Digitally watermarking holograms

• US 8,355,526 B2
• Filed: 03/23/2005
• Issued: 01/15/2013
• Est. Priority Date: 04/16/1998
• Status: Expired due to Term

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Decker, Stephen K., Brunk, Hugh L., Carr, J. Scott, Rhoads, Geoffrey B., Lofgren, Neil E.
• Primary Examiner(s): Bali, Vikkram
• Application Number:
  US11/090,968
• Publication Number:
  US 20060039581A1
• Time in Patent Office: 2,855 Days
• Field of Search: 382/100, 359/2, 359/9, 358/3.28, 380/54
• US Class Current: 382/100
• CPC Class Codes: G03H 1/0011 for security or authentication holograms on information-bearing cards B42D25/328; testing papers with holograms G07D7/0032
• CPC Class Codes: G03H 1/0244 Surface relief holograms replicating hologram without interference recording G03H1/0276
• CPC Class Codes: G03H 1/041 Optical element in the object space affecting the object beam, not otherwise provided for
• CPC Class Codes: G03H 1/08 Synthesising holograms, i.e. holograms synthesized from objects or objects from hologramsusing electric digital computers G06F; G06T
• CPC Class Codes: G03H 2001/0016 Covert holograms or holobjects requiring additional knowledge to be perceived, e.g. holobject reconstructed only under IR illumination microholograms G03H2230/10
• CPC Class Codes: G03H 2001/0022 Deciphering being performed with numerical or optical key, e.g. with the optical scrambler used during recording optical element in object beam G03H1/041
• CPC Class Codes: G03H 2210/40 Synthetic representation, i.e. digital or optical object decomposition
• CPC Class Codes: G03H 2210/441 Numerical processing applied to the object data other than numerical propagation synthesizing propagation G03H1/0808
• CPC Class Codes: G06K 19/16 the marking being a hologram or diffraction grating
• CPC Class Codes: G06Q 20/341 Active cards, i.e. cards including their own processing means, e.g. including an IC or chip
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G07D 7/0032 using holograms
• CPC Class Codes: G07D 7/0034 using watermarks
• CPC Class Codes: G07F 7/08 by coded identity card or credit card or other personal identification means without personal verification means G07F7/02
• CPC Class Codes: G07F 7/086 by passive credit-cards adapted therefor, e.g. constructive particularities to avoid counterfeiting, e.g. by inclusion of a physical or chemical security-layer for security documents G07D7/00; for the reading of record-carriers in general G06K7/00; for the design of coded credit-cards G06K19/10
• CPC Class Codes: G07F 7/12 Card verification
• CPC Class Codes: H04N 1/00249 with a photographic apparatus, e.g. a photographic printer or a projector photographic apparatus per se G03B, G03D
• CPC Class Codes: H04N 2201/3215 of a time or duration
• CPC Class Codes: H04N 2201/3233 of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/3281 Encryption; Ciphering

Abstract

The present invention relates generally to digital watermarking holographic structures. One method recites: creating a computer model; executing a transform domain iterative method to convert the computer model into a holographic structure; combining a digital watermark with the holographic structure; and conveying the combined digital watermark and holographic structure to a surface. Other combinations are provided and claimed as well.

Claims

1. A method comprising:

obtaining a computer model;

performing an iterative transform domain process on a multi-purpose computer processor to convert the computer model into a holographic structure;

embedding a digital watermark into at least one of the group comprising the computer model and the holographic structure to yield a digital watermarked holographic structure; and

recording the digital watermarked holographic structure on a physical medium.

2. The method of claim 1, wherein the digital watermark comprises plural-bit information.

3. The method of claim 1, wherein the digital watermark is imperceptible to a human observer of the digital watermarked holographic structure.

4. The method of claim 1, wherein embedding the digital watermark into the holographic structure produces a composite of the digital watermark and the holographic structure.

5. The method of claim 1, wherein the computer model comprises a digital representation including an array of discrete samples corresponding to spatial locations in a two-dimensional plane.

6. The method of claim 1, wherein the digital watermark and the holographic structure are at distinct focal planes relative to each other.

7. The method of claim 1, wherein the digital watermark is embedded by applying a halftone process.

8. The method of claim 1, wherein the digital watermark is embedded by applying an error diffusion process.

9. The method of claim 1, wherein the digital watermark is embedded by applying an ordered dithering process.

10. The method of claim 1, wherein the digital watermark is embedded into the computer model prior to conversion into a holographic structure.

11. The method of claim 10, wherein the computer model represents a three dimensional model, and further wherein the digital watermark is mapped to a surface of an object represented in the three dimensional model.

12. The method of claim 11, wherein the digital watermark is mapped to the surface of the object by modulating a geometric structure of the surface of the object.

13. The method of claim 12, wherein modulating comprises creating a peak in the surface of the object to encode a one from the watermark signal, and creating a trough in the surface of the object to encode a zero.

14. The method of claim 12, wherein modulating comprises applying a binary anti-podal watermark signal, and further wherein a binary element increases or decreases data representing the geometric structure by a fixed amount.

15. The method of claim 10, wherein the computer model represents a two dimensional image, and further wherein the digital watermark is mapped to samples in a two dimensional block of the two dimensional image.

16. A non-transitory computer readable media comprising instructions stored thereon, the instructions comprising:

instructions for obtaining a computer model;

instructions for performing an iterative transform domain process on a multi-purpose computer processor to convert the computer model into a holographic structure;

instructions for embedding a digital watermark into at least one of the group comprising the computer model and the holographic structure to yield a digital watermarked holographic structure; and

instructions for recording the digital watermarked holographic structure on a physical medium.

17. The instructions of claim 16, wherein the digital watermark and the holographic structure are at distinct focal planes relative to each other.

18. The instructions of claim 16, wherein the digital watermark is embedded by applying a halftone process.

19. The instructions of claim 16, wherein the digital watermark is embedded into the computer model prior to conversion into a holographic structure.

20. The instructions of claim 19, wherein the computer model represents a three dimensional model, and further wherein the digital watermark is mapped to a surface of an object represented in the three dimensional model.

21. The instructions of claim 20, wherein the digital watermark is mapped to the surface of the object by modulating a geometric structure of the surface of the object.

22. The instructions of claim 19, wherein the computer model represents a two dimensional image, and further wherein the digital watermark is mapped to samples in a two dimensional block of the two dimensional image.

23. A digital watermark encoder comprising:

a receiver configured to obtain a computer model;

an encoder operatively coupled to the receiver and configured to;

perform an iterative transform domain process to convert the computer model into a holographic structure, and

embed a digital watermark into at least one of the group comprising the computer model and the holographic structure to yield a digital watermarked holographic structure; and

a recorder operatively coupled to the encoder and configured to record the digital watermarked holographic structure on a physical medium.

24. The digital watermark encoder of claim 23, wherein the digital watermark and the holographic structure are at distinct focal planes relative to each other.

25. The digital watermark encoder of claim 23, wherein the digital watermark is embedded by applying a halftone process.

26. The digital watermark encoder of claim 23, wherein the digital watermark is embedded into the computer model prior to conversion into a holographic structure.

27. The digital watermark encoder of claim 26, wherein the computer model represents a three dimensional model, and further wherein the digital watermark is mapped to a surface of an object represented in the three dimensional model.

28. The digital watermark encoder of claim 27, wherein the digital watermark is mapped to the surface of the object by modulating a geometric structure of the surface of the object.

29. The digital watermark encoder of claim 26, wherein the computer model represents a two dimensional image, and further wherein the digital watermark is mapped to samples in a two dimensional block of the two dimensional image.