Overview of 2d barcode:
Bar codes that store information in two dimensions, both horizontal and vertical, are called two dimensions bar codes.
Mature standards: China has selected compact matrix code (CM code for short) and grid matrix code (GM code for short) as national standards, and GM/CM is the first 2d barcode standard for independent intellectual property rights in China.
Storage capacity: compared with the very low storage capacity of one-dimensional bar code, two-dimensional bar code can store more than 1KB of information, and the storage capacity per unit area of CM can even reach 32KB.
High information density: in a small graphics, can store the number, English, Chinese characters, fingerprints, sound and pictures and other information.
■ fast acquisition speed: the reading speed is below 300MS.
Strong error correction ability: bar code can still be read under the condition of 50% contamination.
■ bit error rate is extremely low. The decoding error rate of common bar codes is about 2 parts per million, and the bit error rate of two-dimensional bar codes is less than 1 part per million, so the decoding reliability is very high.
■ information can be encrypted. 2d bar code has multiple security features, it can use password security, software encryption and the use of the information contained such as fingerprints, photos for security, so it has a strong security performance.
■ wide application. Logistics, goods, security, sporting goods labels and so on.
Along with the development of the information automatic identification technology, with a bar code symbol said more information demand is growing, and length of one-dimensional bar code data is usually not more than 15 characters, therefore, how to keep the Key index (Key), only can be used as a data identification, description of product is not, so need to grab more items of data through the network to the database, so in the absence of a network or database, a one-dimensional bar code will lose their meaning. In addition, one dimension bar code has an obvious disadvantage, that is, the vertical direction does not carry data, so the data density is low.
3. Differences between the two:
One dimensional code: one dimensional code is composed of vertical black and white strips, black and white, and the thickness of the stripes are also different, usually with English letters or Arabic numerals under the stripes.
Two-dimensional code: two-dimensional code is usually a square structure, not only composed of horizontal and vertical bar code, and there will be a polygonal pattern in the code area, the same two-dimensional code texture is black and white, different thickness, two-dimensional code is a lattice form!
One-dimensional code: can identify the basic information of the commodity, such as the commodity name, price, etc., but can not provide more detailed information of the commodity, to call more information, need the further cooperation of the computer database.
Qr code: not only has the distinguishing function, but also can display the more detailed commodity content. For example, clothes can not only show the name and price of clothes, but also show what materials are used, the percentage of each material, the size of clothes, suitable for how much height people wear, as well as some washing precautions, without the cooperation of a computer database, simple and convenient.