Research And Implementation Of License Plate Recognition System Based On Android Mobile Terminal

In recent years, the development of social economy and the rising popularity of car brings huge pressure to urban traffic, and in this situation, Intelligent transportation system become the key to solve this problem. After the development of wireless intelligent transportation system have been proposed, as the core of intelligent transportation system, the license plate recognition system needs to face the reality about the needs of license plate recognition mobility.Based on achieve the mobility of license plate recognition this goal, this paper puts forward a license plate recognition solution based on Android mobile terminal, and also implements the system on the Android platform. After the further research of the locating difficulties, limited computing power equipment and other problems about the mobile terminal license plate recognition, This paper mainly completed the following several aspects:(1)In the image acquisition process on the mobile terminal, the complex background environment, illumination, camera dithering or deflection factors will affect the quality of image and positioning accuracy. In order to get the most precise license plate locating effect, this paper decided to use the camera-side artificial auxiliary locating to get the license plate image.(2) After obtaining the original license plate image, the image cannot be directly to segmentation and recognition, it needs to preprocessing.This paper presents an efficient preprocessing methods:First, using the Otsu method to binarization the license plate image; then smoothing the binary image and processing the edge detection; finally, remove the borders of the image, and ultimately be able to get the license plate image can directly to the character segmentation.(3) After obtaining the image after preprocessing, using the vertical projection method for license plate character segmentation;(4) For mobile devices with limited computing power conditions, this paper decides to use the template matching method to recognition the character, which can both meet the requirements of low computing power and high recognition rate. To this end, this paper had tests the three sets of different sizes of character template, finally choose the 24 x 48 character template, after the template matching with license plate characters, select the template which has the highest matched-degree as the output of results.Finally, this paper realizes the collection of license plate location, license plate character segmentation and license plate character recognition in the integration of the license plate recognition system on Android mobile.