Perceptability model applied to watermark signals

• US 8,098,882 B2
• Filed: 03/28/2008
• Issued: 01/17/2012
• Est. Priority Date: 04/15/2003
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Reed, Alastair M., Rogers, Eliot
• Primary Examiner(s): Mariam, Daniel
• Assistant Examiner(s): RICE, ELISA M
• Application Number:
  US12/057,745
• Publication Number:
  US 20090087018A1
• Time in Patent Office: 1,390 Days
• Field of Search: None
• 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 2201/0051 Embedding of the watermark in the spatial domain
• 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: H04N 1/32149 Methods relating to embedding, encoding, decoding, detection or retrieval operations
• CPC Class Codes: H04N 1/32192 according to calculated or estimated visibility of the additional information in the image
• CPC Class Codes: H04N 1/32229 with selective or adaptive application of the additional information, e.g. in selected regions of the image H04N1/32213 takes precedence
• CPC Class Codes: H04N 1/32309 in colour image data
• CPC Class Codes: H04N 1/3232 Robust embedding or watermarking

Abstract

This document relates generally to digital watermarking. One claim recites a method including: obtaining data representing visual media; determining a model through iteratively embedding a digital watermark signal in the data; and embedding the digital watermark signal in the data according to the model. The model maximizes robustness of the digital watermark signal while minimizing perceptibility of the digital watermark signal when the signal is embedded in the data. A new embedding form or embedding mask is created after each embedding iteration. Of course, other combinations are described and claimed as well.

Claims

1. A method comprising:

obtaining data representing visual media;

analyzing the data with a computing device to determine perceptibility attributes of the data, including applying a color image appearance model to the data to compute the perceptibility attributes based on visibility of color components within the data;

varying a digital watermark signal relative to the data with reference to the perceptibility attributes, wherein varying comprises maintaining a predetermined perceptibility quality level of the visual media across the signal, and wherein the predetermined perceptibility quality level is based at least in part on the data;

embedding the digital watermark signal in the data, wherein the digital watermark signal is varied so that modifications of the visual media to encode digital data of the digital watermark signal do not degrade the visual quality of the visual media signal beyond the predetermined perceptibility quality level.

2. The method of claim 1, wherein analyzing comprises converting the data representing visual media using color conversion.

3. The method of claim 2, wherein said analyzing further comprises performing a visibility metric analysis to compute perceptibility attribute areas within the data.

4. The method of claim 1, further comprising iteratively determining perceptibility attributes of the data after the embedding of the digital watermark signal.

5. The method of claim 4, wherein iteratively determining comprises creating a new embedding form or embedding mask after each embedding iteration.

8. The method of claim 1, wherein varying comprises varying the digital watermark signal relative to the data with reference to both the perceptibility attributes and a model of an expected rendering device.

6. A non-transitory computer-readable medium having instructions stored thereon, the instructions comprising:

instructions to obtain data representing visual media;

instructions to analyze the data to determine perceptibility attributes of the data, including applying a color image appearance model to the data to compute the perceptibility attributes based on visibility of color components within the data;

instructions to vary a digital watermark signal relative to the data with reference to the perceptibility attributes, wherein varying comprises maintaining a predetermined perceptibility quality level of the visual media across the signal, and wherein the predetermined perceptibility quality level is based at least in part on the data; and

instructions to embed the digital watermark signal in the data, wherein the digital watermark signal is varied so that modifications of the visual media to encode digital data of the digital watermark signal do not degrade the visual quality of the visual media signal beyond the predetermined perceptibility quality level.

7. The non-transitory computer readable medium of claim 6, further comprising:

instructions to iteratively determine perceptibility attributes of the data after the digital watermark signal is embedded; and

instructions to create a new embedding form or embedding mask after each iteration.

9. A method comprising:

obtaining data representing visual media;

determining, with a computing device, a model which maximizes robustness of a digital watermark signal while minimizing perceptibility of the digital watermark signal when the signal is embedded in the data, wherein determining the model includes computing visibility based on analysis of visibility of plural different color components of the visual media; and

embedding the digital watermark signal in the data according to the model,

wherein the model and a reference are used to adjust the digital watermark signal embedding in the different color components and maintain a visual quality of the visual media relative to a quality level, wherein the reference is based at least in part on the data.

10. The method of claim 9, wherein determining the model further comprises color converting the data.

11. The method of claim 9, wherein at least one of the robustness or perceptibility relies on color attributes of the data.

12. The method of claim 9, wherein determining the model further comprises iteratively embedding the digital watermark signal in the data.

13. The method of claim 12, further comprising creating a new embedding form or embedding mask after each embedding iteration.

17. The method of claim 9, wherein the model utilizes an approximation of an expected rendering device.

14. A non-transitory computer-readable medium having instructions stored thereon, the instructions comprising:

instructions to obtain data representing visual media;

instructions to determine a model which maximizes robustness of a digital watermark signal while minimizing perceptibility of the digital watermark signal when the signal is embedded in the data, wherein the instructions to determine the model include instructions to compute visibility based on analysis of plural different color components of the visual media; and

instructions to embed the digital watermark signal in the data according to the model, wherein the model and a reference are used to adjust the digital watermark signal embedding in the different color components and maintain a visual quality of the visual media relative to a quality level, and wherein the reference is based at least in part on the data.

15. The non-transitory computer-readable medium of claim 14, wherein the instructions to determine the model further comprise instructions to iteratively embed the digital watermark signal in the data.

16. The non-transitory computer-readable medium of claim 15, further comprising instructions to embed a new embedding form or embedding mask after each embedding iteration.

18. A method comprising:

obtaining data representing visual media;

determining, with a computing device, a model through iteratively embedding a digital watermark signal in the data, wherein the model maximizes robustness of the digital watermark signal while minimizing perceptibility of the digital watermark signal when the signal is embedded in the data, wherein, after each embedding iteration, a new embedding form or embedding mask is created based on analysis of visibility of plural different color components of the visual media with reference to the data; and

embedding the digital watermark signal in the data according to the model.

19. A non-transitory computer-readable medium having instructions stored thereon, the instructions comprising:

instructions to obtain data representing visual media;

instructions to determine a model through iteratively embedding a digital watermark signal in the data, wherein the model maximizes robustness of the digital watermark signal while minimizing perceptibility of the digital watermark signal when the signal is embedded in the data, wherein, after each embedding iteration, a new embedding form or embedding mask is created based on analysis of visibility of plural different color components of the visual media with reference to the data; and

instructions to embed the digital watermark signal in the data according to the model.