Slant Correction of Vehicle License Plate Image
Because of perspective distortion between the camera and the license plate, slanted images commonly appear in License Plate Recognition System (LPR system), and it seriously affects the recognition result. This paper presents two types of image slant, and gives an efficient way to rectify them. For horizontal slant correction, the proposed method is based on connected areas labeling and straight-line fitting. For vertical slant correction, the method is based on rotation experiments with various angles. Practical use in the LPR system shows that this method has a correct rate above 97%.
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