【作者】 刘欣；

【导师】 石敏；

【作者基本信息】 暨南大学 ， 电子与通信工程， 2012， 硕士

【摘要】 二维条码作为对物品描述的一种手段，已经在世界范围内受到了前所未有的关注，特别是QR Code二维条码，由于它可以对中国汉字进行有效的编码，已经在我国有了广泛的应用。但是二维条码通常是以标签的形式存在于物品的表面，所以会难免受到外界的污损，并且识读时，可能会因为设备的原因或者外界光线等对图像的识读造成困难。而QR Code的图像预处理技术能够让受到外界干扰的条码图像在一定程度上被正确还原。正是根据此背景，提出了本文的图像预处理的算法。本文首先对QR Code码的编码原理做了详细的分析，然后介绍基于数字图像处理技术的扫描条码图片的预处理步骤，再介绍了QR Code的译码过程，最后针对我国农产品溯源的现实特点和QR Code的实用特性提出了一个应用方案。本文的重点研究内容包括：针对二维条码的特点，对比现有处理算法的实验结果，选择合适的算法并对其进行改进。在改进的算法中，首先采用中值滤波方法进行滤波，然后采用Otsu阈值算法进行二值化，最后采用Sobel算子进行边缘检测以及二值法插值。经过实验验证表明，本文提出的算法能够很好的解决图像曝光不均、噪声模糊等问题。本文的创新点主要体现在图像校正的问题上，通过对比和分析Hough变换以及Radon变换的优缺点，本文提出了Hough变换和Radon变换结合的方法进行直线检测来确定倾斜角度，大大减少了运算量和提高了准确度。实验结果表明本文提出的算法能够得到较好的效果。更多还原

【Abstract】 As a means of the description and identification for the items, two-dimensional barcode hasbeen widely attended, especially the QR Code, it has had a wide range of applications in ourcountry, because it could be coded effectively for Chinese characters.But becausetwo-dimensional barcode was usually used in the surface of the items with the tag way, it wouldbe hard to avoid being dirtied in the outside, and when we are reading it may be hard to be readbecause of the equipment or outside light.According to the background, the image preprocessing algorithm was put forward in thispaper. Firstly, the encoding principle of the QR Code had been presented; Secondly thepretreatment steps for the scanning bar code pictures were introduced; At last, the QR Codedecoding process has been introduced, and an application solution has been put forward in viewof the reality characteristics of the agricultural products trace and practical characteristics of theQR Code. The algorithm has been improved,the median filter was adopted, Otsu thresholdalgorithm was chose, Sobel Operator was used for the edge detection, the method of combiningHough transform and Radon transformation were used for linear testing to determine the Angle,and two-value method was used after the image rotation. The experimental results show that thecombination of the algorithms can get very good effect.In this paper, the innovation points were embodied in correcting the image, the method ofcombining the Hough transform and Radon transformation were put forward for testing linear todetermine the Angle in this paper, and the complexity of calculation has been reduced, theaccuracy has been improved.更多还原