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What is the two-dimensional bar code classification?

Release Time:2020-07-21

Two-dimensional bar code refers to the one-dimensional bar code on the basis of the expansion of another dimensional readable bar code. The width of the one-dimensional bar code records the data, and its length is not recorded data. The length and width of the two-dimensional bar code are recorded data.

　　

 

Two-dimensional code classification:

There are many types of two-dimensional bar codes, and the two-dimensional bar codes developed by different institutions have different structures and methods of writing and reading. Common two-dimensional bar codes are: QR code, PDF417 code and DM code.

Two-dimensional code features:

Two-dimensional bar code records more data than one-dimensional bar code, two-dimensional bar code is a high-density, high information content of portable data files, is to achieve documents and cards and other large-capacity, high-reliability information automatic storage, carrying and available machine automatic reading of the ideal means. And can record more complex data, such as pictures.

(1) Large information capacity

Depending on the bar space ratio, 250 to 1100 characters per square inch can be accommodated. On the effective area of the international standard card (equivalent to 2/3 of the credit card area, about 76mm * 25mm), the two-dimensional code bar code can accommodate 1848 alphabetic characters or 2729 numeric characters, and about 500 Chinese character information. This two-dimensional bar code is dozens of times higher than the ordinary bar code information capacity.

(2), a wide range of coding

The two-dimensional code barcode can encode all digital information such as photos, fingerprints, palm prints, signatures, sounds, and text.

(3), confidentiality, anti-counterfeiting performance is good.

The two-dimensional code bar code has multiple anti-counterfeiting characteristics, it can use password anti-counterfeiting, software encryption and the use of information such as fingerprints, photos and other anti-counterfeiting, so it has a strong security anti-counterfeiting performance.

(4), high reliability of decoding

The decoding error rate of ordinary bar codes is about two parts per million, while the error rate of two-dimensional bar codes does not exceed one in ten million, and the decoding reliability is extremely high.

(5), the ability to correct errors

The two-dimensional code bar code adopts the most advanced mathematical error correction theory in the world. If the damaged area does not exceed 50%, the lost information of the bar code due to contamination, damage, etc. can be decoded as usual.

(6), easy to produce and low cost

Using the existing dot matrix, laser, inkjet, thermal/thermal transfer printing, business card printing and other printing technology, you can print two-dimensional bar code on paper, card, PVC, and even metal surface. The increased cost is only the cost of ink, so people also called two-dimensional code is a "zero cost" technology.

(7), the shape of the bar code symbol is variable

The same amount of information, the shape of the two-dimensional code bar code can be adjusted according to the carrier area and art design.

The two-dimensional code bar code is of great promotion value in our country: the two-dimensional bar code has the advantages of low cost, information can be moved with the carrier, does not depend on the database and computer network, and has strong security and anti-counterfeiting performance. Combined with the characteristics of China's large population, weak foundation, great difficulty in investing funds in computer network, and higher requirements for anti-counterfeiting measures of certificates.