Towards fitting a 3D dense facial model to a 2D image: A landmark-free approach

Head pose estimation helps to align a 3D face model to a 2D image, which is critical to research requiring dense 2D-to-2D or 3D-to-2D correspondence. Traditional pose estimation relies strongly on the accuracy of landmarks, so it is sensitive to missing or incorrect landmarks. In this paper, we propose a landmark-free approach to estimate the pose projection matrix. The method can be used to estimate this matrix in unconstrained scenarios and we demonstrate its effectiveness through multiple head pose estimation experiments.