License plate recognition based on intrinsic image decomposition algorithm

Traditional methods of license plate location have a poor effect if they are applied into poor lighting conditions. This paper presents an intrinsic image decomposition algorithm to solve this problem. We extract out the reflection intrinsic image which is independent of light and then conduct license plate location. In addition, to work out the shortage of low recognition rate of the Chinese OCR, this paper proposes the use of R-SIFT feature matching method to authenticate vehicle. For every detecting car, we extract out its feature points using R-SIFT feature matching method and sent to various monitoring stations. When a vehicle image is shot, we first conduct license plate location, and then extract out R-SIFT feature points, finally match with photos in vehicle registration database. If the matched points exceed a set threshold, the system will ring and warn that it may be a suspect vehicle. Thus, we implement the license plate recognition.