Multi-color 2D datamatrix codes with poorly readable colors

Abstract

Datamatrix code is a type of 2D codes that can encode much more data on the same or smaller area than the linearbarcodes. This makes 2D codes usable for marking even very small items. 2D codes can be decoded by thereaders in retails but also with the mobile phones equipped with camera and appropriate software. 2D codes canbe depicted in different materials or printed on different printing substrates. The application area of the codes isbroad, from magazines and newspapers to posters and packaging. Successful reading of 2D codes is possible ifthe code is printed in appropriate contrast between the printing ink and substrate, like black ink printed on whitematt paper. Problems can occur if the code is printed in colors. The readability of 2D Datamatrix codes printed incyan, magenta, yellow and black was studied. Yellow is proved to be poorly readable. In addition, the bi-coloredand multi-colored 2D Datamatrix codes were studied. When four colors are used in creation of the 2D Datamatrixcode, poorly readable elements, yellow codewords, may cause the reading failure. 2D Datamatix codes are capableto ensure good readability even if they contain a defined number of poorly readable codewords due to the Reed –Solomon error-correction system. The aim of the study was to investigate the effect of using yellow printed, poorlyreadable, codewords in the multi-colored 2D Datamatrix code on the code readability.

Keywords

• 2D Datamatrix codes
• readability
• raster tone values
• multi-colored codes
• error-correction system
• poorly readable codewords