Methods and apparatus to produce security documents
First Claim
1. A method of producing a marked object comprising pressing a member into a substrate thereby forming a pattern in the substrate, said pattern having plural bits of binary data steganographically encoded therein, said pressing resulting in encoding of the substrate from which said plural bits of binary data can be decoded.
7 Assignments
0 Petitions
Accused Products
Abstract
Security documents (e.g. passports, currency, event tickets, and the like) are encoded to convey machine-readable multi-bit binary information (e.g., a digital watermark), usually in a manner not alerting human viewers that such information is present. The documents can be provided with overt or subliminal calibration patterns. When a document incorporating such a pattern is scanned (e.g. by a photocopier), the pattern facilitates detection of the encoded information notwithstanding possible scaling or rotation of the scan data. The calibration pattern can serve as a carrier for the watermark information, or the watermark can be encoded independently. In one embodiment, the watermark and the calibration pattern are formed on the document by an intaglio process, with or without ink. A photocopier responsive to such markings can take predetermined action if reproduction of a security document is attempted. A passport processing station responsive to such markings can use the decoded binary data to access a database having information concerning the passport holder. Some such apparatuses detect both the watermark data and the presence of a visible structure characteristic of a security document (e.g., a printed seal of the document'"'"'s issuer).
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Citations
20 Claims
- 1. A method of producing a marked object comprising pressing a member into a substrate thereby forming a pattern in the substrate, said pattern having plural bits of binary data steganographically encoded therein, said pressing resulting in encoding of the substrate from which said plural bits of binary data can be decoded.
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6. An apparatus to produce a security document, comprising:
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a press; and a member to form a pattern, said pattern including plural bits of binary data encoded therein, wherein said press is operable to press a substrate and said member together, and wherein pressing the substrate and said member results in textured encoding of the substrate to include the pattern from which the plural bits of binary data can be decoded. - View Dependent Claims (7, 8, 9)
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10. A security document comprising a first surface including:
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a pattern provided in the first surface, the pattern provided in the first surface such that is conveys a machine-readable code, the machine-readable code being readable from optical scan data representing at least a portion of the pattern, and the machine-readable code is generally imperceptible to a human viewer of the security document. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification