Patent ID: 6339651
Filing Date: 2002-01-15
Classification: G06K

Abstract:
A robust method of recognizing a license plate ID of a vehicle, the license plate ID containing a plurality of characters, the method comprising:producing an image of at least a portion of the vehicle, said image containing the license plate ID: selecting a region of interest of said image, said region of interest containing at least a portion of said license plate ID; segmenting at least some characters of said license plate ID; recognizing at least some of said segmented characters using a recognizer to produce recognized characters; groping said recognized characters to form partially recognized ID character groups; recovering at least one character which was not successfully recognized if any characters were not successfully recognized; forming an ID candidate list containing ID candidates formed from said partially recognized ID character groups and any recovered characters, said ID candidates having at least one difference in characters; selecting an ID candidate from said ID candidate list which is most likely to be a legitimate ID based on predetermined factors, said ID candidate being an ID output; measuring a confidence level of said ID output; and determining a result of performing at least one step of the method, determining the acceptability of the result and, if the acceptability determination indicates that the result is unacceptable, reperforming the at least one step of the method using an alternative tool.