QR code – Wikipedia

type of matrix barcode

A QR code ( an initialism for quick response code ) is a type of matrix barcode ( or planar barcode ) [ 1 ] [ 2 ] invented in 1994 by the japanese automotive company Denso Wave. A barcode is a machine-readable optical label that can contain 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 web site or application. QR codes use four standardize encoding modes ( numeral, alphanumeric, byte/binary, and kanji ) to store data efficiently ; extensions may besides be used. [ 3 ] The immediate answer system became popular outside the automotive industry due to its fast legibility and greater storage capacity compared to standard UPC barcodes. Applications include product track, detail identification, time track, document management, and general marketing. [ 4 ]

A QR code consists of black squares arranged in a public square grid on a white background, including some fiduciary markers, 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 compulsory datum is then extracted from patterns that are present in both horizontal and upright components of the effigy. [ 4 ]

history [edit ]

The QR code system was invented in 1994 by Masahiro Hara from the japanese company Denso Wave. [ 5 ] [ 6 ] [ 7 ] The initial design was influenced by the black and white pieces on a Go dining table. [ 8 ] Its determination was to keep track of automotive parts manufactured by Denso, to replace respective prevention codes on each box, each of which had to be scanned individually. [ 9 ]

borrowing [edit ]

A QR code being painted on the side of a building QR codes can be displayed on buildings, as this one being painted in Cape Town QR codes are now used in a a lot broader context, including both commercial track 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 web page on the drug user ‘s device, to add a vCard contact to the drug user ‘s device, to open a Uniform Resource Identifier ( URI ), to connect to a radio receiver network, or to compose an e-mail or text message. There are a capital many QR code generators available as software or as on-line tools that are either free, or require a nonrecreational subscription. [ 10 ] The QR code has become one of the most-used types of two-dimensional code. [ 11 ] 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. [ 12 ] In September 2020, a review found that 18.8 percentage of consumers in the United States and United Kingdom strongly agreed that they had noticed an increase of QR code use since the then-active COVID-19 relate restrictions had begun several months anterior. [ 13 ]

Standards [edit ]

social organization of a QR code ( adaptation 7 ), highlighting functional elements There are several standards that cover the encoding of data as QR codes : [ 14 ]

  • October 1997 – AIM (Association for Automatic Identification and Mobility) International[15]
  • 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)[16]
    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. [ 17 ] The open-source “ ZXing “ project maintains a list of QR code data types. [ 18 ]

Uses [edit ]

A QR code used on a boastfully billboard in Japan, linking to the sagasou.mobi web site 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 web site, thereby obviating the necessitate for a exploiter to type it into a web browser ). QR code has become a focus of advertise strategy, since it provides a way to access a trade name ‘s web site more cursorily than by manually entering a URL. [ 19 ] [ 20 ] Beyond bare convenience to the consumer, the importance of this capability is that it increases the conversion rate : the casual that reach with the ad will convert to a sale. It coaxes concern prospects further depressed the conversion funnel with little delay or campaign, bringing the spectator to the advertiser ‘s web site immediately, whereas a longer and more target sales pitch may lose the spectator ‘s interest. Although initially used to track parts in vehicle fabrication, QR codes are used over a much wide range of applications. These include commercial track, entertainment and tape drive ticket, product and loyalty market and in-store product pronounce. Examples of marketing include where a company ‘s discounted and percentage dismiss can be captured using a QR code decoder which is a mobile app, or storing a company ‘s information such as address and associate data alongside its alpha-numeric text data as can be seen in Yellow Pages directories. They can besides be used in storing personal information for use by organizations. An exemplar of this is Philippines National Bureau of Investigation ( NBI ) where NBI clearances immediately come with a QR code. many of these applications target mobile-phone users ( via mobile tagging ). Users may receive textbook, add a vCard liaison to their device, open a URL, or compose an electronic 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 respective pay or barren QR code-generating sites or apps. Google had an API, nowadays deprecated, to generate QR codes, [ 21 ] and apps for scanning QR codes can be found on about all smartphone devices. [ 22 ]
[23] QR codes have been used and printed on aim tickets in China since 2010. QR codes storing addresses and URLs may appear in magazines, on signs, on buses, on business cards, or on about any aim about which users might want information. Users with a camera earphone equipped with the correct lector application can scan the effigy of the QR code to display text, reach information, connect to a radio network, or open a web page in the call ‘s browser. This act of linking from physical world objects is termed hardlinking or object hyperlinking. QR codes besides may be linked to a localization 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. In 2008, a japanese mason announced plans to engrave QR codes on gravestones, allowing visitors to view information about the dead person, and family members to keep racetrack of visits. [ 24 ] Psychologist Richard Wiseman was one of the first authors to include QR codes in a book, in Paranormality: Why We See What Isn’t There ( 2011 ). [ 25 ] [ failed verification ] QR codes have been incorporated into currentness. In June 2011, The Royal Dutch Mint ( Koninklijke Nederlandse Munt ) issued the world ‘s first official coin with a QR code to celebrate the centennial of its current build and premises. The coin can be scanned by a smartphone and originally linked to a special web site with contents about the historic event and invention of the coin. [ 26 ] In 2014, the Central Bank of Nigeria issued a 100-naira bill to commemorate its centennial, the first bill to incorporate a QR code in its purpose. When scanned with an internet-enabled mobile device, the code goes to a web site which tells the centennial fib of Nigeria. [ 27 ] In 2015, the Central Bank of the russian Federation issued a 100-rubles note to commemorate the annexation of Crimea by the russian Federation. It contains a QR code into its blueprint, and when scanned with an internet-enabled mobile device, the code goes to a web site that details the historic and technical foul background of the commemorative bill. In 2017, the Bank of Ghana issued a 5-cedis bill to commemorate 60 years of Central Banking in Ghana, and contains a QR code in its blueprint, which when scanned with an internet-enabled mobile device, that code goes to the official Bank of Ghana web site. Credit menu functionality is under development. In September 2016, the Reserve Bank of India ( RBI ) launched the eponymously named Bharat QR, a common QR code jointly developed by all the four major menu payment companies – National Payments Corporation of India that runs RuPay cards along with MasterCard, Visa and American Express. It will besides have the capability of accepting payments on the unite payments interface ( UPI ) chopine. [ 28 ] [ 29 ]

Augmented reality [edit ]

QR codes are used in some augment reality systems to determine the positions of objects in three-dimensional space. [ 9 ]

Displaying multimedia contents [edit ]

QR codes besides used to address users to specific multimedia content ( such as videos, audios, images, documents and any type of message accessible from the web ). This type of QR code is called “ Multimedia QR code ” .

Mobile operating systems [edit ]

QR codes can be used on diverse mobile device operating systems. iPhones running on io 11 and higher [ 30 ] and some Android devices can natively read QR codes without downloading an external app. [ 31 ] The camera app is able to scan and display the kind of QR code ( merely on iPhone ) along with the connect ( both on Android and iPhone ). These devices documentation URL redirection, which allows QR codes to send metadata to existing applications on the device. many paid or rid apps are available with the ability to scan the codes and hard-link to an external url .

virtual stores [edit ]

QR codes have been used to establish “ virtual stores ”, where a gallery of merchandise information and QR codes is presented to the customer, e.g. on a caravan post wall. The customers scan the QR codes, and the products are delivered to their homes. This function started in South Korea, [ 32 ] and Argentina, [ 33 ] but is presently expanding globally. [ 34 ] Walmart, Procter & Gamble and Woolworths have already adopted the Virtual Store concept. [ 35 ]

QR code requital [edit ]

QR codes can be used to store bank report data or credit card information, or they can be specifically designed to work with particular payment supplier applications. There are several trial applications of QR code payments across the world. [ 36 ] [ 37 ] In developing countries like China, [ 38 ] [ 39 ] India [ 40 ] and Bangladesh QR code payment is a very popular and commodious method acting of making payments. Since Alipay designed a QR code payment method acting in 2011, [ 41 ] mobile payment has been cursorily adopted in China. As of 2018, around 83 % of all payments were made via mobile requital. [ 42 ] In November 2012, QR code payments were deployed on a larger scale in the Czech Republic when an outdoors format for payment information change – a unretentive Payment Descriptor – was introduced and endorsed by the Czech Banking Association as the official local solution for QR payments. [ 43 ] [ 44 ] In 2013, the european Payment Council provided guidelines for the EPC QR code enabling SCT initiation within the Eurozone. In 2017, Singapore created a taskforce including their government Agencies such as the Monetary Authority of Singapore and Infocomm Media Development Authority to spearhead a system for e-payments using exchangeable QR code specifications. These specific dimensions are specialized for Singapore ’ s market. [ 45 ] The e-payment system, Singapore Quick Response Code ( SGQR ), basically merges respective QR codes into one pronounce which can be used by both parties in the requital arrangement. This allows for versatile bank apps to facilitate payments between multiple customers and a merchant that displays the single QR code. [ 46 ] A single SDQR label contains e-payments and combines multiple payment options. Once consumers spot the SGQR label, they will be able to scan it and see which requital options the merchant accepts. The SGQR outline is co-owned by MAS and IMDA. [ 47 ]

Website login [edit ]

QR codes can be used to log 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 mechanically be logged in. authentication is performed by the smartphone which contacts the server. Google tested such a login method in January 2012. [ 48 ]

Mobile ticket [edit ]

There is a system whereby a QR code can be displayed on a device such as a smartphone and used as an entrance fee ticket. [ 49 ] [ 50 ] [ 51 ] Its use is coarse for J1 League and Nippon Professional Baseball tickets in Japan. [ 52 ] [ 53 ] In some cases, rights can be transferred via the Internet .

restaurant ordering [edit ]

Restaurants can present a QR code near the front door or at the table allowing guests to view an on-line menu, or evening redirect them to an on-line ordering web site or app, allowing them to order and/or possibly pay for their meal without having to use a cashier or waiter. QR codes can besides link to daily or weekly specials that are not printed on the standardize menu, [ 54 ] and enable the establishment to update the entire menu without needing to print copies. At table-serve restaurants, QR codes enable guests to order and pay for their meals without a waiter involved – the QR code contains the table number so servers know where to bring the food. [ 55 ] [ 56 ] This application has grown specially since the need for social outdistance during the 2020 COVID-19 pandemic prompted reduced touch between service staff and customers. [ 55 ]

Joining a Wi‑Fi network [edit ]

A QR code to automatically join a Wi‑Fi network By specifying the SSID, encoding type, password/passphrase, and if the SSID is hidden or not, mobile device users can cursorily scan and join networks without having to manually enter the data. [ 57 ] A MeCard -like format is supported by Android and io 11+. [ 58 ]

  • Common format: WIFI:S:;T:;P:;H:;;
  • Sample: WIFI:S:MySSID;T:WPA;P:MyPassW0rd;;

Funerary function [edit ]

A QR code which links to an obituary and can be placed on a gravestone A QR code can link to an obituary and can be placed on a gravestone. In 2008, 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. [ 59 ] [ 60 ] [ 61 ] other companies, such as Wisconsin-based Interactive Headstones, have besides begun implementing QR codes into tombstones. [ 62 ] In 2014, the jewish Cemetery of La Paz in Uruguay began implementing QR codes for tombstones. [ 63 ]

electronic authentication [edit ]

QR codes are besides used to generate time-based erstwhile passwords ( TOTP ) for electronic authentication .

commitment programs [edit ]

QR codes have been used by assorted retail outlets that have loyalty programs. sometimes these programs are accessed with an app that is loaded onto a telephone and includes a summons triggered by a QR code scan. The QR codes for commitment programs tend to be found printed on the receipt for a buy or on the products themselves. Users in these schemes collect award points by scanning a code .

Counterfeit signal detection [edit ]

Serialised QR codes have been used by brands [ 64 ] and governments [ 65 ] to let consumers, retailers and distributors verify the authenticity of the products and help with detecting counterfeit products, as separate of a stigmatize security course of study. [ 66 ] however, the security charge of a regular QR Code is limited since QR Codes printed on original products are well reproduced on fake products, flush though the analysis of data generated as a result of QR Code scan can be used to detect forge and illegitimate activity. [ 67 ] A higher security level can be attained by embedding a digital watermark or copy detection radiation pattern into the effigy of the QR Code. This makes the QR Code more impregnable against counterfeiting attempts, and fake products which contain a counterfeit QR Code can be detected by scanning the fasten QR Code with a specific app ( even though the QR Code message itself is valid ). [ 68 ] The treaty determine apostilles ( documents bearing a seal of authenticity ), has been updated to allow for the issue of digital apostilles by countries ; a digital apostille is a PDF document with a cryptanalytic signature containing a QR code for a canonic url of the original text file, allowing users to verify the apostille from a print version of the document .

product tracing [edit ]

different studies have been made to assess the potency of QR codes as a entail of conveying labelling information and their use as depart of a food traceability system. In a field experiment, it was found that when provided spare access to a smartphone with QR Code scanning app, 52.6 % of participants would use it to access labelling information. [ 69 ] A study made in South Korea showed that consumers appreciate QR code used in food traceability organization, as they provide detail information about food, a well as information that helps them in their buying decision. [ 70 ] If QR Codes are serialised, consumers can access a world wide web page showing the provide chain for each component, adenine well as information specific to each refer batch, including kernel processors and manufacturers, which helps address the concerns they have about the lineage of their food. [ 71 ]

COVID-19 pandemic [edit ]

After the COVID-19 pandemic began spreading, QR codes began to be used as a “ touchless ” system to display data, appearance menu, or provide update consumer information, specially in the cordial reception industry. Restaurants replaced composition or laminated fictile menus with QR code decals on the table, which opened an on-line adaptation of the menu. This prevented the need to dispose of single-use newspaper menu, or institute clean and sanitize procedures for permanent menu after each manipulation. [ 72 ] Local television stations have besides begun to utilize codes on local newscasts to allow viewers quicker access to stories or information involving the pandemic, including testing and immunization schedule websites, or for links within stories mentioned in the newscasts overall. In respective australian states, patrons are required to scan QR codes at shops, clubs, supermarkets and other service and retail establishments on entry to assist contact tracing. Singapore, Taiwan, the United Kingdom and New Zealand consumption similar systems. [ 73 ] QR codes are besides present on COVID-19 inoculation certificates in places such as Canada, and the EU ( EU Digital COVID security ) where they can be scanned to verify the information on the security. [ 74 ]

design [edit ]

Unlike the older, linear barcodes that were designed to be mechanically scanned by a constrict beam of light, a QR code is detected by a two-dimensional digital image detector and then digitally analyzed by a program processor. The processor locates the three classifiable squares at the corners of the QR code image, using a smaller square ( or multiple squares ) near the fourthly corner to normalize the effigy for size, orientation, and angle of viewing. The small dots throughout the QR code are then converted to binary star numbers and validated with an error-correcting algorithm .

storehouse [edit ]

The measure of data that can be stored in the QR code symbol depends on the data type ( mode, or stimulation character set ), translation ( 1, …, 40, indicating the overall dimensions of the symbol, i.e. 4 × version number + 17 dots on each slope ), and error correction tied. The maximum storehouse capacities occur for version 40 and erroneousness correction charge L ( low ), denoted by 40-L : [ 11 ] [ 75 ]

Maximum character storage capacity (40-L)
Character refers to individual values of the input mode (data type).
Input mode Max. characters Bits/char. Possible characters, default encoding
Numeric only 7,089 3



0, 1, 2, 3, 4, 5, 6, 7, 8, 9
Alphanumeric 4,296 5



0–9, A–Z (upper-case only), space, $, %, *, +, -, ., /, :
Binary/byte 2,953 8 ISO/IEC 8859-1
Kanji/kana 1,817 13 Shift JIS X 0208

hera are some sample distribution QR code symbols :

error correction [edit ]

Damaged but still decodable QR code, link to http : //en.m.wikipedia.org model of a QR code with aesthetic ornamentation that will still scan correctly thanks to error correction

QR codes use Reed–Solomon error correction over the finite field F 256 { \displaystyle \mathbb { F } _ { 256 } } {\displaystyle \mathbb {F} _{256}}, the elements of which are encoded as bytes of 8 bits ; the byte b 7 barn 6 boron 5 b-complex vitamin 4 b 3 bel 2 b-complex vitamin 1 bacillus 0 { \displaystyle b_ { 7 } b_ { 6 } b_ { 5 } b_ { 4 } b_ { 3 } b_ { 2 } b_ { 1 } b_ { 0 } } {\displaystyle b_{7}b_{6}b_{5}b_{4}b_{3}b_{2}b_{1}b_{0}} with a standard numeral respect ∑ i = 0 7 bel one 2 one { \displaystyle \textstyle \sum _ { i=0 } ^ { 7 } b_ { iodine } 2^ { one } } {\displaystyle \textstyle \sum _{i=0}^{7}b_{i}2^{i}} encodes the plain component ∑ one = 0 7 b i α i { \displaystyle \textstyle \sum _ { i=0 } ^ { 7 } b_ { one } \alpha ^ { iodine } } {\displaystyle \textstyle \sum _{i=0}^{7}b_{i}\alpha ^{i}} where α ∈ F 256 { \displaystyle \alpha \in \mathbb { F } _ { 256 } } {\displaystyle \alpha \in \mathbb {F} _{256}} is taken to be a primitive component satisfying α 8 + α 4 + α 3 + α 2 + 1 = 0 { \displaystyle \alpha ^ { 8 } +\alpha ^ { 4 } +\alpha ^ { 3 } +\alpha ^ { 2 } +1=0 } {\displaystyle \alpha ^{8}+\alpha ^{4}+\alpha ^{3}+\alpha ^{2}+1=0}. The Reed–Solomon code uses one of 37 different polynomials over F 256 { \displaystyle \mathbb { F } _ { 256 } }, with degrees ranging from 7 to 68, depending on how many erroneousness correction bytes the code adds. It is implied by the shape of Reed–Solomon used ( taxonomic BCH view ) that these polynomials are all on the form ∏ one = 0 n − 1 ( ten − α one ) { \textstyle \prod _ { i=0 } ^ { n-1 } ( x-\alpha ^ { i } ) } {\textstyle \prod _{i=0}^{n-1}(x-\alpha ^{i})}, however the rules for selecting the academic degree normality { \displaystyle normality } n are particular to the QR standard. When discussing the Reed–Solomon code phase there is some risk for confusion, in that the QR ISO/IEC standard uses the term codeword for the elements of F 256 { \displaystyle \mathbb { F } _ { 256 } }, which with regard to the Reed–Solomon code are symbols, whereas it uses the term block for what with deference to the Reed–Solomon code are the codewords. The number of data versus error correction bytes within each block depends on ( iodine ) the version ( side length ) of the QR symbol and ( two ) the mistake correction horizontal surface, of which there are four. The higher the erroneousness correction horizontal surface, the less repositing capacity. The following table lists the approximate erroneousness correction capability at each of the four levels :

Level L (Low) 7% of data bytes can be restored.
Level M (Medium) 15% of data bytes can be restored.
Level Q (Quartile)[76] 25% of data bytes can be restored.
Level H (High) 30% of data bytes can be restored.

In larger QR symbols, the message is broken up into respective Reed–Solomon code blocks. The parry size is chosen so that no attack is made at correcting more than 15 errors per auction block ; this limits the complexity of the decoding algorithm. The code blocks are then interleaved together, making it less likely that set damage to a QR symbol will overwhelm the capacity of any single block. due to error correction, it is possible to create artistic QR codes with embellishments to make them more clear or attractive to the human eye, and to incorporate colors, logos, and other features into the QR code freeze ; the embellishments are treated as errors, but the codes still scan correctly. [ 77 ] [ 78 ] It is besides possible to design aesthetic QR codes without reducing the erroneousness correction capacitance by manipulating the underlie mathematical constructs. [ 79 ] [ 80 ] Image process algorithm are besides used to reduce errors in QR-code. [ 81 ]

Encoding [edit ]

The format information records two things : the error correction level and the mask model used for the symbol. Masking is used to break up patterns in the data area that might confuse a scanner, such as big blank areas or misleading features that look like the locator marks. The disguise patterns are defined on a power system that is repeated as necessary to cover the whole symbol. Modules corresponding to the blue areas of the mask are inverted. The format data is protected from errors with a BCH code, and two complete copies are included in each QR symbol. [ 4 ] The message dataset is placed from right to left in a zigzag convention, as shown below. In larger symbols, this is complicated by the presence of the alignment patterns and the use of multiple interleave error-correction blocks .

The general social organization of a QR encode is as a succession of 4 moment indicators with cargo length subject on the indicator manner ( e.g. byte encoding cargo length is dependent on the first byte ). [ 82 ]

Mode indicator Description Typical structure ‘[ type : sizes in bits ]’
0001 Numeric [0001 : 4] [ Character Count Indicator : variable ] [ Data Bit Stream : 3



× charcount ]

0010 Alphanumeric [0010 : 4] [ Character Count Indicator : variable ] [ Data Bit Stream : 5



× charcount ]

0100 Byte encoding [0100 : 4] [ Character Count Indicator : variable ] [ Data Bit Stream : 8 × charcount ]
1000 Kanji encoding [1000 : 4] [ Character Count Indicator : variable ] [ Data Bit Stream : 13 × charcount ]
0011 Structured append [0011 : 4] [ Symbol Position : 4 ] [ Total Symbols: 4 ] [ Parity : 8 ]
0111 ECI [0111 : 4] [ ECI Assignment number : variable ]
0101 FNC1 in first position [0101 : 4] [ Numeric/Alphanumeric/Byte/Kanji payload : variable ]
1001 FNC1 in second position [1001 : 4] [ Application Indicator : 8 ] [ Numeric/Alphanumeric/Byte/Kanji payload : variable ]
0000 End of message [0000 : 4]

  • Character Count Indicator depends on how many modules are in a QR code (Symbol Version).
  • ECI Assignment number Size:
    • 8 × 1 bits if ECI Assignment Bitstream starts with ‘0’
    • 8 × 2 bits if ECI Assignment Bitstream starts with ’10’
    • 8 × 3 bits if ECI Assignment Bitstream starts with ‘110’

Four-bit indicators are used to select the encoding manner and convey other information .

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 (Terminator)

Encoding modes can be mixed as needed within a QR symbol. ( for example, a url with a hanker string of alphanumeric characters )

[ Mode Indicator][ Mode bitstream ] --> [ Mode Indicator][ Mode bitstream ] --> etc... --> [ 0000 End of message (Terminator) ]

After every indicator that selects an encoding mode is a distance airfield that tells how many characters are encoded in that mode. The number of bits in the duration field depends on the encode and the symbol translation .

Number of bits in a length field (Character Count Indicator)
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 modality stores a message more succinctly than the byte mode can, but can not store lower-case letters and has only a express excerpt of punctuation marks, which are sufficient for rudimentary web addresses. Two characters are coded in an 11-bit rate by this convention :

V = 45 × C1 + C2

This has the exception that the last character in an alphanumeric string with an leftover length is read as a 6-bit prize alternatively .

Alphanumeric character codes
Code Character Code Character Code Character Code Character Code Character
00 0 09 9 18 I 27 R 36 Space
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 exercise [edit ]

The succeed images offer more information about the QR code .

Variants [edit ]

exemplary 1 [edit ]

Model 1 QR code is an older translation of the specification. It is visually like to the widely seen exemplar 2 codes, but lacks alliance patterns. Differences are in the bottom right corner, and in the midsections of the penetrate and right edges are extra functional regions .

Micro QR code

[edit ]

Micro QR code is a smaller interpretation of the QR code standard for applications where symbol size is limited. There are four different versions ( sizes ) of Micro QR codes : the smallest is 11×11 modules ; the largest can hold 35 numeral characters. [ 83 ]

IQR code [edit ]

IQR Code is an alternative to existing QR codes developed by Denso Wave. IQR codes can be created in square or orthogonal formations ; this is intended for situations where a orthogonal barcode would otherwise be more appropriate, such as cylindrical objects. IQR codes can fit the lapp sum of information in 30 % less space. There are 61 versions of square IQR codes, and 15 versions of rectangular codes. For squares, the minimum size is 9 × 9 modules ; rectangles have a minimum of 19 × 5 modules. IQR codes add error correction level S, which allows for 50 % error correction. [ 84 ] IQR Codes have not however been given an ISO/IEC specification, and only proprietary Denso Wave products can create or read IQR codes. [ 85 ]

Secure QR code

[edit ]

Secure Quick Response ( SQR ) code is a QR code that contains a “ individual data ” section after the exterminator alternatively of the specified filler bytes “ european union 11 ”. [ 86 ] This private datum section must be deciphered with an encoding key. This can be used to store private information and to manage company ‘s internal data. [ 87 ] SQR codes have been developed by the FORUS Foundation to enable secure transactions, and published under a creative Commons Licence. The SQR solution guarantees the integrity of the generator data a well as the robustness of the originating party. The payment instruction string is made up of the electronic teaching data from the scanned QR code appended with a SHA-2 cryptanalytic hashish. The message digest can then be encrypted using the private key of the transmitter, which then creates a digital signature of the message. This key signature validates the integrity of the data and the trustworthiness of the transmitter. This provides non-repudiation, confirming the identity of the sender, and that it has not been tampered with during transmission. By embedding the URL and all the variables required to perform shopping haul type e-commerce, bill requital and peer to peer payments, coupled with a digital certificate eliminates the possibility of spoofing, tampering, and man in the middle attacks. [ 88 ]

frame QR [edit ]

Frame QR is a QR code with a “ canvas sphere ” that can be flexibly used. In the center of this code is the poll area, where graphics, letters, and more can be flexibly arranged, making it possible to lay out the code without losing the design of illustrations, photos, etc. [ 89 ]

HCC2D [edit ]

Samples of the High Capacity Colored two-dimensional ( HCC2D ) code : ( a ) 4-color HCC2D code and ( b ) 8-color HCC2D code. Researchers have proposed a fresh High Capacity Colored two-dimensional ( HCC2D ) Code, which builds upon a QR code footing for preserving the QR robustness to distortions and uses colors for increasing data density ( as of 2014 it is distillery in prototyping phase ). The HCC2D code specification is described in details in Querini et al. ( 2014 ), [ 90 ] while techniques for color classification of HCC2D code cells are described in detail in Querini and Italiano ( 2014 ), [ 91 ] which is an unfold version of Querini and Italiano ( 2013 ). [ 92 ] Introducing colors into QR codes requires addressing extra issues. In particular, during QR code reading lone the brightness information is taken into bill, while HCC2D codes have to cope with chromatic distortions during the decode phase. In order to ensure adaptation to chromatic distortions which arise in each scan code, HCC2D codes make use of an extra field : the Color Palette Pattern. This is because coloring material cells of a Color Palette Pattern are supposed to be distorted in the like means as color cells of the Encoding Region. Replicated color palettes are used for training machine learning classifiers .

JAB code [edit ]

Wikipedia greetings with associate encoded using eight-colour JAB code JAB code ( Just Another Barcode ) is a color 2D matrix symbology made of tinge squares arranged in either straight or rectangle grids. It was developed by Fraunhofer Institute SIT ( Secure Information Technology ). [ 93 ] The code contains one elementary symbol and optionally multiple secondary coil symbols. The elementary symbol contains four finder patterns located at the corners of the symbol. [ 94 ] The code uses either 4 or 8 colours. [ 95 ] The 4 basic colours ( cyan, magenta, yellow, black ) are the 4 basal colours of the subtractive CMYK tinge model which is the most wide secondhand system in diligence for color printing on a flannel base such as newspaper. The other 4 colours ( blue, red, green, egg white ) are secondary colours of the CMYK model and originate as an equal mixture of a pair of basic colours. The barcode is not national to license and was submitted to ISO/IEC standardization as ISO/IEC 23634 expected to be approved at the begin of 2021 [ 96 ] and finalized in 2022. [ 95 ] The software is open-source and published under the LGPL v2.1 license. [ 97 ] The specification is freely available. [ 94 ] Because the color adds a third gear dimension to the planar matrix, a JAB code can contain more information in the like area compared to two-colour ( bootleg and white ) codes – theoretically doubly equally much data for a 4 color code and three times more for 8 colours assuming the like encoding algorithm. This can allow memory of an integral message in the barcode, rather than just storing partial data with a reference to a wax message somewhere else ( such as a link to a web site ), therefore eliminating the need for extra always-available infrastructure beyond the print barcode itself. It may be used to digitally sign code digital version of print legal documents, contracts and certificates ( diploma, training ), medical prescriptions or provide merchandise authenticity assurance to increase protective covering against counterfeits. [ 95 ]

license [edit ]

The use of QR code engineering is freely licensed vitamin a long as users follow the standards for QR Code documented with JIS or ISO / IEC. Non-standardized codes may require special license. [ 98 ] Denso Wave owns a number of patents on QR code technology, but has chosen to exercise them in a limited fashion. [ 98 ] In order to promote widespread custom of the technology Denso Wave chose to waive its rights to a key patent in its possession for standardized codes only. [ 14 ] In the US, the granted QR code patent is US 5726435, and in Japan JP 2938338, both of which have expired. The european Patent Office granted patent EP 0672994 to Denso Wave, which was then validated into french, UK, and german patents, all of which expired in March 2015. [ 99 ] The text QR Code itself is a register trademark and wordmark of Denso Wave Incorporated. [ 100 ] In UK, the hallmark is registered as E921775, the condition QR Code, with a file date of 3 September 1998. [ 101 ] The UK adaptation of the trademark is based on the Kabushiki Kaisha Denso ( DENSO CORPORATION ) brand, filed as Trademark 000921775, the term QR Code, on 3 September 1998 and registered on 16 December 1999 with the European Union OHIM ( Office for Harmonization in the Internal Market ). [ 102 ] The U.S. Trademark for the terminus 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. [ 103 ]

Risks [edit ]

The only context in which park QR codes can carry feasible data is the URL data type. These URLs may host JavaScript code, which can be used to exploit vulnerabilities in applications on the server organization, such as the lector, the web browser or the visualize viewer, since a reviewer will typically send the data to the application associated with the data type used by the QR code. In the event of no software exploits, malicious QR codes combined with a permissive reader can hush put a calculator ‘s contents and exploiter ‘s privacy at risk. This practice is known as “ attagging ”, a portmanteau of “ attack chase ”. [ 104 ] They are easily created and can be affixed over legitimate QR codes. [ 105 ] On a smartphone, the subscriber ‘s permissions may allow use of the television camera, fully Internet access, read/write contact data, GPS, read browser history, read/write local anesthetic storehouse, and ball-shaped system changes. [ 106 ] [ 107 ] [ 108 ] Risks include linking to dangerous web sites with browser exploits, enabling the microphone/camera/GPS, and then streaming those feeds to a remote control server, psychoanalysis of sensible data ( passwords, files, contacts, transactions ), [ 109 ] and sending email/ SMS /IM messages or packets for DDoS as depart of a botnet, corrupting privacy settings, stealing identity, [ 110 ] and evening containing malicious logic themselves such as JavaScript [ 111 ] or a virus. [ 112 ] [ 113 ] These actions could occur in the backdrop while the drug user is only seeing the subscriber opening a apparently harmless world wide web page. [ 114 ] In Russia, a malicious QR code caused phones that scanned it to send premium text at a tip of $ 6 each. [ 104 ] QR codes have besides been linked to scams in which stickers are placed on parking meters, posing as quick payment options, as seen in Austin, San Antonio and Boston, among other cities across the United States and Australia. [ 115 ] [ 116 ] [ 117 ]

See besides [edit ]

References [edit ]

bibliography [edit ]

  • 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.

reference : https://thaitrungkien.com
Category : Tutorial

Related Posts

Trả lời

Email của bạn sẽ không được hiển thị công khai.