As the name implies, with respect to one-dimensional bar code, the bar code and the two-dimensional bar has at least two dimensions.
If the concept of a simple plane, we prefer opposite to a direction perpendicular to the X, Y axis as the expanded code pattern.
(Supplement I, personally think that if there are two different directions can be composed of, but not really necessary vertical stick, although many standard two-dimensional barcode looks square, but in fact they can also make some of the strange appearance, such as adding a change of angle, may be out of a parallelogram of two-dimensional code pattern, if it is a function, that out of the content, or Xu Chaohu imagine)
Dimensional bar code / two-dimensional code (2-dimensional bar code) is recorded with a pattern of black and white data symbols of a particular geometry according to certain rules in a plane (two-dimensional direction) distribution; I suggest you to to understand the phrase sounds more rigorous number.
On Coding of clever use of the computer constituting the basis of internal logic "0", "1" concept bit stream, using the binary number corresponding to the geometry text numerical information represented by the image input device or optoelectronic scanning device automatic reading in order to achieve automatic processing of information : there is a little misunderstanding, I think that we should reminder, the so-called linear generation semi-quasi-two-dimensional barcode, such as PDF, RSS code and so on. The bar code although it can reach the technical elements of the two-dimensional code, but in the image processing computer system is totally two different concepts, mainly because by the time limitations of technical conditions, this time is the 1980s, come on famous the Symbol's laser bar code scanning scheme, although earlier laser emission from the SP companies, so that Symbol's laser scanning technology as the core technology to become mainstream applications, relative to the level of laboratory research is still CCD image sensor, this higher degree of commercial programs. Until CMOS technology, which dramatically reduces the threshold of commercial applications, image processing based on the two-dimensional matrix codes who have played.
Some two-dimensional code having a common bar code technology: each code system has its specific character set; each character occupies a certain width; checksum has a certain function. It also has the function of automatic identification information different rows, and graphic processing and so rotation changes.
Dimensional bar code / two-dimensional code information can be expressed simultaneously in both horizontal and vertical orientations, it is possible to express large amounts of information in a small area.
Because of these features above, two-dimensional code has a certain carrying capacity off-line information and skills for the development of regional economic ideographic characters, such as Chinese, Japanese, Korean, and entrance into a new URL information and other options for personal mobility equipment usage scenarios, including its small size, as well as during the CMOS optical and reduce the cost of processing chip, in traditional industries become consider replacing the one-dimensional application of choice and so these factors, resulting in the current year 2020, two-dimensional code to show a very strong market vitality.
