Recognition of planar objects in 3-D space from single perspective views using cross ratio

An approach for recognition of a planar polygon from a single 2-D perspective projection using the basic viewpoint invariant cross-ratio (CR) is presented. The shape CR-descriptor of a spatial planar polygon, i.e. the CR sequence extracted from its single projective image, is proposed. The minimum mean square error is used as the matching criterion. Examples are given. The approach can be directly applied to the recognition and motion analysis of 3-D objects that contain planar polygons.<
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