Generation Of Robust-scanning Aesthetic QR Codes

With the popularity of smartphones,the use of 2-dimensional bar codes has become ubiquitous,and QR(Quick Response)code is one of the most widely used 2-dimensional codes,so it has raised concerns from many researchers.Nowadays QR code is mainly used in the connection of offline and online life,which has the advantages of large information capacity,low cost,and easy manufacture,etc.But at the same time,its appearance,composed of black and white blocks,is difficult to meet the individualized demands of customers because of the lack of visual beauty.In recent years,in order to solve this problem,the technology of embellishing the QR code has been developing continuously.Researchers try to get more interesting visual appearances of QR code by introducing other colors,changing module shapes,etc.However,on the one hand,the QR code usually need be scanned in the different environments,so it is required to adapt to the variation of illumination,scale,coverage,and camera angle,etc.;On the other hand,subtle changes in the appearance of QR codes may destroy the original information and cause the failure of scanning.Therefore,how to balance the visual effect and the scanning robustness of QR code has become an important research topic.In this paper,we proposed a new method for generating aesthetic QR codes which is scanning robustness.The major contents of this paper are as follows:1)The scanning process of QR code by the general scanner is analyzed,the reason and the steps of the error in the QR code scanning process are studied.Further,an error analysis model is proposed for describing the influence of threshold and sampling errors that affect the robustness of embellished QR codes.2)A new method for generating the embellished QR codes and an optimization strategy based on local luminance adjustment algorithm are proposed,which can balance the tradeoff between visual quality and scanning robustness.This algorithm is very flexible to generate aesthetic QR code images with different styles by adjusting the initialization parameters.3)An easy to implement and effective luminace adjustment algorithm based on linear interpolation is proposed,which can be applied to convert a grayscale aesthetic QR code into a color one.In this paper,a new method adopting the hierarchical,coarse-to-fine strategy for generating the scanning robustness QR code is proposed,which sequentially generate the following three codes: a binary aesthetic QR code,a grayscale aesthetic QR code,and the final color aesthetic QR code.During the generation process,the error correcting ability of QR code is retained and the visual effect of QR code is continuously enriched.User surveys and decoding experiments were adopted for evaluating our method compared with state-of-the-art algorithms,which indicates that the proposed algorithm has excellent performance in terms of both visual quality and scanning robustness.