二维条形码的识别及应用

Datamatrix是矩阵式二维条形码之一,由于其尺寸小、保密性好、纠错能力强而广泛使用在工业、数据安全及其他行业.在实际应用中,由扫描设备得到的二维条码图像通常有噪声、污损及背景干扰,并具有平移、旋转.为提高实际应用中的正确译码率,通过预处理和两次图像定位,从实际图像中分割出Datamatrix图像,再从中读取数据,进行正确译码,完成对Datamatrix的识别.     

基于偏微分方程的噪声消除方法

从Perona&Malik方程离散形式出发 ,对其处理过程进行了分析。通过修改系数分布函数 ,使得消除图像噪声的同时能更好保持边缘。     

基于图像技术的EAN-13条码识别系统设计

条形码技术作为一种数据采集和自动识别技术应用非常广泛。为了更好地满足应用场景的自动化功能需求,利用图像处理相关技术,对EAN-13条形码识别的相关算法进行了研究。首先,针对采集到的条形码图像进行图像预处理,包括图像灰度化、基于Hough变换的图像倾角矫正、目标分割和图像滤波;然后根据条形码编码的既定规则,采用平均值法和校验码验证法对条形码进行译码;最后,利用MATLAB仿真软件,设计了一个条形码识别系统。通过实验验证,所设计的系统识别率可以达到99%以上,取得了很好的效果。     

QR Code二维条形码的图像识别

在现代社会商品流通中,为了提高工作效率,条码识别技术得到了广泛的应用.一维条码受到容量的限制,仅能标识商品,而不能描述商品.二维条码解决了一维条码面I临的容量问题,具有信息量大、可靠性高、保密防伪等优点.文中介绍了QR Code二维条形码的技术,给出了基于数字图像处理的QR Code二维条形码的识别方案.该方案综合运用了图像灰度化、二值化、去噪、边缘检测、图像旋转等多种图像处理方法实现条码图像的预处理、条码定位、条码分割和数据提取.实验表明:该方案大大提高了识读的灵活性和可靠性.     

PDF417图像译码设计及实现

PDF417二维堆积条形码译码的软硬件完全实现,目前在我国还存在着一定的困难。本文主要探讨了条形码及其图像的排列结构分析,译码关键算法,从而完成把条码中存储的有用信息解译出来的软件实现。     

PDF417二维条形码识别技术研究

简要阐述了条形码技术国内外发展状况和二维条形码的编码方法,并对条形码识别过程进行了概述,提出了条码识别过程中图像预处理、二值化、边缘检测等存在的技术难点,并给出了解决方案,指出了条形码识别技术的发展趋势。     

一种层次化的Data Matrix实时解码方法

在实际应用中,Data Matrix二维条形码的解码效果会受到不均匀光照和复杂背景的影响。为此,提出一种层次化的Data Matrix实时解码方法。利用大津法将条码图像的前景和背景进行分割,得到二值化的条码图像,对其进行区域定位和精确定位。在此基础上,设计基于数字信号处理的二维条形码快速解码终端。实验结果表明,该解码方法具有较好的实时性和较高的鲁棒性。     

基于视觉和二维条形码的数字水印

根据人的视觉系统(HVS)的频率响应特性和JND特性,将二维条形码压缩编码后作为数字水印,利用离散小波变换(DWT)嵌入到被保护的数字图像中,较好地解决了二维条形码信息量大与水印隐蔽性之间的问题,同时使二维条码水印在数字图像中有很好的隐蔽性和鲁棒性;嵌入了二维条形码数字水印的图像,经过低通滤波或高通滤波都能提取很好的水印。     

二维条形码编码与译码的计算机实现

介绍了PDF417二维条形码的特点和编码规则，详细阐述了用计算机实现其编码的原理和方法，并采用具体实例介绍了设计步骤，给出了可同时实现中英文编码的程序设计方法。译码采用CCD整图读取条码图像，用计算机进行图像分析、特征提取，完成译码的实现方法。实验证明该方法可有效提高译码准确率。     

基于混沌置乱和二维条形码的数字水印

提出一种基于混沌置乱和二维条形码的数字水印算法,算法以二维条形码作为水印信息,先利用混沌映射产生一个密钥来加密水印信息再对其进行交织、分块编码,然后对其按特定顺序排列等预处理过程与在充分考虑HVS特性的基础上自适应地将水印嵌入到宿主图像小波变换的低频系数上.仿真结果表明该算法在抵抗如JPEG压缩、剪切、旋转等攻击下具有较好的鲁棒性与不可见性.     

A General Selective Averaging Method for Piecewise Constant Signal and Image Processing

Piecewise constant signals and images, which are sampled from piecewise constant functions, are an important kind of data. Typical examples include bar code signals, images of texts, hand-written signatures, Quick Response codes (QR codes), logos and cartoons. Selective averaging method is a powerful technique for this kind of signal and image denoising. In this paper, we propose a general selective averaging method (GSAM) to use more flexible weights compared to the previous one. Some convergence results and a probabilistic interpretation are provided for its iterated version. For the choice of the weight parameter, we discuss its influence on the asymptotic rate of convergence. We also study its influence on the denoising results with a moderate number of iterations. Then, our method is compared to the iterated neighborhood filter in signal denoising. In 2D case, we propose a novel extension called the alternating GSAM (AGSAM). We similarly introduce an alternating neighborhood filter. Experimental results demonstrate that our method is especially effective for Gaussian noise removal from noisy piecewise constant signals and images.     

标刻在金属零件上的二维条码数据提取方法

针对金属零件上二维条码光照分布不均、点扩散、对比度低与污染干扰等问题,提出一种基于原灰度图像小区域相邻模块对比提取二维条码数据的算法.首先通过峰度值排序法及模块区域微调法由粗到精定位每个二维条码模块位置,然后基于原灰度图像利用遗传算法提取二维条码的数据信息,得到最终的提取结果.与传统二维条码数据提取算法的实验结果证明,该算法对于复杂金属背景上的二维条码识读具有更高的可靠性.     

标刻在金属零件上的二维条码识别

直接零件标识(DPM)技术是实现产品标识的重要手段,二维条码技术是其关键技术之一。DPM标识是以金属作为背景用激光在其上面打上二维条码,与印刷品上的二维条码识读相比,基于金属背景下的二维条码识读更为复杂。改进了传统的识别方法,综合运用最大连通域提取、改进的霍夫变换定位边界、基于最大匹配度的网格化分和基于灰度图像的无损信息提取等方法来实现条码图像的粗定位、精定位、校正、条码分割和数据提取。实验表明,本方案对于磨损、轻度污染、畸变及光照不均的金属上的二维条码图像的识读具有较强的抗干扰性,并取得可靠的识读结果。     

二维彩色条码打印系统软件的设计与实现

介绍了利用VB设计并实现的一种二维彩色条码的打印系统。该彩色条码相对于传统的黑白条码在第三维增加了信息容量,实现了在条空横向宽度、条空纵向排列和条空颜色三方面传载信息,可得到远大于目前黑白条码的容量。文中对编码软件系统框架进行整体介绍,实现了条码码字集的编码入库,二维彩色条码字符的打印及条码模块属性设置等关键技术,并附有关键代码。通过对软件系统的测试,效果良好。表明该二维彩色条码编码系统实现了比二维条码更高的信息容量和信息密度,具有广泛的应用前景。     

二维条码图像反模糊算法研究

二维条码作为一种重要的自动识别技术,有着极其广泛的应用前景。有效地解决二维条码图像降质问题是其能够广泛应用的关键。实际应用中,图像模糊是常见的降质,给二维条码识别带来了困难。论文研究二维条码图像反模糊算法,首先应用傅里叶变化确定图像模糊类型;然后根据条码信号,获得模糊函数的参数;最后采用用基于迭代技术的算法复原条码图像。实验结果表明,论文设计的算法具有良好的性能和实时性。     

GB18030汉字信息的二维条码拆分迭代编码算法

为了解决二维码在证件类应用中常常面临的冷僻字编码问题，以GB18030字符集为对象分析汉字编码特点，提出基于该标准的汉字与ASCII混合信息的PDF417编码方法。并针对当前广泛应用的16位编程工具，结合实例给出了一种拆分迭代编码算法来实现字节压缩模式，它能够在保证较高编码效率的基础上有效节省编码存储空间。     

Design of circular dot pattern code (CDPC) for maximum information capacity and robustness on geometric distortion/noise

One dimensional or linear bar code has been used for distribution purposes such as product information and distribution channel identification. Those linear bar codes can support only one directional code layout and also support limited code error detection capability. Two dimensional bar codes (e.g., QR code) extending one dimensional bar codes were developed in database and index based types. Database type barcodes embed full information bits and show weak recognition rate with geometric distortion. Index-based embed only the index information and requires additional network servers to interpret the index information, which leads to limited information storage capacity. Instead of using visible bar codes, we propose CDPC (circular dot pattern code), which is a dot based codes which is more invisible than bar codes. We design CDPC to be more robust to geometric distortion and noise than previous coding schemes using circular template matching. To maximize the information capacity and robustness, we use a circular dot patterns which is more robust to affine transformation. Code can be easily extended according to the number of data circles. If the number of data circle is n, then we can embed \( \left( {5\sum {_{{k = 2}}^{{n + 1}}{\text{k}}} } \right) - {\text{n}} \) data bits. In our experimentation, we set the number of circle to three, and resulting information capacity can be 42 bits per one code. To extract information from a CDPC codes, we perform (1) image capture, (2) identification of dots, (3) graph based topological analysis of dot patterns, (4) template matching between topological graphs using position symbols, and (5) information bit extraction with error correction capability. To evaluate information capacity under various geometric distortions, we experiment our CDPC with StirMark Benchmark’s affine transformation (simulation of geometric and noise attacks) and with real cell phone image captures. Our experimental results also show that our CDPC scheme achieves more robust recognition performance than those proposed in previous research works including QR code.     

Efficient algorithms for the all nearest neighbor and closest pair problems on the linear array with a reconfigurable pipelined bus system

We present two O(1)-time algorithms for solving the 2D all nearest neighbor (2D/spl I.bar/ANN) problem, the 2D closest pair (2D/spl I.bar/CP) problem, the 3D all nearest neighbor (3D/spl I.bar/ANN) problem and the 3D-closest pair (3D/spl I.bar/CP) problem of n points on the linear array with a reconfigurable pipelined bus system (LARPBS) from the computational geometry perspective. The first O(1) time algorithm, which invokes the ANN properties (introduced in this paper) only once, can solve the 2D/spl I.bar/ANN and 2D/spl I.bar/CP problems of n points on an LARPBS of size 1/2n/sup 5/3+c/, and the 3D/spl I.bar/ANN and 3D/spl I.bar/CP problems pf n points on an LARPBS of size 1/2n/sup 7/4+c/, where 0 < /spl epsi/ = 1/2/sup c+1/-1 /spl Lt/ 1, c is a constant and positive integer. The second O(1) time algorithm, which recursively invokes the ANN properties k times, can solve the kD/spl I.bar/ANN, and kD/spl I.bar/CP problems of n points on an LARPBS of size 1/2n/sup 3/2+c/, where k = 2 or 3, 0 < /spl epsi/ = 1/2/sup n+1/-1 /spl Lt/ 1, and c is a constant and positive integer. To the best of our knowledge, all results derived above are the best O(1) time ANN algorithms known.     

Multilevel 2-D Bar Codes: Toward High-Capacity Storage Modules for Multimedia Security and Management

In this paper, we deal with the design of high-rate multilevel 2-D bar codes for the print-and-scan channel. First, we introduce a framework for evaluating the performance limits of these codes by studying an intersymbol-interference (ISI)-free, synchronous, and noiseless print-and-scan channel, where the input and output alphabets are finite and the printer device uses halftoning to simulate multiple gray levels. Second, we present a new model for the print-and-scan channel specifically adapted to the problem of communications via multilevel 2-D bar codes. This model, inspired by our experimental work, assumes perfect synchronization and absence of ISI, but independence between the channel input and the noise is not assumed. We adapt the theory of multilevel coding with multistage decoding (MLC/MSD) to the print-and-scan channel. Finally, we present experimental results confirming the utility of our channel model, and showing that multilevel 2-D bar codes using MLC/MSD can reliably achieve the high-capacity storage requirements of many multimedia security and management applications     

Construction of a Low Cost Custom 2-D Bar Code Reader for Tube Racks

We describe the development of a custom system for reading 2-D DataMatrix bar codes imprinted on the base of tubes stored in a rack. The system software drives a standard flatbed scanner in order to acquire an image, interprets DataMatrix bar codes at predefined locations in the image, and returns in an array the interpreted bar code data along with other associated information. Commercial software components were used for the image acquisition and bar code interpretation portion of the software. An example is given that illustrates how to call the custom software from Microsoft® Excel and insert the returned data directly into a spreadsheet.