AbstractEstimatingtheheadposeofapersonisacrucialprob-lemthathasalargeamountofapplicationssuchasaidingingazeestimation,modelingattention,fitting3Dmodelstovideoandperformingfacealignment.Traditionallyheadposeiscomputedbyestimatingsomekeypointsfromthetar-getfaceandsolvingthe2Dto3D