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

• US 8,281,140 B2
• Filed: 11/23/2009
• Issued: 10/02/2012
• 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:
  US12/592,331
• Publication Number:
  US 20100077220A1
• Time in Patent Office: 1,044 Days
• Field of Search: 713/176
• 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 system for encoding at least one watermark in a content signal, comprising:

a processor for predetermining a number of bits in the content signal to be encoded, based on at least one of a fixed length key and signal characteristics of the content signal; and

an encoder for encoding the watermark in the predetermined bits.

2. The system of claim 1, wherein the processor is configured to perform said predetermining and said encoder is configured to perform said encoding.

3. The system of claim 1, further comprising programming stored in machine memory configured to result in said processor performing said predetermining and said encoder performing said encoding.

4. A system for encoding at least one watermark in a content signal, comprising:

a processor for locating at least one noise-like signal feature in the content signal; and

an encoder for encoding the at least one watermark in substantially the same location as the at least one noise-like signal feature.

5. The system of claim 4, wherein the processor is configured to perform said locating and said encoder is configured to perform said encoding.

6. The system of claim 4, further comprising programming stored in machine memory configured to result in said processor performing said locating and said encoder performing said encoding.

7. A system for encoding at least one digital watermark in a content signal comprising:

a processor for measuring a perceived signal-to-error ratio; and

an encoder for encoding the at least one watermark in a channel bound by a minimum and maximum signal-to-error level for the content signal.

8. The system of claim 7, wherein the processor is configured to perform said measuring and said encoder is configured to perform said encoding.

9. The system of claim 7, further comprising programming stored in machine memory configured to result in said processor performing said measuring and said encoder performing said encoding.

10. A system for digital watermark encode/decode comprising:

a processor for measuring a perceived signal-to-error ratio; and

an encoder for encoding at least one watermark in a signal feature that is bound by a minimum and maximum signal-to-error level for a digital signal.

11. The system of claim 10, wherein the processor is configured to perform said measuring and said encoder is configured to perform said encoding.

12. The system of claim 10, further comprising programming stored in machine memory configured to result in said processor performing said measuring and said encoder performing said encoding.

13. A method for detecting watermarks in a digital content signal, comprising:

identifying, using a processor, a plurality of signal features in the digital content signal; and

detecting, using a processor, watermark data in the identified signal features wherein the identified signal features are identified from relationships between multiple sample windows in the digital content signal.

14. The method of claim 13, wherein the signal features have logical relationships with an analog waveform represented by the digital content signal.

15. The method of claim 13, wherein the signal features comprise mathematical functions of the sample windows.

16. A system for decoding watermarks from a digital content signal, comprising:

a processor for identifying a plurality of signal features in the digital content signal; and

a decoder for decoding watermark data from the signal features wherein the signal features are identified from relationships between multiple sample windows in the digital content signal.

17. The system of claim 16, wherein the signal features have logical relationships with an analog waveform represented by the digital content signal.

18. The system of claim 16, wherein the signal features comprise mathematical functions of the sample windows.

19. The system of claim 16, wherein the processor is configured to perform said identifying and said decoder is configured to perform said encoding.

20. The system of claim 16, further comprising programming stored in machine memory configured to result in said processor performing said identifying and said decoder performing said encoding.