简介:Onthebasisofathoroughunderstandingofthephysicalcharacteristicsofremotesensingimage,thispaperemploysthetheoriesofwavelettransformandsignalsamplingtodevelopanewimagefusionalgorithm.ThealgorithmhasbeensuccessfullyappliedtotheimagefusionofSPOTPANandTMofGuangdongprovince,China.Theexperimentalresultsshowthataperfectimagefusioncanbebuiltupbyusingtheimageanalyticalsolutionandre-constructionintheimagefrequencydomainbasedonthephysicalcharacteristicsoftheimageformation.Themethodhasdemonstratedthattheresultsoftheimagefusiondonotchangespectralcharacteristicsoftheoriginalimage.
简介:Inthisdissertation,sereralkeyproblemsinthefieldofsteganographicimagesecurityaremainlystudiedanddiscussed:(1)Anovelkindofimagecryptosystemisstudied.Theencryptedinformationofsecretimageisembeddedintoanordinaryimage,whichcanbetransmittedpublicly,anditwillnotcauseattentionofillegaleavesdropper.Thefollowingresultsareachieved:(a)Theimagehidingalgorithmanditsimprovedalgorithmbasedonwavelettransformandvectorquantizationareproposed,andbothalgorithmsembedthesecretimageaftertakingfulladvantageofwavelettransform(WT)tocompressit.(b)IntroducingtheCDMAconceptincommunicationtheory,anovelkindofimagecryptosystem—imagehidingcryptosystemofimagedivisionmultipleaccessisproposed.Weencryptkeyinformationofseveralsecretimagesandthenhidethemintoanimage,whichisanordinaryimage.Afterreceiversgettheimage,eachreceivercanrestorecorrespondingsecretimageindependently.Comparedwithotherimageencryptionalgorithms,ournewimagehidingcryptosystemcancompresssecretimagedataefficiently.Moreover,thesecurityandpracticabilityofoursystemisbetter.(2)Digitalwatermarkingisthemostimportantbranchofinformationhiding,whichhasbeenthehotspotofinternationalacademia.Digitalwatermarkinghasbeenproposedasasolutiontotheproblemofcopyrightprotectionofmultimediadocumentsinnetworkedenvironments.Inthisfield,thefollowingresultsareachieved:(a)AnewfrequencyinformationhidingandwatermarkingalgorithmbasedonWTandDiscreteCosineTransform(DCT)ispresented.AftercompressedbyWT,theinformationofsecretimageisembeddedintoDCTdomain.ThealgorithmhasgoodimperceptibilityandsecurityandisrobustagainstJPEGcompressingandcropping.Thealgorithmcanbeusedtoembedwatermarkintoimages,andthewatermarkmaybeone256-colorpictureormoreandmorethanonesecretimagecanbehiddenintoasinglecarrierimage.(b)Anovelwatermarkingalg
简介:WorkhasbeendonewithextendingtheusefulimaginganddetectionrageofCCD.ThiswasaccomplishedthroughdirectopticalcouplingandbondingofimageintensifierstotheCCD.IthasbeenshownthattheusefulrangeofaCCDmaybeextendedtwoordersofmagnitudeusingthesetechniquesincouplingamicrochannelplateimageintensifiertotheCCDarray.AlloftheseworksweredonewithpresentlyavailableCCDmadebyChina
简介:Thispaperpresentssomeresultsoftherelationbetweenwavelettransformandfractaltransform.Thewavelettransformoftheattractoroffractaltransformpossesestranslationalandscaleinvariance.Sowespeedthefractalimageencodingbytestingtheinvarianceofthewavelettransformappropriateforimageencoding.Theclassficationschemeofrangeblocksbywavelettransformisgiveninthispaper.
简介:Specklefilteringofsyntheticapertureradar(SAR)imageswhilepreservingthespatialsignalvariability(textureandfinestructures)stillremainsachallenge.ManyalgorithmshavebeenproposedfortheSARimagerydespeckling.However,simulatedannealing(SA)methodisoneofexcellentchoicescurrently.AcriticalprobleminthestudyonSAistoprovideappropriatecoolingschedulesthatensurefastconvergencetonear-optimalsolutions.Thispapergivesanewnecessaryandsufficientconditionforthecoolingschedulesothatthealgorithmstateconvergesinallprobabilitytothesetofgloballyminimumcoststates.Moreover,itconstructsanappropriateobjectivefunctionforSARimagedespeckling.AnexperimentalresultoftheactualSARimageprocessingisobtained.
简介:Inthispaper,anewtechniqueisproposedforrotation,scalingandtranslation(RST)invariantimagewatermarkingbasedonlog-polarmappings(LPM)andphase-onlyfiltering(POF).ThewatermarkisembeddedintheLPMofFouriermagnitudespectrumoftheoriginalimage,andasmallportionofresultingLPMspectrumisusedtocalculatethewatermarkpositions.Thistechniqueavoidscomputinginverselog-polarmapping(ILPM)topreservethequalityofthewatermarkedimage,andavoidsexhaustivesearchtosavecomputationtimeandreducefalsedetection.Experimentalresultsdemonstratethatthedigitalwatermarkingtechniqueisinvariantandrobusttorotation,scaling,andtranslationtransformation.
简介:Inimagereconstructionalgorithms,thechoicesoffilterfunctionsandinterpolatingfunctionsareveryimportantforthecomputationalspeedandthequalityoftheimagereconstructed,especially,forfan-beamgeometry,theoccurrenceofthesingularintegraloperatormayleadtosomegreatoscillationscomparedtotheoriginalimage.Inthispaperwewillgiveadirectconvolu-tionalgorithmwhichneedsnotthecomplexcomputationsoccuringintheFouriertransform,thenusingacircleintegralweobtainastablecomputationalprogram.Differentfromallotherpreviouswindowfunctionsusedbymanypioneerresearchers,inouralgorithmwechooseawindowfunctionsimilartoGabor'swindowfunctione-x^2/2,whichcanberegardedastheapproximationtotheinverseFouriertransformofalocallyintegrablefrequencyfunction.AlsowepointoutthatsuchreconstructionalgorithmprocedurescanbeusedtodealwiththeSPECTprojectiondatawithconstantattenuation.
简介:Differentmodalitiesinbiomedicalimages,likeCT,MRIandPETscanners,providedetailedcross-sectionalviewsofhumananatomy.Thispaperintroducesthree-dimensionalbrainreconstructionbasedonCTslices.Itcontainsfiltering,fuzzysegmentation,matchingmethodofcontours,cellarraystructureandimageanimation.Experimentalresultshaveshownitsvalidity.TheinnovationismatchingmethodofcontoursandfuzzysegmentationalgorithmofCTslices.
简介:Anovelparadigmforfractalcodingselectivelycorrectsthefractalcodeforselecteddomainblockswithanimage-adaptiveVQcodebook.Thecodebookisgeneratedfromtheinitialuncorrectedfractalcodeandis,therefore,availableatthedecoder.Anefficienttrade-offisgeneratedbetweenincrementalperformanceandbitrate.
简介:Theincreasingusageofmultimediaobjects,suchasRSimages,scannedphotographs,videorecordings,textsandvoiceinformation,demandsanefficientmethodtoorganizeenormousinformation(Taylor,1996).Intwoyears,thesatelliteremotesensingindustrywillprovidegeographicinformationsystem(GIS)userswithasignificantnewtooltocreatebase_mapandupdatetheirGISdatabaseswithdetailedinformation.Thistoolwillbemoreandmoreusefulwhenthesatelliteimagerywith1mspatialresolutionisused(Kevin,1996). Hypermediatechniqueisfrequentlyusedtodealwithdifferentmedia,andtoorganizethediverseandinnumerabledataincomputerswithverylimitedCPUspeedandmemory.ThetechniquehasbeendemonstratedtobeanefficientwayforprocessingalargeamountofRSimagedata. Inthispaperwepresentthehypermediadatamodel,whichisbasedonRSimageinGIS.Usingthemodelconcept,wecanhandlealargeamountofRSimagedataefficientlywithverylimitedcomputingpower.Wehavedevelopedthemodelwiththreekindsofnodes:interiornode,physicalnodeandcomplexnodetoorganizetheinfinityimage.
简介:Thispaperpresentsanautomaticimage-basedapproachforconvertinggreyscaleimagestopencilsketches,inwhichstrokesfollowtheimagefeatures.ThealgorithmfirstextractsadensedirectionfieldautomaticallyusingLogical/Linearoperatorswhichembodythedrawingmechanism.Next,areconstructionapproachbasedonasampling-and-interpolationschemeisintroducedtogeneratestrokepathsfromthedirectionfield.Finally,pencilstrokesarerenderedalongthespecifiedpathswithconsiderationofimagetoneandartificialillumination.Asanimportantapplication,thetechniqueisappliedtorenderportraitsfromimageswithlittleuserinteraction.Theexperimentalresultsdemonstratethattheapproachcanautomaticallyachievecompellingpencilsketchesfromreferenceimages.
简介:Thetheoreticalframeworkofvisualsimulationinvirtualrealityisdiscussed.Thenewconceptofvisualimagespaceissupposed.Onthebasisofvisualimagespace,invisualperceptivesense,VRisconsideredasaspatialsimulation.Theobjectiveofthespatialsimulationistotransformphysicalspacetovisualimagespace.Last,theprototypesystem,surveying&mappingvirtualReality(SMVR),isdeveloped,andthespacesimulationaboveisrealized.ByuseofSMVR,thereal3Drepresentation,3Dvisualanalysis,virtualplananddesignscanbeimplemented.
简介:Thispaperpresentsthebasicconceptsandprinciples,datastructureandhighefficientspatialindexformulti-resolutionimagedatabase.Thedatabaseischaracterizedbyarrangementofmulti-resourceimagedataandseamlessmosaic,distribution-basedstorageandmanagement,integrationwithotherspatialdatabasesoftwaresuchasGeoStarandGeoGriddevelopedbyWuhanTechnicalUniversityofSurveyingandMapping.
简介:ThispaperdescribesanewframeworkforsynthesizingChineselandscapepaintingusinganimage-basedapproach.Theframeworkinvolvestwostages:apreprocessingphase,inwhichafewbrushstroketextureprimitivities(BSTP)arecollectedfromsamplesofhand-madeChinesepaintings,andthecontrolpictureisconstructedtoprovidecolorIDsofmountains,andtheon-linephases,inwhichthefogimageissynthesizedandmountainsare"drawn"bymappingmultiplelayersofBSTPguidedbythecontrolpicture.Whenmorecomplexshadingisneeded,theshadingpictureisconstructedandusedduringtheBSTPmappingphase.Finally,thesynthesizedChineselandscapepaintingsofavarietyofstylesaregivenandtheylookmoreclosetothehandmadeworkthanthoseproducedwithpreviousmodelingmethods.
简介:Anewmethodofcodinganddecodinginthesystemofunderwaterimagetransmissionisintroduced,includingtherapiddigitalfrequencysynthesizerinmultiplefrequencyshiftkeying,imagedatagenerator,imagegrayscaledecoderwithintelligentfuzzyalgorithm,imagerestorationanddisplayonmicrocomputer.
简介:DALAILAMAANDASAHARA:AMirrorImageofEvil¥//SHAZHOUShokoAsahara,the"veneratedmaster"oftheAumShinrikyoSect.admittedresponsibility...
简介:Anewsmoothingmethodisproposed.Thesmoothingprocessadaptstoimagecharacteristicsandisgoodatpreservinglocalimagestructures.Moreimportantly,inthetheoryundertheconditionsweakerthanthoseintheoriginalKacanovmethodanapproximalsequenceofsolutionstothevariationalproblemscanbeconstructedandtheglobalconvergencecanbeproved.AndtheconditionsinthepapersofSchn6rr(1994)andHeers,etal(2001)arediscussed.Numericalsolutionsofthemodelaregiven.
简介:Takingtheadvantageoftheliftingscheme'scharactersthatcanbuildwavelettransformsfortransformingfromintegertointegerandthequalityofthereconstructingimageisindependentofthetopologywayadoptedbytheboundary,animagefusionalgorithmbasedonliftingschemeisproposed.Thispaperdiscussesthefundamentaltheoryofliftingschemefirstlyandthenaftertakingtransformanalysisaccordingtoakindofimagesthatneedtobeconfused.