An overview of two-dimensional bar codeThe origin of two-dimension bar code technology
due to one-dimensional bar code information volume is very small, such as bar code of goods may only be able to accommodate several or dozens of digits or letters, detailed description of the merchandise can only rely on the database to provide, leave a pre-established database, one-dimensional bar code used by the limitations. For this reason, people are eager to invent a new system, in addition to the advantages of the one-dimensional bar code, along with the large information capacity, high reliability, confidentiality of security advantages. In order to meet the needs of people, United States Symbol companies after years of effort, in 1991, the formal launch of PDF417 two dimensional bar code, also known as PDF417 barcode (see above), that is, "portable data file."
what is II dimension barcode/two dimension code:
II dimension barcode/two dimension code (2-dimensional bar code) is with a species specific of geometry by must law in plane (II dimension direction Shang) distribution of black and white-and-of graphics records data symbol information of; in code prepared Shang clever to using constitute computer internal logic based of "0", and "1" bit flow of concept, using several a and II into business phase corresponds to of geometry form to said text numerical information, Through the image input devices or optical scan equipment automatic recognition to achieve information automatically: it has a bar-code technology in common: each system has its own specific character set; each character occupies a certain width has a certain validation functions, and so on. Automatic recognition of information but also has a different function, and graphic rotation of management changes and so on.
two dimensional barcode/QR, in horizontal and vertical direction at the same time expressing a message, and therefore can express large amounts of information in a very small area. Two-dimensional barcode/QR code of
two-dimensional barcode/QR codes can be divided into stacked row/rows of two-dimensional bar codes and matrix two-dimensional bar codes. Stacked type/line row type II dimension barcode form Shang is by more line short cut of a dimension barcode stacked and into; Matrix type II dimension barcode to matrix of form composition, in matrix corresponding elements location Shang with "points" said II into business "1", with "empty" said II into business "0", by "points" and "empty" of arranged composition code.
1. Stacked line of type two-dimensional bar code
-stack/line type of two-dimensional barcode (also known as a stacked two-dimensional barcode or type two dimensional bar code) and its coding principle is based on the one-dimension barcode based on piled two or more rows as needed. It in code design, verification principle, reading method inherited some characteristics of one-dimensional bar codes, reading device compatible with bar code printing and one-dimension bar code technology. But due to the number of lines increase, you need to determine the rows, the decoding algorithm and the software is not identical to one-dimensional bar codes. Representative row rows of two-dimensional bar codes are: Code, such as 16K, Code 49, PDF417.
2. Matrix QR
short matrix two-dimensional barcode (also known as a grid of two-dimensional bar codes) it was a rectangular room with black and white pixel encodes the different distribution in the matrix. On the corresponding element in the matrix, with dots (dot, dot, or other shapes) to indicate a binary "1" and does not indicate a binary "0", permutations and combinations determine the matrix two dimensional bar code means. Matrix two-dimensional bar code is based on computer image processing techniques, combination encoding based on the principle of a new type of automatic recognition processing system of graphical symbols. Representative matrix two-dimensional bar codes are: Code One, and Maxi Code, QR Code, Data Matrix etc.
in currently dozens of species II dimension to code in the, common of code business has: PDF417 II dimension barcode, Datamatrix II dimension barcode, Maxicode II dimension barcode, QR Code, Code 49, Code 16K, Code one,,, except these common of II dimension barcode zhiwai, also has Vericode barcode, and CP barcode, and Codablock f barcode, and field code, and Ultracode barcode, Aztec barcode.
the characteristics of two-dimension barcode/QR
1. high density code information capability: the accommodates up to 1850 uppercase letters or 2,710 numbers or 1108 bytes, and more than 500 characters, dozens of times more times than the common bar code information.
2. wide range of coding: the bar code can be a picture, sound, text, signatures, fingerprints and other digital information encoded with bar codes; can represent multiple languages; can represent image data.
3. fault-tolerant ability, with error correction: that makes two-dimensional barcode for perforation, fouling caused partial damage, can still be read correctly, damage area of 50% is still available for recovery information.
4. decoding reliability: it than the average bar code decoding two out of 10,000 is much lower error rate, error rate less than one out of 10,000.
5. for the introduction of encryption: confidentiality, security is good.
6. low cost, easy to make, and durable.
7. bar code symbol shape, dimensions variable.
8. two-dimensional bar code can use a laser or CCD reader read.
two dimensional bar code used:
two-dimensional bar code has large storage capacity, confidentiality, tracking higher, strong resistance to damage, redundancy, low cost and other features, these features are especially useful for forms, security, tracking, certificates, inventory, data redundancy, and so on.
document forms, business forms, import/export declarations and manifests can exchange information exchange and reduce repeated entry form information and avoid human errors, reduce labor costs
business intelligence, economic intelligence, political intelligence, military intelligence, personal information and other confidential data encryption and transmission.
automatic document tracking, production line automatic tracking, customer service, automated tracking, mail-order delivery of automatic tracking, automated tracking, maintenance records of dangerous goods automatic tracking, automatic tracking logistics automatic tracking, medical supplies, and ecological research (animals, birds, ... ) Automatic tracing.
Passport, identity card, registration card, driver's license, membership cards, identification cards, chain membership cards, certificates of registration and automatic input of information, play "to read", "immediate access" effect of information management.
logistics, warehousing centers, automatic inventory of goods and fixed assets of joint service centre, play "count immediately, immediate decision" results.
paper form data, if unwilling or unable to electronic media such as diskettes, compact discs when the backup is saved, two-dimensional bar code can be used to store backups, easy to carry, not afraid of collapse, long retention time, can be photocopied faxes, do more to back up.
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