METHOD OF AUTHENTICATING PRINTED PRODUCTS BY INTRODUCING LATENT INFORMATION INTO IMAGE Russian patent published in 2019 - IPC G09C5/00 G06K9/00 

FIELD: printing equipment.

SUBSTANCE: invention relates to printing industry, to a method of producing printing products requiring protection and authentication. To protect and confirm authenticity of printed products, it is proposed removal of image areas corresponding to certain part of tone range, creating a map of these sections. When rasterizing an image for seized areas, a raster structure is used with parameters different from the raster structure used for the rest of the image. To verify authenticity of printed products, rasterized image, map of image sections and control grid are compared. Control grid is a transparent base with a regular grating applied to it and having a lineature of the raster, which coincides with the line frequency used for rasterizing an image.

EFFECT: technical result consists in improvement of universality of protection, which is achieved by replacing raster structure of withdrawn tone range on structure with other parameters.

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