FORMS: A Flexible Object Recognition and Modeling System

S. C. Zhu and A. L.Yuille, FORMS: A Flexible Object Recognition and Modeling System,
--- International Journal of Computer Vision, Vol.20, No.3, pp.187-212, 1996. [ps.gz]

1). Compute the medial axis of a shape in a bottom-up and top-down loop. Because the medial axis is ill-defined it must be regularized against some prior shape models. This is accomplished by a set of graph editing operators below. It is a graph matching with graph editing process.

Based on an attributed graph matching, it can be used for object recognition. This work is a truly generative model of shape.

2). Then the shape is decomposed according to the computed medial axes. We assumed a hinge joints for all parts: For example: a dog shape is decompsoed into 7 parts

decomposition of a fish into rectangular and circular parts. Each of these parts are assumed to be flexible deformation from two primitives: a rectangle for elongated limes and a circle for short parts. Such as the fins of the fish. Then the deformation is characterized by principle components analysis, learned from data, the PCA for the two types of parts are shown below.