数字图像处理课件(冈萨雷斯第三版)英文翻译课件

DigitalImageProcessing,TianjinUniversityofTechnologyandEducationSchoolofElectronicEngineering2017,Synopsis,Thecontentsoftheeightweeksareasfollows:Thefirst、secondchapteristheintroductionandthebasicconceptofimageprocessing.Thethird,fourthchapterisspacedomainandfrequencydomaintransformThefifth,eighthchapterisimageenhancementandimagerestoration.,ThesixthchapterisimagecodingTheseventh,ninthchapterisimagesegmentationandmorphologyThetenthchapter,other,Thefirstchapterisintroduction,1.1FromimagetoimageengineeringImageanddigitalimageImagetechnologyandimageengineeringRelateddisciplinesandfields.1.2ImageprocessingandanalysisImageprocessingandanalysissystemImageacquisition,display,storage,communication,processingandanalysismodule,imageprocessing,imageanalysis,Imageunderstanding,Abstractdegree,Dataquantity,Imagefoundation,1.1.1ImageanddigitalimageWhatisanimage?Animageisavisualrepresentationofpictures,animations,etc.Thedifferencebetweengraphicsandcomputergraphicsisthatcomputergraphicsarefrombuildingmathematicalmodelstogeneratinggraphics,andimagesusuallyrefertographsgeneratedfromoutside.Theobjectiveworldisathree-dimensionalspace,butthegeneralimageistwo-dimensional.Twodimensionalimagesinevitablylosepartoftheinformationintheprocessofreflectingthethree-dimensionalworld.Evenrecordedinformationcanbedistortedandevendifficulttorecognizeobjects.Therefore,itisnecessarytorecoverandreconstructinformationfromimages,andtoanalyzeandextractmathematicalmodelsofimagessothatpeoplecanhaveacorrectandprofoundunderstandingofwhatisrecordedintheimage.Thisprocessbecomestheprocessofimageprocessing.,1.1Fromimagetoimageengineering,Whydoyouneeddigitalimages?Ordinaryimagescontainenormousamountsofinformationandrequiretheuseofcomputerstoprocessimages.Therefore,itisnecessarytotransformordinaryimagesintodigitalimagesthatthecomputercanprocess.Todaysdigitalcamerascandirectlyconvertvisualimagesintodigitalimages.Adigitalimage,similartorastergraphics,consistingoffiniterowsandfinitecolumns.Eachbasicunitiscalledapixel.Thevoxelofathree-dimensionalimageisalsocalledvoxel.Thetwo-dimensionaldigitalimageusuallyisarectangle,youcanuseatwo-dimensionalarrayofI(x,y)tosaid,wherex,ycoordinatesinatwo-dimensionalspaceisacoordinatesystem,I(x,y)saidintheimagegrayvalueatthepointandotherproperties.ColorcanbepreparedthreeRGBmonochromaticgrayvalue.Generallyspeaking,thesecoordinatesandgrayvaluesarerealnumbers,notonlydependontheselectionofcoordinatesystem,butalsodependonthemeasurementunitofgrayvalue.However,adigitalcomputercanonlyrepresentfinitenumbersoffinitewordlengths.Therefore,thegrayvaluemustbediscretized.Simplyput,adigitalimageisequivalenttoafinitematrixofintegervalues.Digitalimageistheobjectofdigitalimageprocessingandanalysis.,Theimageontheleftistheimageprocessingtechnique.UsedtotestcomputeralgorithmsAstandardimageofactualeffects.Thenameofthisimageislenna.Itismadeupofasetofnumbers.OriginalimageThewidthandheightare256pixelseach.Thereareeightbitsinpixels.ItisinBMPformatAbout66Kbytesinsize.,AbriefhistoryofdigitalimageprocessingThegenerationofdigitalpicturesisfaraheadofthecomputer.Thefirstdigitalimagetransmittedbytelegraph.Insixand70s,withthedevelopmentofcomputerhardwareandthediscoveryoffastFuLiyetransformalgorithm,itwaspossibletousecomputertoprocessimages.Since80s,threedimensionalimageshavebeenprocessed.Since90s,withtheimprovementofcomputerperformanceandextensiveuse,imageprocessingtechnologyhasbeeninvolvedineverycornerofsociety.Theimagehasgraduallydominatedthemediaandproducedmanynewindustriesandnewopportunities.Thefuturedevelopmentoftheimageprocessingislimitless.Digitalimageprocessingbelongstocomputerscience,but90%ofitreliesonmathematics.Fromthispointofview,thedigitalimageprocessingtechnologyisaveryidealdirectionforthestudentsofthisspecialty.,1.1.2Imagetechnologyandimageengineering,Whichbelongstoimagetechnology?Imagetechnologyisageneraltermforthetechnologyconcernedwithimages.Itisakindofcomprehensivetechnicalengineering.Itincludesimageacquisition,acquisition,encoding,storageandtransmission,imagegeneration,displayandoutput,imagetransformation,enhancement,restorationandreconstruction,imagesegmentation,targetdetection,expressionanddescription,featureextraction,imageclassification,imagerecognition,modelingandmatching,imageandsceneunderstanding.Narrowsensedigitalimageprocessingreferstotheenhancement,restorationandreconstructionofanimage.Theobjectofoperationisthepixelofanimage,andtheoutputisanimage.,Whatisimageengineering?(generalizeddigitalimageprocessing)Itiscomposedofthreesystems:imageprocessing,imageanalysisandimageunderstanding.Imageprocessingincludesimageacquisitionandtransformationfromimagetoimage,soastoimprovethesubjectivevisualeffectandtodopreliminaryprocessingforimageanalysisandimageunderstanding.Imageanalysisistoextractthedataofinterestfromtheimagetodescribethecharacteristicsofthetargetintheimage.Imageunderstandingisbasedonimageanalysistostudythenatureandrelationshipofeachobject,inordertogettheunderstandingofthecontentoftheimageandexplaintheoriginalscene.Imageprocessing,imageanalysisandimageunderstandingarethreedifferentabstractprocessesfromlowtohigh.Thiscoursefocusesonimageprocessingandanalysissystems.,imageprocessing,imageunderstanding,imageanalysis,Abstractdegree,Dataquantity,Image,Data,Symbol,1.1.3Relateddisciplinesandfields,Imageengineeringisasystematicstudyofvariousimagetheories,techniquesandapplications.Fromtheresearchmethod,andmathematics,physics,psychology,biology,electronics,computersciencecanlearnfromeachother,fromthescopeofit,andpatternrecognition,computervision,computergraphicsandotherdisciplines.,1.2Imageprocessingandanalysis,1.2.1ImageprocessingandanalysissystemTheimageprocessingandanalysissystemincludesthefollowingmodules:imageacquisitionmodule,imagedisplaymodule,imagestoragemodule,imagecommunicationmoduleandimageprocessingandanalysismodule.1.2.2ModularImageacquisitionmoduleImagedisplaymoduleImagestoragemoduleImagecommunicationmoduleImageprocessingandanalysismodule,1.2.1Thedatastructureofanimagefile,Thebasicfunctionsofacompleteimageprocessingprogramare:openimagefiles,displayimages,imagefilesforthespecifiedprocessing,storageofimagefiles.Sinceimagefilesarelarge,theyusuallyneedtobecompressedbeforestorage.Soopeningandstoringimagefilesinvolvestheformatofthefile.FormatofimagefileTheimagefilereferstothefilecontainingtheimagedata.Inadditiontotheimagedataitself,thedocumentgenerallyhastheimagedescriptioninformationfortheimagetoreadanddisplay.Representsavectororrasterformofanimage.Invectorform,theimageisrepresentedbyaseriesoflinesegmentsorlinesegments,andthegraylevelsofthesegmentscanbedifferent.Eachpartofthecompositebodycanbefilledwithdifferentgraylevels.Avectorformfilehasaseriesofcommandsanddata,andtheresultisanimage.,Imagedatafileismainlyrasterform,thatis,theimageisacollectionofimagepoints,moresuitableforcompleximageschange.Itsmaindrawbackisthelackoflinksbetweenobjectsandpixels,andchangesintheimageduringtheexpansionoftheimage.Forexample,commonimagefiletypesareBMP,JPG,andsoon.Theimageprocessingprogrammustconsidertheformatoftheimagefile,otherwiseitisnotpossibletoopenandsavetheimagefileproperly.PgmformatManyuniversitiesintheUnitedStatesusepgmformattoavoidusingcompressedfileformats,whichisveryconvenientforbeginners.Hereisanimageofthisformat.,Thisisacolorpictureinpgmformat,Thisisthepgmformat,colorphotos,16partsystemcode.Theoriginalcodeisnotastringofbranches.Itswrittenintheformofabranch(attention：LF=SP=newline;space;#=commentline)：0 x500 x350 x0AexpressP5(LF);0 x230 x200 x200 x490 x0Aexpess#(SP)(SP)I(LF);0 x360 x340 x300 x200 x340 x380 x300 x0Aexpress640(SP)480(LF);0 x320 x350 x350 x0Aexpess255(LF)0 x270 x27express23,23,(Pixelgrayvalue),Thedecodingofthisimagefile:,P5#ImportedfromSUNimage:LEGGO_HOUSE_1.0.intensity6404802550 x270 x270 x270 x270 x270 x270 x270 x270 x270 x270 x270 x270 x270 x260 x270 x270 x270 x280 x270 x270 x270 x270 x270 x270 x270 x270 x270 x270 x270 x270 x270 x270 x270 x270 x270 x260 x270 x260 x270 x280 x270 x270 x260 x270 x270 x270 x280 x270 x270 x270 x270 x270 x270 x280 x280 x270 x280 x290 x280 x270 x280 x280 x280 x270 x270 x270 x270 x270 x270 x270 x280 x270 x280 x280 x280 x280 x280 x280 x280 x280 x280 x290 x290 x290 x280 x280 x280 x28.,PGMformatdigitalimagefileisacommonformofimageprocessing,teachingandresearchinAmericancomputerscience.Althoughthevolumeoffilesisrelativelylarge,thepixelisdirectlyrelatedtothenumber,soitiseasytocheckandmodify.Itconsistsoftwoparts:1、thefirstpartisthefilehead,whichconsistsofseveralrows:Thefirstlineillustratesthetypeoffile,forexample,P2(forblackandwhiteimages)orP5(forcolorimages);Thenisto#atthebeginningoftheannotation,thecommentlinedoesnotperforminthesoftwarewhentheimageisopened,cannotcomment,orhowto#atthebeginningofthecommentline;Thefirstlineafterthecommentlinespecifiesthesizeofthedigitalimage,forexample,640480(640pixelswide,480pixelshigh,withaspaceinthemiddle);Thenextlinespecifiesthegrayscaleoftheimage,forexample,255.Therearenopunctuationmarksattheendofeachline.2、The2andsecondpartsarebitmaparraysthatarenolongersegmented.Forexample,inthe256grayscale,theP2typeisonepixel,onebyte(8bits),andtheP5typeisonepixel,threebytes(R,G,B,8bitseach).,Thesecondchapterisaboutimageandvision,2.1IntroductionandreviewThefoundationincludesthreeparts:visionbase,imagingbaseandimagefoundation:Visualbasis(humaneyesandbrightness,vision,color,vision)ImagingFundamentals(model,geometry,andsamplingquantization)Imagebasis(interpixelrelation,imageoperationandimagecoordinatetransformation)Becareful：Visual:referstothestimulationoflighttothesensesandthesenseofthevisualsystem.Visualperception:howtoformanimageoftheexternalworldthroughvision.,2.2Humaneyeandbrightnessvision,2.2.1HumaneyeimageThehumaneyeisacomplexvisualorgan.Thefrontoftheeyehasalens,thelensofacamera.Theposteriorpartoftheeyeballhastheretina.Therearetwophotoreceptorsonthesurfaceoftheretina:conesandcolumncells.Therearesixandsevenmillionconecellsintheeye,whicharesensitivetobrightlightandcolor.Theeyedividesthedetailswiththeaidofcones,becauseeachconeisconnectedtothenerveending.Thevisionofconesiscalledlightvision.Thereare750thousandto1million500thousandcolumncellsintheeye.Theyarelarge,andseveralcolumncellsareattachedtoonenerveend.Lowresolution,mainlyprovidingoverallvisualimpression.Althoughtheyarenotsensitivetocolor,theyaresensitivetoweaklight.Thevisionofcylindricalcellsiscalleddarkvision.Thecenteroftheretinaisthefovea,anareaofabout1.51.5mm2long,theconecelldensityreached150000/mm2,isthemostsensitiveeyearea.,Humaneyestructure,人眼成像,Densityanddistributionofconesandcolumncells,2.2.2Brightnessadaptationanddifferentiation,Subjectivebrightnessandsubjectiveadaptability,becausethedigitalimagedisplaystheimagewithobjectivebrightness,thehumaneyegetsthevisionwithsubjectivebrightness,sothebrightnessadaptabilityofhumaneyeaffectstheresultofimageprocessing.Thevisualsystemofthehumaneyecanadapttothebrightnesslevelofthelight,fromvisibledarknesstoglare,thedifferencecanreach1010levels.Butthehumaneyedoesnotseeobjectsinsuchalargerangeatthesametime,andcanonlyadapttoasmallrangeofbrightnesschangesatthesametime(level106).,Undercertainconditions,thecurrentsensitivityofavisualsystemiscalledthebrightnessadaptationlevel.Thesensitivityisverifiedbyexperiments.Intheexperiment,graduallyincreasethelightintensityofI,changealotforI,toachieveanumberofobserverscanperceive,whenpeopleperceivedhalfoftheincreaseintheI/IWeberratiohasbecomealot,asthesensitivityofthecurrentvisualsystem.Inverystronglight,itisnecessarytochangetheintensityofthelighttoallowmultipleobserverstoperceive;onthecontrary,inacertainintensityoflight,theslightchangesinlightintensitywillmakepeopleperceive.,Thesubjectivebrightnessofthehumaneyeisnonlinear,forexample,theMachband,Opticalillusionsofhumaneyes,2.3colorvision,Accordingtothestructureofthehumaneye,allcolorsaredifferentcombinationsofthreebasiccolors,Allcolorscanberegardedasthesuperpositionofthreebasiccolors,canbeseenasthethreecolor(acolorremovalfromwhite)superposition,Threebasicfeaturesofcolor:gray,hueandsaturation,andthelatterarecalledchromaticity.Thegrayscaleisproportionaltothereflectivityoftheobject;thehueisrelatedtothemainspectruminthelight;thesaturationisrelatedtothepurityofthehue.ThethreestimulithatmakeupthecolorCareX,Y,Z,andthepercentagesarex,y,ZX=X/(X+Y+Z),y=Y/(X+Y+Z),z=1-X-Y.,2.5imagingtransformation,LetW(X,Y,Z)bethecoordinatesofanypointinthe3Dspace,Z=Accordingtothepropertiesofsimilartriangles,x/=X/(-Z),y/=Y/(-Z),x=X/(-Z),y=Y/(-Z)Makeuseofpointwhhomogeneouscoordinates(kX,kY,kZ,K)1000P=0100001000-1/1ch=Pwh=P(kX,kY,kZ,k)=(kX,kY,kZ,-(k/)Z+k）=(x,y,z,1)x=kX/(-k/Z+k)=X/(-Z),thesamewaytogetyandZ,x,Z,(X,Y,Z),0,wh=P-1ch1000P-1=01000010001/1wh=P-1(x,y,0,1)=(x,y,0,1).ThereisnocoordinatecomponentZ,sothepointof3DcannotberepresentedIfadditionaldepthinformationZisknown,thenthepointof3Dcanberepresented,(X,Y,Z,1)=wh=P-1(x,y,z,1)=(x,y,z,z/+1).其中，X=x/(+z),Y=y/(+z),Z=z/(+z),2.6samplingandquantification,Animageneedstobediscretizedtobecomeadigitalimagebeforeitcanbeprocessedbyacomputer.Thediscretizationofspatialcoordinatesofimagesiscalledspatialsampling,andthediscretizationofgrayscaleiscalledgrayscalequantization.Samplingisdividedintouniformsamplingandquantificationandnonuniformsamplingandquantification.Supposetheimageisarectangle.TakeMlongNthesameasthesizeofthegridintheplane,andthegraylevelisdividedintoG.Theclosestgraynumberateachpointineachgridistakenasthegraylevelofthegrid.Usually,takeM=2m,N=2n,andG=2k.Thenumberofbitsneededtostoreanimageisequaltob=MNk.Forexample,animageof128long128,64graylevelneeds220,512long512,256imagegraylevelto226.Thenumberofsamplingandtheselectionofgraylevelarerelatedtotheresolutionandstorageability,whichneedtobeconsideredcomprehensively.Suchas:Theeffectofchangesinimagespatialresolution.Theeffectofchangesinimagegrayscaleresolution.Theeffectofsimultaneouschangesinimagespaceandgrayscaleresolution.,Theeffectofchangesinimagespatialresolution,Theeffectofchangesinimagegrayscaleresolution,Effectofchangesinimagegrayscaleresolution(2),Nonuniformsamplingandquantization,Giventhespatialresolution,thequalityoftheimagecanbeimprovedbyadaptivesamplingprocessaccordingtotheimagecharacteristics.Forexample,areaswithlargevariationsingraylevelsshouldbesampledmoreclosely.Also,forexample,thefrequencyofallgrayvaluescanbecalculated.Ifarangeofgrayvaluesappearfrequently,andinotherareas,thegrayvaluesappearmoresparse,theninthisrange,thequantizationgrayscaleismoredense,andinotherareaslessdilute.,2.7Pixelconnection,PixelshavefourneighborhoodN4andeightneighborhoodN8。Pixelconnectivityconsistsof4-connections,8-connections,andhybridconnections(m-connections).CallpointsRandParemixedconnections,ifRandPare4-connections,orRandPare8-connected,butnot4-connected.Thehybridconnectionavoidsambiguityarisingfrom8-connectivity.,2.8ArithmeticandlogicThefouroperationsoftheimagearedoneonebyoneasimagepoints.Theadditionisusedtoremovenoisecommonlyusedinmedicalimaging,subtraction,multiplicationanddivisionisoftenusedtocorrecttheimageofthegrayshadow.Commonlyusedlogicaloperationsare（1）（AND）（2）（OR）（3）（NOT)Theaboveoperationscanbeusedeitherforthewholeimageorforneighborhoodoperations.Forexample,thearithmeticmeanofonepointandits8-neighborhoodisusedasthenewvalueofthispoint.Now,theunitALUofarithmeticandlogicoperationsisusedtospeedupoperations.,Thethirdchapteristhespatialrelationofpixels,Imagesaremadeupofpixels.Animageisconstructedinpixels.Usuallyx,axialleft,Yaxisdown.Thecoordinatetransformationofanimageisthecoordinatetransformationofapixel.Theso-calledspatialtransformationisthetransformationofpixelsfromonespacetoanother.Oneoftheapplicationsofcoordinatetransformationistocorrectthegeometricdistortionofanimage.,Theneighborhoodofapixelreferstothesetofpixelsaroundthepixel.ApixelPissurroundedbyeightpixels,whichtogetherformthe8-neighborhoodN8(P)ofthepixel.The4-neighborhoodN4(P)consistsofonepixelandfourpixelsintheupperandlowerparts.ApixelconsistsoffourdiagonalpixelscalleddiagonalneighborhoodND(P).Adjacency,connectionandconnectivitybetweenpixelsofthesamegrayscale:Thetwopixelsfallintoeachothers4-neighborhood,calledthe4-connectionThetwopixelsfallintoeachothers8-neighborhood,calledthe8-connectionIftwopixelsor4-connections,ornot4-connections,fallintoeachothersdiagonalneighborhoodND(P),thentheyarecalledhybridconnections(m-connections).,3.1pixelconnection,Mixedconnectionscanavoidmultipathproblemscausedby8-connections.Theconnectivityoftwosetsofpixelsmeansthattheyhaveapathwithinthespecifiedneighborhood。,Forexample,theupperleftcornerandthelowerrightcornerofthefigureTheconnectionby4-isdisconnected;Theconnectionbym-isconnected;The8-connectionisconnected,butthepathisnotunique.,ThedistancebetweentwopixelsPandQ,i.e.,afunctionthatsatisfiesthefollowingthreeconditionsD：D(p,q)0，ifandonlyifp=q,D(p,q)=0.D(p,q)=D(q,p),D(p,q)+D(q,r)D(p,r).,DE(p,q)representstheEuclideandistancebetweenp=(x_p,y_p)andq=(x_q,y_q)DE(p,q)=(x_px_q)2+(y_py_q)21/2D4(p,q)representsthedistanceunderthe1-normD4(p,q)=|x_px_q|+|y_py_q|.D8(p,q)reresentshedistanceunderthe-normD4(p,q)=max|x_px_q|,|y_py_q|.,1,0,1,1,1.4,1,1.4,1.4,1.4,0,1,1,1,1,2,2,2,2,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,Whatisthedistancefrompixeltoboundaryintherightmostgraph?,EachpixeltocenterdistanceD：,3.2basiccoordinatetransformation,Ithasalreadybeentoldincomputergraphics.Thebasiccoordinatetransformationsaretranslation,expansion,androtation.,Complexcoordinatetransformationsaretheircascade.,Iscutanderrortheproductofthreefundamentaltransformations?,3.3morphologicaltransformation,3.3.1transformsystem1,.morphologicaltransformationanditsclassificationMorphologicaltransformationisthetransformationofaplaneregionintoaplaneregion.,Morphologicaltransformation,Tablesandrules,Analyticformula,Discontinuous,continuity,Unsmooth,smooth,linear,Nonlinear,Affinetransformation,euclideantransformation,Rigidbodytransformation,Similaritytransformation,Translationtransformation,Rotationtransformation,Scalingtransformation,Projectiontransforma