QR Code
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A QR Code is a matrix code (or two-dimensional bar code) created by Japanese corporation Denso-Wave in 1994. The "QR" is derived from "Quick Response", as the creator intended the code to allow its contents to be decoded at high speed. QR Codes are common in Japan, where they are currently the most popular type of two dimensional codes. Moreover, most current Japanese mobile phones can read this code with their camera.
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[edit] Overview
Although initially used for tracking parts in vehicle manufacturing, QR Codes are now used in a much broader context, including both commercial tracking applications and convenience-oriented applications aimed at mobile phone users (known as mobile tagging). QR Codes storing addresses and URLs may appear in magazines, on signs, buses, business cards or just about any object that users might need information about. Users with a camera phone equipped with the correct reader software can scan the image of the QR Code causing the phone's browser to launch and redirect to the programmed URL. This act of linking from physical world objects is known as a hardlink or physical world hyperlinks. Users can also generate and print their own QR Code for others to scan and use by visiting one of several free QR Code generating sites.
[edit] Standards
There are several standards documents covering the physical encoding of QR Code:[1]
- October 1997 — AIM International ISS QR Code
- 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Information technology — Automatic identification and data capture techniques — Bar code symbology — QR Code (now withdrawn)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 Model 1 and QR Code Model 2 symbols. - 1 September 2006 — ISO/IEC 18004:2006 Information technology — Automatic identification and data capture techniques — QR Code 2005 bar code symbology specification
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.
At the application layer, there is some variation between implementations. NTT docomo has established de facto standards for the encoding of URLs, contact information, and several other data types.[2] Google's open-source "zxing" project maintains a list of QR Code data types.[3]
[edit] License
"QR Code is open in the sense that the specification of QR Code is disclosed and that the patent right owned by Denso Wave is not exercised."[1] The Japanese website goes on to state that the term QR Code itself is a "registered trademark of Denso Wave Incorporated in Japan and other countries".[4]
[edit] Storage
| QR Code data capacity[5] | |
|---|---|
| Numeric only | Max. 7,089 characters |
| Alphanumeric | Max. 4,296 characters |
| Binary (8 bits) | Max. 2,953 bytes |
| Kanji/Kana | Max. 1,817 characters |
| Error correction capacity | |
|---|---|
| Level L | 7% of codewords can be restored. |
| Level M | 15% of codewords can be restored. |
| Level Q | 25% of codewords can be restored. |
| Level H | 30% of codewords can be restored. |
QR codes use the Reed–Solomon error correction.
[edit] Micro QR Code
Micro QR Code is a smaller version of the QR Code standard for applications with less ability to handle large scans.
There are different forms of Micro QR Code as well. The highest of these can hold 35 characters.
[edit] Design QR
The design of QR makes it possible to incorporate eye-catching images of logos, characters, or photos into QR code, without losing any information of the code.
The colorized image represents the first 12 stanzas of Lewis Carroll's "The Walrus and the Carpenter". Encoded in binary mode with "Level M" error correction it contains approximately 2300 characters, but, due to the density of the information, decoding it would require a high resolution image that is unavailable to many QR Code readers (particularly mobile phones).
British popgroup Pet Shop Boys used QR-code for the artwork of their download-only single Integral in 2007. The videoclip for the song also features QR-code. When the codes are scanned correctly, users are directed to petshopboys.co.uk, and web pages about the British national identity card plans, respectively.
[edit] Making QR Codes (Encoding)
There are many tools that are available for encoding custom QR Codes. Using these tools it is possible to create QR Codes that represent a phone number, SMS text message, and many other functions.
[edit] See also
- Data Matrix, a competing standard seeing similarly wide use in the Western Hemisphere.
- Semacode
- ShotCode
- PDF417
- Barcode
- Dot code
- Aztec Code
- High Capacity Color Barcode
- CueCat
[edit] References
- ^ a b Denso Wave Incorporated - QR Code Standardization
- ^ "Synchronization with Native Applications". NTT docomo. http://www.nttdocomo.co.jp/english/service/imode/make/content/barcode/function/application/. Retrieved on 17 February 2009.
- ^ "Barcode Contents". zxing – A rough guide to standard encoding of information in barcodes. http://code.google.com/p/zxing/wiki/BarcodeContents. Retrieved on 17 February 2009.
- ^ Denso Wave Incorporated - "QR Code.com"
- ^ Denso Wave Incorporated - About 2D Code
[edit] External links
- Mainstream America is Ready for Bar Codes - Converging “Realspace” and “Mobilespace”
- ARTag fiducial marker system A somewhat related system that also determines the pose and position of, as well as identifying, items containing the markers.
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