摘要 |
There is described a new coding approach for printed document authentication, one objective of which is to increase the difficulty of copying. In addition, this new coding approach provides better performance compared to other 2D coding technologies under certain constraints. The new coding technique requires less print space in comparison to other coding techniques. This is achieved by optimising some of the features which are used in standard 2D-codes for stabilisation and which are necessary for e.g. mobile applications. Furthermore, the code can be decomposed in elementary units, or "byte-units" which can be widely spread over a text document. Such "byte-units" can in particular be used for integration in text symbols. If a document protected with such a coding is copied, at least some of these symbols will be extensively degraded by the copying process. Therefore, copy detection is intrinsically achieved thanks to the new coding technique. |