Patent ID: 7062093
Filing Date: 2006-06-13
Classification: G06K

Abstract:
1. A method for recognizing model object in a first image comprising the steps of: (a) acquiring in electronic memory the first image of the model object; (b) transforming the first image of the model object into a multi-level representation consistent with a recursive subdivision of a search space, said multi-level representation including at least the first image; (c) generating at least one precomputed model of the model object for each level of discretization of the search space, said precomputed model consisting of a plurality of model points with corresponding direction vectors, said model points and direction vectors being generated by an image processing operation that returns a direction vector for at least each model point; (d) acquiring in electronic memory a current image; (e) transforming the current image into a multi-level representation consistent with a recursive subdivision of the search space, said multi-level representation including at least the current image; (f) performing an image processing operation on each transformed image of the multi-level representation that returns a direction vector for a subset of model points within said current image that corresponds to the range of translations for which the at least one precomputed model should be searched; (g) computing a match metric that uses the direction information of the at least one precomputed model and the transformed image for all possible model poses of the at least one precomputed model in the coarsest discretization level of the search space; (h) determining those model poses whose match metric exceeds a user-selectable threshold and whose match metric is locally maximal, and generating a list of instances of the at least one precomputed model in the coarsest discretization level of the search space from said model poses and said match metrics; (i) tracking said instances of the at least one precomputed model in the coarsest discretization level of the search space through the recursive subdivision of the search space until a finest level of discretization is reached; and (j) providing the model pose of the instances of the model object on the finest level of discretization.