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110 个结果
  • 简介:Onthebasisofathoroughunderstandingofthephysicalcharacteristicsofremotesensingimage,thispaperemploysthetheoriesofwavelettransformandsignalsamplingtodevelopanewimagefusionalgorithm.ThealgorithmhasbeensuccessfullyappliedtotheimagefusionofSPOTPANandTMofGuangdongprovince,China.Theexperimentalresultsshowthataperfectimagefusioncanbebuiltupbyusingtheimageanalyticalsolutionandre-constructionintheimagefrequencydomainbasedonthephysicalcharacteristicsoftheimageformation.Themethodhasdemonstratedthattheresultsoftheimagefusiondonotchangespectralcharacteristicsoftheoriginalimage.

  • 标签: 遥感图像 图像融合 小波变换 信号取样 运算法则 人造卫星定位
  • 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

  • 标签: 智能安全 密码 图像 知识产权保护
  • 简介:WorkhasbeendonewithextendingtheusefulimaginganddetectionrageofCCD.ThiswasaccomplishedthroughdirectopticalcouplingandbondingofimageintensifierstotheCCD.IthasbeenshownthattheusefulrangeofaCCDmaybeextendedtwoordersofmagnitudeusingthesetechniquesincouplingamicrochannelplateimageintensifiertotheCCDarray.AlloftheseworksweredonewithpresentlyavailableCCDmadebyChina

  • 标签: 图像强化 图像传感器 CCD 像素
  • 简介:Thispaperpresentssomeresultsoftherelationbetweenwavelettransformandfractaltransform.Thewavelettransformoftheattractoroffractaltransformpossesestranslationalandscaleinvariance.Sowespeedthefractalimageencodingbytestingtheinvarianceofthewavelettransformappropriateforimageencoding.Theclassficationschemeofrangeblocksbywavelettransformisgiveninthispaper.

  • 标签: FRACTAL TRANSFORM WAVELET TRANSFORM CLASSIFICATION scheme.
  • 简介:Specklefilteringofsyntheticapertureradar(SAR)imageswhilepreservingthespatialsignalvariability(textureandfinestructures)stillremainsachallenge.ManyalgorithmshavebeenproposedfortheSARimagerydespeckling.However,simulatedannealing(SA)methodisoneofexcellentchoicescurrently.AcriticalprobleminthestudyonSAistoprovideappropriatecoolingschedulesthatensurefastconvergencetonear-optimalsolutions.Thispapergivesanewnecessaryandsufficientconditionforthecoolingschedulesothatthealgorithmstateconvergesinallprobabilitytothesetofgloballyminimumcoststates.Moreover,itconstructsanappropriateobjectivefunctionforSARimagedespeckling.AnexperimentalresultoftheactualSARimageprocessingisobtained.

  • 标签: Despeckling SA COOLING schedules.
  • 简介:Inthispaper,anewtechniqueisproposedforrotation,scalingandtranslation(RST)invariantimagewatermarkingbasedonlog-polarmappings(LPM)andphase-onlyfiltering(POF).ThewatermarkisembeddedintheLPMofFouriermagnitudespectrumoftheoriginalimage,andasmallportionofresultingLPMspectrumisusedtocalculatethewatermarkpositions.Thistechniqueavoidscomputinginverselog-polarmapping(ILPM)topreservethequalityofthewatermarkedimage,andavoidsexhaustivesearchtosavecomputationtimeandreducefalsedetection.Experimentalresultsdemonstratethatthedigitalwatermarkingtechniqueisinvariantandrobusttorotation,scaling,andtranslationtransformation.

  • 标签: 数字水印 图象处理 图象过滤 LPM光谱 傅立叶变换
  • 简介:Inimagereconstructionalgorithms,thechoicesoffilterfunctionsandinterpolatingfunctionsareveryimportantforthecomputationalspeedandthequalityoftheimagereconstructed,especially,forfan-beamgeometry,theoccurrenceofthesingularintegraloperatormayleadtosomegreatoscillationscomparedtotheoriginalimage.Inthispaperwewillgiveadirectconvolu-tionalgorithmwhichneedsnotthecomplexcomputationsoccuringintheFouriertransform,thenusingacircleintegralweobtainastablecomputationalprogram.Differentfromallotherpreviouswindowfunctionsusedbymanypioneerresearchers,inouralgorithmwechooseawindowfunctionsimilartoGabor'swindowfunctione-x^2/2,whichcanberegardedastheapproximationtotheinverseFouriertransformofalocallyintegrablefrequencyfunction.AlsowepointoutthatsuchreconstructionalgorithmprocedurescanbeusedtodealwiththeSPECTprojectiondatawithconstantattenuation.

  • 标签: 直接回旋法则 图象重构 渗透函数 插值函数
  • 简介:Someshortcomingsofcommonfractalimagecodingmethodsarestudied,thentheyarecorrectedwithanewmethod.ThenewmethodisimprovedfurtherinDCTdomain.Codingresultsshowtheadvantageofthenewmethod.

  • 标签: FRACTAL Image CODING ITERATIVE FUNCTION SYSTEM
  • 简介:Differentmodalitiesinbiomedicalimages,likeCT,MRIandPETscanners,providedetailedcross-sectionalviewsofhumananatomy.Thispaperintroducesthree-dimensionalbrainreconstructionbasedonCTslices.Itcontainsfiltering,fuzzysegmentation,matchingmethodofcontours,cellarraystructureandimageanimation.Experimentalresultshaveshownitsvalidity.TheinnovationismatchingmethodofcontoursandfuzzysegmentationalgorithmofCTslices.

  • 标签: 图像重建 AFCM 头部轮廓 单元阵列结构 计算机图形 CT
  • 简介:Anovelparadigmforfractalcodingselectivelycorrectsthefractalcodeforselecteddomainblockswithanimage-adaptiveVQcodebook.Thecodebookisgeneratedfromtheinitialuncorrectedfractalcodeandis,therefore,availableatthedecoder.Anefficienttrade-offisgeneratedbetweenincrementalperformanceandbitrate.

  • 标签: 分形图像编码 矢量量子化 交互函数
  • 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.

  • 标签: HYPERMEDIA data model NODES LINKS NAVIGATION
  • 简介:Thispaperpresentsanautomaticimage-basedapproachforconvertinggreyscaleimagestopencilsketches,inwhichstrokesfollowtheimagefeatures.ThealgorithmfirstextractsadensedirectionfieldautomaticallyusingLogical/Linearoperatorswhichembodythedrawingmechanism.Next,areconstructionapproachbasedonasampling-and-interpolationschemeisintroducedtogeneratestrokepathsfromthedirectionfield.Finally,pencilstrokesarerenderedalongthespecifiedpathswithconsiderationofimagetoneandartificialillumination.Asanimportantapplication,thetechniqueisappliedtorenderportraitsfromimageswithlittleuserinteraction.Theexperimentalresultsdemonstratethattheapproachcanautomaticallyachievecompellingpencilsketchesfromreferenceimages.

  • 标签: 画笔草图绘制 自动图像 计算机
  • 简介:Thetheoreticalframeworkofvisualsimulationinvirtualrealityisdiscussed.Thenewconceptofvisualimagespaceissupposed.Onthebasisofvisualimagespace,invisualperceptivesense,VRisconsideredasaspatialsimulation.Theobjectiveofthespatialsimulationistotransformphysicalspacetovisualimagespace.Last,theprototypesystem,surveying&mappingvirtualReality(SMVR),isdeveloped,andthespacesimulationaboveisrealized.ByuseofSMVR,thereal3Drepresentation,3Dvisualanalysis,virtualplananddesignscanbeimplemented.

  • 标签: 物理空间 可见图像空间 可视化 空间模拟 SMVR 测量地图
  • 简介:Thispaperpresentsthebasicconceptsandprinciples,datastructureandhighefficientspatialindexformulti-resolutionimagedatabase.Thedatabaseischaracterizedbyarrangementofmulti-resourceimagedataandseamlessmosaic,distribution-basedstorageandmanagement,integrationwithotherspatialdatabasesoftwaresuchasGeoStarandGeoGriddevelopedbyWuhanTechnicalUniversityofSurveyingandMapping.

  • 标签: MULTI-SCALE DATABASE SPATIAL DATABASES data structure
  • 简介:ThispaperdescribesanewframeworkforsynthesizingChineselandscapepaintingusinganimage-basedapproach.Theframeworkinvolvestwostages:apreprocessingphase,inwhichafewbrushstroketextureprimitivities(BSTP)arecollectedfromsamplesofhand-madeChinesepaintings,andthecontrolpictureisconstructedtoprovidecolorIDsofmountains,andtheon-linephases,inwhichthefogimageissynthesizedandmountainsare"drawn"bymappingmultiplelayersofBSTPguidedbythecontrolpicture.Whenmorecomplexshadingisneeded,theshadingpictureisconstructedandusedduringtheBSTPmappingphase.Finally,thesynthesizedChineselandscapepaintingsofavarietyofstylesaregivenandtheylookmoreclosetothehandmadeworkthanthoseproducedwithpreviousmodelingmethods.

  • 标签: 图像处理 风景画合成 毛笔运用法
  • 简介:Anewmethodofcodinganddecodinginthesystemofunderwaterimagetransmissionisintroduced,includingtherapiddigitalfrequencysynthesizerinmultiplefrequencyshiftkeying,imagedatagenerator,imagegrayscaledecoderwithintelligentfuzzyalgorithm,imagerestorationanddisplayonmicrocomputer.

  • 标签: UNDERWATER IMAGE transmission digital FREQUENCY synthesizer
  • 简介:DALAILAMAANDASAHARA:AMirrorImageofEvil¥//SHAZHOUShokoAsahara,the"veneratedmaster"oftheAumShinrikyoSect.admittedresponsibility...

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  • 简介:Anewsmoothingmethodisproposed.Thesmoothingprocessadaptstoimagecharacteristicsandisgoodatpreservinglocalimagestructures.Moreimportantly,inthetheoryundertheconditionsweakerthanthoseintheoriginalKacanovmethodanapproximalsequenceofsolutionstothevariationalproblemscanbeconstructedandtheglobalconvergencecanbeproved.AndtheconditionsinthepapersofSchn6rr(1994)andHeers,etal(2001)arediscussed.Numericalsolutionsofthemodelaregiven.

  • 标签: 偏微分方程 变量图像光滑模型 整体收敛 能量函数 边界条件
  • 简介:THEyear2006seesthelaunchoftheChinesegovernment'scampaignto'buildanewsocialistcountryside.'Aftermorethan20yearsofreformandopening-up,thefocusisnowonChina'shugeruralpopulation.The

  • 标签: 中国 新农村建设 农民收入 生活水平
  • 简介:Takingtheadvantageoftheliftingscheme'scharactersthatcanbuildwavelettransformsfortransformingfromintegertointegerandthequalityofthereconstructingimageisindependentofthetopologywayadoptedbytheboundary,animagefusionalgorithmbasedonliftingschemeisproposed.Thispaperdiscussesthefundamentaltheoryofliftingschemefirstlyandthenaftertakingtransformanalysisaccordingtoakindofimagesthatneedtobeconfused.

  • 标签: 数据压缩 图像压缩 提升方法 图像处理