Vehicle License Plate Location By Comprehensive Feature
Vehicle license plate location is one of the key technologies in vehicle license plate recognition.This paper proposes a novel method of the vehicle license plate locating based on structure feature、texture feature and color feature of the plates.Firstly,it makes use of top-hat transformation to suppress the background of a vehicle-image.Secondly,it does the vertical edge detection and morphological filtering to the image,and fulfills the coarse location of the license plate according to the structure feature.Thirdly,it applies one-dimension wavelet decomposition to the vertical projection of candidate regions to filter the noise,then reconstructs the vertical projection,calculates texture statistics,constructs texture feature vector,and relocates the plate by using BP neural network to recognize the character feature.Finally,it detects the color edge of the candidate regions based on edge color pair,and then fulfills the fine location of the license plate according to the horizontal projection value of the edge images.This method has been applied to 314 vehicle-images which were taken in kinds of conditions for test,and the location accuracy is 98.7%.