A QR code (abbreviated from Quick Response code) is a type of matrix barcode (or two-dimensional barcode) invented in 1994 by the Japanese automotive company Denso Wave. A barcode is a machine-readable optical label that contains information about the item to which it is attached. In practice, QR codes often contain data for a locator, identifier, or tracker that points to a website or application. A QR code uses four standardized encoding modes (numeric, alphanumeric, byte/binary, and kanji) to store data efficiently; extensions may also be used.
The Quick Response system became popular outside the automotive industry due to its fast readability and greater storage capacity compared to standard UPC barcodes. Applications include product tracking, item identification, time tracking, document management, and general marketing.
A QR code consists of black squares arranged in a square grid on a white background, which can be read by an imaging device such as a camera, and processed using Reed–Solomon error correction until the image can be appropriately interpreted. The required data is then extracted from patterns that are present in both horizontal and vertical components of the image.
History
The QR code system was invented in 1994 by Masahiro Hara from the Japanese company Denso Wave. The initial design was influenced by the black and white pieces on a Go board. Its purpose was to track vehicles during manufacturing; it was designed to allow high-speed component scanning. QR codes are now used in a much broader context, including both commercial tracking applications and convenience-oriented applications aimed at mobile-phone users (termed mobile tagging). QR codes may be used to display text to the user, to open a webpage on the user’s device, to add a vCard contact to the user’s device, to open a Uniform Resource Identifier (URI), to connect to a wireless network, or to compose an email or text message. There are a great many QR code generators available as software or as online tools that are either free, or require a paid subscription. The QR code has become one of the most-used types of two-dimensional code.
Adoption
During the month of June 2011, 14 million American mobile users scanned a QR code or a barcode. Some 58% of those users scanned a QR or barcode from their homes, while 39% scanned from retail stores; 53% of the 14 million users were men between the ages of 18 and 34.
Standards
Structure of a QR code (version 7), highlighting functional elements
There are several standards that cover the encoding of data as QR codes:
- October 1997 – AIM (Association for Automatic Identification and Mobility) International
- January 1999 – JIS X 0510
- June 2000 – ISO/IEC 18004:2000 Information technology – Automatic identification and data capture techniques – Bar code symbology – QR code (now withdrawn)
Defines QR code models 1 and 2 symbols. - 1 September 2006 – ISO/IEC 18004:2006 Information technology – Automatic identification and data capture techniques – QR code 2005 bar code symbology specification (now withdrawn)[12]
Defines QR code 2005 symbols, an extension of QR code model 2. Does not specify how to read QR code model 1 symbols, or require this for compliance. - 1 February 2015 – ISO/IEC 18004:2015 Information – Automatic identification and data capture techniques – QR Code barcode symbology specification
Renames the QR Code 2005 symbol to QR Code and adds clarification to some procedures and minor corrections.
At the application layer, there is some variation between most of the implementations. Japan’s NTT DoCoMo has established de facto standards for the encoding of URLs, contact information, and several other data types. The open-source “ZXing” project maintains a list of QR code data types.
