简介:Thispaperpresentsanewclassofsurfacesthatgivetwoquitedifferentappearanceswhentheyareseenfromtwospecialviewpoints.Theinconsistentappearancescanbeperceivedbysimultaneouslyviewingthemdirectlyandinamirror.Thisphenomenonisanewtypeofopticalillusion,andwehavenameditthe"ambiguouscylinderillusion",becauseitistypicallygeneratedbycylindricalsurfaces.Weconsiderwhythisillusionarises,andwepresentamathematicalmethodfordesigningambiguouscylinders.
简介:Thispaperpresentsanewalgorithmforgenerating3DimagesofB-repsobjectswithtrimmedsurfaceboundaries.The3Dimageisadiscretevoxel-maprepresentationwithinaCubicFrameBuffer(CFB).Thedefinitionof3Dimagesforcurve,surfaceandsolidobjectareintroducedwhichimplytheconnectivityandfidelityrequirements.AdaptiveForwardDifferencingmatrix(AFD-matrix)for1D-3Dmanifoldsin3Dspaceisdeveloped.BysettingrulestoupdatetheAFD-matrix,theforwarddifferencedirectionandstepwisecanbeadjusted.Finally,anefficientalgorithmispresentedbasedontheAFD-matrixconceptforconvertingtheobjectin3Dspaceto3Dimagein3Ddiscretespace.
简介:Inrecentyears,accordingtotheneedofintelligentvideosurveillancesystemincreasingrapidlyinmetropolitancities,adesignbasedonS3C2440microprocessorandembeddedLinuxoperatingsystemisadoptedforreal-timevideotargettracking.However,itisverychallengingasembeddedsystemsusuallyaffordlimitedprocessingpowerandlimitedresources.Therefore,toaddressthisproblem,areal-timetrackingalgorithmusingmulti-featuresbasedoncompressivesensingisproposedandimplemented.Thealgorithmusesmultiplematrixastheprojectionmatrixofthecompressivesensingandthecompresseddateasthemultiplefeaturestoextractusefulinformationneededbytrackingprocess.FunctionsandlibrariesinOpenCVwhichweredevelopedbyIntelCorporationareutilizedforbuildingthetrackingalgorithms.Itistestedwithvariantvideosequencesandtheresultsshowthatthealgorithmachievesstabletrackingforthetargetmovedofthelightchanged.
简介:3Dobjectscanbestoredincomputerofdifferentdescribingways,suchaspointset,polyline,polygonalsurfaceandEuclideandistancemap.Momentinvariantsofdifferentordersmayhavethedifferentmagnitude.Amethodfornormalizingmomentsof3Dobjectsisproposed,whichcansetthevaluesofmomentsofdifferentordersroughlyinthesamerangeandbeappliedtodifferent3Ddataformatsuniversally.Thenaccuratecomputationofmomentsforseveralobjectsispresentedandexperimentsshowthatthiskindofnormalizationisveryusefulformomentinvariantsin3Dobjectsanalysisandrecognition.