Supervised learning of a parts-based model can be for-
mulated as an optimization problem with a large (exponen-
tial in the number of parts) set of constraints. We show how
this seemingly difficult problem can be solved by (i) reducing
it to an equivalent convex problem with a small, polynomial
number of constraints (taking advantage of the fact that the
model is tree-structured and the potentials have a special
form); and (ii) obtaining the globally optimal model using
an efficient dual decomposition strategy. Each component of
the dual decomposition is solved by a modified version of the
highly optimized SVM-Light algorithm. To demonstrate the
effectiveness of our approach, we learn human upper body
models using two challenging, publicly available datasets.
Our model accounts for the articulation of humans as well
as the occlusion of parts. We compare our method with a
baseline iterative strategy as well as a state of the art algo-
rithm and show significant efficien...
M. Pawan Kumar, Andrew Zisserman, Philip H.S. Torr