【作者】 罗春玲；

【导师】 肖攸安；

【作者基本信息】 武汉理工大学 ， 通信与信息系统， 2012， 硕士

【摘要】 二维条码与一维条码相比,它不需要依赖数据库,存储信息量大,可以表达多种多媒体及文字信息,同时它还可以嵌入加密机制,具有纠错能力。快速响应矩阵码(QR码)是一种矩阵二维条码,它能够全方位的识别和有效的表达汉字,目前在我国有着广泛的应用。针对传统的QR码的纠错能力有限,本文提出了一种将纠错码LDPC码替换RS码运用到QR图像中的方案,并利用图形预处理技术对摄取到的有噪声和倾斜的图形进行处理,最后通过分割处理以及译码流程对QR码进行识别,从而得到我们想要的信息。目的是在采用纠错码LDPC的编译码的基础上,提高QR码的纠错能力,改进了QR码的识别效果。在使用方面由于纠错能力提高了,那么它的使用范围也就可以扩展了。本文通过分析国内外的二维条码技术的发展现状,然后对QR码的符号特征以及编译码原理进行了研究,提出了一种新的QR生成方案。通过对纠错码LDPC码的编译码思想以及性能仿真进行研究,然后把它与RS码进行仿真对比。同时对生成的新的QR码的图像预处理过程进行了详细的研究,包括图像的灰度化处理、中值滤波、二值化处理、图形的分割等。对于新的QR码,在生成的过程中需要注意里面纠错码的构成,它的结构直接影响了最后QR码的纠错能力。通过理论研究之后,本文设计了QR码的编译码处理的流程,并且进行了相关的实验检测和分析。实验结果表明,新的QR码的译码能力提高了,在污损程度很大的时候也能够提取出正确的信息,相对于原来的QR来讲,纠错能力提高了,同时算法复杂度降低了。该技术不仅能够解决现有的二维条码QR码所遇到的问题,它还可以运用到其他的二维条码的系统中。经过对本文的工作的总结,文中的创新工作有：1)提出了一种新的QR码生成方案,把LDPC码代替RS码运用到QR码中。2)针对采集到的QR图像,采用了图像中值滤波和二值化处理,用新的纠错码算法译码,把纠错能力从30%提高到50%。3)在不改变原来的QR码的编解码机制的基础上,扩展了QR码的应用,降低算法复杂度。更多还原

【Abstract】 Compared two dimensional barcode with one dimensional barcode the former does not need to rely on database, and it can store large amount of information and express a variety of multimedia and text information, at the same time it also can be embedded encryption system, having error correction ability. Quick response matrix codes (QR code) is a kind of matrix two dimensional barcode, it can be a full range of recognition and effectively express Chinese characters, at present it has been widely applied in our country. For traditional QR code the error correction ability is limited, this paper proposes a solution that error correcting codes LDPC codes will replace RS code to the QR image, and graphics pretreatment is used to deal with obtained noise and tilted graphics, finally through the segmentation processing and decode process QR code is identified, so the information what we want is gotten. The purpose is that on the basis of error-correcting codes LDPC encoding and decoding QR Code error correction ability is improved and the QR code recognition effect is also better. Due to the improved error correction ability, the use scope of QR code is also can be extended.Through the analysis of the two-dimensional barcode technology’s development status at home and abroad, and then the QR code symbols characteristics and encoding and decoding principles are studied, the paper puts forward a kind of new QR generation scheme. First it gives a study of the error correction code LDPC codes encoding and decoding thinking and performance simulation, and then puts it with the RS code simulation contrast. At the same time a detailed study is carried for the generated QR code image preprocessing, including image graying, median filtering, binarization, image segmentation and so on. For new QR code in the process of generation error-correcting codes composition need attention, because its structure directly affect the final QR code of error correction ability.After theoretical study, this paper introduces the design processing of QR encoding and decoding, and some experimental detection and analysis. The experimental results show that the new QR code decoding ability has been improved, and it can extract the correct information in the large degree fouling, when compared to the original QR, the error correction ability is improved, and the complexity of the algorithm is reduced. This technology can not only solve the existing two dimensional barcode QR code with problem, it also can be applied to other two dimensional bar code system.Pass by a summary of the present work, the innovations in the text are as follows:1) A new QR code generation scheme is proposed that the LDPC codes are applied to the QR code instead of the RS Code.2) For the collected QR image, the images median filter and binary processing are used, and with new error decoding algorithm the error correction ability is increased from30%to50%.3) On the basis of not changing the coding scheme of the QR code, the QR code application is extended and the complexity of the algorithm is reduced.更多还原