QR code specification and internals

The ISO/IEC 18004 machinery: versions, capacity, error correction, masks, encoding modes. Every number here is implemented and tested in our open-source core.

• How a QR code is generated, step by stepEncoding runs in eight steps: choose the mode, choose the version, build the bit stream, split into codewords, compute Reed–Solomon error correction,…
• QR code error correction levels explainedL, M, Q and H tolerate roughly 7%, 15%, 25% and 30% damage. Higher levels cost capacity, so the same payload needs a bigger version — which means smaller…