How is information stored in and read from a QR code?



How is information stored in and read from a QR code?

In: Technology

A QR code is an image that represents a binary code (black block = 1, white block = 0).

This binary code can represent text by associating each text character with a number. For example, in ASCII, the character ‘h’ is assigned the number 104, which is 1101000 in binary. So you’d have [black, black, white, black, white, white, white] in the QR code.

So then you can make the QR code represent a URL. A QR code that seems to be storing information is probably a URL pointing to a website that’s doing the work.

The black dots and white dots represent binary bits 1 and 0 respectively.
Every 8 bits makes a byte, and a byte can hold one character (it can do other things but don’t worry about it)

Usually it will only hold small bits of info like phone numbers or URLs, and then direct you to the website with more info.

There are little squares in three of the corners, so that it can be determined if the image is distorted or rotated. And by knowing where the squares should be, it can compensate for that.
It really is quite robust.