Annotation free license plate recognition method and system

摘要

Methods and systems for recognizing a license plate character. Synthetic license plate character images are generated for a target jurisdiction. A limited set of license plate images can be captured for a target jurisdiction utilizing an image-capturing unit. The license plate images are then segmented into license plate character images for the target jurisdiction. The license plate character images collected for the target jurisdiction can be manually labeled. A domain adaptation technique can be utilized to reduce the divergence between synthetically generated and manually labeled target jurisdiction image sets. Additionally, OCR classifiers are trained utilizing the images after the domain adaptation method has been applied. One or more input license plate character images can then be received from the target jurisdiction. Finally, the trained OCR classifier can be employed to determine the most likely labeling for the character image and a confidence associated with the label.

主权项

1. A method for recognizing a license plate character, said method comprising:
applying a domain adaptation in at least one offline training phase to reduce a divergence between synthetic license plate character images that are synthetically generated and license plate character images manually labeled for a target jurisdiction; training in said at least one offline training phase a set of OCR classifiers using said license plate character images after said domain adaptation has been applied; receiving in an online classification phase at least one input license plate character image from said target jurisdiction; and determining a most likely label for a character image and a confidence associated with said label utilizing said trained OCR classifiers, thereby minimizing manual labeling required for training an OCR engine in a license plate recognition system.