MaxiCode
The MaxiCode was developed by United Parcel Service (UPS) in 1989 for the rapid identification, tracking and sorting of parcels. It contains the UPS control number, the weight, the type of service of the shipment and the address details and represents a 2D code .
structure
It has a fixed size of approximately 25.4 mm × 25.4 mm (1 in. × 1 in.). In the resulting area of 645 mm² (1 sq in.) 144 symbol characters, i.e. H. 93 ASCII characters or 138 digits can be encoded.
The two-dimensional pattern consists of hexagons arranged in 30 horizontal and 33 vertical rows. Including the quiet zone, the barcode size is 28.14 mm × 26.91 mm (width × height).
In the center of the code is the search pattern, which consists of three concentric circles. This enables the reading system to compensate for distortions in all three directions. 866 honeycomb hexagons are arranged in 33 rows around the search pattern. The Reed-Solomon error correction supports several user-specific levels and offers a high level of data security. Reconstruction is still possible when up to 25% of the code has been destroyed. It contains six orientation patterns on the hexagonal grid, which makes omnidirectional reading easier.
The finder pattern enables the code to be found within other printing or structures, the position, size and possible distortion of the code to be determined.
The alternating pattern specifies the density of the data cells and thus allows a grid to be set up to localize the data cells.
The data region contains the user data. An error correction method allows reading errors to be recognized and corrected. This guarantees an extremely high level of reading reliability and is relatively insensitive to interference. The individual bits (black or white cells) must be grouped into symbols according to defined rules. These are then arranged in the data region according to also defined rules.
All real matrix or area codes have these structures.
The very compact Maxicode was developed for high-speed sorting and distribution. It is also very easy to find in a very large reading field (clear search pattern). The fixed parameters and the fact that it can only be read with image processing systems are disadvantageous.