Patent ID: 8638476
Filing Date: 2014-01-28
Classification: G06F,G06K,G07D,H04N,Y10S

Abstract:
1. A document identification method, comprising: a step of generating an image comprising a matrix of black dots separated by a plain other color, said matrix not being readable with the naked eyes; a step of marking a plurality of documents to form said image on each document of said plurality of document with unique variations on each document, the majority of the images formed on said documents presenting a physical anti-copy characteristic satisfying a pre-defined criterion such that said characteristic of the majority of the copies that can be produced based on these images do not satisfy said predefined criterion; for each document of said plurality of documents, a step of characterizing said variations using frequency analysis to determine a unique imprint representative of a frequency spectrum of the image marked on said document; and a step of memorizing said unique imprint.