Patent ID: 8781153
Filing Date: 2014-07-15
Classification: G06K,G07D,H04N

Abstract:
1. A method for authenticating a portion of a non-digital medium for a document, comprising: receiving at least one image of at least one first marked portion of the non-digital medium for the document, wherein the at least one image is based on a radiation generated by at least one of an ambient light source or a partially coherent light source; extracting at least one first speckle pattern of the at least one first marked portion; and using a computer arrangement, comparing the first speckle pattern of the at least one first marked portion with at least one second speckle pattern relating to the non-digital medium to determine if a similarity measure based on at least one of local descriptors or global descriptors of the first and second speckle patterns is at least one of equal to a predetermined amount or within a predetermined range, wherein the at least one first speckle pattern is based on the radiation, and wherein the at least one second speckle pattern is based on at least one of (i) the radiation or (ii) a further radiation generated by at least one of a further ambient light source or a further partially coherent light source.