Machine-read method for faded 2-D color barcodes using self-adaptive threshold

The fading law of 2-D paper-based color barcodes is analyzed with the ultraviolet aging test. The relation between the accumulative ultraviolet irradiation time and the chromatic aberration of 2-D color barcodes is analyzed based on the CIELAB model. The detection results of four-color printed label show that the fading velocity of fuchsine is faster than cyan, yellow and black. A self-adaptive threshold method, which can correct color aberration effectively and can machine-read the 2-D barcodes correctly, is put forward based on RGB trichromatic histogram and the principle of probability statistics. The experiment indicates that the machineread bit error rate of the self-adaptive threshold method is less then 0.05%, which was acquired from 25h ultraviolet aging test of barcodes. The result provides a criterion for the service period of the color barcodes.