Bar code is a machine-readable optical label that can contain information about additional items. In practice, QR codes usually contain data pointing to locators, identifiers or trackers of websites or applications. Two-dimensional code uses four standardized coding modes (number, alphanumeric, byte/binary and Chinese characters) to effectively store data; You can also use extensions.
Compared with the standard UPC bar code, the rapid response system has become popular outside the automobile industry because of its fast readability and larger storage capacity. Applications include product tracking, project identification, time tracking, document management and general marketing.
QR code (two-dimensional code) is composed of black squares arranged in a square grid on a white background, which can be read by imaging devices such as cameras and processed by Reed-Solomon error correction until the image can be correctly interpreted. Then extract the required data from the patterns existing in the horizontal and vertical components of the image.
App application
Two-dimensional code, like the previous one-dimensional bar code, is widely used in commercial activities, especially in high-tech industries, storage and transportation industries, wholesale and retail industries and other industries that need to label items cheaply and quickly. In some countries and regions such as China and Japan, bar codes are as easy to generate and read as two-dimensional codes, and have become a fast and convenient way of information exchange in life.
In some provinces of the United States and Canada, as well as Hong Kong and other countries or regions, the code PDF4 17 has been adopted as the identification label and printed directly on the identification document.