2D Barcode Image Decoding

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1. Introduction

Barcode technology is one of the most important parts of Automatic Identification and Data Capture (AIDC); we can obtain decoded data through analysis of a barcode. According to the encoding type of barcodes, we divide barcode into two categories: one-dimensional barcode and two-dimensional barcode. One-dimensional barcode typically consists of varying the widths and spacings of parallel lines. Moreover, two-dimensional barcode is a graphical image that stores information both horizontally and vertically. Two-dimensional barcode compared with the one-dimensional barcode has the following advantages: (1) high data capacity; (2) no additional storages; (3) error correction ability.

Quick Response code (QR code) is one of the most popular types of two-dimensional barcodes developed in Japan by Denso Corporation in 1994. Although QR code was first designed for the automotive industry, QR codes are now used over much wider range of applications, including commercial tracking, transport ticketing, website Uniform Resource Locator (URL), and identity verification. QR code has several advantages. First, QR code has strong error correcting capability, which can restore 30% data for the maximum error correction level. Second, QR code can be scanned from any direction because the proportion of position detection patterns is not changed with the scanning direction. Third, QR code supports different encoding types and versions. We can choose an appropriate encoding type and version to reduce the size of QR code image.

Although there exist many commercial programs for QR code decoding, inventing more robust QR code decoding strategy still attracts many attentions from researchers. Many works are proposed recently. In [1, 2], Belussi and Hirata proposed a fast component-based two-stage approach for detecting QR codes in arbitrarily acquired images. Moreover Ohbuchi et al. [3] and Liu et al. [4] focused on enabling mobile phone to recognize QR code under poor conditions in real time. For decoding QR code image correctly and efficiently,...