Optimization methods for the insertion, protection, and detection of digital watermarks in digitized data

• US 7,457,962 B2
• Filed: 08/02/2006
• Issued: 11/25/2008
• Est. Priority Date: 07/02/1996
• Status: Expired due to Fees

• Current Assignee: Wistaria Trading Inc.
• Original Assignee: Wistaria Trading Inc.
• Inventors: Moskowitz, Scott A.
• Primary Examiner(s): SMITHERS, MATTHEW
• Application Number:
  US11/497,822
• Publication Number:
  US 20070011458A1
• Time in Patent Office: 846 Days
• Field of Search: None
• US Class Current: 713/176
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 2201/0064 for copy protection or copy management, e.g. CGMS, copy only once, one-time copy

Abstract

Disclosed herein are methods and systems for encoding digital watermarks into content signals. Also disclosed are systems and methods for detecting and/or verifying digital watermarks in content signals. According to one embodiment, a system for encoding of digital watermark information includes: a window identifier for identifying a sample window in the signal; an interval calculator for determining a quantization interval of the sample window; and a sampler for normalizing the sample window to provide normalized samples. According to another embodiment, a system for pre-analyzing a digital signal for encoding at least one digital watermark using a digital filter is disclosed. According to another embodiment, a method for pre-analyzing a digital signal for encoding digital watermarks comprises: (1) providing a digital signal; (2) providing a digital filter to be applied to the digital signal; and (3) identifying an area of the digital signal that will be affected by the digital filter based on at least one measurable difference between the digital signal and a counterpart of the digital signal selected from the group consisting of the digital signal as transmitted, the digital signal as stored in a medium, and the digital signal as played backed. According to another embodiment, a method for encoding a watermark in a content signal includes the steps of (1) splitting a watermark bit stream; and (2) encoding at least half of the watermark bit stream in the content signal using inverted instances of the watermark bit stream. Other methods and systems for encoding/decoding digital watermarks are also disclosed.

Claims

1. A method for pre-processing a digital data signal to authorize a plurality of unique descendant copies of the digital data signal, comprising:

providing the digital data signal;

identifying a plurality of candidate bits in the digital data signal that can be manipulated during embedding;

generating a digital watermark message to be embedded based on at least one predetermined criterion; and

embedding the digital watermark message in the plurality of candidate bits.

2. The method of claim 1, wherein the step of identifying candidate bits of the digital data signal to be manipulated comprises:

generating a psychoacoustic model of the digital data signal.

3. The method of claim 1, wherein the step of identifying candidate bits of the digital data signal to be manipulated comprises:

generating a psychovisual model of the digital data signal.

4. The method of claim 1, wherein the digital data signal comprises compressed digital data.

5. The method of claim 1, wherein the step of generating a digital watermark message comprises:

generating a unique digital watermark message for each authorized descendant copy.

6. The method of claim 1, wherein the criterion are selected from the group consisting of a geographical territory, a transaction identification, an individual identification, a use limitation, and a signal domain.

7. The method of claim 1, wherein the digital watermark message is encoded in a subset of the plurality of candidate bits identified.

8. The method of claim 1, wherein the plurality of candidate bits that are embedded with the digital watermark message have a relationship that creates additional uniqueness of the digital watermark message.

9. The method of claim 8, wherein the relationship is at least one of a sequential relationship, a linear relationship, and a logically-ordered relationship.

10. The method of claim 1, wherein a subset of the plurality of the candidate bits share at least one function.

11. The method of claim 10, wherein the function is selected from the group consisting of mapping, error correction, and signal processing.

12. The method of claim 1 further comprising:

selectively adding noise to the digital data signal.

13. A method for pre-processing a digital data signal to authorize a plurality of unique descendant copies of the digital data signal, comprising:

providing a digital data signal;

identifying candidate bits of the digital data signal that will be manipulated during scrambling;

generating a key on at least one predetermined criterion; and

manipulating the digital data signal at the plurality of candidate bits with the scrambling key.

14. The method of claim 13, wherein the step of identifying candidate bits of the digital data signal to be manipulated comprises:

generating a psychoacoustic model of the digital data signal.

15. The method of claim 13, wherein the step of identifying candidate bits of the digital data signal to be manipulated comprises:

generating a psychovisual model of the digital data signal.

16. The method of claim 13, wherein the step of providing a digital data signal comprises providing a digital data signal comprised of compressed digital data.

17. The method of claim 13, wherein the step of generating a scrambling key comprises:

generating a unique scrambling key for each authorized descendant copy.

18. The method of claim 13, wherein the criterion are selected from the group consisting of a geographical territory, a transaction identification, an individual identification, a use limitation, and a signal domain.

19. The method of claim 13, wherein a subset of the plurality of candidate bits identified are manipulated with the key.

20. The method of claim 13, wherein the step of manipulating the digital data signal at the plurality of candidate bits with the scrambling key comprises:

manipulating the plurality of candidate bits with a key to embed a watermark and to add noise to digital signal.

21. The method of claim 20, wherein the relationship is at least one of a sequential relationship, a linear relationship, and a logically-ordered relationship.

22. The method of claim 13, wherein a subset of the plurality of the candidate bits are selected based upon their ability to survive a predetermined test of robustness.

23. The method of claim 22, wherein the function is selected from the group consisting of mapping, error correction, and signal processing.

24. A method for creating a copy of a digital data signal, comprising:

obtaining a model for the digital data signal wherein the model describes watermarking parameters;

generating a watermark for the copy of the digital data signal based on at least one criterion; and

embedding the generated watermark based on the obtained model of the digital data signal to create the copy of the digital data signal.

25. The method of claim 24, wherein the step of obtaining a model of the digital data signal comprises:

generating the psychoacoustic model for the digital data signal.

26. The method of claim 24, wherein the step of obtaining a model of the digital data signal comprises:

retrieving a stored psychoacoustic model for the digital data signal.

27. The method of claim 24, wherein the step of obtaining a model of the digital data signal comprises:

generating the psychovisual model for the digital data signal.

28. The method of claim 24, wherein the step of obtaining a model of the digital data signal comprises:

retrieving a stored psychovisual model for the digital data signal.

29. The method of claim 24, wherein the criterion are selected from the group consisting of a geographical territory, a transaction identification, an individual identification, a use limitation, and a signal domain.

30. A method for pre-processing a digital data signal, comprising:

providing a digital signal;

identifying a plurality of candidate bits in the digital data signal that can be manipulated during embedding;

generating at least one digital watermark message to be embedded based on at least one predetermined criterion;

selecting candidate bits to manipulate; and

embedding the at least one digital watermark message in the selected candidate bits.

31. The method of claim 30, wherein the at least one predetermined criterion includes at least one characteristic of the digital signal.

32. The method of claim 30, wherein the step of selecting candidate bits to manipulate comprises:

selecting candidate bits that provide optimal locations for the digital watermark.

33. The method of claim 30, further comprising the step of:

inverting at least one watermark out of a plurality of embedded watermarks.

34. The method of claim 30, further comprising the step of:

decoding the at least one digital watermark from the digital data signal.

35. The method of claim 34, wherein the step of decoding the at least one digital watermark from the digital data signal comprises:

degrading the watermarked digital data signal responsive to an unauthorized attempt to decode the digital watermark form the digital data signal.

36. The method of claim 34, wherein the step of decoding the at least one digital watermark from the digital data signal comprises:

degrading the watermarked digital signal responsive to fewer than all embedded watermarks being decoded from the digital signal.

37. The method of claim 34, wherein the step of decoding the at least one digital watermark from the digital data signal is asymmetric.

38. The method of claim 30, wherein a key corresponding each of the at least one watermark comprises a greater number of bits than the corresponding watermark message.

39. The method of claim 30, wherein a key corresponding each of the at least one watermark comprises the same greater number of bits as the corresponding watermark message.