Examine individual changes

'{{Distinguish|Quadratic residue code}} [[File:Wikipedia mobile en.svg|thumb|QR code for the [[URL]] of the English Wikipedia Mobile main page, "''<nowiki>http://en.m.wikipedia.org</nowiki>''"]] '''QR code''' (abbreviated from '''Quick Response Code''') is the trademark for a type of [[matrix barcode]] (or two-dimensional [[barcode]]) first designed for the [[automotive industry in Japan]]. A barcode is a machine-readable optical label that contains information about the item to which it is attached. A QR code uses four standardized encoding modes (numeric, alphanumeric, byte / binary, and [[kanji]]) to efficiently store data; extensions may also be used.<ref name=QRCodefeatures>{{cite web |url=http://www.qrcode.com/en/qrfeature.html |title=QR Code features |publisher=Denso-Wave |accessdate=3 October 2011 |archiveurl=http://archive.is/20120915/http://www.qrcode.com/en/qrfeature.html |archivedate=2012-09-15}}</ref> The QR Code system has become popular outside the automotive industry due to its fast readability and greater storage capacity compared to standard [[Universal Product Code|UPC barcodes]]. Applications include product tracking, item identification, time tracking, document management, general marketing, and much more.<ref name=autogenerated1>{{cite web |url=http://www.nacs.org/LinkClick.aspx?fileticket=D1FpVAvvJuo%3D&tabid=1426&mid=4802 |title=QR Code Essentials |publisher=Denso ADC |year= 2011 |accessdate=12 March 2013}}</ref> A QR code consists of black modules (square dots) 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 are then extracted from patterns present in both horizontal and vertical components of the image.<ref name=autogenerated1 /> == History == The QR code system was invented in 1994 by [[Denso]] Wave. Its purpose was to track vehicles during manufacture; it was designed to allow high-speed component scanning.<ref>{{cite book |title=Handbook of Augmented Reality |author=Borko Furht |url=http://books.google.com/books?id=fG8JUdrScsYC&lpg=PP1&dq=Handbook%20of%20Augmented%20Reality&pg=PA341 |page=341 |publisher=Springer |year=2011}}</ref> Although initially used for tracking parts in vehicle manufacturing, QR codes now are 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 add a vCard contact to the user's device, to open a Uniform Resource Identifier (URI), or to compose an e-mail or text message. Users can generate and print their own QR codes for others to scan and use by visiting one of several paid and free QR code generating sites or apps. The technology has since become one of the most-used types of two-dimensional barcode.<ref name=About2DCode>{{cite web |url=http://www.qrcode.com/en/aboutqr.html |title=QR Code&nbsp;— About 2D Code |publisher=Denso-Wave |accessdate=3 October 2011 |archiveurl=http://archive.is/20120915/http://www.qrcode.com/en/aboutqr.html |archivedate=2012-09-15}}</ref> == Standards == [[File:QR Code Structure Example 3.svg|right|400px|Structure of a QR code, highlighting functional elements]] There are several standards that cover the encoding of data as QR codes:<ref name="qrstandard1">{{cite web |url=http://www.qrcode.com/en/qrstandard.html |title=QR Code Standardization |publisher=Denso-Wave |work=QR Code.com |accessdate=23 April 2009 |archiveurl=http://archive.is/20120915/http://www.qrcode.com/en/qrstandard.html |archivedate=2012-09-15}}</ref> *October 1997{{spaced ndash}}AIM (Association for Automatic Identification and Mobility) International<ref>{{cite web |url=https://www.aimglobal.org/estore/ProductDetails.aspx?ProductID=31 |title=AIM Global Online Store |publisher=Aimglobal.org |accessdate=23 April 2009 |archiveurl=http://archive.is/20120915/https://www.aimglobal.org/estore/ProductDetails.aspx?ProductID=31 |archivedate=2012-09-15}}</ref> *January 1999{{spaced ndash}}[[Japanese Industrial Standards|JIS]] X 0510 *June 2000{{spaced ndash}}[[International Organization for Standardization|ISO]]/IEC 18004:2000 ''[http://www.iso.org/iso/iso_catalogue/catalogue_ics/catalogue_detail_ics.htm?csnumber=30789 Information technology{{spaced ndash}}Automatic identification and data capture techniques{{spaced ndash}}Bar code symbology{{spaced ndash}}QR code]'' (now withdrawn)<br /> Defines QR code models 1 and 2 symbols. *1 September 2006{{spaced ndash}}ISO/IEC 18004:2006 ''[http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=43655 Information technology{{spaced ndash}}Automatic identification and data capture techniques{{spaced ndash}}QR code 2005 bar code symbology specification]''<br /> 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 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.<ref>{{cite web |url=http://www.nttdocomo.co.jp/english/service/imode/make/content/barcode/function/application/ |title=Synchronization with Native Applications |publisher=[[NTT DoCoMo]] |accessdate=17 February 2009 |archiveurl=http://archive.is/20120905/http://www.nttdocomo.co.jp/english/service/imode/make/content/barcode/function/application/ |archivedate=2012-09-05}}</ref> The open-source "ZXing" project maintains a list of QR code data types.<ref>{{cite web |url=http://code.google.com/p/zxing/wiki/BarcodeContents |title=Barcode Contents |work=zxing&nbsp;– A rough guide to standard encoding of information in barcodes |accessdate=17 February 2009 |archiveurl=http://archive.is/20120530/http://code.google.com/p/zxing/wiki/BarcodeContents |archivedate=2012-05-30}}</ref> == Uses == Originally designed for industrial uses, QR codes have become common in consumer advertising. Typically, a [[smartphone]] is used as a QR code scanner, displaying the code and converting it to some useful form (such as a standard [[URL]] for a website, thereby obviating the need for a user to type it into a [[web browser]]).[[File:Japan-qr-code-billboard.jpg|thumb|A QR code in Japan used on a large billboard. ''http://sagasou.mobi'' MEBKM:TITLE:探そうモビで専門学校探し！;URL:http://sagasou.mobi;]] "In the shopping industry, knowing what causes the consumers to be motivated when approaching products by the use of QR codes, advertisers and marketers can use the behavior of scanning to get consumers to buy, causing it to have the best impact on ad and marketing design."<ref>{{cite journal | author = Tolliver-Walker, Heidi | year = 2011 | title = Making Best Use of QR codes: Gleaning Lessons from the Latest Data | url = | journal = Seybold Report: Analyzing Publishing Technologies | volume = 11 | issue = 23 | pages = 2–7 }}</ref> As a result, the QR code has become a focus of [[advertising]] strategy, since it provides quick and effortless access to the brand's website.<ref>{{cite web |url=http://www.mobilemarketer.com/cms/news/software-technology/11930.html |title=http://www.mobilemarketer.com/cms/news/software-technology/11930.html |archiveurl=http://archive.is/20120912/http://www.mobilemarketer.com/cms/news/software-technology/11930.html |archivedate=2012-09-12}}</ref><ref>{{cite web |url=http://blogs.vancouversun.com/2012/01/04/tescos-cool-qr-code-advertising-campaign/ |title=http://blogs.vancouversun.com/2012/01/04/tescos-cool-qr-code-advertising-campaign/ |archiveurl=http://archive.is/20120720/http://blogs.vancouversun.com/2012/01/04/tescos-cool-qr-code-advertising-campaign/ |archivedate=2012-07-20}}</ref> Beyond mere convenience to the consumer, the importance of this capability is that it increases the [[conversion rate]] (that is, it increases the chance that contact with the advertisement will convert to a sale), by coaxing interested prospects further down the [[conversion funnel]] without any delay or effort, bringing the viewer to the advertiser's website immediately, where a longer and more targeted sales pitch may continue. Although initially used to track parts in vehicle manufacturing, QR codes are now ({{as of | 2012 | lc = on}}) used over a much wider range of applications, including commercial tracking, entertainment and transport ticketing, product/loyalty marketing (examples: mobile couponing where a company's discounted and percent discount can be captured using a QR code decoder which is a mobile app, or storing a company's information such as address and related information alongside its alpha-numeric text data as can be seen in Yellow Pages directory), and in-store product labeling. It can also be used in storing personal information for use by organizations. An example of this is Philippines National Bureau of Investigation (NBI) where NBI clearances now come with a QR code. Many of these applications target [[mobile phone|mobile-phone]] users (via [[mobile tagging]]). Users may receive text, add a [[vCard]] contact to their device, open a [[Uniform Resource Identifier]] (URI), or compose an [[email#Message format|e-mail]] or text message after scanning QR codes. They can generate and print their own QR codes for others to scan and use by visiting one of several pay or free QR code-generating sites or apps. [[Google]] had a popular [[API]] to generate QR codes,<ref>{{cite web | url=http://code.google.com/apis/chart/infographics/ | title=Google Chart Tools |archiveurl=http://archive.is/20120707/http://code.google.com/apis/chart/infographics/ |archivedate=2012-07-07}}</ref> and apps for scanning QR codes can be found on nearly all smartphone devices.<ref>{{cite web | url=http://www.708media.com/qrcode/qr-code-readers-iphone-android-blackberry-windows-phone-7/ | title=QR Code Readers for iPhone, Android, Blackberry and Windows Phone 7 |archiveurl=http://archive.is/20120718/http://www.708media.com/qrcode/qr-code-readers-iphone-android-blackberry-windows-phone-7/ |archivedate=2012-07-18}}</ref> QR codes storing addresses and [[Uniform Resource Locator]]s (URLs) may appear in magazines, on signs, on buses, on business cards, or on almost any object about which users might want information. Users with a [[camera phone]] equipped with the correct reader application can scan the image of the QR code to display text, contact information, connect to a [[wireless LAN|wireless network]], or open a web page in the telephone's browser. This act of linking from physical world objects is termed [[hardlink (homonymy)|hardlinking]] or [[object hyperlinking]]. QR codes also may be linked to a location to track where a code has been scanned. Either the application that scans the QR code retrieves the geo information by using GPS and cell tower triangulation (aGPS) or the URL encoded in the QR code itself is associated with a location.<ref name=GeotaggedQRCodes>{{cite web |url=http://qrd.by |title=Geo Tagged QR Codes |accessdate=27 October 2011 |archiveurl=http://archive.is/20120714/http://qrd.by |archivedate=2012-07-14}}</ref> [[File:Z80-Tianjin -Beijing.jpg|right|266px|thumbnail|QR codes have been used and printed on Chinese train tickets since 2010<ref>{{cite news|first=Staff Reporter|title=QR codes on China's train tickets may leak personal information|url=http://www.wantchinatimes.com/news-subclass-cnt.aspx?id=20121216000074&cid=1103|accessdate=16 March 2013|newspaper=Want China Times}}</ref>]] Recruiters have started placing QR codes in job advertisements,<ref name="articles.timesofindia.indiatimes.com">{{cite news| url=http://articles.timesofindia.indiatimes.com/2013-10-19/job-trends/43198946_1_qr-code-website-business-card | work=The Times Of India | title=How to jazz up your CV with QR codes - The Times of India}}</ref> while applicants have started sporting it in their CVs and visiting cards.<ref name="articles.timesofindia.indiatimes.com"/> In June 2011, The Royal Dutch Mint (Koninklijke Nederlandse Munt) issued the world's first official coin with a QR code to celebrate the centenary of its current building and premises. The coin can be scanned by a [[smartphone]] and link to a special website with contents about the historical event and design of the coin.<ref>{{cite web| url=http://www.q5g.nl/|title= World's first QR code coin website |archiveurl=http://archive.is/20120915/http://www.q5g.nl/ |archivedate=2012-09-15}}</ref> In 2008, a Japanese stonemason announced plans to engrave QR codes on gravestones, allowing visitors to view information about the deceased, and family members to keep track of visits.<ref>{{cite news | url=http://www.wired.com/underwire/2008/03/japanese-graves/ | title=Japanese Gravestones Memorialize the Dead With QR Codes | publisher=Wired | date=2008-03-23 | accessdate=2013-05-08 | author=Novak, Asami}}</ref> === Mobile operating systems === QR codes can be used in Google's [[Android (operating system)|Android]], [[BlackBerry]] OS, [[Nokia]] [[Symbian]] Belle and [[Apple Inc.|Apple]] [[Apple iOS|iOS]] devices (iPhone/iPod/iPad), as well as Microsoft's Windows Phone operating system, [[Google Goggles]], 3rd party barcode scanners, and the [[Nintendo 3DS]]. The browser supports [[URL redirection]], which allows QR codes to send [[metadata]] to existing applications on the device. mbarcode<ref>{{cite web |url=http://maemo.org/packages/view/mbarcode/ |title=package overview for mbarcode |publisher=Maemo.org |accessdate=28 July 2010 |archiveurl=http://archive.is/20120711/http://maemo.org/packages/view/mbarcode/ |archivedate=2012-07-11}}</ref> is a QR code reader for the [[Maemo]] operating system. In Apple's iOS, a QR code reader is not natively included, but more than fifty paid and free apps are available with both the ability to scan the codes and hard-link to an external URL. [[Google Goggles]] is an example of one of many applications that can scan and hard-link URLs for iOS and Android. [[BlackBerry 10]] devices have a native QR reader as well as several third party readers. [[Windows Phone 7.5]] is able to scan QR codes through the [[Bing]] search app. === URLs === [[Uniform resource locator|URLs]] aided [[conversion rate|marketing conversion rates]] even in the pre-smartphone era, but during those years faced several limitations: ad viewers usually had to type the URL and often did not have a web browser in front of them at the moment they viewed the ad. The chances were high that they would forget to visit the site later, not bother to type a URL, or forget what URL to type. [[Clean URL]]s decreased these risks but did not eliminate them. Some of these disadvantages to URL conversion rates are fading away now that smartphones are putting web access and voice recognition in constant reach. Thus an advert viewer need only reach for his or her phone and speak the URL, at the moment of ad contact, rather than remember to type it into a PC later.<ref name=QRCodesInMarketing>{{cite web |url=http://www.hswsolutions.com/services/mobile-web-development/qr-code-marketing |title=QR Codes for Marketing: A Unique Way to Bridge Offline and Online Media |year= 2011 |publisher=Human Service Solutions, LLC |accessdate=12 March 2013 }}</ref> === Virtual stores === During the month of June 2011, according to one study, 14 million 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.<ref>{{cite web |url=http://www.internetretailing.net/2011/08/14m-americans-scanned-qr-and-bar-codes-with-their-mobiles-in-june-2011/ |title=16 August 2011 |archiveurl=http://archive.is/20120906/http://www.internetretailing.net/2011/08/14m-americans-scanned-qr-and-bar-codes-with-their-mobiles-in-june-2011/ |archivedate=2012-09-06}}</ref> The use of QR codes for "virtual store" formats started in South Korea,<ref>{{cite web |url=http://www.shop2mobi.com/tesco-qr-code-virtual-store/ |title=Tesco QR Code Virtual Store |archiveurl=http://archive.is/20120915/http://www.shop2mobi.com/tesco-qr-code-virtual-store/ |archivedate=2012-09-15}}</ref> and Argentina,<ref>{{cite web |url=http://www.ieco.clarin.com/empresas/Marketing-futurista-comprar-camara-celular_0_555544518.html |title=Marketing futurista: ya se puede comprar con la cámara del celular |archiveurl=http://archive.is/20120915/http://www.ieco.clarin.com/empresas/Marketing-futurista-comprar-camara-celular_0_555544518.html |archivedate=2012-09-15}}</ref> but is currently expanding globally.<ref>{{cite web |url=http://www.physorg.com/news/2010-11-phone-friendly-codes-ads.html |title=11 November 2010 |archiveurl=http://archive.is/20120915/http://www.physorg.com/news/2010-11-phone-friendly-codes-ads.html |archivedate=2012-09-15}}</ref> Big companies such as Walmart, Procter & Gamble and Woolworths have already adopted the Virtual Store concept.<ref>{{cite web |url=http://www.shop2mobi.com/virtual-qr-code-store-examples/ |title=Top 10 QR Code Store examples |archiveurl=http://archive.is/20120915/http://www.shop2mobi.com/virtual-qr-code-store-examples/ |archivedate=2012-09-15}}</ref> === Code payments === QR codes can be used to store bank account information or credit card information, or they can be specifically designed to work with particular payment provider applications. There are several trial applications of QR code payments across the world.<ref>{{cite web |url=http://mashable.com/2011/10/12/scvngr-levelup-redo/ |title=SCVNGR Unveils QR Code Payment System }}</ref><ref>{{cite web |url=http://gigaom.com/2012/01/26/mastercard-starts-piloting-qkr-mobile-payment-app/ |title=MasterCard starts piloting QkR mobile payment app }}</ref> In November 2012, QR code payments were deployed on a larger scale in the [[Czech Republic]] when an open format for payment information exchange - a [[Short Payment Descriptor]] - was introduced and endorsed by the Czech Banking Association as the official local solution for QR payments.<ref>{{cite web |url=https://www.czech-ba.cz/aktivity/standardy/format-pro-sdileni-platebnich-udaju-v-czk-qr-kody |title=Standard No. 26: Format for exchanging the payment information for Czech domestic payments using the QR codes |publisher=Czech Banking Association |date=November 2012 }}</ref> QR codes are commonly used in the field of cryptographic currencies, particularly those based off and including [[Bitcoin]].<ref>http://bitcoin.org/en/faq</ref> Payment addresses, cryptographic keys and transaction information are often shared between digital wallets in this way.<ref>https://blockchain.info/wallet/features</ref> === Website login === QR codes can be used to log in into websites: a QR Code is shown on the login page on a computer screen, and when a registered user scans it with a verified smartphone, they will automatically be logged in on the computer. Authentication is performed by the smartphone which contacts the server. Google tested such a login method in January 2012.<ref>{{cite web |url=http://www.zdnet.com/blog/security/google-testing-login-authentication-via-qr-codes/10105 |title=Google testing login authentication via QR codes}}</ref> === Funerary use === In 2008-04-01, Ishinokoe in Yamanashi Prefecture, Japan began to sell tombstones with QR codes produced by IT DeSign, where the code leads to a virtual grave site of the deceased.<ref>[http://www.j-cast.com/mono/2008/03/20018046.html お墓参りも「ネット」の時代　携帯サイトで故人を偲ぶ]</ref><ref>[https://web.archive.org/web/20120502174456/http://www.japantrends.com/qr-code-graves-give-a-memorial-window/ QR code graves give a “Memorial Window”]</ref><ref>[http://mobile.ishinokoe.co.jp/ 供養の窓 - 石の声 株式会社]</ref> In 2011, Seattle-based Quiring Monuments Inc. began to sell an item branded as a 'Living Headstone,' where a QR code is added to a grave marker through a small plastic-metal composite tag affixed to the gravestone and a QR-operated website to back it up. Anyone can scan a grave maker with their smartphone and learn more about the person buried there.<ref>[http://www.bizjournals.com/seattle/blog/2011/04/seattle-company-quiring-monuments-adds.html Quiring Monuments adds smartphone codes to gravestones]</ref> In 2014, in the [[Jewish Cemetery of La Paz]], Uruguay, QR codes are being implemented for tombstones, in order to enable [[remote access]] to cemetery images and know the exact location of every tomb via websites; it is the first cemetery in the world to introduce this innovation.<ref>{{cite web |url=http://www.elpais.com.uy/informacion/cementerio-judio-se-moderniza-codigos.html |title=Uruguayan Jewish Cemetery QRfied |date=24 March 2014 |publisher=[[El País (Uruguay)|EL PAIS]] }} {{es icon}}</ref> === Encryption === [[File:Japan Visa with QR code.jpg|thumb|141px|Japanese visa with a QR code (content is not deciphered)]] Encrypted QR codes, which are not very common, have a few implementations. An [[Android (operating system)|Android]] app,<ref>{{cite web |url=https://market.android.com/details?id=la.droid.qr |title=QR Droid |publisher=Google |date=19 August 2011 |accessdate=5 September 2011 |archiveurl=http://archive.is/20120915/https://market.android.com/details?id=la.droid.qr |archivedate=2012-09-15}}</ref> for example, manages encryption and decryption of QR codes using the [[Data Encryption Standard|DES algorithm]] (56 bits).<ref>{{cite web |url=http://qrdroid.com/encrypted-qr-codes-share-secret-messages.html |title=Encrypted QR Codes |publisher=QR Droid |date=24 October 2011 |accessdate=5 September 2011 |archiveurl=http://archive.is/20120713/http://qrdroid.com/encrypted-qr-codes-share-secret-messages.html |archivedate=2012-07-13}}</ref> The Japanese immigration system uses encrypted QR codes when issuing visa in passports <ref>{{cite web |url=http://blog.cliffano.com/2009/05/18/qr-code-usage-in-japan/ |title=QR Code Usage In Japan |publisher=Studio Cliffano |date=18 May 2009 |accessdate=18 May 2009 |archiveurl=http://archive.is/20120915/http://blog.cliffano.com/2009/05/18/qr-code-usage-in-japan/ |archivedate=2012-09-15}}</ref> as shown in the figure here. == Design == Unlike the older, one-dimensional barcode that was designed to be mechanically scanned by a narrow beam of light, a QR code is detected by a 2-dimensional digital [[image sensor]] and then digitally analyzed by a programmed processor. The processor locates the three distinctive squares at the corners of the QR code image, using a smaller square (or multiple squares) near the fourth corner to normalize the image for size, orientation, and angle of viewing. The small dots throughout the QR code are then converted to binary numbers and validated with an error-correcting code. ==Software== Software for scanning and processing QR codes are availible for multiple platforms. === Storage === The amount of data that can be stored in the QR code symbol depends on the datatype (''mode'', or input character set), version (1, …, 40, indicating the overall dimensions of the symbol), and [[#Error correction|error correction]] level. The maximum storage capacities occur for 40-L symbols (version 40, error correction level L):<ref name=About2DCode/><ref>{{cite web |url=http://www.qrcode.com/en/vertable1.html |title=Version and Maximum capacity table |publisher=Denso-Wave |archiveurl=http://archive.is/20120915/http://www.qrcode.com/en/vertable1.html |archivedate=2012-09-15}}</ref> {| class="wikitable" |+ Maximum character storage capacity (40-L) <br><small>''character'' refers to individual values of the input mode/datatype</small> |- ! Input mode ! max. characters !! bits/char !! possible characters, default encoding |- !Numeric only | 7,089 || 3⅓ || 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 |- ![[Alphanumeric]] | 4,296 || 5½ || 0–9, A–Z (upper-case only), space, $, %, *, +, -, ., /, : |- ![[Binary numeral system|Binary]]/byte | 2,953 || 8 || [[ISO 8859-1]] |- ![[Kanji]]/[[kana]] | 1,817 || 13 || [[Shift JIS]] [[JIS X 0208|X 0208]] |} Here are some sample QR code symbols: <gallery widths=220 heights=220> File:Qr-1.png|Version 1 (21×21). Content: "Ver1" File:Qr-2.png|Version 2 (25×25). Content: "Version 2" File:Qr-3.png|Version 3 (29×29). Content: "Version 3 QR code" File:Qr-4.png|Version 4 (33×33). Content: "Version 4 QR Code, up to 50 char" File:Qr-code-ver-10.png|Version 10 (57×57). Content: "VERSION 10 QR CODE, UP TO 174 CHAR AT H LEVEL, WITH 57X57 MODULES AND PLENTY OF ERROR CORRECTION TO GO AROUND. NOTE THAT THERE ARE ADDITIONAL TRACKING BOXES" File:QR_Droid_2663.png|Version 25 (117×117 enlarged to 640x640) File:Qr-code-ver-40.png|Version 40 (177×177). Content: 1,264 characters of ordinary/ASCII text: A description of QR codes taken from an [http://en.wikipedia.org/w/index.php?title=QR_code&oldid=446640692 early version] of this Wikipedia article </gallery> === Error correction === [[File:QR Code Damaged.jpg|thumb|141px|Damaged but still decodable QR code]] [[File:Extreme QR code to Wikipedia mobile page.png|thumb|141px|Example of a QR code with artistic embellishment that will still scan correctly thanks to error correction]] Codewords are [[Octet (computing)|8 bits]] long and use the [[Reed–Solomon error correction]] algorithm with four error correction levels. The higher the error correction level, the less storage capacity. The following table lists the approximate error correction capability at each of the four levels: {| |- | Level L (Low) || 7% of codewords can be restored. |- | Level M (Medium) || 15% of codewords can be restored. |- | Level Q (Quartile)<ref>{{cite web |url=http://www.tec-it.com/de/support/knowbase/symbologies/qrcode/Default.aspx |title=2D Barcode: QR-Code |archiveurl=http://archive.is/20120915/http://www.tec-it.com/de/support/knowbase/symbologies/qrcode/Default.aspx |archivedate=2012-09-15}} — TEC-IT</ref> || 25% of codewords can be restored. |- | Level H (High) || 30% of codewords can be restored. |} In larger QR symbols, the message is broken up into several Reed–Solomon code blocks. The block size is chosen so that at most 15 errors can be corrected in each block; this limits the complexity of the decoding algorithm. The code blocks are then interleaved together, making it less likely that localized damage to a QR symbol will overwhelm the capacity of any single block. Thanks to error correction, it is possible to create artistic QR codes that still scan correctly, but contain intentional errors to make them more readable or attractive to the human eye, as well as to incorporate colors, logos, and other features into the QR code block.<ref>{{cite web | url = http://blog.360i.com/emerging-media/creative-qr-codes | title = Form Meets Function: Extreme Makeover QR Code Edition | author = Orli Sharaby | date = 18 October 2010 | accessdate =29 July 2011 |archiveurl=http://archive.is/20120708/http://blog.360i.com/emerging-media/creative-qr-codes |archivedate=2012-07-08}}</ref><ref>{{cite web | url = http://mashable.com/2011/04/18/qr-code-design-tips/ | title = HOW TO: Make Your QR Codes More Beautiful | author = Hamilton Chan | date = 18 April 2011 | accessdate =29 July 2011 |archiveurl=http://archive.is/20120710/http://mashable.com/2011/04/18/qr-code-design-tips/ |archivedate=2012-07-10}}</ref> === Encoding === The format information records two things: the error correction level and the mask pattern used for the symbol. Masking is used to break up patterns in the data area that might confuse a scanner, such as large blank areas or misleading features that look like the locator marks. The mask patterns are defined on a grid that is repeated as necessary to cover the whole symbol. Modules corresponding to the dark areas of the mask are inverted. The format information is protected from errors with a [[BCH code]], and two complete copies are included in each QR symbol.<ref name=autogenerated1 /> The message dataset is placed from right to left in a zigzag pattern, as shown below. In larger symbols, this is complicated by the presence of the alignment patterns and the use of multiple interleaved error-correction blocks. <gallery widths=280 heights=200> File:QR Format Information.svg|Meaning of format information File:QR Character Placement.svg|Message placement within a QR symbol File:QR Ver3 Codeword Ordering.svg|Larger symbol illustrating interleaved blocks </gallery> Four-bit indicators are used to select the encoding mode and convey other information. Encoding modes can be mixed as needed within a QR symbol. {| class="wikitable" |+ Encoding modes ! Indicator !! Meaning |- | 0001 || Numeric encoding (10 bits per 3 digits) |- | 0010 || Alphanumeric encoding (11 bits per 2 characters) |- | 0100 || Byte encoding (8 bits per character) |- | 1000 || Kanji encoding (13 bits per character) |- | 0011 || Structured append (used to split a message across multiple QR symbols) |- | 0111 || [[Extended Channel Interpretation]] (select alternate character set or encoding) |- | 0101 || FNC1 in first position (see [[Code 128]] for more information) |- | 1001 || FNC1 in second position |- | 0000 || End of message |} After every indicator that selects an encoding mode is a length field that tells how many characters are encoded in that mode. The number of bits in the length field depends on the encoding and the symbol version. {| class="wikitable" |+ Number of bits per length field ! Encoding !! Ver. 1–9 !! 10–26 !! 27–40 |- ! Numeric | 10 || 12 || 14 |- ! Alphanumeric | 9 || 11 || 13 |- ! Byte | 8 || 16 || 16 |- ! Kanji | 8 || 10 || 12 |} Alphanumeric encoding mode stores a message more compactly than the byte mode can, but cannot store lower-case letters and has only a limited selection of punctuation marks, which are sufficient for rudimentary [[web address]]es. Two characters are coded in an 11-bit value by this formula: :V = 45 × C₁ + C₂ {| class="wikitable" |+ Alphanumeric character codes ! Code !! Character !! Code !! Character !! Code !! Character !! Code !! Character !! Code !! Character |- | 00 || 0 || 09 || 9 || 18 || I || 27 || R || 36 || SP |- | 01 || 1 || 10 || A || 19 || J || 28 || S || 37 || $ |- | 02 || 2 || 11 || B || 20 || K || 29 || T || 38 ||% |- | 03 || 3 || 12 || C || 21 || L || 30 || U || 39 || * |- | 04 || 4 || 13 || D || 22 || M || 31 || V || 40 || + |- | 05 || 5 || 14 || E || 23 || N || 32 || W || 41 || – |- | 06 || 6 || 15 || F || 24 || O || 33 || X || 42 || . |- | 07 || 7 || 16 || G || 25 || P || 34 || Y || 43 || / |- | 08 || 8 || 17 || H || 26 || Q || 35 || Z || 44 ||: |} === Decoding example === The following images offer more information about the QR code. <!-- This information is sourced from the QR code specification document --> <gallery widths=130 heights=100 perrow=5> File:QRCode-1-Intro.png|1 — Introduction File:QRCode-2-Structure.png|2 — Structure File:QRCode-3-Layout,Encoding.png|3 — Layout & Encoding File:QRCode-4-Levels,Masks.png|4 — Levels & Masks File:QRCode-5-Protocols.png|5 — Protocols </gallery> == License == The use of QR codes is free of any license. The QR code is clearly defined and published as an ISO standard. [[Denso#DENSO WAVE|Denso Wave]] owns the [[patent]] rights on QR codes, but has chosen not to exercise them.<ref name="qrstandard1"/> In the USA, the granted QR code patent is {{patent|US|5726435}}, and in Japan {{patent|JP|2938338}}. The European Patent Office granted patent {{cite web |url=http://worldwide.espacenet.com/publicationDetails/biblio?DB=EPODOC&II=0&ND=3&adjacent=true&locale=en_EP&FT=D&date=19950920&CC=EP&NR=0672994A1&KC=A1 |title=EPO 0672994}} to Denso Wave, which was then validated into French, UK, and German patents, all of which are still in force as of November 2011. The word '''QR code''' itself is a [[registered trademark]] of Denso Wave Incorporated.<ref name="qrtrademark01">{{cite web |url=http://www.qrcode.com/en/index.html |title=QR Code.com |publisher=Denso-Wave |date=6 November 2003 |accessdate=23 April 2009 |archiveurl=http://archive.is/20120915/http://www.qrcode.com/en/index.html |archivedate=2012-09-15}}</ref> In UK, the trademark is registered as E921775, the word "QR Code", with a filing date of 03/09/1998.<ref name="qrtrademarkuk">{{cite web |url=http://www.ipo.gov.uk/types/tm/t-os/t-find/t-find-number?detailsrequested=C&trademark=E921775 |title=UK QR Code Trademark |archiveurl=http://archive.is/20120915/http://www.ipo.gov.uk/types/tm/t-os/t-find/t-find-number?detailsrequested=C&trademark=E921775 |archivedate=2012-09-15}}</ref> The UK version of the trademark is based on the Kabushiki Kaisha Denso (DENSO CORPORATION) trademark, filed as Trademark 000921775, the word "QR Code", on 03/09/1998 and registered on 6/12/1999 with the European Union OHIM (Office for Harmonization in the Internal Market).<ref name="qrtrademarkeu">{{cite web |url=http://esearch.oami.europa.eu/copla/trademark/data/000921775 |title=EU QR Code Trademark |archiveurl=http://archive.is/20120915/http://esearch.oami.europa.eu/copla/trademark/data/000921775 |archivedate=2012-09-15}}</ref> The U.S. Trademark for the word "QR Code" is Trademark 2435991 and was filed on 29 September 1998 with an amended registration date of 13 March 2001, assigned to Denso Corporation.<ref name="qrtrademarkus">{{cite web |url=http://tess2.uspto.gov/bin/showfield?f=doc&state=4010:nrb6eh.2.6 |title=US QR Code Trademark |archiveurl=http://archive.is/20120915/http://tess2.uspto.gov/bin/showfield?f=doc&state=4010:nrb6eh.2.6 |archivedate=2012-09-15}}</ref> == Variants == <!-- the word "version" is confused in this section; it is used to refer to both symbol sizes and the generation of a specification. --> ''Micro QR code'' is a smaller version of the QR code standard for applications where symbol size is limited. There are 4 different versions (sizes) of Micro QR codes: the smallest is 11×11 modules; the largest can hold 35 numeric characters.<ref>Information technology — Automatic identification and data capture techniques — QR Code 2005 bar code symbology specification, ISO/IEC 18004:2006 cor. 2009, pages 3, 6.</ref> ''Model 1 QR code'' is an older version of the specification. It is visually similar to the widely seen model 2 codes, but lacks alignment patterns. <gallery widths=100 heights=100> File:Micro QR Example.svg|Micro QR code example File:Micro QR Version 3M Layout.svg|Micro QR code functional regions File:QR Code Model 1 Example.svg|Model 1 QR code example File:Model 1 QR Version 2 Layout.svg|Model 1 QR code functional regions </gallery> == Risks == The only context in which common QR codes can carry executable data is the [[URL]] data type, which may carry Javascript, but is only supposed to be executed in a regular browsing context, therefore carrying only minimal risk of abuse (no more than opening any web page). However, QR codes may be used to exploit flaws in other applications on the host system, such as the reader, the browser or the image viewer, since a reader will typically send the data to the application associated with the data type used by the QR code. Malicious QR codes combined with a permissive reader can put a computer's contents and user's privacy at risk. This practice is known as "attagging", a [[portmanteau]] of "attack tagging".<ref name="Wired">{{citation |periodical=[[Wired (magazine)|Wired]] |title=Jargon Watch |page=22 |date=January 2012 |volume=20 |issue=1 }}.</ref> They are easily created and can be affixed over legitimate QR codes.<ref>{{cite web |url=http://isc.sans.edu/diary.html?storyid=11305 |title=Malicious Images: What's a QR Code |publisher=SANS Technology Institute |date=3 August 2011 |accessdate=31 August 2011 |archiveurl=http://archive.is/20120713/http://isc.sans.edu/diary.html?storyid=11305 |archivedate=2012-07-13}}</ref> On a [[smartphone]], the reader's permissions may allow use of the camera, full Internet access, read/write contact data, [[GPS]], read [[web browser|browser]] history, read/write local storage, and global system changes.<ref>{{cite web |url=https://market.android.com/details?id=com.google.zxing.client.android |publisher=Google |date=1 June 2011 |title=Barcode Scanner |accessdate=31 August 2011 |archiveurl=http://archive.is/20120915/https://market.android.com/details?id=com.google.zxing.client.android |archivedate=2012-09-15}}</ref><ref>{{cite web |url=https://market.android.com/details?id=la.droid.qr |title=QR Droid |publisher=Google |date=19 August 2011 |accessdate=31 August 2011 |archiveurl=http://archive.is/20120915/https://market.android.com/details?id=la.droid.qr |archivedate=2012-09-15}}</ref><ref>{{cite web |url=https://market.android.com/details?id=com.ScanLife |title=ScanLife Barcode Reader |publisher=Google |date=24 May 2011 |accessdate=31 August 2011 |archiveurl=http://archive.is/20120915/https://market.android.com/details?id=com.ScanLife |archivedate=2012-09-15}}</ref> Risks include linking to dangerous web sites with browser exploits, enabling the microphone/camera/GPS, and then streaming those feeds to a remote server, analysis of sensitive data (passwords, files, contacts, transactions),<ref>{{cite web |url=http://sandiego.bbb.org/article/consumer-alert-qr-code-safety-28037 |title=Consumer Alert: QR Code Safety |publisher=Better Business Bureau |date=23 June 2011 |accessdate=31 August 2011 |archiveurl=http://archive.is/20120715/http://sandiego.bbb.org/article/consumer-alert-qr-code-safety-28037 |archivedate=2012-07-15}}</ref> and sending email/[[Short Message Service|SMS]]/IM messages or [[DDOS]] packets as part of a [[botnet]], corrupting privacy settings, stealing identity,<ref>{{cite web |url=http://www.pcworld.idg.com.au/mediareleases/12655/avg-aunz-cautions-beware-of-malicious-qr-codes/ |title=AVG Cautions: Beware of Malicious QR Codes |publisher= PC World |date=28 June 2011 |accessdate=31 August 2011 |archiveurl=http://archive.is/20120907/http://www.pcworld.idg.com.au/mediareleases/12655/avg-aunz-cautions-beware-of-malicious-qr-codes/ |archivedate=2012-09-07}}</ref> and even containing malicious logic themselves such as [[JavaScript]] <ref>{{cite web |url=https://appsec-labs.com/blog/tag/qrcode |title=EvilQR – When QRCode goes bad |publisher=AppSec-Labs Blog |date=14 August 2011 |accessdate=31 August 2011 |archiveurl=http://archive.is/20120915/https://appsec-labs.com/blog/tag/qrcode |archivedate=2012-09-15}}</ref> or a virus.<ref>{{cite web |url=http://www.cyveillanceblog.com/malware/qr-codes-a-recipe-for-a-mobile-malware-tsunami |title=QR Codes: A Recipe for a Mobile Malware Tsunami |publisher=Cyveillance, Inc |date=20 October 2010 |accessdate=31 August 2011 |archiveurl=http://archive.is/20120728/http://www.cyveillanceblog.com/malware/qr-codes-a-recipe-for-a-mobile-malware-tsunami |archivedate=2012-07-28}}</ref><ref>QR Codes hold up to 2.9 KB whereas the smallest known computer virus is about one-tenth that size {{cite web |url= http://www.wiw.org/~meta/vlad.php?read=ARTICLE.5_2&issue=3&desc=Small%20Virus |title=The Smallest Virus I Could Manage |publisher=Virus Labs and Distribution |year=1995 |accessdate=31 August 2011 |archiveurl=http://archive.is/20120915/http://www.wiw.org/~meta/vlad.php?read=ARTICLE.5_2&issue=3&desc=Small%20Virus |archivedate=2012-09-15}}</ref> These actions could occur in the background while the user is only seeing the reader opening a seemingly harmless web page.<ref>{{cite web |url=http://www.abc.net.au/technology/articles/2011/06/08/3238443.htm |title=Beware of Malicious QR Codes|publisher=ABC |date=8 June 2011 |accessdate=31 August 2011 |archiveurl=http://archive.is/20120801/http://www.abc.net.au/technology/articles/2011/06/08/3238443.htm |archivedate=2012-08-01}}</ref> In Russia, a malicious QR code caused phones that scanned it to send premium texts at a fee of US$6 each.<ref name="Wired" /> == See also == <!-- Please keep entries in alphabetical order & add a short description [[WP:SEEALSO]] --> {{div col|colwidth=20em|small=yes}} * [[CueCat]] * [[QRpedia]] * [[SPARQCode]] * [[Touchatag]] {{div col end}} <!-- please keep entries in alphabetical order --> == References == {{Reflist|30em}} == Bibliography == * {{cite book |title=BS ISO/IEC 18004:2006. Information technology. Automatic identification and data capture techniques. Bar code symbology. QR Code|location=[[Geneva]]| publisher=[[International Organization for Standardization|ISO]]/[[International Electrotechnical Commission|IEC]]|year=2000|page=114|url=http://www.worldcat.org/title/information-technology-automatic-identification-and-data-capture-techniques-bar-code-symbology-qr-code-technologies-de-linformation-techniques-didentification-automatique-et-de-capture-de-donnees-symboles-de-codes-a-barres-code-qr/oclc/60816353?lang=en }} * {{cite book |title=BS ISO/IEC 18004:2006. Information technology. Automatic identification and data capture techniques. QR Code 2005 bar code symbology specification| location=[[London]] |publisher=[[British Standards Institution|BSI]]|year=2007|page=126|isbn=978-0-580-67368-9|url=http://shop.bsigroup.com/en/ProductDetail/?pid=000000000030201420 }} == External links == {{Commons category|Quick Response Codes}} * {{Official website|http://www.qrcode.com/en/index.html}} * [http://en.wikiversity.org/wiki/Reed%E2%80%93Solomon_codes_for_coders Reed Solomon Codes for Coders] – an elaborate tutorial on Wikiversity, covering both QR code structure and the Reed Solomon codes used to encode the data. * {{cite news |title=Q&A: how to Make a Quick Response Code |author=J. D. Biersdorfer |url=http://www.nytimes.com/2011/03/03/technology/personaltech/03askk.html |publisher=''[[The New York Times]]'' |date=2 March 2011 |accessdate=11 December 2012}} Information on converting a URL into a QR code <!-- Do NOT add links to external sites which generate QR codes, or provide QR solutions. Wikipedia is not a directory of links. If you really believe you have something to link which is utterly unique, please bring it up on the discussion page. --> {{Use dmy dates|date=August 2012}} {{Barcodes}} {{ISO standards}} [[Category:Barcodes]] [[Category:Encodings]] [[Category:Automatic identification and data capture]] [[Category:1994 introductions]]'