High capacity color barcodes using dot orientation and color separability

Barcodes are widely utilized for embedding data in printed format to provide automated identification and tracking capabilities in a number of applications. In these applications, it is desirable to maximize the number of bits embedded per unit print area in order to either reduce the area requirements of the barcodes or to offer an increased payload, which in turn enlarges the class of applications for these barcodes. In this paper, we present a new high capacity color barcode. Our method operates by embedding independent data in two different printer colorant channels via halftone-dot orientation modulation. In the print, the dots of the two colorants occupy the same spatial region. At the detector, however, by using the complementary sensor channels to estimate the colorant channels we can recover the data in each individual colorant channel. The method therefore (approximately) doubles the capacity of encoding methods based on a single colorant channel and provides an embedding rate that is higher than other known barcode alternatives. The effectiveness of the proposed technique is demonstrated by experiments conducted on Xerographic printers. Data embedded at a high density by using the two cyan and yellow colorant channels for halftone dot orientation modulation is successfully recovered by using the red and blue channels for the detection, with an overall symbol error rate that is quite small.