m sequence SS code

Vol.13,No.2©2002JournalofSoftware1000-9825/2002/13(02)0298-06Ã,(,200030)E-mail:[e-mail];[e-mail]:;;;:TP309:A,.,.,.,.,,.,,.,.,,.,,,.11.1,(cover-image);;(stego-image).[8]1.Ã:2000-05-20;:2000-08-07:(1972),,,,;(1940),,,,,,,.:299Modulation/emissionReception/demodulationStego-imageCover-imageDisturb/AttackKeyEmbeddedwatermarkChannelRecoveredwatermark,/,,,,,,/,/.Fig.1CommunicationmodelofdigitalImagewatermarking1,.,,,[2].1.2[1],..(Shannon),)/1(log2NSWC+=.(1)(1),C,bits/pixel,W,N,..S1/NS,(1):SNCW/44.11⋅=.(2)(2),,,.,,,,.,,,.,m[1,3].m,n,01.12−n[1],m,.p=2n-1m,1≤i≤2−==pi/1)(1)0(ρρn−2,(3),n0,,.,m,.10,1023m,,m{0,1}{1,–1},01,1–1,.1.3[6~8],,,.,[4],300JournalofSoftware2002,13(2),.Canny[5],Canny,,,.1.41616“Playboy”.,.,,[2],.BCH(bose-chaudhuri-hocquenghem),.,BCH(7,4),7,4,71.mBCH,(binaryphaseshiftkeying,BPSK)[1,2,6],.,P,Pm,m,.,,G,3,,2.I′=I+MW,(4)I,W,M,I′.BCHEncodingWatermarklogoCover-ImageModulationVisualmaskStego-ImagemSequenceSScodeSSG,BCH,m,,,,,.Fig.2Watermarkembeddingprocess21.5m.[7],,,,[8].,,,.,.,,(5)m()(),,,BCH,3.kMkI(5)∑=+=pkkkMIR1)(ττ:301Cover-ImageBCHdecodingStego-ImageVisualmaskDemodulationmsequenceSScodeWatermarklogoDe-SS,,BCH,,,,,m.Fig.3Watermarkrecoveringprocess32512512256Lenna,4(a).,4(b),PSNR38.60,4(c).4(d),PSNR41.73,4(e).4(f),4(g).,,12,4,,5.,5(a),5(b),5(c),.,33,6(a),6(b),.,,.,.(c)DifferenceofFig.4(a)andFig.4(b)(c)4(a)4(b)(a)Coverimage‘Lena’(a)Lena,(b)Stegoimagewithoutvisualmask(b)(g)Watermarklogo(g)(f)Visualmask(f)(e)DifferenceofFig.4(a)andFig.4(d)(e)4(a)4(d)(d)Stegoimagewithvisualmask(d)Fig.4Experimentimagesofwatermarkembedding4302JournalofSoftware2002,13(2)(c)Recoveredlogo(c)(b)DifferenceofFig.5(a)andFig.5(b)(b)5(a)5(b)(a)Stegoimagewithaveragenoise(a)Fig.5Watermarkrecoveringunderaveragenoise5(b)Recoveredlogo(b)(a)Stegoimageaftermedianfiltering(a)Fig.6Watermarkrecoveringaftermedianfiltering63.,,,.,.,,.,,JPEG(jointphotographicexpertsgroup),.,,,.,.References:[1]Shen,Yun-shan.SpreadSpectrumTechnology.Beijing:PublishingHouseofDefenseIndustry,1995(inChinese).[2]Gui,Shao-sheng.TechnologyandApplicationofErrorCorrectCoding.Shanghai:PublishingHouseofShanghaiJiaotongUniversity,1988(inChinese).[3]McWilliams,F.J.,Sloane,N.J.A.Pseudo-Randomsequencesandarrays.ProceedingsoftheIEEE,1976,64(12):1715~1729.[4]Bartolini,F.,Barni,M.,Cappellini,V.,etal.Maskbuildingforperceptuallyhidingfrequencyembeddedwatermarks.In:Zhang,Y.Q.,ed.ProceedingsoftheInternationalConferenceonImageProcessing,Vol1.Chicago,1998.450~454.[5]Canny,J.F.Acomputationalapproachtoedgedetection.IEEETransactionsonPatternAnalysisandMachineIntelligence,1986,8(6):678~698.[6]Su,K.J.,Hartung,F.,Girod,B.Digitalwatermarkingoftext,image,andvideodocuments.Computer&Graphics,1998,22(6):687~695.:303[7]Tirkel,A.Z.,Osborne,C.F.Imagewatermarkingaspreadspectrumapplication.In:ProceedingsoftheIEEEInternationalSymposiumonSpreadSpectrumTechniquesandApplications.MainzGermany,1996.785~789.[8]Charles,G.,Boncelet,J.Hidinginformationinimages.In:Ramchandran,K.,ed.ProceedingsoftheInternationalConferenceonImageProcessing,Vol2.Chicago,1998.396~398.:[1]..:,1995.[2]..:,1988.SpatialDomainImageWatermarkingTechnologyBasedonDirectSequenceSpreadSpectrumCodesÃZHOULi-jun,ZHOUYuan-hua(InstituteofImageCommunicationandInformationProcessing,ShanghaiJiaotongUniversity,Shanghai200030,China)E-mail:[e-mail];[e-mail](DSSS)codesisproposedinthispaper.Onthebasisofestablishingthecommunicationmodelofdigitalimagewatermarking,theauthorsgenerateavisualmaskfromthecoverimagetokeepthefidelityoftheimage,andthenembedthespreadspectrummodulatedwatermarkintothecorrespondingspatialdomainofthedigitalimage.Atthesametime,theerrorcorrectioncodingtechniqueisusedtoimprovetheanti-jammingcapabilityofthewatermark.Thedetectionisrealizedbycomputingthecorrelationbetweenthedifferenceimageandtheoriginalspreadspectrumcodes.Experimentalresultsshowthattheschemeimprovestherobustnessandinvisibilityoftheimagewatermark,whilehaspreferablesubjectiveeffects.Keywords:digitalimagewatermarking;directsequencespreadspectrum;visualmask;errorcorrectioncodingÃReceivedMay20,2000;acceptedAugust7,2000