Method and system for identifying a license plate

摘要

A license plate localization method and system based on a combination of a top-down texture analysis and a bottom-up connected component. An image with respect to a vehicle captured by an image capturing unit can be processed in order to locate and binarize a busy area. A black run with respect to the binarized image can be analyzed and classified and one or more objects (connected components) can be generated based on the black run classification. The objects can be further classified in accordance with their size utilizing a run-length based filter to filter out a non-text object. The leftover objects can then be spatially clustered and the uniformity and linearity of the clustered objects can be examined based on a linearity test. The clustered objects can be rejected if they fail the linearity test and the detected objects can further be matched with a plate edge characteristic in order to locate a license plate.

主权项

1. A method for locating a license plate, said method comprising:
analyzing an image of a vehicle utilizing a top-down analysis method to identify a potential license plate area of a license plate by producing a binarized image of said image of said vehicle; locating and binarizing a busy area of said image of said vehicle and thereafter classifying a black run with respect to a binarized image and generating a plurality of objects based on a black run classification; classifying said black run of said binarized image into at least three categories based on length by a run classification unit; utilizing a run-length based filter to filter out non-text objects by retaining at least two smallest categories of said at least three categories of said black run in order to thereafter spatially cluster at least one leftover object; analyzing said at least one leftover object utilizing a bottom-up analysis method by examining a uniformity and a linearity of a clustered object of said at least one leftover object based on a linearity test in order to thereafter match a detected object with a plate edge characteristic in order to locate a license plate; and generating a license plate identification of said license plate.