License plate recognition system and method

A license plate recognition system for use in recognizing a license plate attached to a vehicle, the license plate bearing a license plate number, the license plate recognition system comprising:

• a database module comprising a license plate position database and a license plate number database, the license plate position database storing a plurality of license plate position sample type-related data, and the license plate number database storing a plurality of license plate number sample type-related data;
• a reducing module connected to the database module and adapted to reduce quantity of the license plate position sample type-related data and quantity of the license plate number sample type-related data in the database module;
• an image capturing unit for capturing a license plate image at a first imaging resolution to compute the license plate image with a histogram of oriented gradients (HOG) algorithm and thereby generate an eigenvalue of license plate position image, and capturing a license plate image at a second imaging resolution to compute the license plate image with the HOG algorithm and thereby generate an eigenvalue of license plate number image, wherein the second imaging resolution is of a level higher than that of the first imaging resolution;
• a sorting unit connected to the image capturing unit to compute an eigenvalue of the license plate position image with principal component analysis (PCA) and support vector machine (SVM) and thereby create license plate position type-related data, and compute an eigenvalue of the license plate number image with the PCA and the SVM and thereby create license plate number type-related data;
• and
• a recognizing module connected to the sorting unit and the database module to compare the license plate position type-related data with the license plate position sample type-related data, compare the license plate number type-related data with the license plate number sample type-related data after determining that the license plate position type-related data is identical with one of the license plate position sample type-related data, and recognize the license plate number of the license plate by the license plate number sample type-related data identical with the license plate number type-related data after determining that the license plate number type-related data is identical with one of the license plate number sample type-related data.