Data Matrix is a 2D barcode symbology which consists of a rectangular array of square elements, which can signify 1 or 0 bits by being either blank or filled in (there are codings where a filled-in square can be either a 1 or a 0 bit). The size can range from 9x9 to 144x144. Many of the squares are not actually part of the main data, since some are allocated to error correction or finder and timing signals, among other things.
US Patent 5,612,524 was claimed to apply to this system, but this was defeated in the courts, and the patent is now expired at any rate.
The Data Matrix symbology was standardized in ISO/IEC 16022:2006, and other ISO documents describe related matters.
Developer libraries and modules
- zxing (Zebra Crossing) (barcode library for Java, ported to some other systems)