Accurate plate number recognition based on Sobel edge detection and weighted morphological structuring element

Abstract

Number plate recognition (NPR) became a very important in our daily life because of the unlimited increase of cars and transportation systems which make it impossible to be fully managed and monitored by humans, examples are like traffic monitoring, tracking stolen cars, managing parking toll, red-light traffic violation enforcement, border, and customs checkpoints. Yet it is a very challenging problem, due to the diversity of plate formats, different scales, rotations, and non-uniform illumination conditions during image acquisition. The proposed system is simple but efficient for recognizing plate numbers. The Sobel edge detection and morphological process are used in the proposed framework with weighted structuring element. This approach simplifies the task by using the bounding box method for character segmentation to segment all the characters on the plate number. Template matching is then applied to recognize the numbers and characters. This approach produces accurate results as shown by the experimental process.