Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY 14627-0126, USA.
IEEE Trans Image Process. 2011 May;20(5):1337-50. doi: 10.1109/TIP.2010.2092437. Epub 2010 Nov 15.
We present a new high capacity color barcode. The barcode we propose uses the cyan, magenta, and yellow (C,M,Y) colorant separations available in color printers and enables high capacity by independently encoding data in each of these separations. In each colorant channel, payload data is conveyed by using a periodic array of elliptically shaped dots whose individual orientations are modulated to encode the data. The orientation based data encoding provides beneficial robustness against printer and scanner tone variations. The overall color barcode is obtained when these color separations are printed in overlay as is common in color printing. A reader recovers the barcode data from a conventional color scan of the barcode, using red, green, and blue (R,G,B) channels complementary, respectively, to the print C, M, and Y channels. For each channel, first the periodic arrangement of dots is exploited at the reader to enable synchronization by compensating for both global rotation/scaling in scanning and local distortion in printing. To overcome the color interference resulting from colorant absorptions in noncomplementary scanner channels, we propose a novel interference minimizing data encoding approach and a statistical channel model (at the reader) that captures the characteristics of the interference, enabling more accurate data recovery. We also employ an error correction methodology that effectively utilizes the channel model. The experimental results show that the proposed method works well, offering (error-free) operational rates that are comparable to or better than the highest capacity barcodes known in the literature.
我们提出了一种新的高容量彩色条码。我们提出的条码利用彩色打印机中的青色、品红色和黄色（C、M、Y）着色剂分离，并通过在每个分离中独立编码数据来实现高容量。在每个着色剂通道中，通过使用周期性的椭圆形状点阵列来传输有效负载数据，其各个方向被调制以对数据进行编码。基于方向的数据编码提供了对打印机和扫描仪色调变化的有益鲁棒性。当这些颜色分离像在彩色打印中那样重叠打印时，就会获得整体彩色条码。读取器使用分别互补于打印 C、M 和 Y 通道的红色、绿色和蓝色（R、G、B）通道从常规彩色扫描中恢复条码数据。对于每个通道，首先在读取器中利用点的周期性排列来实现同步，补偿扫描中的全局旋转/缩放和打印中的局部失真。为了克服来自非互补扫描仪通道中着色剂吸收的颜色干扰，我们提出了一种新颖的最小化干扰数据编码方法和一种统计通道模型（在读取器中），该模型捕获干扰的特性，从而实现更准确的数据恢复。我们还采用了一种错误纠正方法，该方法有效地利用了通道模型。实验结果表明，所提出的方法效果很好，提供的（无误码）操作率可与文献中已知的最高容量条码相媲美或更好。
