Beautified QR Code With High Storage Capacity Based On Module Modulation

With the advancement of computer science and the widely use of smart phones,2D(two-dimensional)barcode has been gradually applied to all aspects of life.Among the various two-dimensional barcodes,QR code(quick response code)occupies a dominant position due to its high capacity,supporting for error correction and rapid response.Popular applications include offline payments by scanning code,railway ticket authentication,product promotions,and so on.Even though the QR code can provide larger capacity than 1D bar code,it is still not sufficient for applications that require large storage space.For example,if a QR code is associated with personal identification,then the biometric data should be embedded into it.Such data,such as feature vector of a finger print,may exceed the current capacity of QR code.On the other hand,only limited space is provided for printed QR code,which limits the version and capacity.For example,when a QR code is used for product advertisement and promotion,the printed QR code can only occupy a small corner of the poster so as not to interfere with the images of this poster.To encode more data into QR code with lower versions,we must increase the capacity of standard QR code.The most common use of QR codes is for product promotions that can provide additional message to consumers about a given product.When the printing area is limited,it is desirable for a QR code to have product characteristics and store more product information.So,in this case,the QR code should have a beautified appearance and a higher capacity.This thesis provides a unified approach to beautification and capacity expansion by modulating the modules with the second-level message and background image.This module modulation is decomposed into three steps.First,the modules for the padding codewords are modulated by the module-based binarized background image.Then,to increase the storage capacity,low-pass textured patterns are designed for both the black modules and the white modules.The modules of the standard QR code are modulated by the second-level message.Finally,these modulated modules are further modulated by the L-channel of the background image in Lab color space.In order to verify the feasibility of the proposed algorithm.the proposed algorithm is implemented and tested by using MATLAB.We conducted experiments on image quality and storage capacity and compared them with existing algorithms.The experimental results show that the proposed algorithm outperforms the existing algorithms in terms of visual quality and storage capacity,which verifies the effectiveness of the proposed algorithm.