Method and system for embedding message data in a digital image sequence

• US 6,870,931 B2
• Filed: 12/13/2000
• Issued: 03/22/2005
• Est. Priority Date: 12/13/2000
• Status: Active Grant

• Current Assignee: Monument Peak Ventures, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Eastman Kodak Company
• Inventors: Rabbani, Majid, Honsinger, Chris W., Jones, Paul W.
• Primary Examiner(s): Vu, Kim
• Assistant Examiner(s): Son, Linh L D
• Application Number:
  US09/735,783
• Publication Number:
  US 20020094082A1
• Time in Patent Office: 1,560 Days
• Field of Search: 380/216, 380/200, 380/201, 380/217, 380/219, 713/176
• US Class Current: 380/219
• CPC Class Codes: G06T 1/0071 using multiple or alternating watermarks
• CPC Class Codes: G06T 1/0085 Time domain based watermarking, e.g. watermarks spread over several images
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0061 Embedding of the watermark in each block of the image, e.g. segmented watermarking

Abstract

A method for embedding message data in a digital image sequence having two or more frames, includes the steps of: providing a dispersed message image representative of the message data; and adding spatially shifted versions of the dispersed message image to successive frames of the digital image sequence.

Claims

1. A method for embedding message data in an image sequence having two or more frames, comprising the steps of:

a) providing a dispersed message image representative of the message data;

b) producing a cyclically shifted version of the dispersed message image corresponding to a spatial offset;

c) combining the cyclically shifted version of the dispersed message image with a frame of the image sequence; and

d) repeating steps b) and c) for one or more additional frames of the image sequence.

2. The method claimed in claim 1, wherein the step of producing a cyclically shifted version of the dispersed message image includes the steps of:

a1) producing a message image representing the message data;

a2) providing a carrier image;

a3) convolving the message image with the carrier image to produce a dispersed message image; and

a4) cyclically shifting the dispersed message image by a spatial offset to produce a cyclically shifted version of the dispersed message image.

3. The method claimed in claim 1, wherein the cyclically shifted dispersed message images are not visible when added to the frames of the image sequence.

4. The method claimed in claim 2, wherein the carrier image has random phase and substantially flat Fourier amplitude.

5. The method claimed in claim 1 wherein the cyclically shifted versions of the dispersed message image are shifted randomly for successive frames.

6. The method claimed in claim 1, further comprising the steps of:

e) determining the spatial shift corresponding to each cyclically shifted version of the dispersed message image in a plurality of frames;

f) aligning the plurality of frames based on the determined spatial shifts corresponding to the respective dispersed message images and combining the aligned frames to produce a combined frame; and

g) extracting the message image from the combined frame.

7. The method claimed in claim 2, further comprising the steps of:

e) determining the spatial shift corresponding to each cyclically shifted version of the dispersed message image in a plurality of frames;

f) aligning the plurality of frames based on the determined spatial shifts corresponding to the respective dispersed message images and combining the aligned frames to produce a combined frame; and

g) extracting the message image from the combined frame by correlating the carrier image with the combined frame.

15. The method claimed in claim 1, wherein the step of producing a cyclically shifted version of the dispersed message image includes the steps of:

a1) producing a message image representing the message data;

a2) cyclically shifting the message image by a spatial offset to produce a cyclically shifted message image;

a3) providing a carrier image; and

a4) convolving the cyclically shifted message image with the carrier image to produce a cyclically shifted version of the dispersed message image.

16. The method claimed in claim 1, wherein the step of producing a cyclically shifted version of the dispersed message image includes the steps of:

a1) producing a message image representing the message data;

a2) providing a carrier image;

a3) cyclically shifting the carrier image by a spatial offset to produce a cyclically shifted carrier image; and

a4) convolving the message image with the cyclically shifted carrier image to produce a cyclically shifted version of the dispersed message image.

8. A system for embedding message data in an image sequence having two or more frames, comprising:

a) means for providing a dispersed message image representative of the message data;

b) means for producing a cyclically shifted version of the dispersed message image corresponding to a spatial offset;

c) means for combining the cyclically shifted version of the dispersed message image with a frame of the image sequence; and

d) means for repeating initiating repetition of the means for producing and means for combining.

9. The system claimed in claim 8, wherein the means for producing a cyclically shifted version of the dispersed message data image includes:

a1) means for producing a message image representing the message data;

a2) means for providing a carrier image;

a3) means for convolving the message image with the carrier image to produce the dispersed message image; and

a4) means for cyclically shifting the dispersed message image by a spatial offset to produce a cyclically shifted version of the dispersed message image.

10. The system claimed in claim 8, wherein the cyclically shifted versions of the dispersed message image are not visible when added to the frames of the image sequence.

11. The system claimed in claim 9, wherein the carrier image has random phase and substantially flat Fourier amplitude.

12. The system claimed in claim 8 wherein the means for cyclically shifting the dispersed message image employs random spatial shifts.

13. The system claimed in claim 8, further comprises:

e) means for determining the spatial shift corresponding to each cyclically shifted version of the dispersed message image in a plurality of frames;

f) means for aligning the plurality of frames based on the determined shift applied spatial shifts corresponding to the respective dispersed message images and combining the aligned frames to produce a combined frame; and

g) means for extracting the message image from the combined frame.

14. The system claimed in claim 9, further comprises:

e) means for determining the spatial shift corresponding to each cyclically shifted version of the dispersed message image in a plurality of frames;

f) means for aligning the plurality of frames based on the determined spatial shifts corresponding to the respective dispersed message images and combining the aligned frames to produce a combined frame; and

g) means for extracting the message image from the combined frame by correlating the carrier image with the combined frame.