1. A method comprising: receiving a test facial image; receiving a plurality of training facial images having a plurality of previously identified facial landmarks; identifying a subset of the training facial images that have a greater similarity with the test facial image than the plurality of training facial images not within the subset of training facial images; calculating a plurality of shape constraints for each landmark within the subset of training facial images, wherein the plurality of shape constraints comprises a plurality of weights that estimates each landmark location within a given facial image from a plurality of other landmark locations within the given training facial image; and identifying landmark locations for the test facial image using the plurality of shape constraints.