AUTHENTICATION PROTECTED DOCUMENTS, IN PARTICULAR BANKNOTES Russian patent published in 2015 - IPC G07D7/20 

FIELD: printing.

SUBSTANCE: invention relates to authentication of security documents, in particular banknotes. In the method and device the security documents comprise security elements (41-49; 30; 10; 51, 52) printed, applied or otherwise provided on security documents and comprising the specific visual elements inherent in the processes used for manufacturing security documents with different quality of printing. In the method, the digital processing of sample image of at least one test site on the surface of the document tested to authenticity is carried out, at that the test site covers at least part of the security elements, and digital processing comprises performing decomposition of sample image by the wavelet transforming (WT) of the said sample image. This decomposition of sample image is based on wavelet packet transforming (WPT) of the said sample image, preferably on a two-dimensional invariant transformation of WPT relative to shift (2D-SIWPT).

EFFECT: providing a test of distinctive features of texture of printing.

29 cl, 16 dwg