In this paper, we address the problem of discriminative dictionary learning
(DDL), where sparse linear representation and classification are combined in a
probabilistic framework. As such, a single discriminative dictionary and linear
binary classifiers are learned jointly. By encoding sparse representation and
discriminative classification models in a MAP setting, we propose a general
optimization framework that allows for a data-driven tradeoff between faithful
representation and accurate classification.
In this paper, we present a new multiple instance learning (MIL) method,
called MIS-Boost, which learns discriminative instance prototypes by explicit
instance selection in a boosting framework. Unlike previous instance selection
based MIL methods, we do not restrict the prototypes to a discrete set of
training instances but allow them to take arbitrary values in the instance
feature space. We also do not restrict the total number of prototypes and the
number of selected-instances per bag; these quantities are completely
data-driven.