Method and apparatus for analog insertion of low frequency watermarks

• US 7,756,288 B2
• Filed: 05/28/2004
• Issued: 07/13/2010
• Est. Priority Date: 05/29/2003
• Status: Active Grant

• Current Assignee: Transpacific Information, LLC
• Original Assignee: Transpacific Information, LLC
• Inventors: Polyzois, Christos Alkivladis, Lubin, Jeffrey
• Primary Examiner(s): Le; Vu
• Assistant Examiner(s): WANG, CLAIRE X
• Application Number:
  US10/856,022
• Publication Number:
  US 20040240705A1
• Time in Patent Office: 2,237 Days
• Field of Search: 382/100, 382/218, 352/40, 356/425, 348/744
• 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 2201/0052 Embedding of the watermark in the frequency domain

Abstract

A method and apparatus for inserting a watermark onto an illuminated image sequence. A light modulator modulates a light source. A controller controls the light modulator such that a low frequency watermark is inserted onto the illuminated image sequence.

Claims

1. An apparatus for inserting a watermark onto an illuminated image sequence, comprising:

a light modulator configured for modulating a light source; and

a controller configured for controlling the light modulator to selectively alter light transmissivity over space and time such that a low frequency watermark is inserted onto the illuminated image sequence.

2. The apparatus of claim 1, wherein the controller is configured to selectively alter light transmissivity over space and time based on a previous profiling stage.

3. The apparatus of claim 1, wherein the controller is configured to receive feedback from a projector or a printer in order to maintain temporal registration.

4. The apparatus of claim 1, wherein the controller is configured to receive feedback from a projector or a printer in order to maintain spatial registration.

5. The apparatus of claim 1, wherein the controller is configured to receive feedback from a projector or a printer in order to maintain spatio-temporal registration.

6. The apparatus of claim 1, wherein said light modulator is a slit modulator.

7. The apparatus of claim 1, wherein the low frequency watermark is inserted onto the illuminated image sequence using a serial configuration.

8. The apparatus of claim 7, wherein the low frequency watermark comprises a positive luminance excursion.

9. The apparatus of claim 7, wherein the low frequency watermark comprises a negative luminance excursion.

10. The apparatus of claim 7, wherein the low frequency watermark comprises positive luminance excursions and negative luminance excursions.

11. The apparatus of claim 7, wherein the light modulator is configured to cause appropriate levels of blur in the low frequency watermark.

12. The apparatus of claim 1, wherein the low frequency watermark is inserted onto the illuminated image sequence using a parallel configuration.

13. The apparatus of claim 12, wherein the low frequency watermark comprises a positive luminance excursion.

14. The apparatus of claim 1, wherein the low frequency watermark is inserted onto the illuminated image sequence using a serial configuration and a parallel configuration.

15. The apparatus of claim 14, wherein the low frequency watermark comprises negative luminance excursions and positive luminance excursions.

37. The apparatus of claim 1 wherein the low frequency watermark is dependent on the time of projecting the illuminated image sequence.

38. The apparatus of claim 1 wherein the low frequency watermark is unique for each presentation of the illuminated image sequence.

16. An apparatus for inserting a watermark, comprising:

a light source for illuminating an image sequence;

a lens for modifying the light from the light source;

a light modulator configured for modulating the modified light; and

a controller configured for controlling the light modulator to selectively alter light transmissivity over space and time such that a low frequency watermark is inserted onto the illuminated image sequence.

17. The apparatus of claim 16, further comprising:

an illuminated image sequence.

18. An apparatus for inserting a watermark, comprising:

a first light source configured for illuminating an image sequence;

a first lens configured for modifying the light from the first light source;

a first light modulator configured for modulating the modified light from the first light source;

a second light source;

a second lens configured for modifying the light from the second light source;

a second light modulator configured for modulating the modified light from the second light source; and

a controller configured for controlling the first light modulator and the second light modulator to selectively alter light transmissivity over space and time such that a low frequency watermark is inserted onto the illuminated image sequence.

19. A method for inserting a watermark onto an illuminated image sequence, comprising:

modulating a light source with a light modulator; and

controlling the light modulator to selectively alter light transmissivity over space and time such that a low frequency watermark is inserted onto the illuminated image sequence.

20. The method of claim 19, further comprising selecting an appropriate modulation based on a previous profiling stage.

21. The method of claim 19, further comprising receiving feedback from a projector or printer in order to maintain temporal registration.

22. The method of claim 19, further comprising receiving feedback from a projector or printer in order to maintain spatial registration.

23. The method of claim 19, further comprising receiving feedback from a projector or printer in order to maintain spatio-temporal registration.

24. The method of claim 19, wherein said light modulator is a slit modulator.

25. The method of claim 19, further comprising inserting the low frequency watermark onto the illuminated image sequence using a serial configuration.

26. The method of claim 25, wherein the low frequency watermark comprises a positive luminance excursion.

27. The method of claim 25, wherein the low frequency watermark comprises a negative luminance excursion.

28. The method of claim 25, wherein the low frequency watermark comprises positive and negative luminance excursions.

29. The method of claim 19, wherein the light modulator is configured to cause appropriate levels of blur in the low frequency watermark.

30. The method of claim 19, further comprising inserting the low frequency watermark onto the illuminated image sequence using a parallel configuration.

31. The method of claim 19, wherein the low frequency watermark comprises a positive luminance excursion.

32. The method of claim 19, further comprising inserting the low frequency watermark onto the illuminated image sequence using a serial configuration and a parallel configuration.

33. The method of claim 32, wherein the low frequency watermark comprises negative luminance and positive luminance excursions.

34. The method of claim 19, further comprising:

printing the illuminated image sequence.

35. The method of claim 19, wherein the low frequency watermark comprises temporally dynamic information.

36. The method of claim 19, further comprising:

projecting the illuminated image sequence.

39. An apparatus for inserting a watermark onto an illuminated image sequence, comprising:

means for modulating a light source; and

means for controlling the means for modulating to selectively alter light transmissivity over space and time such that a low frequency watermark is inserted onto the illuminated image sequence.

40. The apparatus of claim 39, further comprising means for receiving feedback from a projector or printer in order to maintain spatio-temporal registration.

41. The apparatus of claim 39, wherein the means for modulation further comprise means for causing appropriate levels of blur in the low frequency watermark.

42. The apparatus of claim 39, further comprising means for printing the illuminated image sequence.

43. The apparatus of claim 39, further comprising:

means for projecting the illuminated image sequence.

44. A method, comprising:

selecting one or more locations for watermark insertion;

modulating a light source using a light modulator; and

controlling the light modulator to selectively alter light transmissivity over space and time such that a low frequency watermark is inserted onto an image sequence at the one or more locations.

45. The method of claim 44, wherein selecting the one or more locations for watermark insertion comprises selecting the one or more locations based on a profile.

46. The method of claim 45, wherein selecting the one or more locations based on the profile comprises:

determining the one or more locations using a profiling stage; and

storing the determined one or more locations in the profile.

47. The method of claim 44, further comprising:

printing the illuminated image sequence.

48. The method of claim 44, further comprising:

projecting the illuminated image sequence.

49. A method, comprising:

modulating a light source using a light modulator; and

receiving a sync signal configured to register a frame of an image sequence;

controlling the light modulator to selectively alter light transmissivity over space and time such that a low frequency watermark is inserted onto the frame of the image sequence based on the sync signal.

50. The method of claim 49, wherein the sync signal is configured to maintain spatial registration of the frame of the image sequence.

51. The method of claim 49, wherein the sync signal is configured to maintain temporal registration of the frame of the image sequence.

52. The method of claim 49, wherein the sync signal is configured to maintain spatio-temporal registration of the frame of the image sequence.

53. The method of claim 49, further comprising:

displaying the illuminated image sequence.