Research On Correction And Recognition Of QR Code On Metal Cans

In the actual application,the QR code is affected by the collection conditions,environment and the surface of substrate,which will cause a series of defects such as noise pollution,local highlight and geometric distortion.These defects will lead to the reduction of recognition rate.The research of preprocessing,area detection,extraction and correction processing for these defects was based on the principle of image processing.Methods were proposed to optimize the QR code and improve the recognition rate.According to the basic principles of digital image processing,the processing and recognition technology of QR code was analyzed.The platform about correction and recognition processing of QR code was built with Python and HTML.The algorithm of grayscale and denoising was used to process the collected image;According to the principle of threshold segmentation,the molecular block Otsu method was used to deal with the uneven illumination.Based on the special structural features of the position detection pattern,the QR code was detected and extracted from the image.The method of anti-perspective transformation was used to correct the QR code with geometric distortion.The QR code printed on the surface was fitted to the surface area,and the corrected graphic was obtained;Then grayscale was interpolated into the corresponding coordinates to get the corrected QR code;The jagged and virtual dots in the image were eliminated by the morphological close operation.The results show that:The Otsu method that combined with the principle of threshold segmentation was applied to process the QR code with uneven lighting and low brightness.With the structural similarity index,it could be seen that the information loss in the image has been improved.The method of anti-perspective transformation and surface area fitting were used to correct the distorted two-dimensional code,and then the jagged and virtual dots in the corrected image were eliminated.Combined with subjective vision and recognition time,it could be seen that the information in the QR code has been completely preserved and the recognition rate was improved.