
A barcode or bar code is a method of representing data in a visual,
machine-readable form. Initially, barcodes represented data by varying the widths, spacings and sizes of parallel lines. These barcodes, now commonly referred to as linear or one-dimensional (1D), can be scanned by special
optical scanner
An image scanner (often abbreviated to just scanner) is a device that optically scans images, printed text, handwriting, or an object and converts it to a digital image. The most common type of scanner used in the home and the office is the flatbe ...
s, called
barcode reader
A barcode reader or barcode scanner is an optical scanner that can read printed barcodes and send the data they contain to computer. Like a flatbed scanner, it consists of a light source, a lens, and a light sensor for translating optical impul ...
s, of which there are several types.
Later, two-dimensional (2D) variants were developed, using rectangles, dots,
hexagons and other patterns, called ''2D barcodes'' or ''matrix codes'', although they do not use bars as such. Both can be read using purpose-built 2D optical scanners, which exist in a few different forms. Matrix codes can also be read by a digital camera connected to a microcomputer running software that takes a photographic image of the barcode and analyzes the image to deconstruct and decode the code. A
mobile device
A mobile device or handheld device is a computer small enough to hold and operate in hand. Mobile devices are typically battery-powered and possess a flat-panel display and one or more built-in input devices, such as a touchscreen or keypad. ...
with a built-in camera, such as a
smartphone
A smartphone is a mobile phone with advanced computing capabilities. It typically has a touchscreen interface, allowing users to access a wide range of applications and services, such as web browsing, email, and social media, as well as multi ...
, can function as the latter type of barcode reader using specialized
application software
Application software is any computer program that is intended for end-user use not operating, administering or programming the computer. An application (app, application program, software application) is any program that can be categorized as ...
and is suitable for both 1D and 2D codes.
The barcode was invented by
Norman Joseph Woodland and
Bernard Silver and patented in the US in 1952.
The invention was based on
Morse code
Morse code is a telecommunications method which Character encoding, encodes Written language, text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code i ...
that was extended to thin and thick bars. However, it took over twenty years before this invention became commercially successful. UK magazine ''
Modern Railways'' December 1962 pages 387–389 record how
British Railways
British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most rail transport in Great Britain from 1948 to 1997. Originally a trading brand of the Railway Executive of the British Transport Commis ...
had already perfected a barcode-reading system capable of correctly reading rolling stock travelling at with no mistakes. An early use of one type of barcode in an industrial context was sponsored by the
Association of American Railroads in the late 1960s. Developed by
General Telephone and Electronics (GTE) and called
KarTrak ACI (Automatic Car Identification), this scheme involved placing colored stripes in various combinations on steel plates which were affixed to the sides of railroad rolling stock. Two plates were used per car, one on each side, with the arrangement of the colored stripes encoding information such as ownership, type of equipment, and identification number.
The plates were read by a trackside scanner located, for instance, at the entrance to a classification yard, while the car was moving past.
The project was abandoned after about ten years because the system proved unreliable after long-term use.
Barcodes became commercially successful when they were used to automate supermarket checkout systems, a task for which they have become almost universal. The Uniform Grocery Product Code Council had chosen, in 1973, the barcode design developed by
George Laurer. Laurer's barcode, with vertical bars, printed better than the circular barcode developed by Woodland and Silver.
Their use has spread to many other tasks that are generically referred to as
automatic identification and data capture (AIDC). The first successful system using barcodes was in the UK supermarket group
Sainsbury's
J Sainsbury plc, trading as Sainsbury's, is a British supermarket and the second-largest chain of supermarkets in the United Kingdom.
Founded in 1869 by John James Sainsbury with a shop in Drury Lane, London, the company was the largest UK r ...
in 1972 using shelf-mounted barcodes which were developed by
Plessey.
In June 1974,
Marsh supermarket in
Troy, Ohio used a scanner made by
Photographic Sciences Corporation to scan the
Universal Product Code
The Universal Product Code (UPC or UPC code) is a barcode#Symbologies, barcode symbology that is used worldwide for tracking trade items in stores.
The chosen symbology has bars (or spaces) of exactly 1, 2, 3, or 4 units wide each; each decimal ...
(UPC) barcode on a pack of
Wrigley's chewing gum.
QR codes, a specific type of 2D barcode, rose in popularity in the second decade of the 2000s due to the growth in smartphone ownership.
Other systems have made inroads in the
AIDC market, but the simplicity, universality and low cost of barcodes has limited the role of these other systems, particularly before technologies such as
radio-frequency identification
Radio-frequency identification (RFID) uses electromagnetic fields to automatically Automatic identification system, identify and Tracking system, track tags attached to objects. An RFID system consists of a tiny radio transponder called a tag, ...
(RFID) became available after 2023.
History
In 1948,
Bernard Silver, a graduate student at
Drexel Institute of Technology in Philadelphia, Pennsylvania, US overheard the president of the local food chain,
Food Fair, asking one of the deans to research a system to automatically read product information during checkout. Silver told his friend
Norman Joseph Woodland about the request, and they started working on a variety of systems. Their first working system used
ultraviolet
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of ...
ink, but the ink faded too easily and was expensive.
Convinced that the system was workable with further development, Woodland left Drexel, moved into his father's apartment in Florida, and continued working on the system. His next inspiration came from Morse code, and he formed his first barcode from sand on the beach. "I just extended the dots and dashes downwards and made narrow lines and wide lines out of them."
[ To read them, he adapted technology from optical soundtracks in movies, using a 500-watt incandescent light bulb shining through the paper onto an RCA935 photomultiplier tube (from a movie projector) on the far side. He later decided that the system would work better if it were printed as a circle instead of a line, allowing it to be scanned in any direction.
On 20 October 1949 Woodland and Silver filed a patent application for "Classifying Apparatus and Method", in which they described both the linear and bull's eye printing patterns, as well as the mechanical and electronic systems needed to read the code. The patent was issued on 7 October 1952 as US Patent 2,612,994.] In 1951, Woodland moved to IBM
International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...
and continually tried to interest IBM in developing the system. The company eventually commissioned a report on the idea, which concluded that it was both feasible and interesting, but that processing the resulting information would require equipment that was some time off in the future.
IBM offered to buy the patent, but the offer was not accepted. Philco
Philco (an acronym for Philadelphia Battery Company) is an American electronics industry, electronics manufacturer headquartered in Philadelphia. Philco was a pioneer in battery, radio, and television production. In 1961, the company was purchase ...
purchased the patent in 1962 and then sold it to RCA sometime later.
Collins at Sylvania
During his time as an undergraduate, David Jarrett Collins worked at the Pennsylvania Railroad and became aware of the need to automatically identify railroad cars. Immediately after receiving his master's degree from MIT in 1959, he started work at GTE Sylvania and began addressing the problem. He developed a system called ''KarTrak'' using blue, white and red reflective stripes attached to the side of the cars, encoding a four-digit company identifier and a six-digit car number. Light reflected off the colored stripes was read by photomultiplier vacuum tubes.
The Boston and Maine Railroad
The Boston and Maine Railroad was a United States, U.S. Class I railroad in northern New England. It was chartered in 1835, and became part of what was the Pan Am Railways network in 1983 (most of which was purchased by CSX in 2022).
At the e ...
tested the KarTrak system on their gravel cars in 1961. The tests continued until 1967, when the Association of American Railroads (AAR) selected it as a standard, automatic car identification, across the entire North American fleet. The installations began on 10 October 1967. However, the economic downturn and rash of bankruptcies in the industry in the early 1970s greatly slowed the rollout, and it was not until 1974 that 95% of the fleet was labeled. To add to its woes, the system was found to be easily fooled by dirt in certain applications, which greatly affected accuracy. The AAR abandoned the system in the late 1970s, and it was not until the mid-1980s that they introduced a similar system, this time based on radio tags.
The railway project had failed, but a toll bridge in New Jersey requested a similar system so that it could quickly scan for cars that had purchased a monthly pass. Then the US Post Office requested a system to track trucks entering and leaving their facilities. These applications required special retroreflector
A retroreflector (sometimes called a retroflector or cataphote) is a device or surface that reflects light or other radiation back to its source with minimum scattering. This works at a wide range of angle of incidence (optics), angle of incidenc ...
labels. Finally, Kal Kan asked the Sylvania team for a simpler (and cheaper) version which they could put on cases of pet food for inventory control.
Computer Identics Corporation
In 1967, with the railway system maturing, Collins went to management looking for funding for a project to develop a black-and-white version of the code for other industries. They declined, saying that the railway project was large enough, and they saw no need to branch out so quickly.
Collins then quit Sylvania and formed the Computer Identics Corporation. As its first innovations, Computer Identics moved from using incandescent light bulbs in its systems, replacing them with helium–neon lasers, and incorporated a mirror as well, making it capable of locating a barcode up to a meter (3 feet) in front of the scanner. This made the entire process much simpler and more reliable, and typically enabled these devices to deal with damaged labels, as well, by recognizing and reading the intact portions.
Computer Identics Corporation installed one of its first two scanning systems in the spring of 1969 at a General Motors
General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. The company is most known for owning and manufacturing f ...
(Buick) factory in Flint, Michigan. The system was used to identify a dozen types of transmissions moving on an overhead conveyor from production to shipping. The other scanning system was installed at General Trading Company's distribution center in Carlstadt, New Jersey to direct shipments to the proper loading bay.
Universal Product Code
In 1966 the National Association of Food Chains (NAFC) held a meeting on the idea of automated checkout systems. RCA, which had purchased the rights to the original Woodland patent, attended the meeting and initiated an internal project to develop a system based on the bullseye code. The Kroger
The Kroger Company, or simply Kroger, is an American retail company that operates (either directly or through its subsidiaries) supermarkets and multi-department stores throughout the United States.
Founded by Bernard Kroger in 1883 in Cinc ...
grocery chain volunteered to test it.
In the mid-1970s the NAFC established the Ad-Hoc Committee for U.S. Supermarkets on a Uniform Grocery-Product Code to set guidelines for barcode development. In addition, it created a symbol-selection subcommittee to help standardize the approach. In cooperation with consulting firm, McKinsey & Co., they developed a standardized 11-digit code for identifying products. The committee then sent out a contract tender to develop a barcode system to print and read the code. The request went to Singer, National Cash Register (NCR), Litton Industries, RCA, Pitney-Bowes
Pitney Bowes Inc. is an American technology company most known for its postage meters and other mailing equipment, services, and other technologies. The company was founded by Arthur Pitney, who invented the first commercially available postage m ...
, IBM and many others. A wide variety of barcode approaches was studied, including linear codes, RCA's bullseye concentric circle code, starburst patterns and others.
In the spring of 1971 RCA demonstrated their bullseye code at another industry meeting. IBM executives at the meeting noticed the crowds at the RCA booth and immediately developed their own system. IBM marketing specialist Alec Jablonover remembered that the company still employed Woodland, and he established a new facility in Research Triangle Park to lead development.
In July 1972 RCA began an 18-month test in a Kroger store in Cincinnati. Barcodes were printed on small pieces of adhesive paper, and attached by hand by store employees when they were adding price tags. The code proved to have a serious problem; the printers would sometimes smear ink, rendering the code unreadable in most orientations. However, a linear code, like the one being developed by Woodland at IBM, was printed in the direction of the stripes, so extra ink would simply make the code "taller" while remaining readable. So on 3 April 1973 the IBM UPC was selected as the NAFC standard. IBM had designed five versions of UPC symbology for future industry requirements: UPC A, B, C, D, and E.
NCR installed a testbed system at Marsh's Supermarket in Troy, Ohio, near the factory that was producing the equipment. On 26 June 1974, a 10-pack of Wrigley's Juicy Fruit gum was scanned, registering the first commercial use of the UPC.
In 1971 an IBM team was assembled for an intensive planning session, threshing out, 12 to 18 hours a day, how the technology would be deployed and operate cohesively across the system, and scheduling a roll-out plan. By 1973, the team were meeting with grocery manufacturers to introduce the symbol that would need to be printed on the packaging or labels of all of their products. There were no cost savings for a grocery to use it, unless at least 70% of the grocery's products had the barcode printed on the product by the manufacturer. IBM projected that 75% would be needed in 1975.
Economic studies conducted for the grocery industry committee projected over $40 million in savings to the industry from scanning by the mid-1970s. Those numbers were not achieved in that time-frame and some predicted the demise of barcode scanning. The usefulness of the barcode required the adoption of expensive scanners by a critical mass of retailers while manufacturers simultaneously adopted barcode labels. Neither wanted to move first and results were not promising for the first couple of years, with ''Business Week'' proclaiming "The Supermarket Scanner That Failed" in a 1976 article.
Sims Supermarkets were the first location in Australia to use barcodes, starting in 1979.
Barcode system
A barcode system is a network of hardware and software, consisting primarily of mobile computers
Mobile computing is human–computer interaction in which a computer is expected to be transported during normal usage and allow for transmission of data, which can include voice and video transmissions. Mobile computing involves mobile communi ...
, printers, handheld scanners, infrastructure, and supporting software. Barcode systems are used to automate data collection where hand recording is neither timely nor cost effective. Despite often being provided by the same company, Barcoding systems are not radio-frequency identification
Radio-frequency identification (RFID) uses electromagnetic fields to automatically Automatic identification system, identify and Tracking system, track tags attached to objects. An RFID system consists of a tiny radio transponder called a tag, ...
(RFID) systems. Many companies use both technologies as part of larger resource management
In organizational studies, resource management is the efficient and effective development of an organization's resources when they are needed. Such resources may include the financial resources, inventory, human skills, production resources, or ...
systems.
A typical barcode system consist of some infrastructure, either wired or wireless that connects some number of mobile computers, handheld scanners, and printers to one or many databases that store and analyze the data collected by the system. At some level there must be some software to manage the system. The software may be as simple as code that manages the connection between the hardware and the database or as complex as an ERP, MRP, or some other inventory management software.
Hardware
A wide range of hardware is manufactured for use in barcode systems by such manufacturers as Datalogic, Intermec, HHP (Hand Held Products), Microscan Systems, Unitech, Metrologic, PSC, and PANMOBIL, with the best known brand of handheld scanners and mobile computers being produced by Symbol
A symbol is a mark, Sign (semiotics), sign, or word that indicates, signifies, or is understood as representing an idea, physical object, object, or wikt:relationship, relationship. Symbols allow people to go beyond what is known or seen by cr ...
, a division of Motorola
Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois. It was founded by brothers Paul and Joseph Galvin in 1928 and had been named Motorola since 1947. Many of Motorola's products had been ...
.
Software
Some ERP, MRP, and other inventory management software have built in support for barcode reading. Alternatively, custom interfaces can be created using a language such as C++, C#, Java
Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...
, Visual Basic.NET, and many others. In addition, software development kits are produced to aid the process.
Industrial adoption
In 1981 the United States Department of Defense
The United States Department of Defense (DoD, USDOD, or DOD) is an United States federal executive departments, executive department of the federal government of the United States, U.S. federal government charged with coordinating and superv ...
adopted the use of Code 39 for marking all products sold to the United States military. This system, Logistics Applications of Automated Marking and Reading Symbols (LOGMARS), is still used by DoD and is widely viewed as the catalyst for widespread adoption of barcoding in industrial uses.
Use
Barcodes are widely used around the world in many contexts. In stores, UPC barcodes are pre-printed on most items other than fresh produce from a grocery store. This speeds up processing at check-outs and helps track items and also reduces instances of shoplifting involving price tag swapping, although shoplifters can now print their own barcodes. Barcodes that encode a book's ISBN
The International Standard Book Number (ISBN) is a numeric commercial book identifier that is intended to be unique. Publishers purchase or receive ISBNs from an affiliate of the International ISBN Agency.
A different ISBN is assigned to e ...
are also widely pre-printed on books, journals and other printed materials. In addition, retail chain membership cards use barcodes to identify customers, allowing for customized marketing and greater understanding of individual consumer shopping patterns. At the point of sale, shoppers can get product discounts or special marketing offers through the address or e-mail address provided at registration.
Barcodes are widely used in healthcare and hospital settings, ranging from patient identification (to access patient data, including medical history, drug allergies, etc.) to creating SOAP notes with barcodes to medication management. They are also used to facilitate the separation and indexing of documents that have been imaged in batch scanning applications, track the organization of species in biology, and integrate with in-motion checkweighers to identify the item being weighed in a conveyor line for data collection.
They can also be used to keep track of objects and people; they are used to keep track of rental cars, airline luggage, nuclear waste, express mail, and parcels. Barcoded tickets (which may be printed by the customer on their home printer, or stored on their mobile device) allow the holder to enter sports arenas, cinemas, theatres, fairgrounds, and transportation, and are used to record the arrival and departure of vehicles from rental facilities etc. This can allow proprietors to identify duplicate or fraudulent tickets more easily. Barcodes are widely used in shop floor control applications software where employees can scan work orders and track the time spent on a job.
Barcodes are also used in some kinds of non-contact 1D and 2D position sensors. A series of barcodes are used in some kinds of absolute 1D linear encoder. The barcodes are packed close enough together that the reader always has one or two barcodes in its field of view. As a kind of fiducial marker, the relative position of the barcode in the field of view of the reader gives incremental precise positioning, in some cases with sub-pixel resolution. The data decoded from the barcode gives the absolute coarse position. An "address carpet", used in digital paper, such as Howell's binary pattern and the Anoto dot pattern, is a 2D barcode designed so that a reader, even though only a tiny portion of the complete carpet is in the field of view of the reader, can find its absolute X, Y position and rotation in the carpet.
Matrix codes can embed a hyperlink
In computing, a hyperlink, or simply a link, is a digital reference providing direct access to Data (computing), data by a user (computing), user's point and click, clicking or touchscreen, tapping. A hyperlink points to a whole document or to ...
to a web page. A mobile device with a built-in camera might be used to read the pattern and browse the linked website, which can help a shopper find the best price for an item in the vicinity. Since 2005, airlines use an IATA-standard 2D barcode on boarding passes ( Bar Coded Boarding Pass (BCBP)), and since 2008 2D barcodes sent to mobile phones enable electronic boarding passes.
Some applications for barcodes have fallen out of use. In the 1970s and 1980s, software source code was occasionally encoded in a barcode and printed on paper ( Cauzin Softstrip and Paperbyte are barcode symbologies specifically designed for this application), and the 1991 '' Barcode Battler'' computer game system used any standard barcode to generate combat statistics.
Artists have used barcodes in art, such as Scott Blake's Barcode Jesus, as part of the post-modernism movement.
Symbologies
The mapping between messages and barcodes is called a '' symbology''. The specification of a symbology includes the encoding of the message into bars and spaces, any required start and stop markers, the size of the quiet zone required to be before and after the barcode, and the computation of a checksum.
Linear symbologies can be classified mainly by two properties:
; Continuous vs. discrete
* Characters in discrete symbologies are composed of ''n'' bars and ''n'' − 1 spaces. There is an additional space between characters, but it does not convey information, and may have any width as long as it is not confused with the end of the code.
* Characters in continuous symbologies are composed of ''n'' bars and ''n'' spaces, and usually abut, with one character ending with a space and the next beginning with a bar, or vice versa. A special end pattern that has bars on both ends is required to end the code.
;Two-width vs. many-width
* A two-width, also called a binary bar code, contains bars and spaces of two widths, "wide" and "narrow". The precise width of the wide bars and spaces is not critical; typically, it is permitted to be anywhere between 2 and 3 times the width of the narrow equivalents.
* Some other symbologies use bars of two different heights ( POSTNET), or the presence or absence of bars ( CPC Binary Barcode). These are normally also considered binary bar codes.
* Bars and spaces in many-width symbologies are all multiples of a basic width called the ''module''; most such codes use four widths of 1, 2, 3 and 4 modules.
Some symbologies use interleaving. The first character is encoded using black bars of varying width. The second character is then encoded by varying the width of the white spaces between these bars. Thus, characters are encoded in pairs over the same section of the barcode. Interleaved 2 of 5 is an example of this.
Stacked symbologies repeat a given linear symbology vertically.
The most common among the many 2D symbologies are matrix codes, which feature square or dot-shaped modules arranged on a grid pattern. 2D symbologies also come in circular and other patterns and may employ steganography, hiding modules within an image (for example, DataGlyphs).
Linear symbologies are optimized for laser scanners, which sweep a light beam across the barcode in a straight line, reading a ''slice'' of the barcode light-dark patterns. Scanning at an angle makes the modules appear wider, but does not change the width ratios. Stacked symbologies are also optimized for laser scanning, with the laser making multiple passes across the barcode.
In the 1990s development of charge-coupled device
A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a ...
(CCD) imagers to read barcodes was pioneered by Welch Allyn. Imaging does not require moving parts, as a laser scanner does. In 2007, linear imaging had begun to supplant laser scanning as the preferred scan engine for its performance and durability.
2D symbologies cannot be read by a laser, as there is typically no sweep pattern that can encompass the entire symbol. They must be scanned by an image-based scanner employing a CCD or other digital camera sensor technology.
Barcode readers
The earliest, and still the cheapest, barcode scanners are built from a fixed light and a single photosensor that is manually moved across the barcode. Barcode scanners can be classified into three categories based on their connection to the computer. The older type is the RS-232 barcode scanner. This type requires special programming for transferring the input data to the application program. Keyboard interface scanners connect to a computer using a PS/2 or AT keyboard–compatible adaptor cable (a " keyboard wedge"). The barcode's data is sent to the computer as if it had been typed on the keyboard.
Like the keyboard interface scanner, USB
Universal Serial Bus (USB) is an industry standard, developed by USB Implementers Forum (USB-IF), for digital data transmission and power delivery between many types of electronics. It specifies the architecture, in particular the physical ...
scanners do not need custom code for transferring input data to the application program. On PCs running Windows the human interface device emulates the data merging action of a hardware "keyboard wedge", and the scanner automatically behaves like an additional keyboard.
Most modern smartphones are able to decode barcode using their built-in camera. Google's mobile Android operating system can use their own Google Lens application to scan QR codes, or third-party apps like Barcode Scanner
A barcode reader or barcode scanner is an optical scanner that can read printed barcodes and send the data they contain to computer. Like a flatbed scanner, it consists of a light source, a lens, and a light sensor for translating optical impulses ...
to read both one-dimensional barcodes and QR codes. Google's Pixel
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a Raster graphics, raster image, or the smallest addressable element in a dot matrix display device. In most digital display devices, p ...
devices can natively read QR codes inside the default Pixel Camera app. Nokia's Symbian operating system featured a barcode scanner, while mbarcode is a QR code reader for the Maemo operating system. In Apple iOS 11
iOS 11 is the iOS version history, eleventh major release of the iOS mobile operating system developed by Apple Inc., Apple, being the successor to iOS 10. It was announced at the company's Worldwide Developers Conference on June 5, 2017, and w ...
, the native camera app can decode QR codes and can link to URLs, join wireless networks, or perform other operations depending on the QR Code contents. Other paid and free apps are available with scanning capabilities for other symbologies or for earlier iOS versions. With BlackBerry
BlackBerry is a discontinued brand of handheld devices and related mobile services, originally developed and maintained by the Canadian company Research In Motion (RIM, later known as BlackBerry Limited) until 2016. The first BlackBerry device ...
devices, the App World application can natively scan barcodes and load any recognized Web URLs on the device's Web browser. Windows Phone 7.5 is able to scan barcodes through the Bing
Bing most often refers to:
* Bing Crosby (1903–1977), American singer
* Microsoft Bing, a web search engine
Bing may also refer to:
Food and drink
* Bing (bread), a Chinese flatbread
* Bing (soft drink), a UK brand
* Bing cherry, a varie ...
search app. However, these devices are not designed specifically for the capturing of barcodes. As a result, they do not decode nearly as quickly or accurately as a dedicated barcode scanner or portable data terminal.
Quality control and verification
It is common for producers and users of bar codes to have a quality management system which includes verification and validation
Verification and validation (also abbreviated as V&V) are independent procedures that are used together for checking that a product, service, or system meets requirements and specification (technical standard), specifications and that it fulf ...
of bar codes. Barcode verification examines scanability and the quality of the barcode in comparison to industry standards and specifications. Barcode verifiers are primarily used by businesses that print and use barcodes. Any trading partner in the supply chain
A supply chain is a complex logistics system that consists of facilities that convert raw materials into finished products and distribute them to end consumers or end customers, while supply chain management deals with the flow of goods in distri ...
can test barcode quality. It is important to verify a barcode to ensure that any reader in the supply chain can successfully interpret a barcode with a low error rate. Retailers levy large penalties for non-compliant barcodes. These chargebacks can reduce a manufacturer's revenue by 2% to 10%.
A barcode verifier works the way a reader does, but instead of simply decoding a barcode, a verifier performs a series of tests. For linear barcodes these tests are:
* Edge contrast (EC)
**The difference between the space reflectance (Rs) and adjoining bar reflectance (Rb). EC=Rs-Rb
* Minimum bar reflectance (Rb)
**The smallest reflectance value in a bar.
* Minimum space reflectance (Rs)
**The smallest reflectance value in a space.
*Symbol contrast (SC)
**Symbol contrast is the difference in reflectance values of the lightest space (including the quiet zone) and the darkest bar of the symbol. The greater the difference, the higher the grade. The parameter is graded as either A, B, C, D, or F. SC=Rmax-Rmin
* Minimum edge contrast (ECmin)
**The difference between the space reflectance (Rs) and adjoining bar reflectance (Rb). EC=Rs-Rb
* Modulation (MOD)
**The parameter is graded either A, B, C, D, or F. This grade is based on the relationship between minimum edge contrast (ECmin) and symbol contrast (SC). MOD=ECmin/SC The greater the difference between minimum edge contrast and symbol contrast, the lower the grade. Scanners and verifiers perceive the narrower bars and spaces to have less intensity than wider bars and spaces; the comparison of the lesser intensity of narrow elements to the wide elements is called modulation. This condition is affected by aperture size.
*Inter-character gap
**In discrete barcodes, the space that disconnects the two contiguous characters. When present, inter-character gaps are considered spaces (elements) for purposes of edge determination and reflectance parameter grades.
* Defects
* Decode
**Extracting the information which has been encoded in a bar code symbol.
* Decodability
**Can be graded as A, B, C, D, or F. The Decodability grade indicates the amount of error in the width of the most deviant element in the symbol. The less deviation in the symbology, the higher the grade. Decodability is a measure of print accuracy using the symbology reference decode algorithm.
2D matrix symbols look at the parameters:
* Symbol contrast
* Modulation
* Decode
* Unused error correction
* Fixed (finder) pattern damage
* Grid non-uniformity
* Axial non-uniformity
Depending on the parameter, each ANSI
The American National Standards Institute (ANSI ) is a private nonprofit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organiz ...
test is graded from 0.0 to 4.0 (F to A), or given a pass or fail mark. Each grade is determined by analyzing the scan reflectance profile (SRP), an analog graph of a single scan line across the entire symbol. The lowest of the 8 grades is the scan grade, and the overall ISO symbol grade is the average of the individual scan grades. For most applications a 2.5 (C) is the minimal acceptable symbol grade.
Compared with a reader, a verifier measures a barcode's optical characteristics to international and industry standards. The measurement must be repeatable and consistent. Doing so requires constant conditions such as distance, illumination angle, sensor angle and verifier aperture. Based on the verification results, the production process can be adjusted to print higher quality barcodes that will scan down the supply chain.
Bar code validation may include evaluations after use (and abuse) testing such as sunlight, abrasion, impact, moisture, etc.
Barcode verifier standards
Barcode verifier standards are defined by the International Organization for Standardization
The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries.
M ...
(ISO), in ISO/IEC 15426-1 (linear) or ISO/IEC 15426-2 (2D). The current international barcode quality specification is ISO/IEC 15416 (linear) and ISO/IEC 15415 (2D). The European Standard
European Standards, sometimes called Euronorm (abbreviated EN, from the German name , "European Norm"), are technical standards which have been ratified by one of the three European Standards Organizations (ESO): European Committee for Standardizat ...
EN 1635 has been withdrawn and replaced by ISO/IEC 15416. The original U.S. barcode quality specification was ANSI
The American National Standards Institute (ANSI ) is a private nonprofit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organiz ...
X3.182. (UPCs used in the US – ANSI/UCC5). As of 2011 the ISO workgroup JTC1 SC31 was developing a Direct Part Marking (DPM) quality standard: ISO/IEC TR 29158.
Benefits
In point-of-sale management, barcode systems can provide detailed up-to-date information on the business, accelerating decisions and with more confidence. For example:
* Fast-selling items can be identified quickly and automatically reordered.
* Slow-selling items can be identified, preventing inventory build-up.
* The effects of merchandising changes can be monitored, allowing fast-moving, more profitable items to occupy the best space.
* Historical data can be used to predict seasonal fluctuations very accurately.
* Items may be repriced on the shelf to reflect both sale prices and price increases.
* This technology also enables the profiling of individual consumers, typically through a voluntary registration of discount cards. While pitched as a benefit to the consumer, this practice is considered to be potentially dangerous by privacy advocates.
Besides sales and inventory tracking, barcodes are very useful in logistics and supply chain management.
* When a manufacturer packs a box for shipment, a unique identifying number (UID) can be assigned to the box.
* A database can link the UID to relevant information about the box; such as order number, items packed, quantity packed, destination, etc.
* The information can be transmitted through a communication system such as electronic data interchange
Electronic data interchange (EDI) is the concept of businesses electronically communicating information that was traditionally communicated on paper, such as purchase orders, advance ship notices, and invoices. Technical standards for EDI exist to ...
(EDI) so the retailer has the information about a shipment before it arrives.
* Shipments that are sent to a distribution center (DC) are tracked before forwarding. When the shipment reaches its final destination, the UID gets scanned, so the store knows the shipment's source, contents, and cost.
Barcode scanners are relatively low cost and extremely accurate compared to key-entry, with only about 1 substitution error in 15,000 to 36 trillion characters entered. The exact error rate depends on the type of barcode.
Types of barcodes
Linear barcodes
A first generation, "one dimensional" barcode that is made up of lines and spaces of various widths or sizes that create specific patterns.
2D barcodes
2D barcodes consist of bars, but use both dimensions for encoding.
Matrix (2D) codes
A ''matrix code'' or simply a ''2D code'', is a two-dimensional way to represent information. It can represent more data per unit area. Apart from dots various other patterns can be used.
Example images
File:UPC-A-036000291452.png, GTIN-12 number encoded in UPC-A barcode symbol. First and last digit are always placed outside the symbol to indicate Quiet Zones that are necessary for barcode scanners to work properly
File:EAN-13-5901234123457.svg, EAN-13 (GTIN-13) number encoded in EAN-13 barcode symbol. First digit is always placed outside the symbol, additionally right quiet zone indicator (>) is used to indicate Quiet Zones that are necessary for barcode scanners to work properly
File:Code93.png, "Wikipedia" encoded in Code 93
File:Code39.png, "*WIKI39*" encoded in Code 39
File:Wikipedia barcode 128.svg, "Wikipedia" encoded in Code 128
File:Codablock-F Example.png, An example of a ''stacked barcode''. Specifically a "Codablock" barcode.
File:Better Sample PDF417.png, PDF417 sample
File:Lorem Ipsum.png, Lorem ipsum boilerplate text
Boilerplate text, or simply boilerplate, is any written text ( copy) that can be reused in new contexts or applications without significant changes to the original. The term is used about statements, contracts, and source code, and is often used p ...
as four segment Data Matrix 2D
File:Azteccodeexample.svg, "This is an example Aztec symbol for Wikipedia" encoded in Aztec Code
File:EZcode.png, Text 'EZcode'
File:High Capacity Color Barcode.png, High Capacity Color Barcode of the URL for Wikipedia's article on High Capacity Color Barcode
File:Dataglyph511140.png, "Wikipedia, The Free Encyclopedia" in several languages encoded in DataGlyphs
File:35mm film audio macro.jpg, Two different 2D barcodes used in film: Dolby Digital between the sprocket holes with the "Double-D" logo in the middle, and Sony Dynamic Digital Sound in the blue area to the left of the sprocket holes
File:WikiQRCode.svg, The QR code for the Wikipedia URL. "Quick Response", the most popular 2D barcode. It is open in that the specification is disclosed and the patent is not exercised.
File:MaxiCode.svg, MaxiCode example. This encodes the string "Wikipedia, The Free Encyclopedia"
File:Shotcode.png, ShotCode sample
File:Twibright Optar Detail Scanned.png, detail of Twibright Optar scan from laser printed paper, carrying 32 kbit/s Ogg Vorbis digital music (48 seconds per A4 page)
File:KarTrak code.jpg, A KarTrak railroad Automatic Equipment Identification label on a caboose in Florida
In popular culture
In architecture, a building in Lingang New City by German architects Gerkan, Marg and Partners incorporates a barcode design, as does a shopping mall called ''Shtrikh-kod'' (Russian for ''barcode'') in Narodnaya ulitsa ("People's Street") in the Nevskiy district of St. Petersburg, Russia.
In media, in 2011, the National Film Board of Canada
The National Film Board of Canada (NFB; ) is a Canadian public film and digital media producer and distributor. An agency of the Government of Canada, the NFB produces and distributes documentary films, animation, web documentaries, and altern ...
and ARTE France launched a web documentary entitled ''Barcode.tv'', which allows users to view films about everyday objects by scanning the product's barcode with their iPhone
The iPhone is a line of smartphones developed and marketed by Apple that run iOS, the company's own mobile operating system. The first-generation iPhone was announced by then–Apple CEO and co-founder Steve Jobs on January 9, 2007, at ...
camera.
In professional wrestling
Professional wrestling, often shortened to either pro wrestling or wrestling,The term "wrestling" is most often widely used to specifically refer to modern scripted professional wrestling, though it is also used to refer to Real life, real- ...
, the WWE stable D-Generation X incorporated a barcode into their entrance video, as well as on a T-shirt.
In video games, the protagonist of the ''Hitman'' video game series has a barcode tattoo on the back of his head; QR codes can also be scanned in a side mission in '' Watch Dogs''.
The 2018 videogame ''Judgment
Judgement (or judgment) is the evaluation of given circumstances to make a decision. Judgement is also the ability to make considered decisions.
In an informal context, a judgement is opinion expressed as fact. In the context of a legal trial ...
'' features QR Codes that protagonist Takayuki Yagami can photograph with his phone camera. These are mostly to unlock parts for Yagami's Drone.
Interactive Textbooks were first published by ''Harcourt College Publishers to Expand Education Technology with Interactive Textbooks.''
Designed barcodes
Some companies integrate custom designs into barcodes on their consumer products without impairing their readability.
File:Design Barcode Grasvodka IMG 5574.JPG
File:Barcode Tall Horse1.jpg
File:Hühner-Bouillon K Designbarcode 4337185009907 IMG 8716.jpg
File:Sardinendose K Barcode Art valid IMG11829.jpg
File:Barcode_peanut.jpg
Opposition
Some have regarded barcodes to be an intrusive surveillance
Surveillance is the monitoring of behavior, many activities, or information for the purpose of information gathering, influencing, managing, or directing. This can include observation from a distance by means of electronic equipment, such as ...
technology. Some Christians, pioneered by a 1982 book ''The New Money System 666'' by Mary Stewart Relfe, believe the codes hide the number 666, representing the "Number of the beast
The number of the beast (, ) is associated with the The Beast (Revelation), Beast of Revelation in chapter 13, verse 18 of the Book of Revelation. In most manuscripts of the New Testament and in English translations of the Bible, the number of ...
". Old Believers, a separation of the Russian Orthodox Church
The Russian Orthodox Church (ROC; ;), also officially known as the Moscow Patriarchate (), is an autocephaly, autocephalous Eastern Orthodox Church, Eastern Orthodox Christian church. It has 194 dioceses inside Russia. The Primate (bishop), p ...
, believe barcodes are the stamp of the Antichrist
In Christian eschatology, Antichrist (or in broader eschatology, Anti-Messiah) refers to a kind of entity prophesied by the Bible to oppose Jesus in Christianity, Jesus Christ and falsely substitute themselves as a savior in Christ's place before ...
. Television host Phil Donahue described barcodes as a "corporate plot against consumers".
See also
* Automated identification and data capture (AIDC)
* Barcode printer
* Campus card
* European Article Numbering-Uniform Code Council
* Global Trade Item Number
* Identifier
An identifier is a name that identifies (that is, labels the identity of) either a unique object or a unique ''class'' of objects, where the "object" or class may be an idea, person, physical countable object (or class thereof), or physical mass ...
* Inventory control system
* Object hyperlinking
* Semacode
* SPARQCode (QR code)
* List of GS1 country codes
References
Further reading
* ''Automating Management Information Systems: Barcode Engineering and Implementation'' – Harry E. Burke, Thomson Learning,
* ''Automating Management Information Systems: Principles of Barcode Applications'' – Harry E. Burke, Thomson Learning,
* ''The Bar Code Book'' – Roger C. Palmer, Helmers Publishing, , 386 pages
* ''The Bar Code Manual'' – Eugene F. Brighan, Thompson Learning,
* ''Handbook of Bar Coding Systems'' – Harry E. Burke, Van Nostrand Reinhold Company, , 219 pages
* ''Information Technology for Retail:Automatic Identification & Data Capture Systems'' – Girdhar Joshi, Oxford University Press
Oxford University Press (OUP) is the publishing house of the University of Oxford. It is the largest university press in the world. Its first book was printed in Oxford in 1478, with the Press officially granted the legal right to print books ...
, , 416 pages
* ''Lines of Communication'' – Craig K. Harmon, Helmers Publishing, , 425 pages
* ''Punched Cards to Bar Codes'' – Benjamin Nelson, Helmers Publishing, , 434 pages
* ''Revolution at the Checkout Counter: The Explosion of the Bar Code'' – Stephen A. Brown, Harvard University Press
Harvard University Press (HUP) is an academic publishing house established on January 13, 1913, as a division of Harvard University. It is a member of the Association of University Presses. Its director since 2017 is George Andreou.
The pres ...
,
* ''Reading Between The Lines'' – Craig K. Harmon and Russ Adams, Helmers Publishing, , 297 pages
* ''The Black and White Solution: Bar Code and the IBM PC'' – Russ Adams and Joyce Lane, Helmers Publishing, , 169 pages
* ''Sourcebook of Automatic Identification and Data Collection'' – Russ Adams, Van Nostrand Reinhold, , 298 pages
* ''Inside Out: The Wonders of Modern Technology'' – Carol J. Amato, Smithmark Pub, , 1993
{{Authority control
Encodings
Automatic identification and data capture
1952 introductions
American inventions
Records management technology