Research On The Algorithm Of License Plate Location And Character Segmentation In Vehicle Image

License plate number as the identity of vehicles, is the only evidence which atraffic management uses to do the vehicle violation penalties, charges, registration. Withthe development of society and improvement of living standards, the traffic more andmore developed, and the license plate recognition is the key to realize the intelligenttraffic management. Now, the license plate recognition technology has been widely usedin many fields of traffic management. As the increasingly high demand of the trafficmanagement, the further research on the license plate recognition technology isnecessary.This paper collects and analyzes the recent achievement of scholars about licenseplate location and character segmentation algorithm in and abroad in recent years. Thealgorithm for vehicle license plate location and character segmentation is studied deeply.Furthermore, combined with license plate characters and image location technology, thepaper locates the target license plate and segments the characters of license plate, layingthe foundation for the single plate character recognition. The main works of this paperare as follows:①The paper presents a method of license plate location based on fuzzyidentification. First, use the median filter to smooth color vehicle image. Use the Prewittoperator to extract vehicle image edge, eliminating some noise interference, andmaintaining a complete license plate edge. At the same time, combined with colordifference of vehicle and license plate, license plate characters and the license platebackground gray level jumping significantly, the fuzzy theory is applied to do vehiclelicense plate image, removing most of the body interference and retaining the licenseplate area. Then use the corrosion and expansion of morphology to do vehicle licenseplate image, looking for the candidate region. Finally combined with the features oflicense plate, determine the final license plate area.②License plate characters segmentation First of all, use image processing technologyto do color vehicle license plate after location, such as image graying, imagebinarization, uniform background, median filter, tilt correction processing, removing thelicense plate frame. Then use a character segmentation algorithm which combined withthe connected domain and projection to do license plate image, extracting individualcharacter. Finally using normalization and thinning, the sizes of various characters is unified and the skeleton of each character is extracted, readying for extracting characterfeature of license plate character.This algorithm was achieved in Visual C++6.0programming environment. Theexperiments show that the algorithm is proposed for vehicle image positioning andcharacter segmentation, has high accuracy, fast computation speed.