Out of Phase Digital Watermarking in Two Chrominance Directions

• US 20100150396A1
• Filed: 12/09/2009
• Published: 06/17/2010
• Est. Priority Date: 12/17/2008
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Reed, Alastair M.
• Granted Patent: US 8,199,969 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0021 Image 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 2207/10024 Color image
• CPC Class Codes: G06T 2207/20224 Image subtraction
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: H04B 1/3833 Hand-held transceivers
• CPC Class Codes: H04N 9/68 for controlling the amplitude of colour signals, e.g. automatic chroma control circuits H04N9/71, H04N9/73 take precedence; camera processing pipelines for controlling the colour saturation of colour signals H04N23/86

Abstract

The present invention relate generally to digital watermarking. One claim recites an apparatus comprising: electronic memory for buffering a color video signal comprising a first frame and a second frame; and one or more electronic processors programmed for: transforming a first color channel and a second color channel of the first frame by hiding a digital watermark in the first color channel such that the first digital watermark includes a first signal polarity, and hiding the digital watermark in the second color channel such that the digital watermark includes a second signal polarity that is inversely related to the first signal polarity; transforming a first color channel and a second color channel of the second frame by hiding a digital watermark in the first color channel such that the first digital watermark includes the second signal polarity, and hiding the digital watermark in the second color channel such that the digital watermark includes the first signal polarity. Of course, different combinations and claims are provided too.

Claims

1. A method comprising:

receiving a color video signal comprising a first frame and a second frame;

transforming the first frame by separating the first frame into at least first data representing a first color channel of the first frame and second data representing a second color channel of the first frame, in which the first data representing a first color channel of the first frame comprises a digital watermark signal embedded therein with a first signal polarity and the second data representing a second color channel of the first frame comprises the digital watermark signal embedded therein with a second signal polarity that is inversely related to the first signal polarity of the digital watermark signal in the first data;

transforming the second frame by separating the second frame into at least third data representing a first color channel of the second frame and fourth data representing a second color channel of the second frame, in which the third data representing a first color channel of the second frame comprises the digital watermark signal embedded therein with the second signal polarity and the fourth data representing a second color channel of the second frame comprises the digital watermark signal embedded therein with the first signal polarity;

subtracting the third data from the first data to yield first subtracted data;

subtracting the fourth data from the second data to yield second subtracted data;

subtracting the second subtracted data from the first subtracted data to yield third subtract data;

using one or more programmed electronic processors, analyzing the third subtracted data to detect the digital watermark signal;

once detected, providing information associated with the digital watermark signal.

2. A computer readable medium comprising instructions stored thereon to cause one or more electronic processors to perform the method of claim 1.

3. The method of claim 1 in which the digital watermark signal comprises an orientation signal, and said act of analyzing utilizes the orientation signal to detect the digital watermark signal.

4. The method of claim 1 in which said acts of subtracting increase the digital watermark signal-to-video ratio.

5. The method of claim 1 in which said acts of subtracting decrease video interference for said act of analyzing.

6. The method of claim 1 in which the digital watermark signal comprises a plural-bit message or payload.

7. The method of claim 6 in which said act of providing information associated with the digital watermark signal provides the message or payload to a remote database.

20. A programmed computing device comprising instructions to cause said programmed computing device to perform the method of claim 1.

8. An apparatus comprising:

electronic memory for buffering a color video signal comprising a first frame and a second frame;

one or more electronic processors programmed for;

i) transforming the first frame by separating the first frame into at least first data representing a first color channel of the first frame and second data representing a second color channel of the first frame, in which the first data representing a first color channel of the first frame comprises a digital watermark signal embedded therein with a first signal polarity and the second data representing a second color channel of the first frame comprises the digital watermark signal embedded therein with a second signal polarity that is inversely related to the first signal polarity of the digital watermark signal in the first data;

ii) transforming the second frame by separating the second frame into at least third data representing a first color channel of the second frame and fourth data representing a second color channel of the second frame, in which the third data representing a first color channel of the second frame comprises the digital watermark signal embedded therein with the second signal polarity and the fourth data representing a second color channel of the second frame comprises the digital watermark signal embedded therein with the first signal polarity;

iii) subtracting the third data from the first data to yield first subtracted data;

iv) subtracting the fourth data from the second data to yield second subtracted data;

v) subtracting the second subtracted data from the first subtracted data to yield third subtract data;

vi) analyzing the third subtracted data to detect the digital watermark signal;

vii) once detected, providing information associated with the digital watermark signal.

9. The apparatus of claim 8 in which said one or more electronic processors are operating to perform at least one of the functions recited therein.

10. The apparatus of claim 9 in which the digital watermark signal comprises an orientation signal, and said act of analyzing utilizes the orientation signal to detect the digital watermark signal.

11. The apparatus of claim 8 in which said functions of subtracting increase the digital watermark signal-to-video ratio.

12. The apparatus of claim 8 in which said functions of subtracting decrease video interference for said act of analyzing.

13. The apparatus of claim 8 in which the digital watermark signal comprises a plural-bit message or payload.

14. The apparatus of claim 13 in which said providing information associated with the digital watermark signal provides the message or payload to a remote database.

15. An apparatus comprising:

electronic memory for buffering a color video signal comprising a first frame and a second frame;

one or more electronic processors programmed for;

transforming a first color channel and a second color channel of the first frame by hiding a digital watermark in the first color channel such that the first digital watermark includes a first signal polarity, and hiding the digital watermark in the second color channel such that the digital watermark includes a second signal polarity that is inversely related to the first signal polarity,

transforming a first color channel and a second color channel of the second frame by hiding a digital watermark in the first color channel such that the first digital watermark includes the second signal polarity, and hiding the digital watermark in the second color channel such that the digital watermark includes the first signal polarity.

16. The apparatus of claim 15 in which said one or more electronic processors are operating to perform at least one of the functions recited therein.

17. A method comprising:

receiving a color video signal comprising at least a first frame and a second frame;

using one or more programmed electronic processors, transforming a first color channel and a second color channel of the first frame by hiding a digital watermark in the first color channel of the first frame such that the first digital watermark includes a first signal polarity, and hiding the digital watermark in the second color channel of the second frame such that the digital watermark includes a second signal polarity that is inversely related to the first signal polarity; and

using one or more programmed electronic processors, transforming a first color channel and a second color channel of the second frame by hiding a digital watermark in the first color channel of the second frame such that the first digital watermark includes the second signal polarity, and hiding the digital watermark in the second color channel of the second frame such that the digital watermark includes the first signal polarity.

18. A computer readable medium comprising instructions stored thereon to cause one or more electronic processors to perform the method of claim 17.

19. A programmed computing device comprising instructions to cause said programmed computing device to perform the method of claim 17.