QR码图像预处理技术研究

Research on Technique of QR Code Images Preprocessing

针对光照不均条件下基于图像模式采集到的QR(Quick Response)码图像存在背景比较复杂的情况,提出基于背景灰度扩展的二值化处理方法.对于QR码识别过程中的几何失真,首先通过边界扫描找到畸变矫正控制点,再进行双线性变换矫正失真的条码图像,最后根据探测图形对图像进行旋转矫正.实验表明,方法简单有效,可提高QR码的识别率.

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 .