| With the development of barcode technology and the popularity of personal smart terminals,black and white QR codes have been widely used in daily life scenarios such as mobile social networking,unconscious payment,and transportation.Nevertheless,when the era of big data is considered,people’s increasing need for information storage cannot be satisfied by QR codes anymore,due to their restricted data capacity.At this time,it is necessary to study a new type of barcode technology with higher information capacity,and three-dimensional code technology came into being.In recent years,with the popularity of black and white QR codes,color QR codes have gradually become a research hotspot in 3D code technology.The color QR code introduces a color space based on the black and white QR code,which expands the data capacity of the two-dimensional code,but it needs to deal with complex color cast problems when reading and decoding.At the same time,the research on the application of color QR codes on mobile devices is very scarce,far less than black and white QR codes,and there is still a long way to go before widespread popularization.The following are the main contents of this paper,considering the aforementioned issues:(1)Investigated and analyzed the domestic and foreign research status of color barcode technology,focusing on the research progress of color QR code technology.The coding and decoding principle and implementation ideas of black QR codes are analyzed with examples,as well as the logic and process of scanning codes on Android smart terminals.(2)Two color QR codes with 4-color and 16-color modes are developed based on QR codes,and the codec principles are described in depth.A multi-threshold processing algorithm based on HSV mode is developed to address the color distortion problem of 4-color QR code.Based on the principle of spatial mapping,a positioning and reading method that adapts to color QR code pictures with any resolution is suggested for the encoding and decoding algorithm,and its feasibility and reading and decoding performance are verified.The picture resolution is the most important factor affecting decoding.A major factor in performance,increasing the number of colors has a smaller impact on decoding time.(3)Based on the design theory and algorithm ideas of color QR codes,the codec system of color QR codes is designed and realized on the Android platform,and the performance of the system is verified by tests on smart terminals.According to the difference between 4-color and 16-color QR codes,a conversion control algorithm between the two color modes is designed to realize the selection function of the color mode.Referring to the scanning example of black and white QR code,the reading principle of color QR code is explored,and the function of calling the camera data and passing the data into the decoding algorithm is realized in the code scanning function.The system test proves that the color QR code codec system designed in this paper is effective and robust,and can tolerate a maximum image compression rate of 7.29%,which is equivalent to compressing the original image by12.2 times,which is important for the practical application of color QR codes.In addition,compared with the traditional two-dimensional code,the capacity of the 4-color QR code is increased by 2 times,and the capacity of the 16-color QR code is increased by 4 times.The number of colors has little influence on the encoding time,but it is the main factor affecting the decoding time. |
