杨庆华，王　玲，荀　一，鲍官军，张　盛

(1.浙江工业大学 特种装备制造与先进加工技术教育部重点实验室，浙江 杭州 310032；2.浙江茶乾坤食品股份有限公司, 浙江 湖州 313100)

基于机器视觉的袋泡茶包缺陷检测方法

杨庆华1，王玲1，荀一1，鲍官军1，张盛2

(1.浙江工业大学 特种装备制造与先进加工技术教育部重点实验室，浙江 杭州 310032；2.浙江茶乾坤食品股份有限公司, 浙江 湖州 313100)

摘要：针对袋泡茶包的缺陷，设计了基于机器视觉的袋泡茶包缺陷检测装置，提出了识别袋泡茶包缺陷的图像处理方法.通过最大类间差算法对茶包图像进行阈值分割，去除背景.根据茶包外形特点以及不同的缺陷特征，对茶包进行四边形拟合并划分成不同区域.通过计算茶包边缘夹角以及统计分析各区域灰度信息的方法，识别斜包、皱包、空包、夹渣包、左右不对称包缺陷；通过形态学运算和边缘检测识别破包缺陷.实验结果表明：各种缺陷的正检率均达到85%以上，总的缺陷正检率达91.8%。

关键词：机器视觉;最大类间差;区域划分;灰度信息;形态学

Method based on machine vision for teabag defects detection

YANG Qinghua1, WANG Ling1, XUN Yi1, BAO Guanjun1, ZHANG Sheng2

(1.Key Laboratory of Special Purpose Equipment and Advanced Manufacturing Technology, Ministry of Education,

Zhejiang University of Technology, Hangzhou 310014, China；2.Zhejiang Tea World Food Co., Ltd., Huzhou 313100, China)

Abstract:To detect the defects of teabags, a defects detection device based on machine vision was proposed, and an image processing method was developed in this paper. The otsu algorithm was used to segment the object image so the background can be removed. According to the shape feature and different defects’ characteristics of the teabags, rectangle fitting was applied to fit the teabag outline. As the included angles of the teabag edge lines were figured out, the inclined teabags can be found out. The teabag was divided into several areas within the rectangle. As the gray value information of each area was drawn, the teabag, whether it was a crinkle bag, empty bag, left-right asymmetry bag or had dross contained in margin, can be tested out. Morphological algorithm and border detection algorithm were operated to extract the damage defect of the teabag. The experiment verified that all the detection rates can be higher than 85%, and the overall detection rate is 91.8%。

Keywords:machine vision; otsu; area division; gray value information; morphological algorithm

袋泡茶是将茶叶封装在薄滤纸袋中,用时连同滤纸袋一同放入茶具内.袋泡茶使用可以提高浸出率,使得茶末得到充分的利用，并且袋泡茶有冲泡快速,清洁卫生、用量标准,可以混饮,排渣方便,携带容易等优点，符合快节奏的生活需要,在国际市场中需求量大[1].袋泡茶要求外袋方正，表面平整、洁净，无污迹、皱褶、破洞.然而，加工后部分茶包存在着一些缺陷，主要有夹料包、破包、皱包、空包、斜包以及左右不对称等[2-3].目前这些缺陷的检测主要由人工观测完成，这种方法效率低、劳动强度大、准确度不稳定，检测结果随着工人积极性与精神集中度而变化。……