QR code is a type of barcode that can be easily read by digital devices, which stores information as a series of pixels in a rectangular grid.
QR codes are often used to track information about products in the supply chain and because many smartphones have built-in QR readers, they are often used in marketing and advertising campaigns. More recently, it has played a key role in helping to track coronavirus exposure and slow the spread of the virus.
QR code is a two-dimensional graphic block containing a monochromatic pattern that represents a sequence of data. QR codes are designed to be scanned or scanned by cameras, including cameras found in mobile phones, and are often used to encode Digital Asset Wallet addresses.
QR codes can be used for a variety of purposes, but there are four widely accepted versions of the QR code.
The version used determines how the data can be stored and is called the “input mode”. It can be numeric, alphanumeric, binary, or kanji. The mode type is communicated through the version information field in the QR code.
- Numerical mode – This is for decimal numbers 0 to 9. Numerical mode is the most effective storage mode, with up to 7,089 characters available.
- Alphanumeric mode – This is for digital decimals 0 to 9, plus uppercase letters A to Z, and the symbols $, %, *, +, –, ., /, and : and spaces. This allows up to 4,296 characters to be stored.
- Byte mode – This is for characters from the ISO–8859–1 character set. This allows 2,953 characters to be stored.
- Kanji Mode – This is for double-byte characters from the JIS Shift character set and is used to encode characters in Japanese. This is the original mode, first developed by Denso Wave. However, it has since become the least effective, with only 1,817 characters available for storage. A second kanji mode called the Extended Channel Interpretation (ECI) mode can define the UTF–8 kanji character set. However, some newer readers of this code will not be able to read this character set.