简介:Inthispaperweproposeathreedimensionalmultiplierlessdiscretecosinetransform(DCT)withliftingschemecalled3D-binDCT.Basedon3D-binDCT,anovelvideocodingalgorithmwithoutmotionestimation/compensationisproposed.Itusesthe3D-binDCTtoexploitspatialortemporalredundancy.ThecomputationofbinDCTonlyneedsshiftandadditionoperations,thusthecomputationalcomplexityisminimized.DCcoefficientprediction,modifiedscanmodeandarithmeticcodingtechniquesarealsoadopted.Extensivesimulationresultsshowthattheproposedcodingschemeprovideshighercodingefficiencyandimprovesvisualquality,anditiseasytoberealizedbysoftwareandhardware.
简介:Theclosephotogrammetric3-Dcoordinatemeasurementisanewmeasuringtechnologyinthefieldsofthecoordinatemeasurementmachine(CMM)inrecentyears.Inthismethod,weusuallyplacesometargetsonthemeasuredobjectandtakeimageoftargetstodeterminetheobjectcoordinate.Thesubpixellocationoftargetimageplaysanimportantroleinhighaccuracy3-Dcoordinatemeasuringprocedure.Inthispaper,somesubpixellocationmethodsarereviewedandsomefactorswhichaffectlocationprecisionareanalyzed.Thenweproposebilinearinterpolationcentroidalgorithm.Theexperimentshaveshownthisalgorithmcanimproveaccuracyoftargetcentroidbyincreasingavailablepixels.
简介:Byusingthecenterprojectionimagesequencetoestimate3-Dmotionparameters,oneneedstoknowthecorrespondingrelationshipbetweenthefeatureofmotionobjectinspaceandtheprojectioncoordinateonimageplane.Inordertoavoidusingtherelationshipoffeaturecorrespondence,thetensoranalysismethodintheaffinetransformationsystemispresented,andthesimulationdataofexperimentalresultsaregiven.
简介:Thispaperpresentsahandheld3Dvision-basedscannerforsmallobjectsbyusingKinect.Itisdifferentfromthepreviouscolor-glove-basedapproacheswhichrequiresegmentingthetargetobject.First,weeliminatethenoisesandtheoutlierscausedbyholdinghands.Second,weapplyKinect-fusionalgorithmandtruncatedsigneddistancefunction(TSDF)torepresent3Dsurfaces.Third,weproposeamodifiedintegrationstrategytoeliminatethehandeffect.Fourth,wetakeadvantageoftheparallelcomputationofGPUsforreal-timeoperation.Themajorcontributionsofthispaperare(1)theregistrationprecisionisimproved,(2)theofflineamendmentandloopclosureoperationarenotrequired,and(3)concave3Dobjectreconstructionisfeasible.IndexTermsHandheld3Dscanning,Kinect-fusion,Truncatedsigneddistancefunction(TSDF).1.IntroductionRecently,thesensor-based3Dmodelreconstructionmethodshavebeenproposed[1].Thesensordeviceshavedifferentpropertiessothatthe3Dreconstructionalgorithmsvaryaccordingly.Thecommonlyusedsensordevicesaretime-of-flight(ToF)cameras[2]-[4],laserscanners[5],andstructuredlightscanners[6],[7].Lasershavegainedareputationforaccuracy;however,caremustbetakentouseeye-safelaserswhenoperatinginproximitytohumans.Foraninteractivesystem,thestructuredlightscannerwhichisbasicallyapassivevision-basedsensordeviceissuperiorbecauseitprovidesa2DdepthimageperframeandismoreaccuratethanthatofaToFcamera.Here,wepresentareal-time3DscannerusingthedepthimagescapturedbyKinect.
简介:Micro-structures3-Dprofilemeasurementisanimportantmeasurementcontentforresearchonmicro-machiningandcharacterizationofmicro-dimension.Inthispaper,anewmethodinvolved2-Dstructuretemplate,whichguidesphaseunwrapping,isproposedbasedonphase-shiftingmicroscopicinterferometry.Itisfitnotonlyforstaticmeasurement,butalsofordynamicmeasurement,especiallyformotionofMEMSdevices.3-Dprofileofactivecombofmicro-resonatorisobtainedbyusingthemethod.Thetheoreticprecisioninout-of-planedirectionisbetterthan0.5nm.Thein-planetheoreticprecisioninmicro-structuresisbetterthan0.5μm.Butattheedgeofmicro-structures,itisonthelevelofmicrometermainlycausedbyimpreciseedgeanalysis.Finally,itsdisadvantagesandthefollowingdevelopmentarediscussed.
简介:Satisfactoryresultscannotbeobtainedwhenthreedimensional(3D)targetswithcomplexmaneuveringcharacteristicsaretrackedbythecommonlyusedtwo-dimensionalcoordinatedturn(2DCT)model.Toaddresstheproblemof3Dtargettrackingwithstrongmaneuverability,onthebasisofthemodifiedthree-dimensionalvariableturn(3DVT)model,anadaptivetrackingalgorithmisproposedbycombiningwiththecubatureKalmanfilter(CKF)inthispaper.Throughideologyofreal-timeidentification,theparametersofthemodelarechangedtoadjustthestatetransitionmatrixandthestatenoisecovariancematrix.Therefore,statesofthetargetarematchedinreal-timetoachievethepurposeofadaptivetracking.Finally,foursimulationsareanalyzedindifferentsettingsbytheMonteCarlomethod.Allresultsshowthattheproposedalgorithmcanupdateparametersofthemodelandidentifymotioncharacteristicsinreal-timewhentargetstrackingalsohasabettertrackingaccuracy.
简介:Asimplifiedthree-dimension(3D)fadingchannelmodeldeployedinamulti-inputmulti-output(MIMO)beamformingsystemisexploredinthisarticle.Bothangleofarrival(AoA)andangleofdeparture(AoD)whichimpacttheoverallsystemperformanceareexamined.Thenumericalresultsaregivenforvalidatingtheaccuracyofthetheoreticalderivedformulas.Furthermore,theperformancesofthemodelwithdifferentnumberoftransmittersandreceiversarestudiedandcompared.TheincrementinAoAparametersdefinitelygeneratestheimpactofthesystemperformancewhentheconsiderationofsimplified3Dchannels.