Digital watermarking of tonal and non-tonal components of media signals

• US 20050025334A1
• Filed: 06/15/2004
• Published: 02/03/2005
• Est. Priority Date: 01/11/1999
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Zhu, Bin, Tewfik, Ahmed, Swanson, Mitchell D.
• Granted Patent: US 7,454,034 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 1/005 Robust watermarking, e.g. average attack or collusion attack resistant
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection
• CPC Class Codes: G06T 2201/0202 whereby the quality of watermarked images is measured; Measuring quality or performance of watermarking methods; Balancing between quality and robustness
• CPC Class Codes: G10L 19/018 Audio watermarking, i.e. embedding inaudible data in the audio signal

Abstract

A digital watermarking method performs tonal detection on a signal (e.g., audio) to identify tonal and non-tonal components. These components are analyzed to compute appropriate weighting of a digital watermark for the tonal and non-tonal components. This tonal detection method is also used in recovering the watermark. A decoding method performs tonal detection on a watermarked signal, computes weights for tonal and non-tonal components, and recovers the embedded watermark using the weights. The same or different watermark embedding schemes may be used to embed digital watermarks in the tonal and non-tonal components. Tonal analysis is used in conjunction with frequency and temporal shaping to adapt the digital watermark to the signal in which it is embedded.

Claims

1. A method of embedding a digital watermark in a signal comprising:

performing tonal detection on the signal to identify tonal components and non-tonal components;

embedding a digital watermark in the tonal and non-tonal components, including weighting the digital watermark more in the non-tonal components than the non-tonal components.

2. The method of claim 1 wherein the signal comprises audio.

3. The method of claim 1 wherein the digital watermark carries message bits and the bits are represented with pseudo-random sequences.

4. The method of claim 1 wherein the digital watermark comprises weighted pseudorandom sequences.

5. The method of claim 1 including weighting the digital watermark based on frequency shaping, temporal shaping and tonal analysis.

6. A machine readable medium having instructions for performing a method of embedding a digital watermark in a signal, the method comprising:

performing tonal detection on the signal to identify tonal components and non-tonal components;

embedding a digital watermark in the tonal and non-tonal components, including weighting the digital watermark more in the non-tonal components than the non-tonal components.

7. A method of decoding a digital watermark in a signal comprising:

performing tonal detection on the signal to identify tonal components and non-tonal components;

generating weights of the digital watermark in the tonal and non-tonal components from the tonal detection;

decoding a digital watermark from the tonal and non-tonal components, including using the weights to recover the digital watermark.

8. The method of claim 7 wherein the signal comprises audio.

9. The method of claim 7 wherein the digital watermark carries message bits and the bits are represented with pseudo-random sequences.

10. The method of claim 7 wherein the digital watermark comprises weighted pseudorandom sequences.

11. The method of claim 7 including weighting the digital watermark based on frequency shaping, temporal shaping and tonal analysis.

12. A machine readable medium comprising instructions for performing a method of decoding a digital watermark in a signal, the method comprising:

performing tonal detection on the signal to identify tonal components and non-tonal components;

generating weights of the digital watermark in the tonal and non-tonal components from the tonal detection;

decoding a digital watermark from the tonal and non-tonal components, including using the weights to recover the digital watermark.

13. A method of embedding a digital watermark in a signal comprising:

performing tonal detection on the signal to identify tonal components and non-tonal components;

embedding a digital watermark in the tonal and non-tonal components, including performing different watermark embedding methods in the non-tonal components and the non-tonal components.

14. The method of claim 13 wherein one of the watermark embedding methods uses tonal shifting to modify the tonal components to embed the digital watermark.