毕业设计基于图像的工件外形缺陷检测技术研究

摘要随着图像处理技术的发展，缺陷检测在现代工业连续、大批量自动化生产中起着重要的作用，它涉及各种各样的工件检查、测量和分类等应用，如检测工件的表面是否有划痕、印刷品形体是否有缺陷、IC字符是否完整、电路板焊点是否完善、饮料瓶盖的画面是否完整等。传统的抽样检查已无法保证人们对产品高质量的要求，基于机器视觉的在线高速检测为其提供了可能。本文首先介绍了缺陷检测技术的研究背景和发展历程，其次介绍了实现缺陷检测图像处理技术的算法，最后为了确定光盘表面划痕缺陷的存在，设计了一个基于数字图像处理的缺陷检测系统。首先采集图像，接着对采集所得的图像在Matlab仿真环境下进行灰度转换、去噪、增强和分割处理，最后在Matlab环境下计算处理后的缺陷图像的面积和周长，进而求得其圆形度来确定缺陷的存在，并通过圆形度的取值范围判定光盘的缺陷类型为划痕。关键词：机器视觉，缺陷检测，表面划痕，圆形度ABSTRACTWiththedevelopmentofimageprocesstechnology,disfigurementtestisplayingamoreandmoreimportantroleinthecontinuousandlargebatchautomaticprodutionofmodemindustry.Itinvolvesallkindsofworkpiecetest,measure,classificationandanyotherapplicationsuchastestingwhethertherearenicksonthesurfaceofworkpiece,whethertherearedisfigurementonthepressworkphysique,whethertheICbyteisintegrited,whethertheweldingspotonthecircuitboardareperfect,whethertheimageoflidofabeveragebottleisintegreted,etc.Traditionalsampletestcan’tmeetpeople’srequirementtowardshighqualityofproducts,andonlinetellingtestbasedonmachinevisionmakesitpossible.Thetext,atthebeginning,introducesthestudybackgroundanddevelopingprocessofdisfigurementtesttechnology,thenintroducesthearithmeticsofimageprocesstechnologyoftesting,andfinallydesignsadisfigurementtestsystembasedondigitalimageprocesstechnologytoensuretheexistanceofnickdisfigurementonthesurfaceofCD.Thedesigncanbediscribedasfollows:firstly,collecttheimage;secondly,usetheimageingrayconvert,removingnoise,amplifyingandsplittingundertheMatlabsimulationenvironment,finally,computetheareaandcircumferenceoftheprocesseddisfiguredimage,soastogetthedegreeofcircularityoftheimagetoensuretheexistanceofdisfigurementandjudgewhetherthetypeofdisfigurementoftheCDisnickaccordingtherangedimensionofthedegreeofcircularity.KEYWORDS:machinevision,disfigurementtest,surfacenick,degreeofcircularityI目录第1章前言................................................................................................................11.1研究背景.........................................................................................................11.2缺陷检测技术的研究现状.............................................................................11.2.1缺陷检测技术的发展历程..................................................................11.2.2存在的问题..........................................................................................41.3缺陷检测的分类方法.....................................................................................51.4基于图像处理的缺陷检测技术的应用.........................................................61.5本文的内容与章节安排.................................................................................6第2章缺陷检测的数字图像处理实现......................................................................72.1数字图像处理的概念.....................................................................................72.1.1数字图像..............................................................................................72.1.2数字图象处理的三个层次..................................................................82.2图像增强提取目标缺陷的研究.....................................................................92.2.1图像平滑去除检测图像的噪声........................................................102.2.2中值滤波降噪....................................................................................112.2.3直方图均衡........................................................................................112.3待检测图像的形态学处理...........................................................................132.4图像的边缘提取...........................................................................................142.4.1边缘提取概述....................................................................................142.4.2几种经典的边缘检测算子................................................................142.5缺陷图像的特征提取与选择.......................................................................162.5.1特征提取............................................................................................162.5.2特征选取............................................................................................17第3章基于Matlab的缺陷检测算法研究..............................................................183.1总流程图设计...............................................................................................183.2基于Matlab的工件图像预处理.................................................................193.2.1工件图像的Matlab读入与格式转换..............................................19II3.2.2工件图像的去噪和增强处理............................................................203.2.3工件裂纹的分割................................................................................213.3工件图像的特征提取与识别.......................................................................223.3.1特征提取............................................................................................223.3.2判断识别............................................................................................243.4图像处理所用Matlab函数.........................................................................25第4章实验结果对比与分析....................................................................................304.1试验参数...........................