Towards a Unified Framework for Pose, Expression, and Occlusion Tolerant Automatic Facial Alignment
We propose a facial alignment algorithm that is able to jointly deal with the presence of facial pose variation, partial occlusion of the face, and varying illumination and expressions. Our approach proceeds from sparse to dense landmarking steps using a set of specific models trained to best account for the shape and texture variation manifested by facial landmarks and facial shapes across pose and various expressions. We also propose the use of a novel <inline-formula><tex-math notation="LaTeX">$\ell _1$</tex-math><alternatives> <inline-graphic xlink:type="simple" xlink:href="seshadri-ieq1-2505301.gif"/></alternatives></inline-formula>-regularized least squares approach that we incorporate into our shape model, which is an improvement over the shape model used by several prior Active Shape Model (ASM) based facial landmark localization algorithms. Our approach is compared against several state-of-the-art methods on many challenging test datasets and exhibits a higher fitting accuracy on all of them.