Vehicle license plate location based on mathematical morphology and variance projection

In a vehicle license plate identification system, license plate location is the first key step. Whether the plate location is successful or not and how accurate it is directly determines the characters segmentation in the following part. This paper presents an efficient and smart approach to the vehicle license plate location based on mathematical morphology and variance projection. The proposed algorithm consists of four major parts: rough detection of level location, rough detection of vertical location, exact detection of license plate location and extraction of candidate regions. The outstanding advantage of this algorithm is simple, smart and fast as it takes full advantage of open arithmetic, which can eliminate a large number of useless details and highlight the edge information of the license plate.