公开(公告)号：US09947163B2

公开(公告)日：2018-04-17

申请号：US14764061

申请日：2014-02-04

Applicant: KBA-NOTASYS SA

Inventor： Volker Lohweg ,  Jan Leif Hoffmann ,  Helene Dörksen ,  Roland Hildebrand ,  Eugen Gillich ,  Jürg Hofmann ,  Johannes Georg Schaede

IPC: G06K9/00 ,  G07D7/20 ,  G06K9/22 ,  G06K9/48 ,  G06T7/00 ,  G06T7/168 ,  G07D7/00

CPC classification number: G07D7/20 ,  G06K9/00442 ,  G06K9/00516 ,  G06K9/22 ,  G06K9/48 ,  G06K2009/488 ,  G06T7/0002 ,  G06T7/168 ,  G06T2207/20064 ,  G06T2207/30176 ,  G07D7/003 ,  G07D7/2016

Abstract: A method of authenticating security documents and a mobile device, especially a smartphone, programmed to carry out the method, based on an analysis of features which are produced by intaglio printing, which analysis involves a decomposition of sample images of a candidate document to be authenticated based on Wavelets, each sample image being digitally processed by performing a Wavelet transform of the sample image in order to derive a set of classification features. The method is based on an adaptive approach, which includes the following steps: —prior to carrying out the Wavelet transform, defining a categorization map containing local information about different intaglio line structures that are found on the security documents; —carrying out a Wavelet selection amongst a pool of Wavelet types based on the categorization map; and —performing the Wavelet transform of the sample image on the basis of the selected Wavelet.

公开(公告)号：US09900463B2

公开(公告)日：2018-02-20

申请号：US15114422

申请日：2015-01-28

Applicant: KBA-NOTASYS SA

Inventor： Jan-Friedrich Ehlenbröker ,  Volker Lohweg

IPC: H04N1/32 ,  G07D7/2033 ,  H04N1/00 ,  G07D7/005

CPC classification number: H04N1/32149 ,  G07D7/005 ,  G07D7/2033 ,  H04N1/00838 ,  H04N2201/327

Abstract: 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 optimizing some of the features which are used in standard 2D-codes for stabilization 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.