Patent ID: 7175090

Claim:
A method of reading two-dimensional (2D) bar codes of the type having a machine-readable component and, optionally, having a human-readable component, where the machine-readable component comprises a plurality of bars, dots or other machine-readable symbols (collectively, “machine-readable symbols”) encoding data, the method comprising; (A) providing multiple models, each discerned from a successful respective decode of a 2D image of a 2D bar code, (B) analyzing a 2D image of a further 2D bar code to decode the machine-readable symbols thereof, the analyzing step including (i) using a model provided in step (A) to determine the machine-readable symbols of the further 2D bar code in the image thereof, where that model is used in lieu of one discerned from the image of the further 2D bar code, (ii) testing for error data so decoded from the machine-readable symbols of the further 2D bar code, (B) responding to an unfavorable result in step (B)(ii) by executing step (C) with each of one or more additional models provided in step (A), (D) responding to an unfavorable result in execution of step (B)(ii) per step (C) by analyzing said 2D image of said further 2D bar code to decode the machine-readable symbols thereof, the analyzing step including (i) discerning from that image a model of representation of the further 2D bar code therein, where that model comprises one or more characteristics of that representation and (ii) testing for error data so decoded from the machine-readable symbols of the further 2D bar code, (E) responding to a favorable result in step (D)(ii) by using said model discerned in step (D)(i) in further execution of one or more of steps (B) and (C), and (F) where the 2D image of the further 2D bar code may comprise all or portions of the same 2D image or images from which the models were discerned.