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AssigneeDigimarc Corporation
InventorGeoffrey B. Rhoads
Estimating the term…
Machine readable data is digitally watermarked into banknotes by slight alterations to ink color, density, distribution, etc., or by texturing the microtopology of the banknote surface. Such watermarking can be optically sensed and detected by scanners, photocopiers, or printers. In response, such devices can intervene to prevent banknote reproduction. This arrangement addresses various problems, e.g., the use of digital image editing tools to circumvent prior art banknote anti-copy systems. In some embodiments, visible structures characteristic of banknotes are also detected (e.g. by pattern recognition analysis of image data), and reproduction can be halted if either the visible structures or the digital watermark data are detected. In other embodiments, automatic teller machines that accept, as well as dispense, banknotes can check for the presence of digitally watermarked data to help confirm the authenticity of banknotes input to the machines. In other embodiments, scanners, printers and photocopiers can be provided with digital watermarking capabilities so that image data, or printed output, produced by such devices includes digital watermark data, permitting subsequent identification of the particular device used.
A method of producing a banknote having digital data encoded therein, the method comprising:
A method of enhancing the security of a banknote, the method including digitally watermarking a banknote with machine readable, generally imperceptible, digital data, characterized by generating a pattern corresponding to said digital data, and physically texturing the surface of the banknote in accordance with said pattern, said texturing being independent of printing on the banknote.
A method of producing a security document having digital data encoded therein comprising:
A method of producing a security document having digital data encoded therein, the method comprising:
The method of claim 40 in which the calibration signal is adapted to facilitate deconding of the digital data from the encoded security document notwithstanding rotation.
Dependencies are inferred from the claim text.