基于指纹预处理的指纹识别及MATLAB仿真

编号：审定成绩:重庆邮电大学毕业设计（论文）设计（论文）题目：基于图像预处理算法的指纹识别及MATLAB仿真学院名称：重庆邮电大学学生姓名：吴自龙专业：通信工程班级：0111013学号：2010211764指导教师：姚玉坤答辩组负责人：填表时间：年月重庆邮电大学教务处制重庆邮电大学本科毕业设计（论文）-I-摘要指纹的唯一性与稳定性使指纹识别技术发展迅猛，在生物特征识别中占据了越来越重要的地位。虽然在指纹识别领域已经有了不少研究成果，但是随着社会的发展与进步对指纹识别系统提出了更高的要求，所以对指纹识别技术进行研究，仍然具有重要意义。本文对指纹识别算法进行了分析和研究，主要包括指纹图像预处理、指纹特征提取以及特征匹配算法。在指纹图像预处理阶段，着重对比分析了Gabor滤波增强算法和短时傅里叶变换算法（ShortTimeFourierTransform-STFT）。在特征提取阶段，采用基于细化图像的特征提取算法，对细化后的指纹图像的每个像素点进行8领域计算，提取出所有的终结点和分叉点，然后对提取到两类特征点进行伪特征点的剔除，为后续匹配创造了条件。指纹匹配阶段，本文简要介绍基于极坐标的特征点匹配算法。通过MATLAB对指纹图像预处理和特征提取算法进行了仿真分析，实验结果表明STFT算法比Gabor滤波增强算法更能有效地连接断脊，去除粘连脊线，大大减少了后续提取的伪特征点数量，为进一步的匹配创造了条件。【关键词】指纹识别算法预处理特征提取特征匹配MATLAB重庆邮电大学本科毕业设计（论文）-II-ABSTRACTTheuniquenessandstabilityoffingerprintcausetherapiddevelopmentoffingerprintidentificationtechnology,whichmakesitplayamoreandmoreimportantroleinbiometricfeaturesrecognition.Althoughtherearealreadyquiteafewresearchachievementsintheareaoffingerprintidentification,increasinglyhighrequestsforfingerprintidentificationsystemaremadetouswiththedevelopmentofthesociety.Therefore,theresearchoffingerprintidentificationtechnologyisstillofgreatsignificance.Thisthesismainlyanalyzesandresearchesonthealgorithmoffingerprintidentification,includingpreprocessingoffingerprintimage,featureextractionandfingerprintmatching.Inthecourseofpreprocessing,thisthesiscomparesandanalyzestheeffectofGabor-filter-enhancementalgorithmandShort-time-fourier-transformation(STFT)enhancementalgorithm.Atthestageoffeatureextraction,featureextractionalgorithmbasedonthinningimageisadopted.Simplecalculationisconductedon8-connectedtofindalltheendpointsandbifurcations,afterwhichspuriousminutiaeisremovedfromthem,whichcreatetheconditionsforthelaterfeaturematchingprocess.Asforfeaturematching,thisthesishasabriefintroductionofminutiaematchingalgothrim.SimulationexperimentisperformedwithMATLABonthealgorithmoffingerprintimagepreprocessingandfeatureextraction,whichdemonstratesthatSTFTalgorithmismoreeffectiveonconnectingthebrokenridgeandgetridofadhesiveridgethantheGabor-filter-enhancementalgorithm,whichwillgreatlyreducethenumberoffalseminutiaeafterwardsandcreateabetterconditionforlattermatchingprocedure.【Keywords】FingerprintIdentificationAlgorithmPreprocessingfeatureextractionfeaturematching重庆邮电大学本科毕业设计（论文）-III-目录前言...................................................................................................................................1第一章绪论.....................................................................................................................2第一节研究背景及现状..............................................................................................2一、指纹识别概述.................................................................................................2二、指纹识别研究现状.........................................................................................4第二节课题研究目的及意义......................................................................................5第三节本文主要工作和章节安排..............................................................................5一、本文主要工作.................................................................................................5二、章节安排.........................................................................................................6第四节本章小结..........................................................................................................6第二章指纹识别的基本理论与评价标准.........................................................................7第一节AFIS的基本结构............................................................................................7第二节指纹识别的基本原理......................................................................................8一、指纹采集的原理...........................................................................................10二、指纹图像预处理的原理...............................................................................10三、指纹图像特征提取的原理...........................................................................11四、指纹特征匹配的原理...................................................................................11第三节指纹识别效果的评价方法............................................................................12一、指纹图像增强效果评价方法.......................................................................12二、指纹识别效果评价方法...............................................................................12第四节本章小结........................................................................................................13第三章指纹图像预处理及识别算法概述.......................................................................14第一节指纹图像预处理算法....................................................................................14一、归一化算法...................................................................................................14二、指纹图像增强算法.......................................................................................15三、二值化算法...................................................................................................23四、细化算法............................................................................................