License Plate Recognition System Based On Smart Handheld Device

In recent years, as the rapid development of the internet of things and vehicle,and the rising number of the Chinese car, the intelligent transportation system isrequired more new applications. As one part of intelligent transportation systems,the license plate recognition system, which are consisted of the signal processing,computer vision, pattern recognition and other technologies, has to face some newchallenges, The LPRS can also be used in the areas of the mobile robot thatsupervises the parking lot, and the traffic management department that can registerthe illegal license plate automatically, except of those traditional areas, such as thesupervision of the highway speeding violation, parking management and vehicleelectronic charge system, etc.This article puts forward one kind of LPRS which is based on the Androidplatform on the smart handheld device. Firstly, according to the vehicle images thatare taken by the unfixed camera, this article adopts the algorithm to get thegrayscale which is3levels, then uses the prior knowledge of vehicle license plate tofind the position of the plate, which is programmed with Visual C++. Secondly, thetile angle can be computed through using the Hough transformation and the vehicleimage can be corrected through using the bilinear interpolation. Then thebinarization image can be obtained through the Otsu algorithms and the licenseplate characters can be obtained based on the segmentation method of the verticalprojection. Thirdly, the Chinese character、numeric character and English characterfeature vectors can be obtained through different feature extraction algorithms. Atlast the license plate numbers can be recognized by the classifiers which are trainedthrough the support vector machine algorithms.Finally, after the survey of the Android platform, through Android NDKtechnology, the license plate recognition algorithms, which are programmed with Clanguage can be transplanted and compiled to android platform with the type ofdynamic link library. The Android-based license plate recognition system softwarecan be achieved by using the android java application interface and the license platerecognition library.