Understanding Quick Response (QR) Codes
A Quick Response (QR) code is a two-dimensional barcode invented in 1994 by Masahiro Hara from the Japanese company Denso Wave. Unlike standard barcodes that store data horizontally across lines, QR codes store information in both horizontal and vertical directions.
Error Correction Levels
QR codes use Reed-Solomon error correction to restore data if the code is damaged, dirty, or partly obscured. The 4 standard levels are:
- Level L: Up to 7% error recovery
- Level M: Up to 15% error recovery
- Level Q: Up to 25% error recovery
- Level H: Up to 30% error recovery