Research on Technique of QR Code Images Preprocessing

Due to the ununiform lighting condition,the light background of QR(Quick Response) codes’ images captured on the basis of image pattern might be complicated.Based on this phenomenon,a binary processing method,which is based on background gray-scale extension,was proposed.In the correction process of geometric distortion happened in recognition of QR codes’ images,control point of distortion correction should be identified by boundary scan in the first stage;distorted QR codes’ images should be corrected by means of bilinear transformation in the second stage;and the obtained images should be corrected by revolving the images at last.Experimental results showed that the method,which is simple and effective,can be used to improve precision of QR codes’ recognition rate.