农业工程学报Issue(3)：112-119,8.DOI:10.3969/j.issn.1002-6819.2014.03.015
利用单目视觉获取钵苗移栽适合度信息的方法
Information acquisition method of potted-seedling transplanting fitness using monocular vision
摘要
Abstract
The potted-seedling growth state varies in the tray. Transplanting is the key in the nursery seedling process. In order to improve the survival rate of a transplanted potted-seedling, and solve the emergence problems such as seedlings growth, or irregular or broken seedlings, the fitness information of the perpendicularity and height of transplanted potted seedlings was comprehensively evaluated, and filtered out potted seedlings meeting the transplanting requirements. The potted-seedling jacked up by the push rod of the image acquisition system can be rotated 90°. A camera captured two images of the potted-seedling before and after it was rotated 90°. The gray-value probabilities histogram of the grayscale images RGB channels existing concentrated areas. At first,the image was pre-processed by 24-bit RGB source image converting to 8 bit grayscale algorithm, median filtering algorithm and gray stretching algorithm. Then, the trunk features of the potted-seedling were extracted by the image processing algorithms of thinning, horizontal expansion, and vertical erosion. Finally, the key points of every potted-seedling trunk were extracted by a Harris corner detection algorithm of 3×3 Gauss templates of the standard deviation was 0.65, and the fitting line was obtained by the weighted least-squares linear fitting with the key points, and the converted line slope was used as the identification parameter of the potted-seedling upright, and found out the maximumy-coordinate difference of all corners coordinates in each strain of potted-seedling, 110% of the difference was used as the identification parameters of the potted-seedling height. The perpendicularity and height of potted-seedlings had to meet evaluation requirements before being considered suitable for transplant. The perpendicularity and height of 30 strains of a pepper potted-seedling in twelve images were distinguished by machine vision technology at the 0 and 90°position, and the average time consuming of each image being processed was 0.35 s. According to evaluating indicators of the perpendicularity (45°<α<135°) and height (H>105 mm), it was determined that five potted-seedlings were suitable for transplanting, and wherein the measurement results of two potted-seedlings were converse using the vision measurement method or the manual measuring method. The error rate was 6.67% between the machine vision recognition results and the manual measurement results. The main reason for the deviation was that the manual measuring accuracy was affected by the leaves of the potted-seedlings obscuring the stems and the vibrations of the transplanting machine causing location changes during the process of rotating 90°.关键词
图像处理/机器视觉/图像识别/钵苗移栽/直立度/高度/角点检测Key words
image processing/machine vision/image recognition/potted-seedling transplanting/perpendicularity/height/corner detection分类
农业科技引用本文复制引用
杨振宇,张文强,李伟,陈英,宋鹏..利用单目视觉获取钵苗移栽适合度信息的方法[J].农业工程学报,2014,(3):112-119,8.基金项目
国家科技支撑计划子课题（2012BAF07B02-03）、国家自然科学基金（31071320）和中央高校基本科研业务费专项资金资助 （）
