IMAGE AUTHENTICATION USING SURFACE DEFORMATION CHARACTERISTICS

A method for printing an image with authentication features, including: printing a media treatment material onto a print medium in accordance with a pattern of predefined authentication features, and printing one or more visible printing materials onto the print medium in accordance with an image pattern, thereby providing a printed visible image. The media treatment material, the one or more visible printing materials and the print medium interact to produce surface deformations of the print medium. Characteristics of the surface deformations are different in image regions where the media treatment material was printed than in image regions where the media treatment material was not printed, so that the difference between the characteristics of the surface deformations causes the pattern of authentication features to be detectable.