ed.Wedesignedavotingmethodtoverifythetargetsbasedonaprioriknowledgeofthetargets.Forthecaseofvehicledetectionweusedverticalandhorizontalgradientstolocateinterestingfeaturesaswellasconstraintonareaofthetargetasdiscussedinthissection..BackgroundmotionestimationAffinetransformation[]hasbeenusedtomodelmotionofthecamera.Thismodelincludesrotation,scalingandtranslation.~Daffinetransformationisdescribedasfollow:aayxaaaaYXiiii()where(xi,yi)arelocationsofpointsinthepreviousframeand(Xi,Yi)arelocationsofpointsinthecurrentframeanda~aaremotionparameters.Thistransformationhassixparameters;therefore,threematchingpairsarerequiredtofullyrecoverthemotion.Itisnecessarytoselectthethreepointsfromthestationaryback~groundtoassureanaccuratemodelforcameramotion.WeusedMoravecoperator[]tofinddistinguishedfeaturepointstoensureprecisematch.Moravecoperatorselectspi。