Deformable model fitting has been actively pursued in the computer vision
community for over a decade. As a result, numerous approaches have
been proposed with varying degrees of success. A class of approaches that
has shown substantial promise is one that makes independent predictions regarding
locations of the model’s landmarks, which are combined by enforcing
a prior over their joint motion. A common theme in innovations to this
approach is the replacement of the distribution of probable landmark locations,
obtained from each local detector, with simpler parametric forms. This
simplification substitutes the true objective with a smoothed version of itself,
reducing sensitivity to local minima and outlying detections. In this
work, a principled optimization strategy is proposed where a nonparametric
representation of the landmark distributions is maximized within a hierarchy
of smoothed estimates. The resulting update equations are reminiscent of
mean-shift but with a ...
Jason M. Saragih, Simon Lucey, Jeffrey F. Cohn