Per-Colorant-Channel Color Barcodes for Mobile Applications: An Interference Cancellation Framework

Abstract

Abstract-We propose a color barcode framework for mobile phone applications by exploiting the spectral diversity afforded by the cyan (C), magenta (M), and yellow (Y) print colorant channels commonly used for color printing and the complementary red (R), green (G), and blue (B) channels, respectively, used for capturing color images. Specifically, we exploit this spectral diversity to realize a three-fold increase in the data rate by encoding independent data in the C, M, and Y print colorant channels and decoding the data from the complementary R, G, and B channels captured via a mobile phone camera. To mitigate the effect of cross-channel interference among the printcolorant and capture color channels, we develop an algorithm for interference cancellation based on a physically-motivated mathematical model for the print and capture processes. To estimate the model parameters required for cross-channel interference cancellation, we propose two alternative methodologies: a pilot block approach that uses suitable selections of colors for the synchronization blocks and an expectation maximization approach that estimates the parameters from regions encoding the data itself. We evaluate the performance of the proposed framework using specific implementations of the framework for two of the most commonly used barcodes in mobile applications, QR and Aztec codes. Experimental results show that the proposed framework successfully overcomes the impact of the color interference, providing a low bit error rate and a high decoding rate for each of the colorant channels when used with a corresponding error correction scheme.

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“…If higher capacity codes are used, or dedicated Tags are designed, the problem would be simpler. We could beautify the current QR code by introducing stylish design [25] without affecting the performance, such as Halftone QR Codes [27], Visualead QR codes [17]. Or we could also adopt new kind of picture-embedding 2D barcode, such as PiCode [31].…”

A novel approach for color barcode decoding using smart phones

“…Blasinski and et al [5] use a model-based interference cancellation procedure to recover the encoded data from each color channel. They propose a color interference cancellation algorithm that estimates the cyan (C), magenta (M), and yellow (Y) print colorant Channels from the Red (R), Green (G), and Blue (B) channels of the captured barcode.…”

To increase data capacity of QR code using multiplexing with color coding: An example of embedding speech signal in QR code

“…Areas in which this increment of data capacity can be focused includes data hiding techniques [4][5][6][7]8], use of color QR codes [2,9,11], multiplexing of several QR code images [10], data compression before encoding it into QR code [12].…”

“…However only three colors apart from black and white -Cyan, Magenta, Yellow or Red, Green, Blue have been used [2,9,11]. Using more colors at a time may further increase the capacity.…”