Aztec Code
Encyclopedia
Encoding
The symbol is built on a square grid with a bulls-eye pattern at its centre for locating the code. Data is encodedCode
A code is a rule for converting a piece of information into another form or representation , not necessarily of the same type....
in concentric square rings around the bulls-eye pattern. The central bulls-eye is 9×9 or 13×13 pixel
Pixel
In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....
s, and one row of pixels around that encodes basic coding parameters, producing a "core" of 11×11 or 15×15 squares. Data is added in "layers", each one containing 2 rings of pixels, giving total sizes of 15×15, 19×19, 23×23, etc.
The corners of the core include orientation marks, allowing the code to be read if rotated or reflected. Decoding begins at the corner with three black pixels, and proceeds clockwise to the corners with two, one and zero black pixels. The variable pixels in the central core encode the size, so it is not necessary to mark the boundary of the code with a blank "quiet zone", although some bar code readers require one.
The compact Aztec code core supports symbols from 15×15 (room for 13 digits or 12 letters) through 27×27. There is additionally a special 11×11 "rune" that encodes one byte of information. The full core supports sizes up to 151x151, which can encode 3832 digits, 3067 letters, or 1914 bytes of data.
The level of Reed–Solomon error correction
Reed–Solomon error correction
In coding theory, Reed–Solomon codes are non-binary cyclic error-correcting codes invented by Irving S. Reed and Gustave Solomon. They described a systematic way of building codes that could detect and correct multiple random symbol errors...
is configurable, from 5% to 95% of the data region. The recommended level is 23% of symbol capacity plus codewords.
Aztec Code is supposed to be robust according to various printer technologies. It is also well suited for displays of cell phones and other mobile devices.
Standard: ISO/IEC 24778 (published February 2008)
Character set
All 8-bit values can be encoded. The default interpretation shall be:- for values 0–127, ANSI X3.4 (i.e., ASCIIASCIIThe American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
) and - for values 128–255, ISO 8859-1: Latin Alphabet No. 1. This corresponds to ECI 000003.
Two non-data characters can be encoded, FNC1 for compatibility with some existing applications and ECI, escape sequence for the standardized encoding of message interpretation information.
Compact encoding modes are defined for storing text with five bits per character, and numeric data with four bits per character.
Usage
Transport
An Aztec code barcode is used by EurostarEurostar
Eurostar is a high-speed railway service connecting London with Paris and Brussels. All its trains traverse the Channel Tunnel between England and France, owned and operated separately by Eurotunnel....
, Deutsche Bahn
Deutsche Bahn
Deutsche Bahn AG is the German national railway company, a private joint stock company . Headquartered in Berlin, it came into existence in 1994 as the successor to the former state railways of Germany, the Deutsche Bundesbahn of West Germany and the Deutsche Reichsbahn of East Germany...
, Trenitalia
Trenitalia
Trenitalia is the primary train operator in Italy. Trenitalia is owned by Ferrovie dello Stato, itself owned by the Italian Government. It was created in 2000 following the EU directive on the deregulation of rail transport.-Passenger transport:...
, Nederlandse Spoorwegen
Nederlandse Spoorwegen
Nederlandse Spoorwegen , or NS, is the principal passenger railway operator in the Netherlands.Its trains operate over the tracks of the Dutch national railinfrastructure, operated by ProRail, which was split off from NS in 2003...
, PKP Intercity
PKP Intercity
PKP Intercity is a company of PKP Group responsible for long-distance passenger transport. It runs about 350 trains daily, connecting mainly large aglomerations and smaller towns, also servicing most of the international trains....
, Virgin Trains
Virgin Trains
Virgin Trains is a train operating company in the United Kingdom. It operates long-distance passenger services on the West Coast Main Line between London, the West Midlands, North West England, North Wales and Scotland...
, Swiss Federal Railways, SNCF
SNCF
The SNCF , is France's national state-owned railway company. SNCF operates the country's national rail services, including the TGV, France's high-speed rail network...
and its subsidiary iDTGV
IDTGV
iDTGV is a TGV high speed train service from SNCF, the French national railroad company. It only sells its tickets online. Carriages are separated into two zones: iDZen for customers wishing a quiet trip, where mobile phones and loud conversations are banned, and iDZap for customers looking for...
for tickets sold online and printed out by customers. An Aztec code barcode is used by Heathrow Express
Heathrow Express
Heathrow Express is an airport rail link from London Heathrow Airport to London Paddington station in London operated by the Heathrow Express Operating Authority, a wholly owned subsidiary of BAA. It was opened by the then Prime Minister Tony Blair in 1998...
, East Coast
East Coast (train operating company)
East Coast is a British train operating company running high-speed passenger services on the East Coast Main Line between London, Yorkshire, the North East and Scotland...
, and VR Group
VR Group
VR or VR Group is a state-owned railway company in Finland. Formerly known as Suomen Valtion Rautatiet until 1922 and Valtionrautatiet / Statsjärnvägarna until 1995...
in tickets delivered to mobile phones and displayed on their screens, and on self print tickets. The barcode is scanned by a handheld scanner by on-train staff to validate the ticket.
The Aztec Code has been selected by the airline industry (IATA's BCBP standard) for the electronic boarding passes. Several airlines send Aztec Codes to passengers' mobile phones for ticketing purposes, relating to online (or paperless) ticketing. Air New Zealand
Air New Zealand
Air New Zealand Limited is the national airline and flag carrier of New Zealand. Based in Auckland, New Zealand, the airline operates scheduled passenger flights to 26 domestic destinations and 24 international destinations in 15 countries across Asia, Europe, North America and Oceania, and is...
will be using the code domestically for ticketing, but this deployment is still in progress.
Governmental
Car registration documents in PolandPoland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
bear an encrypted summary encoded as Aztec Code. Works are underway to enable car insurance companies to automatically fill in the relevant information based on digital photographs of the document as the first step of closing a new insurance contract.
Commercial
Many bills in Canada are now using this technology as well, including EastLink (company)EastLink (company)
EastLink is a Canadian cable television and telecommunications company. In 1970, EastLink was established in Amherst, Nova Scotia, when it was issued one of the first cable licences granted by the CRTC...
, Shaw Cable, Bell Aliant and many more.