2D (two dimensional) barcodes have data encoded in both horizontal and vertical directions. They contain more information than 1D barcodes with data encoded in horizontal direction only. Conventional 1D barcodes have a single row of bars that get wider as more data is encoded. In 2D barcodes hundreds of characters can be embedded in a single barcode.The main advantage of using 2D barcodes is that a large amount of easily and accurately read data could be placed on the barcode without increasing the size of the label significantly. In addition to holding large amounts of data, 2D barcodes require much less quiet zone (only one cell width around), which allows symbol location to be much closer to surrounding text and/or graphics. One of amazing aspects of 2D barcodes is their durability as compared to conventional barcodes. This is due in part to its excellent error checking and correction.The goal of our research was focused on determination of the limited intensity between printing color and substrate, which could enable accurate code capturing and reading. Two standard 2D codes (differ in size and amount of encoded information) were printed separately with cyan, magenta, yellow and black color by using inkjet-printing technology. The color intensities of printed codes were in the range from 15 % (20, 25, 30, 50) to 100 % raster tone values. One half of the printed samples was exposed to light fastness test according to standard SIST ISO 12040. All samples exposed and not exposed were captured with 2D reader. At the end the limiting intensity for all samples were determined and evaluated by 2D reader and image analysis (ImageJ software).
Tadeja Muck, Urška Bogataj, Sabina Bračko, "2D Codes - Light Fastness and Readability" in Proc. IS&T Int'l Conf. on Digital Printing Technologies and Digital Fabrication (NIP25), 2009, pp 154 - 157, https://doi.org/10.2352/ISSN.2169-4451.2009.25.1.art00043_1