Detecting embedded information in images

• US 6,754,365 B1
• Filed: 02/16/2000
• Issued: 06/22/2004
• Est. Priority Date: 02/16/2000
• Status: Expired due to Fees

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Wen, Xin, Honsinger, Chris W.
• Primary Examiner(s): Boudreau, Leo
• Assistant Examiner(s): Miller, Ryan J.
• Application Number:
  US09/505,327
• Time in Patent Office: 1,588 Days
• Field of Search: 382/100, 382/232, 382/278, 713/176, 380/210, 380/252, 380/287
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0078 using multiple thresholds
• CPC Class Codes: G06T 2201/0061 Embedding of the watermark in each block of the image, e.g. segmented watermarking
• CPC Class Codes: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection

Abstract

A method of detecting an embedded message in a digital image, the embedded message being embedded in periodic blocks in the image, including the steps of: selecting a first area in the digital image; selecting a second area in the digital image; performing a correlation between the first and the second image areas; and if the correlation exceeds an predetermined threshold value at at least one pixel location, producing a signal indicating the existence of embedded message in the digital image.

Claims

1. A method of detecting an embedded message in a digital image, the embedded message being embedded in periodic blocks in the image, the method comprising the steps of:

a) providing a plurality of stored properties from different manufacturers;

b) selecting a first area in the digital image;

c) selecting a second area in the digital image;

d) performing a correlation between the first and the second image areas; and

e) if the correlation exceeds a predetermined threshold value at at least one pixel location, measuring a property of the embedded image and comparing the measured property to at least one of the stored properties, and, if the measured property is the same as the stored property, producing a signal indicating the existence of the embedded message within the digital image.

2. The method of claim 1 wherein the correlation between the first image and the second image areas is performed in two-dimensions;

and wherein the second area in the digital image is different than the first image area, and the correlation of step d) is not an autocorrelation.

3. The method of claim 1 wherein a same area is selected for the first and the second image areas in the digital image, thereby providing an autocorrelation of the area.

4. The method of claim 1 wherein there are at least two digital images and the first image and the second image areas are selected from the two different digital images.

5. The method of claim 1 wherein the signal is produced when the correlation exceeds the predetermined threshold value at a plurality of pixel locations.

6. The method of claim 5 wherein the plurality of pixel locations are distributed in a one-dimensional or a two-dimensional array.

7. The method of claim 6 wherein when the correlation does not exceed the predetermined threshold value at at least one pixel location, no embedded message is detected and detection ends.

8. The method of claim 1 wherein the digital image is scanned and digitized by a scanner from an image printed on a receiver.

9. The method of claim 8 wherein the correlation exceeds the predetermined threshold value at a plurality of locations and such plurality of locations are distributed in a one-dimensional or a two-dimensional array.

10. The method of claim 9 wherein in step d), where the correlation exceeds a predetermined threshold value at a plurality of the pixel locations, detecting whether these pixel locations are distributed in a periodic array, and, if they are not, ending the method.

11. The method of claim 1 wherein the signal is employed to generate a warning that the image may be copyright protected.

12. The method of claim 1 wherein the signal is used to restrict the use of the digital image without proof of proper authorization.

13. The method of claim 1 further including the step of sending a notification to a copyright holder requesting permission for the use of copyright images.

14. The method of claim 13 wherein the step of sending the message to the copyright holder includes sending the message to an electronic address associated with the copyright holder.

15. The method of claim 13 wherein the step of sending the message to the copyright holder includes pre-storing properties of the correlation functions from different manufacturers, determining the manufacturer whose embedding software produced the embedded message using the pre-stored properties, and sending the message to the manufacturer.

16. The method of claim 1, wherein the method is practiced in a computer.

17. An apparatus for detecting an embedded message in a digital image, the embedded message being embedded in periodic blocks in the image, the apparatus comprising:

a) means for selecting a first area in the digital image;

b) means for selecting a second area in the digital image;

c) means for performing a correlation between the first and the second image areas;

d) means for storing a plurality of properties from different manufacturers and

e) means responsive to the correlation exceeding a predetermined threshold value at at least one pixel location measuring a property of the embedded image and comparing the measured property to at least one of the plurality of properties, and, if the measured property is the same as the at least one of the plurality of properties, for producing a signal indicating the existence of the embedded message in the digital image.

18. A method of detecting an embedded message in a digital image, the embedded message being embedded in periodic blocks in the image, comprising the steps of:

a) selecting a first area in the digital image;

b) selecting a second area in the digital image;

c) performing a correlation between the first and the second image areas; and

d) if the correlation exceeds a predetermined threshold value at at least one pixel location, measuring a property of the embedded image and comparing the measured property to at least one stored property selected from a plurality of pre-stored properties from more than one manufacturer, and, if the measured property is the same as the stored property, producing a signal indicating the existence of the embedded message in the digital image.

19. The method of claim 18 wherein the property is correlation amplitude.

20. The method of claim 18 wherein a same area is selected for the first and the second image areas in the digital image, thereby providing an autocorrelation of the area.

21. The method of claim 18 wherein the property is periodicity.

22. The method of claim 18 wherein the signal is produced when the correlation exceeds the predetermined threshold value at a plurality of pixel locations.

23. The method of claim 22 wherein the plurality of pixel locations are distributed in a one-dimensional or a two-dimensional array.

24. The method of claim 23 wherein the periods in of the one-dimensional or two-dimensional array are in the range of 16 to 2048 pixels.

25. The method of claim 18 wherein the digital image is scanned and digitized by a scanner from an image printed on a receiver.

26. The method of claim 25 wherein the correlation exceeds the predetermined threshold value at a plurality of locations and such plurality of locations are distributed in a one-dimensional or a two-dimensional array.

27. The method of claim 26 wherein the periods in of the one-dimensional or the two-dimensional array correspond to 0.05 inch to 5 inch on the receiver.

28. The method of claim 18 wherein the signal is employed to generate a warning that the image may be copyright protected.

29. The method of claim 18 wherein the signal is used to restrict the use of the digital image without proof of proper authorization.

30. The method of claim 18 further including the step of sending a notification to a copyright holder requesting permission for the use of copyright images.

31. The method of claim 30 wherein the step of sending the message to the copyright holder includes sending the message to an electronic address associated with the copyright holder.

32. The method of claim 30 wherein the step of sending the message to the copyright holder includes pre-storing properties of the correlation functions from different manufacturers, determining the manufacturer whose embedding software produced the embedded message using the pre-stored properties, and sending the message to the manufacturer.

33. A computer readable storage medium having instructions stored therein for causing a computer to perform the method of claim 18.

34. A method of detecting an embedded message in a digital image, the embedded message being embedded in periodic blocks in the image, the method comprising the steps of:

a) selecting a first area in the digital image;

b) selecting a second area in the digital image;

c) performing a correlation between the first and the second image areas; and

d) if the correlation exceeds a predetermined threshold value at at least one pixel location, measuring a property of the embedded image and comparing the measured property to at least one stored property selected from a plurality of pre-stored properties having different periodicity values, and, if the measured property is the same as the stored property, producing a signal indicating the existence of the embedded message in the digital image.

35. The method of claim 34 wherein the correlation between the first image and the second image areas is performed in two-dimensions.

36. The method of claim 34 wherein a same area is selected for the first and the second image areas in the digital image, thereby providing an autocorrelation of the area.

37. The method of claim 34 wherein there are at least two digital images and the first image and the second image areas are selected from the two different digital images.

38. The method of claim 34 wherein the signal is produced when the correlation exceeds the predetermined threshold value at a plurality of pixel locations.

39. The method of claim 38 wherein the plurality of pixel locations are distributed in a one-dimensional or a two-dimensional array.

40. The method of claim 39 wherein the periods in of the one-dimensional or two-dimensional array are in the range of 16 to 2048 pixels.

41. The method of claim 34 wherein the digital image is scanned and digitized by a scanner from an image printed on a receiver.

42. The method of claim 41 wherein the correlation exceeds the predetermined threshold value at a plurality of locations and such plurality of locations are distributed in a one-dimensional or a two-dimensional array.

43. The method of claim 42 wherein the periods in of the one-dimensional or the two dimensional array correspond to 0.05 inch to 5 inch on the receiver.

44. The method of claim 34 wherein the signal is employed to generate a warning that the image may be copyright protected.

45. The method of claim 34 wherein the signal is used to restrict the use of the digital image without proof of proper authorization.

46. The method of claim 34 further including the step of sending a notification to a copyright holder requesting permission for the use of copyright images.

47. The method of claim 46 wherein the step of sending the message to the copyright holder includes sending the message to an electronic address associated with the copyright holder.

48. The method of claim 46 wherein the step of sending the message to the copyright holder includes pre-storing properties of the correlation functions from different manufacturers, determining the manufacturer whose embedding software produced the embedded message using the pre-stored properties, and sending the message to the manufacture.

49. A computer readable storage medium having instructions stored therein for causing a computer to perform the method of claim 34.