Optimization methods for the insertion, protection, and detection of digital watermarks in digitized data
View Patent ↗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.
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.