least squares method, a relationship model between the logarithm LnV of the tree crown volume and area S can be obtained through fitting; and when measurement is carried out, only the fruit tree images are required to be acquired, and the tree crown area can be obtained through image processing, and the tree crown volume can be obtained according to the relationship model. With the image analysis-based fruit tree crown volume measurement method of the invention adopted, the defects of low efficiency and high strength of manual measurement and the defects of complex operation and large data processing amount of an existing electronic measurement method can be eliminated; the relationship model can be calibrated at any time with the changes of seasons and environments, so that measurement accuracy can be differentiated. The image analysis-based fruit tree crown volume measurement method is simple in operation steps and is suitable for being used by ordinary farmers and has a bright market prospect.

Description

Technical field [0001] The invention belongs to the field of fruit tree planting, in particular to a method for measuring the crown volume of fruit trees based on image analysis. Background technique [0002] The crown is an important factor affecting the production capacity of fruit trees, and its growth status directly affects the yield and quality of the fruit. Therefore, the volume of the crown is an important indicator for evaluating tree structure and yield measurement. It is used in fruit tree breeding, yield measurement and fine management of the crown. Extremely important reference value, such as: fruit tree yield estimation, pesticide variable spraying, precise fertilization, fruit tree biomass calculation, leaf density calculation, etc. It can be said that measuring the crown volume of fruit trees is a prerequisite for healthy fruit tree growth and reasonable management. [0003] At present, the commonly used methods of fruit tree volume measurement include traditional m...

AI Technical Summary

Problems solved by technology

Among them, the traditional manual measurement method is simple, easy to operate, and requires low knowledge level of the grower, but it is time-consuming and laborious, and the measurement accuracy is easily affected by the subjective factors of the measurer; in the automatic measurement of the sensor, the ultrasonic sensor (“based on Ultrasonic 3D reconstruction and volume measurement of fruit tree canopy [J]" Yu Long et al., Journal of Agricultural Engineering, 2010, 26(11): 204-208), 3D laser scanner ("Tree canopy based on 3D laser scanning point cloud Volume calculation method [J]" Wei Xuehua et al., Journal of Agricultural Machinery, 2013, 44(7), 235-240.) and prism-free total station ("Canopy volume measurement method based on cubic grid method [J]" He Cheng et al., Journal of Agricultural Mechanics 2014, 45(12), 308-313) is the most widely used. At present, ultrasonic sensors have been widely used to measure the crown volume of fruit trees such as grapes and citrus. However, there is diffraction phenomenon in the propagation of ultrasonic waves, and the divergence angle is relatively large. Moreover, the ultrasonic intensity will decrease proportionally with the change of the measurement distance, resulting in low measurement accuracy; 3D laser technology can achieve higher measurement accuracy, but its cost is high, the acquired point cloud data is huge, and the processing efficiency is low. ; The prism-free total station constructs three-dimensional information of the canopy by obtaining point cloud data of the canopy, and then uses the grid method to obtain the volume of the canopy. In the 8 directions of northwest, southwest and northwest, multiple sampling points are carried out at the same height, which is heavy workload and difficult to operate

thus making it difficult for these measurements to be widely used in orchard management

[0004] Image processing technology is a technology that uses computer to analyze images to achieve the desired results, Wang Yongjiao (Measurement method of plant leaf area based on image processing [J]. Computer Engineering, 2006,32(8), 210— 212.), Zhang Yuanyuan (Research and Application of the Projected Area Measurement Method of Irregular Objects Based on Digital Image Processing [D]. Changchun, Changchun University of Science and Technology, 2010) proposed to use OpenCV or Matlab and other image processing methods to obtain plant two However, in the process of converting two-dimensional area data into three-dimensional volume data, although Liao Caixia et al. (4), 478-483.) proposed a polynomial model, Wang Shuang et al. (Research on the growth model of larch crown volume and surface area [D]. Harbin, Northeast Forestry University, 2014.) proposed multiple transformation models such as the power function model, However, these models all need to process massive amounts of data, which takes a long time and cannot correct the existing models in real time according to changes in seasons and environments, which greatly affects the accuracy of measurement

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