数字图像处理ENGLISH

基于DCT的图像压缩技术研究与仿真实现题目：基于DCT的图像压缩技术研究与仿真实现院系名称：信息工程学院专业班级：集成电路工程专业学生姓名：刘家明学号：2011118562011年12月15号AbstractDiscreteCosineTransform(DiscreteCosineTransform,referredtoasDCT)isoftenconsideredtobethevoiceandimagesignalsasthebestwayoftransforming.Inordertoachievetherequiredengineering,manyscholarsathomeandabroadtospendalotofenergytofindorimprovefastDCTalgorithms.withthedevelopmentofDSPinrecentyears,couplingwiththeadvantagesofASICdesign,DCTfirmlyestablishedanimportantpositioninthecurrentimagecodingalgorithm,astobeanimportantpartofthecodingofH.261,JPEG,MPEGandotherinternationalstandardsonthepublic.MATLABisbytheAmericanMath-Worksintroducedforthenumericalcomputationandgraphicsprocessingforscientificcomputingsoftware,whichcombinesnumericalanalysis,matrixcomputation,signalprocessingandgraphicsdisplayfunctionsinoneandconstitutesaconvenientuser-friendlyenvironment.TheImageProcessingToolboxsinMATLAB,isthesetofpackagesofmanyMATLABtechnicalcomputingenvironment.ThispaperdiscussestheDCTtransformmethods,anddiscussesappliedfunctionsoftheimageprocessingtoolboxinMATLABandimplementrelatedtotheuseofClanguagetoimplementthediscretecosinetransformimagecompressionalgorithmsimulation.KEYWORD:DiscreteCosineTransform(DCT);MATLAB;VC6.0,DCTTransformationmethod;ImageProcessing;ImageCompression;CATALOGABSTRACT.................................................................................................................V1INRODUCTION.....................................................................................................72BASICPRINCIPLESANDMODELOFIMAGECOMPRESSION..............92.1BASICPRINCIPLESOFIMAGECOMPRESSION.......................................................92.1.1Thebasicideaofimagecompression....................................................................92.1.2Imagecompressionmethod..............................................................................92.1.3Imagecompressionstandard.........................................................................102.2IMAGECOMPRESSIONSYSTEMFLOWCHART.....................................................102.3ANALYSISOFTHEMAINMODULEOFIMAGECOMPRESSION...............................112.3.1Colorspaceconversion...................................................................................112.3.2DiscreteCosineTransform..............................................................................122.3.3Quantization......................................................................................................132.3.4Zshapedscan................................................................................................132.3.5Encodinganddecoding...................................................................................142.4THEPURPOSEOFIMAGEDATACOMPRESSION....................................................162.5BASICMODELOFIMAGECOMPRESSION............................................................173DISCRETECOSINETRANSFORMINCLANGUAGEANDMATLABSIMULATION.............................................................................................................193.1DISCRETECOSINETRANSFORM........................................................................193.2THEFUNCTIONOFMATLAB..............................................................................203.3DISCRETECOSINETRANSFORMINCLANGUAGEANDMATLABSIMULATION......................21CONCLUSION...........................................................................................................25APPENDIX.................................................................................................................261INRODUCTIONInthe21stcentury,mankindhasenteredtheinformationsociety,andnewinformationtechnologyrevolutiontothegrowinghumanbeingsurroundedbymultimediainformation,alsohappenstocatertothehuman'sdemandofvisualinformation.Therearethreemainformsofmultimediainformation:text,soundandimages.Fromthehistoryofthedevelopmentofinformationtransmission(telegraph,telephone,fax,radio,TV,networkuntilnow),wecansee,peoplegraduallyshiftthefocusfromthesoundtransmissiontotheimagetransmission,however,theimagedataintheformofthreetypesofinformationisthelargest,whichgivestheimagetransmissionandstoragebringwithgreatdifficulties.Forexample,thedatasofa640×480resolution24-bittruecolorimageareabout900kb;a100Mbharddiskcanstoreonlyaboutl00inactivepictures.Forsuchahugeamountofdigitalimagedata,ifnotcompressed,itisnotonlybeyondthecomputer'smemoryandprocessingpower,butalsointheexistingcommunicationchanneltransmissionrate,unabletocompletealargenumberofreal-timetransmissionofmultimediainformation,thus,thehigh-speeddigitalimagetransmissionandthehugestoragecapacityhasbecomethebiggestobstacletopromotethedigitalimagecommunication.Therefore,inordertostore,processandtransmit,thesedatasmustbecompressed.ImagecompressionhasbeenabletoCompressedbecausetheoriginalimagedataishighlyrelevant,withabigdataredundancy.Redundantinformationcontainedthedigitalimagesgenerallyhavetheseveralasthefollowing:spatialredundancy,temporalredundancy,entropyredundancy