Abstract
This paper proposes a method for generative learning
of hierarchical random field models. The resulting model,
which we call the hierarchical sparse FRAME (Filters, Random field, And Maximum Entropy) model, is a generalization of the original sparse FRAME model by decomposing
it into multiple parts that are allowed to shift their locations, scales and rotations, so that the resulting model becomes a hierarchical deformable template. The model can
be trained by an EM-type algorithm that alternates the following two steps: (1) Inference: Given the current model,
we match it to each training image by inferring the unknown
locations, scales, and rotations of the object and its parts by
recursive sum-max maps, and (2) Re-learning: Given the
inferred geometric configurations of the objects and their
parts, we re-learn the model parameters by maximum likelihood estimation via stochastic gradient algorithm. Experiments show that the proposed method is capable of learning
meaningful and interpretable templates that can be used for
object detection, classification and clustering.