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,(,430071):,2,,,:;;;;:TG115.28:A:100026656(2003)0620279204WAVELETDENOISINGANDMULTI2SCALEEDGEDETECTIONINULTRASONICIMAGINGZHANGYang,CHENJian2zheng(MathematicsandPhysicsInstitute,ChineseAcademyofScience,WuhanHubei430071,China)Abstract:Aflawdiscriminationmethodbywaveletdenoisingaccompaniedwiththegivenmulti2scaleedgedetectionsignalaccordingtoultrasonicimagewaspresented.Basedonaunifiedscale2spatialanalysisframe,statisticalmodel,andsoft2threshold2ingandclassicalWienerestimationmethods,apracticalalgorithmwithminimumerrorwasprovided.Thentheinformationintheimageindicatingflawcharacterwasextractedbymulti2scaleedgedetection.Keywords:Ultrasonictesting;Image;Denoising;Signalprocessing;StatisticalmodelB,,(),,,(),,:2003203224:(10134020)1989Mallat[1],(GGD),,,Witkin[2],,,,,,,97225620036NDTVol.25No.6Jun.2003©1995-2003TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.1[16]:1.1(1)wj,k2-jk,2-jf02/2jj,2;,1/f(2),Q(,,,,Q,Q)(3),,(4),(5),1.2(1)(2)()[7](3)1.3(1)(2)22.1,,[8],,Besov,[6],,;,,,2.2,,;,,f(W)=f(wi),;(),P(Gsig)=1-P(Ginsig)Gsig,GinsigP(Gi)Gsig;Ginsig,G,[4]fw(W)=2m=1P(G)fw|G(w|G=m)=P(Gsig)fw|Gsig(w|Gsig)+P(Ginsig)fw|Ginsig(w|Ginsig),T(GsigGinsig),,(EZW[9])T,,GsigGinsig1,Gsig;Ginsig(T),GGDGinsig(),GGD;Gsig(),Laplace082:©1995-2003TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.1(i,j)T,(i,j)Gsig(i,j)T,(i,j)Ginsig,[6]GGD,GGD(2)GGD()=()211e-()||()31=2;=1Laplace;,,01,GGDGGD,[6]2.3,,,[8]n(x)2,wj,wx,n(x),w,2j^[8],w2j^,,,,,(),,,T[10],2j^T2.4Y,2^NW=Y+N,WY,,2y,j(j,j(H,V,T)),:(1),(SNR),(2)(),Laplace,2y,j=max{0,Var{wi(ij)}-2n};jWiener;MAPy,=22x/2y,j,T2GGD182:©1995-2003TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.(a)GsigLaplace,,y,2y,Gsig=max{0,Var{yi,iGsig}-2n}(b)Ginsig,,,,Ginsig2i,y,WienerMAPy,^yi=^2iwi/(^2i+2n)T,,,,y,3,,,,,,,,Lipchitsz,;,,,,,,,4B,MATLAB5.3(x)B,Holschneider[11,12],2^(j-1)-1(j,13)VB6.0,34635,,,,,456(286)282:©1995-2003TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.3LSPRCHgHc,2.3HgHc2LSPRC(LSP(7)(8),RC=8s),2Hw,2Hw2Hw2Hw,22,2Hw,RC,LSP,,RC,,LSP[9](7)(8)1aN0=147,LSPf,N0=147LSP,RC(=32s)2LSPRC()Hg=Hc2HwLSPRCLSPRC1.00.000-0.2680.0220.0851.5-0.001-0.2710.0170.0812.0-0.002-0.2740.0200.0682.50.001-0.2750.0270.0563.00.000-0.2750.0310.0443.50.000-0.2760.0320.0324.0-0.002-0.2770.0290.0184.50.000-0.2800.0390.0094X,LSPRCLSPX,(290)(282),(2),,,,:[1]MallatSG.Theoryformultiresolutionsignaldecomposition[J].IEEETransonPatternAnalysisandMachineIntelli2gence,1989,11(7):686.[2]XuY,WeaverJB,HealyDM,etal.Wavelettransformdo2mainfilters:aspatiallyselectivenoisefiltrationtechnique[J].IEEETransonImageProcessing,1994,3(6):747-758.[3]DonohoL,JohnstoneIM.Idealspatialadaptationviawaveletshrinkage[J].Biometrika,1994,81(3):425.[4]ChoiH,BaraniukR.Multiplebasiswaveletdenoisingusingbesovprojections[A].InternationalConferenceonImageProcessing(Vol.1)[C].KobeJapan:1999.595.[5]DohonoDL.Denoisingbysoft2thresholding[J].IEEETransonInformationTheory,1995,41(5):613-627.[6]MihcakMK,KozintsevI,RamchandranK.Localstatisticalmodelingofwaveletimagecoefficientsanditsapplicationtodenoising[A].ProcIEEEIntConfAcoustSpeechandSignalProc[C].PhoenixAZ:1999.[7]MoulinP,LiuJ.Analysisofmultiresolutionimagedenoisingschemesusinggeneralized2Gaussianpriors[A].ProcIEEETFTSSymposium[C].PittsburghPA:1998.633-636.[8]ZhengY,TayDBH,LiL.Signalextractionandpowerspec2trumestimationusingwavelettransformscalespacefilterandBayesshrinkage[J].SignalProces2sing.2000,80(8):1535.[9]ShapiroJ.Embeddedimagecodingusingzero2treesofwaveletcoefficients[J].IEEETransactionsonSignalPro2cessing,1993,41(12):3445-3462.[10],.[M].:,1994.86.[11].[M].:,1998.209.[12].[M].:,1999.682:X©1995-2003TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.