Patent ID: 7027651

Claim:
A method of pattern matching for recognition of objects within an image using a model defined by a set of one or more model primitives representative of large scale structures of an archetype, the method comprising steps of: deriving at least one target primitive representative of a large scale structure of the image, said deriving at least one target primitive representative of a large scale structure of the image comprises: detecting geometric features within the image; analyzing the detected geometric features to find large scale structures of the image; approximating each large scale structure with at least one respective primitive, said approximating comprises: mapping a respective primitive through at least a sub-set of the geometric features forming the large scale structure, wherein the step of mapping a respective primitive comprises a step of finding a largest primitive that can be mapped along the respective large scale structure, consistent with a predetermined maximum error tolerance between the primitive and the geometric features spanned by the primitive; deriving a basis from at least one of the primitives; and representing each of the primitives as invariants in the derived basis; and for each target primitive: identifying any model primitives that at least partially match the target primitive; and for each identified model primitive, calculating a figure of merit indicative of a degree of correspondence between the target primitive and the model primitive.