4. The method according to claim 1 , wherein estimating landmark point locations comprises minimizing an objective function defined as the summation of pairwise L2 distances between warped images.
4. The method according to claim 1 , wherein estimating landmark point locations comprises minimizing an objective function defined as the summation of pairwise L2 distances between warped images. 7. The method according to claim 4 , further comprising constraining the estimated landmark locations in response to shape statistics learned from relatively low-error estimations in an on-line manner.