The Aztec barcode was developed in 1995 by Andrew Longacre, Jr. and Robert Hussey. Its name is derived from the similarity of the barcode’s central “finder” pattern to square, multi-stepped Aztec pyramids. While it was originally patented by Longacre and Hussey, the patent was made public domain in 2008 and is now registered as ISO/IEC 24778:2008 which defines the requirements for developing both the barcode itself and devices capable of reading this barcode.
The Aztec barcode is classified as “2D,” meaning information is encoded across two dimensions — horizontal and vertical. Because of its unique central pattern, the Aztec barcode type is often smaller than similar 2D barcodes because it doesn’t require a “quiet zone” of white space before the black barcode data begins.
Encoding Aztec barcodes requires six steps:
- Converting source message data to a string of bits.
- Calculating the needed symbol and barcode size which in turn determines the Reed-Solomon codeword values.
- Bit-stuffing the message using Reed-Solomon codewords.
- Creating a codeword boundary.
- Applying check codewords for verification.
- Distributing the message in a spiral pattern around the core.