Security Document Carrying Machine Readable Pattern

• US 20100163629A1
• Filed: 06/29/2009
• Published: 07/01/2010
• Est. Priority Date: 05/08/1995
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B., Rodriguez, Tony F.
• Granted Patent: US 8,009,893 B2
• Time in Patent Office: Days
• US Class Current: 235/487
• CPC Class Codes: G06T 1/0064 Geometric transfor invariant watermarking, e.g. affine transform invariant
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: H04N 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 1/32203 Spatial or amplitude domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/32309 in colour image data
• CPC Class Codes: Y10S 283/902 Anti-photocopy

Abstract

The present invention relates generally to security documents (e.g., banknotes, ID documents, certificates, packaging, etc.). One claim recites a security document including a security pattern provided thereon. The security pattern includes a line structure in which lines width or line spacing is adjusted to convey a predefined, machine-readable pattern in a frequency transform domain. Another claim recites a security document including a security pattern provided thereon. The security pattern is provided in the security document through modifications to a color provided on the security document. The security pattern conveys a predefined, machine-readable pattern in a frequency transform domain. Of course, additional combinations and claims are provided as well.

Claims

1. A security document comprising a security pattern provided thereon, the security pattern comprises a line structure in which lines width or line spacing is adjusted to convey a predefined, machine-readable pattern in a frequency transform domain.

2. The security document of claim 1 wherein the security pattern is repeated in blocks across the security document.

3. The security document of claim 1 in which the predefined, machine-readable pattern is readable despite rotation of the security document.

4. The security document of claim 1 in which the predefined, machine-readable pattern is readable despite spatial scaling of the security document.

5. The security document of claim 1 in which the predefined, machine-readable pattern conveys a device control signal to control reproduction of the security document.

6. A security document comprising a security pattern provided thereon, the security pattern is provided in the security document through modifications to a color provided on the security document, the security pattern conveys a predefined, machine-readable pattern in a frequency transform domain.

7. The printed security document of claim 6 wherein the security pattern is repeated in blocks across the security document.

8. The security document of claim 6 in which the predefined, machine-readable pattern is readable despite rotation of the security document.

9. The security document of claim 6 in which the predefined, machine-readable pattern is readable despite spatial scaling of the security document.

10. The security document of claim 6 in which the predefined, machine-readable pattern conveys a device control signal to control reproduction of the security document.