Research And Implementation Of The Encoding And Decoding Technology Of QRcode

As the global information developing, people request for improved barcodetechnology. It’s required that presenting more information in limited area. As therequirement came out, two-dimensional (2D) symbol technology was proposed.Two-dimensional (2D) Barcode has played an important role in the informationautomation field because of its higher capacity, higher density, more powerfulerror-correction ability and higher security ability. So, the research on the encodingand distinguishing technology is very important to develop the application oftwo-dimensional barcode.The thesis is mainly an analysis and study of coding, image processing andrecognition. It studies the QRcode encoding algorithm including encoding rules anderror correction coding algorithm. Also, there are some noise problems caused by theuneven illumination, noise reduce has been done by gray-scale, median-filter andbinarization. By finding the position detection pattern of QRcode and with themethod of Hough transform, the paper has solved the problem of code imagelocation and rotation. Besides, a modified method of Hough transform based on edgedetection has been put forward to effectively reduce the computation and improvethe efficiency of QRcode image rotation correction. As devices collect QRcodeimages from different perspectives and barcode labels are bending, which result inthe problem of image geometric distortion, and then with the help of bilinearinterpolation, the correction is achieved.On the basis of these studies, the paper designed and implemented a softwaresystem of encoding and decoding of QRcode. The experimental results on theplatform of Visual Studio.net demonstrated that the system could encode numeric,letters, Chinese character and their mixed characters, and system processed the QRcode image with noise and distortion, then got little distorted the image, which iseasy for identification and decoding.