Silhouette-based object recognition through curvature scale space

A complete and practical isolated-object recognition system has been developed which is very robust with respect to scale, position and orientation changes of the objects as well as noise and local deformations of shape due to perspective projection, segmentation errors and non-rigid material used in some objects. The system has been tested on a wide variety of 3-D objects with different shapes and surface properties. A light-box setup is used to obtain silhouette images which are segmented to obtain the physical boundaries of the objects which are classified as either convex or concave. Convex curves are recognized using their four high-scale curvature extrema points. Curvature scale space (CSS) representations are computed for concave curves. The CSS representation is a multi-scale organization of the natural invariant features of a curve. A three-stage coarse-to-fine matching algorithm quickly detects the correct object in each case