车辆图像的车牌字符分割方法设计与实现

车辆图像的车牌字符分割方法设计与实现DesignandImplementationMethodofVehicleLicensePlateCharacterImageSegmentationI摘要随着社会的发展，车辆将越来越多，为了更好地管理车辆，智能交通系统将是发展的方向，而车牌自动识别系统是智能交通系统中一个重要的环节，它主要包括三个关键技术：车牌定位、车牌字符分割以及车牌字符识别。本文针对车牌自动识别系统中关键技术之一的车牌字符分割部分做了深入的研究。首先，本文对车牌字符分割前的预处理进行了较深入研究，尤其是车牌图像二值化后的去噪处理，包括开闭运算、去除边缘、去除圆点等。其次，在字符分割算法中，给出两种分割算法，一种是固定边界法，另一种是垂直投影法，并对车牌字符进行了分割。然后，在分析了这两种方法的优缺点后，将这两种方法相结合进而得到改进的投影法，实验表明，就算是在除噪后仍然有少量噪声的车牌进行分割时，该方法也可以得到很好的字符分割效果。关键词：字符分割；二值化；投影法IIAbstractTherewillbemoreandmorecarswiththedevelopmentofsociety.IntelligentTransportSystemwillbethedirectionofdevelopment.SystemofLicensePlateAutomaticRecognitionisanimportantpartoftheIntelligentTransportSystem.Itiscontainofthreekeytechnologies:thelocationoflicenseplate,thedivisionoflicenseplatecharacterandtherecognitionoflicenseplatecharacter.ThispaperstudiedatcharacterrecognitiontechnologywhichisonekeytechnologyoftheSystemofLicensePlateAutomaticRecognition.Atfirst,Istudythelicenseplatecharactersegmentationimagepreprocessing,especiallythelicenseplateimagebinarizationofdenoisingprocessing,includingopenarithmetic,closearithmetic,wipeoftheedge,andwipeoftheroundspotetc.Thesecond,therearetwowaystodividetheplate.onewayisthefixedboundary,andtheotherisaverticalprojection.ThenIseparatethelicenseplatecharacters.finally,Icomparedtwokindsofmethods,theycanbeincorporatedintothenewprojectionmethod.Theexperimentalresultsshowthatevenafterthenoisereductionstillcontainsasmallamountofnoiseofthelicenseplatesegmentation,themethodalsocangetverygoodeffect.Keywords:Thedivisionoflicenseplatecharacter；Binarization；ThemethodofshadowIII目录第一章绪论................................................................................................................................11.1车牌识别技术的应用背景及前景....................................................................................11.2车牌识别系统的工作原理及组成....................................................................................21.3字符分割的发展现状........................................................................................................31.4本文研究主要内容............................................................................................................31.5本文的结构........................................................................................................................4第二章车牌字符分割的相关理论基础......................................................................................52.1数字图像处理技术............................................................................................................52.1.1灰度图像.....................................................................................................................52.1.2二值图像.....................................................................................................................52.2数学形态学理论基础........................................................................................................52.2.1数学形态学的基本概念.............................................................................................52.2.2二值形态学的基本运算.............................................................................................6第三章车牌图像的预处理.........................................................................................................83.1车牌图像的灰度化............................................................................................................83.2车牌图像的二值化............................................................................................................83.3车牌图像的去噪处理........................................................................................................93.3.1车牌图像的开运算...................................................................................................103.3.2车牌图像的闭运算...................................................................................................103.3.3去除车牌边框...........................................................................................................103.3.4去除车牌图像中的圆点...........................................................................................12第四章车牌字符分割方法及结果分析....................................................................................134.1基于垂直投影的车牌字符分割方法..............................................................................134.1.1垂直投影法的原理...................................................................................................134.1.2应用垂直投影法的实现步骤...................................................................................144.2基于固定边界法的车牌字符分割方法..........................................................................144.2.1固定边界法的原理...................................................................................................144.2.2应用固定边界法的实现步骤...................................................................................15IV4.3投影法与边界法相结合..................................................................................................154.3.1改进法的原理...........................................................................................................154.3.2应用改进法的实现步骤......