Optically based bankenote authentication system having broke discrimination

A method and a system are disclosed for processing a banknote. The method includes providing a banknote having at least one photonically active security feature, the banknote being moved along a conveyance path; illuminating the at least one security feature with light from a stimulus source; identifying a location of the at least one security feature by detecting an emission from the security feature; directing an excitation source at the identified location; illuminating the at least security feature with light from the excitation source; and detecting a further emission from the photonically active security feature in response to the light from the excitation source. Further the process includes the step of analyzing the shape and size of each object within an image during the search phase to determine if the object has the expected physical attributes of the real feature.