Application of Embedded License Plate Detection and Recognition for Parking Garages

• Main Authors: Heng-Chin Chu, 朱恆志
• Other Authors: 陳文輝
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/yavrwr

碩士 === 國立臺北科技大學 === 自動化科技研究所 === 101 === Transportation is an important topical subject to a country. Under the public demand for convenience, the number of vehicles has continued to increase, which has led to the problems concerning the effective management of vehicle access control and parking fee collection. The automatic license plate recognition technology can solve these problems efficiently. However, the computer-based license plate recognition system has large volume and is power-consuming, thus, is disadvantageous for long-term operation. If the system can be operated on an embedded platform, the problems can thus be solved. Therefore, this study used Texas Instrument DM6437 EVM as the development platform, as well as cameras and LCD display to complete a real-time license plate recognition system. The license plate images are first captured by the cameras installed over or on the side of the parking garage entrance. As the distance and angle between the parking vehicles and the cameras are variable, the images may have angle of tilts. Hough transform is used to detect the inclination. After tilt correction, the character labeling is performed for character segmentation, and the segmented characters are put into the hierarchical character recognition system to identify the results. In order to validate the system feasibility, this study conducted experiments on the vehicles in the parking garages, and proved that the success rate of tilt correction is 88.89% and the overall recognition rate is 81.63%.