Purely bottom-up, unsupervised segmentation of a single
image into two segments remains a challenging task for
computer vision. The co-segmentation problem is the process
of jointly segmenting several images with similar foreground
objects but different backgrounds. In this paper, we
combine existing tools from bottom-up image segmentation
such as normalized cuts, with kernel methods commonly
used in object recognition. These two sets of techniques
are used within a discriminative clustering framework: we
aim to assign foreground/background labels jointly to all
images, so that a supervised classifier trained with these
labels leads to maximal separation of the two classes. In
practice, we obtain a combinatorial problem which is relaxed
to a continuous convex optimization problem, that can
be solved efficiently for up to dozens of images. We show
that our framework works well on images with very similar
foreground objects, which are usually considered in the
literature...