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70 个结果
  • 简介:Anewmethodofsuper-resolutionimagereconstructionisproposed,whichusesathree-step-trainingerrorbackpropagationneuralnetwork(BPNN)torealizethesuper-resolutionreconstruction(SRR)ofsatelliteimage.ThemethodisbasedonBPNN.First,threegroupslearningsampleswithdifferentresolutionsareobtainedaccordingtoimageobservationmodel,andthenvectormappingsarerespectivelyusedtothosethreegrouplearningsamplestospeeduptheconvergenceofBPNN,atlast,threetimesconsecutivetrainingarecarriedontheBPNN.Trainingsamplesusedineachstepareofhigherresolutionthanthoseusedintheprevioussteps,sotheincreasingweightsstoreagreatamountofinformationforSRR,andnetworkperformanceandgeneralizationabilityareimprovedgreatly.Simulationandgeneralizationtestsarecarriedonthewell-trainedthree-step-trainingNNrespectively,andthereconstructionresultswithhigherresolutionimagesverifytheeffectivenessandvalidityofthismethod.

  • 标签: 误差反向传播神经网络 训练样本 超分辨率 图像重建 BP神经网络 学习样本
  • 简介:Inthispaper,elitistreconstructiongeneticalgorithm(ERGA)basedonMarkovrandomfield(MRF)isintroducedforimagesegmentation.Inthisalgorithm,apopulationofpossiblesolutionsismaintainedateverygeneration,andforeachsolutionafitnessvalueiscalculatedaccordingtoafitnessfunction,whichisconstructedbasedontheMRFpotentialfunctionaccordingtoMetropolisfunctionandBayesianframework.Aftertheimprovedselection,crossoverandmutation,anelitistindividualisrestructuredbasedonthestrategyofrestructuringelitist.ThisprocedureisprocessedtoselectthelocationthatdenotesthelargestMRFpotentialfunctionvalueinthesamelocationofallindividuals.Thealgorithmisstoppedwhenthechangeoffitnessfunctionsbetweentwosequentgenerationsislessthanaspecifiedvalue.Experimentsshowthattheperformanceofthehybridalgorithmisbetterthanthatofsometraditionalalgorithms.

  • 标签: 遗传算法 图像分割 MRF 磁共振 马尔可夫随机场 健身功能
  • 简介:无人的天线车辆(UAV)遥远的成像被坏天气影响,并且获得的图象有低对比的劣势,复杂质地并且变模糊。在这份报纸,我们基于多重散布建议一个盲目deconvolution模型空气点传播功能(APSF)评价到恢复遥感图象。根据Narasimhan分析理论,一个新多重散布恢复模型基于改进二色的模型被建立。然后使用L0标准到估计APSF污迹核的坡度和黑暗隧道的稀少的priors,快Fourier变换被用来由过滤的维纳恢复原来的清楚的图象。由与另外的最先进的方法作比较,建议方法能正确地估计污迹核,有效地移开大气的降级现象,保存图象详细信息并且增加优秀评估索引。

  • 标签: 退化图像 遥感图像 多重散射 核估计 无人机 大气
  • 简介:Theeffectofcarrierphaseerrorindigitalimagetransmissionsystemisdiscussed.CodeerrorrateandSNRwithcarrierphaseerrorinGausswhitenoisechannelarecalculated,andthetransmissionsystemissimuatedoncomputer.

  • 标签: 错误代码速率 群集 多正交调幅 数据传输
  • 简介:Inthispaper,weproposeanewmethodthatcombinescollageerrorinfractaldomainandHumomentinvariantsforimageretrievalwithastatisticalmethod-variablebandwidthKernelDensityEstimation(KDE).TheproposedmethodiscalledCHK(KDEofCollageerrorandHumoment)anditistestedontheVistextexturedatabasewith640naturalimages.ExperimentalresultsshowthattheAverageRetrievalRate(ARR)canreachinto78.18%,whichdemonstratesthattheproposedmethodperformsbetterthantheonewithparametersrespectivelyaswellasthecommonlyusedhistogrammethodbothonretrievalrateandretrievaltime.

  • 标签: 图像检索方法 核密度估计 拼贴误差 不变性矩 统计方法 可变带宽
  • 简介:Theconceptofdualimagereversibledatahiding(DIRDH)isthetechniquethatcanproducetwocamouflageimagesafterembeddingsecretdataintooneoriginalimage.Moreover,notonlycanthesecretdatabeextractedfromtwocamouflageimagesbutalsotheoriginalimagecanberecovered.Toachievehighimagequality,Luetal.'smethodappliedleast-significant-bit(LSB)matchingrevisitedtoDIRDH.Inordertofurtherimprovetheimagequality,theproposedmethodmodifiesLSBmatchingrevisitedrulesandappliesthemtoDIRDH.Accordingtotheexperimentalresults,theimagequalityoftheproposedmethodisbetterthanthatofLuetal.'smethod.

  • 标签: 图像数据 数据隐藏 有效位 检验规则 可逆 配重
  • 简介:Side-matchvectorquantization(SMVQ)achievesbettercompressionperformancethanvectorquantization(VQ)inimagecodingduetoitsexplorationofthedependenceofadjacentpixels.However,SMVQhasthedisadvantageofrequiringexcessivetimeduringtheprocessofcoding.Therefore,thispaperproposesafastimagecodingalgorithmusingindirect-indexcodebookbasedonSMVQ(IIC-SMVQ)toreducethecodingtime.Twocodebooks,namedindirect-indexcodebook(II-codebook)andentire-statecodebook(ES-codebook),aretrainedandutilized.TheII-codebookistrainedbyusingtheLinde-Buzo-Gray(LBG)algorithmfromside-matchinformation,whiletheES-codebookisgeneratedfromtheclusteredresidualblocksonthebasisoftheII-codebook.Accordingtotherelationshipbetweenthesetwocodebooks,thecodewordintheII-codebookcanberegardedasanindicatortoconstructafastsearchpath,whichguidesinquicklydeterminingthestatecodebookfromtheES-codebooktoencodetheto-be-encodedblock.TheexperimentalresultsconfirmthatthecodingtimeoftheproposedschemeisshorterthanthatofthepreviousSMVQ.

  • 标签: 图像编码算法 码本 间接 编码时间 矢量量化 相邻像素
  • 简介:Withtheadvanceofmultimediatechnologyandcommunications,imagesandvideosbecomethemajorstreaminginformationthroughtheInternet.HowtofastretrievedesiredsimilarimagespreciselyfromtheInternetscaleimage/videodatabasesisthemostimportantretrievalcontroltarget.Inthispaper,acloudbasedcontent-basedimageretrieval(CBIR)schemeispresented.Database-categorizingbasedonweighted-invertedindex(DCWII)anddatabasefilteringalgorithm(DFA)isusedtospeedupthefeaturesmatchingprocess.IntheDCWII,theweightsareassignedtodiscretecosinetransform(DCT)coefficientshistogramsandthedatabaseiscategorizedbyweightedfeatures.Inaddition,theDFAfiltersouttheirrelevantimageinthedatabasetoreduceunnecessarycomputationloadingforfeaturesmatching.ExperimentsshowthattheproposedCBIRschemeoutperformspreviousworkintheprecision-recallperformanceandmaintainsmeanaverageprecision(mAP)about0.678inthelarge-scaledatabasecomprisingonemillionimages.Ourschemealsocanreduceabout50%to85%retrievaltimebypre-filteringthedatabase,whichhelpstoimprovetheefficiencyofretrievalsystems.

  • 标签: 图像检索系统 视频数据库 过滤算法 倒排索引 加权 基于内容的图像检索
  • 简介:EstimationprecisionofDisplacedPhaseCenterAlgorithm(DPCA)isaffectedbythenumberofdisplacedphasecenterpairs,thebandwidthoftransmittingsignalandmanyotherfactors.DetailedanalysisismadeonDPCA'sestimationprecision.AnalysisresultsshowthatthedirectionalvectorestimationprecisionofDPCAislow,whichwillproduceaccumulatingerrorswhenphasecen-ters'trackisestimated.Becauseofthisreason,DPCAsuffersfromaccumulatingerrorsseriously.Toovercomethisproblem,amethodcombiningDPCAwithSubApertureImageCorrelation(SAIC)ispresented.Largesyntheticapertureisdividedintosub-apertures.Microerrorsinsub-apertureareestimatedbyDPCAandcompensatedtorawechodata.Bulkerrorsbetweensub-aperturesareesti-matedbySAICandcompensateddirectlytosub-apertureimages.Afterthat,sub-apertureimagesaredirectlyusedtogenerateultimateSASimage.Themethodisappliedtothelake-trialdatasetofa20kHzSASprototypesystem.ResultsshowthemethodcansuccessfullyremovetheaccumulatingerrorandproduceabetterSASimage.

  • 标签: 合成孔径声纳 神龙公司 图像相关 运动补偿 估计精度 相位中心
  • 简介:Classifyingthetextureofgranulesin2Dimageshasarousedmanifoldresearchatten-tionforitstechnicalchallengesinimageprocessingareas.ThisletterpresentsanaggregatetextureidentificationapproachbyjointlyusingGrayLevelCo-occurrenceProbability(GLCP)andBPneuralnetworktechniques.First,upto8GLCP-associatedtexturefeatureparametersaredefinedandcomputed,andtheseconsequentparametersnextserveastheinputsfeedingtotheBPneuralnetworktocalculatethesimilaritytoanyofgivenaggregatetexturetype.Afinitenumberofaggregateimagesof3kinds,witheachcontainingspecifictypeofmineralparticles,areputtotheidentificationtest,experimentallyprovingthefeasibilityandrobustnessoftheproposedmethod.

  • 标签: BP神经网络 纹理识别 二维图像 概率 共生 灰度