Patent ID: 9602719
Date: 2017-03-21
CPC Classifications: G06K,G07D,H04N

Claim:
1. A method comprising: capturing a series of images of a print medium using an imaging device, a first plurality of illumination sources located around a surface of the imaging device, and a second plurality of illumination sources located below the surface of the imaging device, wherein capturing each image in the series of images includes turning on a different combination of the first and second pluralities of illumination sources and capturing the respective image of the print medium through the surface of the imaging device, the series of images corresponding to different orientations of the print medium relative to the first and second pluralities of illumination sources; generating, by a processor, a forensic signature for the print medium using the series of images, resulting in the forensic signature of the print medium being orientation invariant; and outputting the forensic signature for the print medium.