An article to understand the principle of QR code

QR code has been applied in all aspects of life nowadays, so what is the principle of QR code? Why can it become a part of our daily life? QR code is a binary code composed of 0 and 1, which is an open information storage. People use QR code generator to convert the information to be stored into 0 and 1, and then store it in the black and white squares of QR code. Why 0 and 1? Because there are too many ways of human language expression. In order to facilitate the machine to quickly recognize, the unified standard using 0 and 1 binary method can be more efficient.

So why are QR codes in black and white instead of color? This is also related to binary, that is, a small black square represents 1, and a small white square represents 0, so our common QR codes are all displayed in black and white. Of course, there are also color QR codes, which are special QR codes that have all the functions of ordinary black and white QR codes, but present a color appearance. There are also requirements for making color QR codes, that is, the foreground color must be dark, the background color must be light, and the color of the positioning point must be as similar as possible to the colors of other squares, otherwise it will affect recognition.

Before QR codes, everyone used barcodes to store data because they did not require much from the equipment, as long as there was a camera. Barcodes can be understood as one-dimensional codes, with limited information storage and can only be identified in the horizontal direction. Due to the horizontal limitation, it is difficult to expand the barcode information. QR codes change the black and white stripes into small black and white squares, increasing the amount of information storage. In addition, when reading information, it can be read from both the horizontal and vertical directions at the same time, so that more information can be added to the QR code.