Localization of license plates using optimized edge and contour detection technique

There are a lot of existing studies in the field of plate detection. However, most of them focused on using still images and only a few have applied the process on video streams. This research proposes to automate the plate detection process by the use of intelligent transport system through image processing techniques such as edge detection and contour matching. The region of interest of the vehicle image was reduced to the lower half since statistically, license plates were located on the bottom half of a vehicle to improve the computational complexity of the system. The edges of the vehicle image were computed, from which contours were calculated. The detected contours were filtered based on three parameters - area, aspect ratio and diagonal. The results show that the system achieved 96.67% accuracy.