FIELD: physics; image processing.
SUBSTANCE: present invention pertains to means of protection from unauthorised copying of bank notes, bond paper, documents and also relates to the method of coding a latent image. The method involves providing the latent image to be coded, with several latent image elements, each of which has a visual characteristic which assumes values from a given set of values. The method also involves provision for a secondary pattern with several secondary image elements and capable of decoding the given latent image after coding. Compatibility is established between the latent image elements and the secondary image elements. A primary pattern is formed, containing several primary image elements, which correspond to the given secondary image elements, shifted depending on the values of the visual characteristic of latent image elements, which correspond to the given secondary image elements.
EFFECT: provision for means of protection, designed for increasing efficiency of measures against valuable documents counterfeiting.
60 cl, 26 dwg, 1 ex
Authors
Dates
2009-01-20—Published
2004-07-07—Filed