1, barcode recognition technology basic situation
Barcode recognition technology is a comprehensive technology integrating barcode theory, photoelectric technology, computer technique, communication technology and electronic mechanical technology. Barcode has the advantages of simple production, fast information collection, high accuracy, large quantity, low cost and easy to use, and so on, the basic types of barcode and the principle of recognition technology are as follows:
(1) Barcode type
At present, the bar code is mainly divided into one-dimensional code and two-dimensional code two major categories.
A one-dimensional code is an identifier in one direction (generally horizontal) consisting of a set of bars and empty widths and their corresponding characters, arranged according to certain coding rules, to represent certain information. Commonly used one-dimensional code coding rules are EAN code, UPC code, 128 yards, 39 yards, Kudba code and so on. One-dimension code is simple and intuitive, the management scheme is mature and widely used.
Two-dimensional codes are developed on the basis of one-dimensional codes, which can store information in two-dimensional two-dimensional space in both horizontal and vertical directions. Compared with one-dimensional code, two-dimensional code information capacity is large, in a two-dimensional code can store more than 1000 bytes; The information density is high, the same size of two-dimensional code can be more than 100 times times the density of one dimension code, and the recognition rate is very high.
(2) Barcode recognition technology
A barcode is a graphical identification of a set of information by arranging a plurality of black strips/blocks and white stripes/blocks of varying width/size according to certain coding rules. and the bar code information reading mainly through the reading equipment in the optical system to scan the bar code, and then through the decoding software will be the graphic identification information translated into the corresponding data, so as to achieve the bar code contains information read. According to the difference between scanning and decoding, barcode recognition technology mainly includes two kinds of laser scanning technology and image scanning technology, its basic situation is as follows:
① Laser Scanning technology
The laser scanning system consists of three parts, scanning system, signal shaping and decoding.
② Image Scanning Technology
According to the difference of image scanning dimension, image scanning technology can be divided into linear image scanning technology and image scanning technology. Linear image scanning technology can read only one dimension code, and the surface array image scanning technology can be read in one-dimensional code and two-dimensional code. At present, the surface array image scanning technology is the main development trend of image scanning technology, the following content is mainly based on the surface array image scanning technology.