RA Code: A Robust and Aesthetic Code for Resolution-Constrained Applications

Changsheng Chen, Baojian Zhou, Wai Ho Mow

Abstract: Recently, some picture-embedding schemes have been proposed to improve the aesthetic appearance of 2D barcodes. However, these aesthetic 2D barcodes are not robust to the distortions incurred by the print/display-and-capture channel under limited rendering space and resolution. In this paper, a picture-embedding 2D barcode named the Robust and Aesthetic (RA) Code is proposed to counter the channel impairments, such as downsampling error and inter-symbol interference. Experimental results demonstrate that the proposed RA Code is more robust than the existing picture-embedding 2D barcodes, especially under limited printing/displaying space. The RA Code of a size as small as 1.5 × 1.5 cm 2 can be successfully decoded with a demodulated bit error probability of less than 0.1, which corresponds to more than 50% improvement over those of the state-of-the-art picture-embedding 2D barcodes. In addition, the correct decoding probability is improved significantly from as low as 0 to more than 0.8650. The decoding algorithm has been implemented on the Android platform, and the practicality of the RA Code has been successfully demonstrated.