Advances in object detection have made it possible to
collect large databases of certain objects. In this paper we
exploit these datasets for within-object classification. For
example, we classify gender in face images, pose in pedestrian
images and phenotype in cell images. Previous work
has mainly targeted the above tasks individually using object
specific representations. Here, we propose a general
Bayesian framework for within-object classification. Images
are represented as a regular grid of non-overlapping
patches. In training, these patches are approximated by a
predefined library. In inference, the choice of approximating
patch determines the classification decision. We propose
a Bayesian framework in which we marginalize over
the patch frequency parameters to provide a posterior probability
for the class. We test our algorithm on several challenging
“real world” databases.
Jania Aghajanian, Jonathan Warrell, Simon J.D. Pri