We propose a novel framework for contour based object
detection and recognition, which we formulate as a joint
contour fragment grouping and labeling problem. For a
given set of contours of model shapes, we simultaneously
perform selection of relevant contour fragments in edge images,
grouping of the selected contour fragments, and their
matching to the model contours. The inference in all these
steps is performed using particle filters (PF) but with static
observations. Our approach needs one example shape per
class as training data. The PF framework combined with
decomposition of model contour fragments to part bundles
allows us to implement an intuitive search strategy for the
target contour in a clutter of edge fragments. First a rough
sketch of the model shape is identified, followed by fine tuning
of shape details. We show that this framework yields
not only accurate object detections but also localizations in
real cluttered images.