# QR Code Generation

The more words, the harder it is to scan

## Principle of QR code

Two-dimensional barcode/two-dimensional code can be divided into stacked/row two-dimensional barcode and matrix two-dimensional barcode. The stacked/row bar code is composed of multiple lines of truncated one-dimensional 5 bar codes. The matrix two-dimensional bar code is composed in the form of a matrix, and the position of corresponding elements in the matrix is represented by "dot" to represent binary "1". The binary 0 is represented by "null", and the permutations of "dot" and "null" form the code.

## Data representation method

A dark module represents a binary "1" and a light module represents a binary "0".

## error correcting capability

- level L : About 7% of data code words can be corrected
- level M : About 15% of data code words can be corrected
- level Q : About 25% of data code words can be corrected
- level H : About 30% of data code words can be corrected