Method and apparatus for an optical function generator for seamless tiled displays

• US 6,727,864 B1
• Filed: 07/13/2000
• Issued: 04/27/2004
• Est. Priority Date: 07/13/2000
• Status: Expired due to Fees

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Johnson, Michael, Chen, Chung-Jen
• Primary Examiner(s): CHOW, DOON Y
• Application Number:
  US09/615,498
• Time in Patent Office: 1,384 Days
• Field of Search: 345/1, 345/87, 345/903, 345/103, 348/383, 348/744, 348/778, 348/785, 348/751, 348/745, 348/746, 348/747, 349/5, 349/6, 349/7, 349/8, 349/9, 349/10
• US Class Current: 345/1.3
• CPC Class Codes: G03B 21/13 Projectors for producing special effects at the edges of picture, e.g. blurring
• CPC Class Codes: G03B 37/04 with cameras or projectors providing touching or overlapping fields of view
• CPC Class Codes: G05B 2219/25056 Automatic configuration of monitoring, control system as function of operator input, events
• CPC Class Codes: G05B 2219/25092 Customized control features, configuration
• CPC Class Codes: H04L 41/082 the condition being updates or upgrades of network functionality
• CPC Class Codes: H04L 41/0859 by keeping history of different configuration generations or by rolling back to previous configuration versions
• CPC Class Codes: H04L 41/0863 by rolling back to previous configuration versions
• CPC Class Codes: H04L 41/0886 Fully automatic configuration
• CPC Class Codes: H04N 9/3147 Multi-projection systems displays in general H04N9/12; video walls G06F3/1446, G09G2300/026
• CPC Class Codes: Y10S 345/903 Modular display

Abstract

Producing seamless tiled images from multiple displays includes measuring a luminance profile of each of the displays, computing a desired luminance profile for each of the displays, and determining a spatial gradient profile of each of the displays based on the measured luminance profile and the computed desired luminance profile. The determined spatial gradient profile is applied to a spatial filter to be inserted into each of the displays to produce the seamless tiled display image.

Claims

1. A method of producing a seamless tiled display image from multiple overlapping discrete images displayed by multiple displays, comprising:

measuring a luminance profile of each of the multiple displays used in producing the seamless tiled display image;

computing a desired luminance profile of each of the multiple displays producing the seamless tiled display image, wherein the desired luminance profile includes a fall-off luminance profile computed using a mathematical function for outside a center region of the seamless tiled display image for each display; and

determining a spatial gradient profile of each of the multiple displays based on the measured luminance profile and the computed desired luminance profile of each of the multiple displays, respectively, to modulate a light to produce a seamless tiled display image from the multiple displays.

2. The method of claim 1, further includes applying the determined spatial gradient profile to a spatial filter to be applied to each of the multiple displays, respectively, to produce a seamless tiled display image from the multiple displays.

3. The method of claim 2, further includes disposing the spatial filter including the determined spatial gradient profile in an image formation path of each of the multiple displays.

4. The method of claim 3, wherein the image formation path is between light sources of the displays and a display screen.

5. The method of claim 4, wherein the displays are projectors.

6. The method of claim 4, wherein measuring the luminance profile further comprises:

using an electronic camera to obtain an electronic image pattern for each of the multiple displays;

normalizing the electronic camera performance for each of the multiple displays; and

removing the electronic camera inherent distortion for each of the multiple displays to measure the luminance profile of each of the multiple displays.

7. The method of claim 6, wherein the distortion is a spatial distortion.

8. The method of claim 6, wherein the distortion is a color distortion.

9. The method of claim 6, wherein measuring the luminance profile of each of the multiple displays comprises measuring the luminance profile of each of the multiple displays based on parameters selected from the group consisting of projection distance, digital image pattern of a set of iso-luminance images, electronic camera to screen distance, curvature of display screen, distortion induced by the electronic camera, and distortion induced by the display screen.

10. The method of claim 6, further includes calibrating the electronic camera to have a linear response to color for each of the multiple displays.

11. The method of claim 6, further includes calibrating the electronic camera to have a linear response to a luminance for each of the multiple displays.

12. The method of claim 6, wherein computing the desired luminance profile comprises using a minimum peak luminance occurring near an edge of each of the multiple displays as the luminance across the whole region of each of the multiple displays for the desired luminance profile.

13. The method of claim 6, wherein determining the spatial gradient profile is determined from

14. The method of claim 13, wherein the Operator is a division when the spatial filter is disposed in close proximity to an imaging device of a projector.

15. The method of claim 14, wherein the spatial filter is disposed next to the imaging device.

16. The method of claim 14, wherein the Operator is a convolution when the spatial filter is disposed substantially away from the imaging device of the projector.

17. The method of claim 16, wherein the spatial filter is disposed outside the projector.

18. The method of claim 14, wherein an output of the imaging device is modulated using a projection lens.

19. The method of claim 6, wherein disposing the spatial filter comprises incorporating the spatial filter into light integrators of the projectors.

20. The method of claim 6, wherein disposing the spatial filter comprises incorporating the spatial filter into a light pipe of each of the projectors.

21. The method of claim 6, wherein disposing the spatial filter comprises incorporating the spatial filter into an X-cube of each of the projectors.

22. The method of claim 6, wherein disposing the spatial filter comprises incorporating the spatial filter into a light source of each of the projectors.

23. The method of claim 6, wherein the spatial filter is an optical filter.

24. The method of claim 23, wherein the optical filter is a transmissive medium.

25. The method of claim 24, wherein the transmissive medium is a neutral density filter which acts uniformly regardless of hue of the light.

26. The method of claim 6, wherein the spatial filter is incorporated onto a light valve of each of the projectors.

27. A method of producing a seamless tiled display image from multiple overlapping discrete images displayed by multiple displays, comprising:

using an electronic camera to obtain an electronic image pattern for each of the multiple displays;

normalizing the electronic camera performance for each of the multiple displays;

removing the electronic camera inherent distortion for each of the multiple displays to measure the luminance profile of each of the multiple displays;

computing a desired luminance profile by selecting a reference luminance (L_c) from each of the multiple displays for a center region of the seamless tiled display image, and computing a fall-off luminance profile for outside the center region for each of the multiple displays using a mathematical function;

determining a spatial gradient profile of each of the multiple displays based on the measured luminance profile and the computed desired luminance profile of each of the multiple displays, respectively, to modulate a light to produce a seamless tiled display image from the multiple displays;

applying the desired spatial gradient profile to a spatial filter to be applied to each of the multiple displays, respectively, to produce a seamless tiled display image from the multiple displays; and

disposing the spatial filter including the determined spatial gradient profile in an image formation path of each of the multiple displays to produce the seamless tiled display image from the multiple displays.

28. The method of claim 27, where the center region comprises a summation of light energy at a display center of each of the multiple displays.

29. The method of claim 27, wherein the mathematical function is based on selecting from the group consisting of sinusoidal function, gaussian function, polynomial function, and piecewise approximations.

30. The method of claim 27, wherein the fall-off profile outside the center region is determined from $L$

(x,y)=Lc

[Lx,min+(1-Lx,min)

cos

(Δ



 



xDx

π

)]

[Ly,min+(1-Ly,min)

cos

(Δ



 



yDy

π

)],

where Δ

x is a horizontal distance to a left or right edge of the center region for left fall off, D_x is a horizontal dimension of each tiled image, and L_x,min is a desired minimum luminance of a fall-off horizontally, and where Δ

y is a vertical distance to a right or left edge of the center region for right fall off, D_y is a vertical dimension of each of the tiled image, and L_y,min is a desired minimum luminance of a fall-off vertically.

31. A method of producing a seamless tiled display image from multiple overlapping discrete images displayed by multiple displays, comprising:

using an electronic camera to obtain an electronic image pattern for each of the multiple displays;

normalizing the electronic camera performance for each of the multiple displays;

removing the electronic camera inherent distortion for each of the multiple displays to measure the luminance profile of each of the multiple displays;

computing a desired luminance profile of each of the multiple displays producing the seamless tiled display image;

determining a spatial gradient profile of each of the multiple displays based on the measured luminance profile and the computed desired luminance profile of each of the multiple displays, respectively, to modulate a light to produce a seamless tiled display image from the multiple displays, wherein the spatial gradient profile is determined using the equation

32. The method of claim 31, further including applying the desired spatial gradient profile to a spatial filter to be inserted into each of the multiple displays, to produce a seamless tiled display image from the multiple displays.

33. The method of claim 31, wherein determining the predetermined tolerance margin comprises allowing a tolerance margin to provide more luminance than desired to correct for alignment errors that can be incurred during a spatial filter insertion process.

34. The method of claim 31, wherein the electronics calibration comprises adjusting an input video applied to the projector of each of the multiple displays to obtain the desired spatial gradient profile.

35. A method of producing a seamless tiled display image from multiple overlapping discrete images displayed by multiple displays, comprising

using an electronic camera to obtain an electronic image pattern for each of the multiple displays;

normalizing the electronic camera performance for each of the multiple displays;

removing the electronic camera inherent distortion for each of the multiple displays to measure the luminance profile of each of the multiple displays;

computing a desired luminance profile of each of the multiple displays producing the seamless tiled display image;

determining a spatial gradient profile of each of the multiple displays based on the measured luminance profile and the computed desired luminance profile of each of the multiple displays, respectively, to modulate a light to produce a seamless tiled display image from the multiple displays;

applying the determined spatial gradient profile to a spatial filter to be applied to each of the multiple displays, respectively, to produce a seamless tiled display image from the multiple displays; and

disposing the spatial filter including the determined spatial gradient profile in an image formation path of each of the multiple displays to produce the seamless tiled display image from the multiple displays, wherein disposing the spatial filter comprises incorporating the spatial filter into a holographic film for bending the light toward other spatial regions without a loss of a total light intensity in each of the projectors.

36. A method of producing a seamless tiled display image from multiple overlapping discrete images displayed by multiple displays, comprising:

using an electronic camera to obtain an electronic image pattern for each of the multiple displays;

normalizing the electronic camera performance for each of the multiple displays;

removing the electronic camera inherent distortion for each of the multiple displays to measure the luminance profile of each of the multiple displays;

computing a desired luminance profile of each of the multiple displays producing the seamless tiled display image;

determining a spatial gradient profile of each of the multiple displays based on the measured luminance profile and the computed desired luminance profile of each of the multiple displays, respectively, to modulate a light to produce a seamless tiled display image from the multiple displays;

applying the determined spatial gradient profile to a spatial filter to be applied to each of the multiple displays, respectively, to produce a seamless tiled display image from the multiple displays, wherein the spatial filter is a transmissive medium, wherein the transmissive medium is a monochrome filter tuned for a specific color in the light; and

disposing the spatial filter including the determined spatial gradient profile in an image formation path of each of the multiple displays to produce the seamless tiled display image from the multiple displays.

37. A display system for producing a seamless tiled display image from multiple discrete images, comprising:

multiple displays for displaying each of the multiple discrete images separately onto the display screen, the multiple displays displaying the multiple discrete images such that at least one of the multiple discrete images partially overlaps with another of the at least one multiple discrete images; and

a spatial filter, disposed in each of the multiple displays, to produce the seamless tiled display image from the multiple overlapping discrete images, wherein the spatial filter modulates a light based on a determined spatial gradient profile of each of the multiple displays, wherein the determined spatial gradient profile is based on a measured luminance profile of each of the multiple displays and a computed desired luminance profile for each of the multiple displays, respectively, wherein the desired color profile includes a fall-off luminance profile, computed using a mathematical function, for outside a center region of the seamless tiled display image for each display.

38. The display system of claim 37, wherein the display system receives multiple discrete video signals that is used to generate the multiple discrete images.

39. The display system of claim 37, wherein the spatial filter is disposed in an image formation path of each of the multiple displays.

40. The display system of claim 37, further includes a display screen.

41. The display system of claim 40, wherein the display screen is a projection screen.

42. The display system of claim 37, wherein the multiple displays are multiple projectors.

43. The display system of claim 42, wherein the spatial filter is disposed between an imaging device of each of the multiple projectors and the projection screen.

44. The display system of claim 37, wherein the spatial filter is an optical filter.

45. The display system of claim 44, wherein the optical filter is a transmissive medium.

46. The display system of claim 45, wherein the transmissive medium is a neutral density filter which acts uniformly regardless of hue of the light.

47. The display system of claim 45, wherein the transmissive medium is an optical film.

48. The display system of claim 37, wherein the measured luminance profile is determined by obtaining an electronic image pattern using an electronic camera and normalizing the electronic camera performance and removing the electronic camera distortion to measure the luminance profile of each of the multiple displays.

49. The display system of claim 48, wherein the distortion is a spatial distortion.

50. The display system of claim 48, wherein the distortion is a color distortion.

51. The display system of claim 48, wherein the measured luminance profile of each of the multiple displays is computed based on selecting from the group consisting of a projection distance, a digital image pattern of a set of iso-luminance images, an electronic camera to screen distance, and a screen curvature.

52. The display system of claim 37, wherein the computed desired luminance profile comprises using a minimum peak luminance occurring near an edge of each of the multiple displays as the luminance across a whole region of each of the multiple displays for the desired luminance profile.

53. The display system of claim 37, wherein the determined spatial gradient profile is based on Spatial Gradient Profile (x,y)=Desired luminance profile (x,y) [Operator] Measured Luminance Profile (x,y).

54. The display system of claim 53, wherein the Operator is a division when the spatial filter is disposed in close proximity to an imaging device of a projector.

55. The display system of claim 54, wherein the spatial filter is disposed next to the imaging device.

56. The display system of claim 53, wherein the Operator is a convolution when the spatial filter is disposed substantially away from the imaging device of a projector.

57. The display system of claim 56, wherein the spatial filter is disposed outside the projector.

58. The display system of claim 53, wherein the imaging device is a projection lens.

59. The display system in claim 37, wherein the spatial filter comprises incorporating the spatial filter into a light integrator of each of the projectors.

60. A method of producing a seamless tiled display image from multiple overlapping discrete images displayed by multiple displays, comprising:

using an electronic camera to obtain an electronic image pattern for each of the multiple displays;

normalizing the electronic camera performance for each of the multiple displays;

removing the electronic camera inherent distortion for each of the multiple displays to measure the luminance profile of each of the multiple displays;

computing a desired luminance profile of each of the multiple displays producing the seamless tiled display image;

determining a spatial gradient profile of each of the multiple displays based on the measured luminance profile and the computed desired luminance profile of each of the multiple displays, respectively, to modulate a light to produce a seamless tiled display image from the multiple displays;

applying the determined spatial gradient profile to a spatial filter to be applied to each of the multiple displays, respectively, to produce a seamless tiled display image from the multiple displays, wherein the spatial filter is an electronic shutter having a spatial gray shade capability; and

disposing the spatial filter including the determined spatial gradient profile in an image formation path of each of the multiple displays to produce the seamless tiled display image from the multiple displays.

61. The method of claim 60, wherein the spatial filter is a modulator of light.

62. The method of claim 61, wherein the modulation of light is based on selecting from the group consisting of transmitting, reflecting, refracting, and polarization.

63. A method of producing a seamless tiled display image from multiple displays, comprising:

measuring a color profile of each of the multiple displays used in producing the seamless tiled display image;

computing a desired color profile for each of the multiple displays producing the seamless tiled display image, wherein the desired color profile includes a fall-off luminance profile, computed using a mathematical function, for outside a center region of the seamless tiled display image for each display; and

determining a spatial gradient profile of each of the multiple displays based on the measured color profile and the computed desired color profile of the each of the multiple displays, respectively, to produce a seamless tiled display image from the multiple displays.

64. The method of claim 63, further includes applying the determined spatial gradient profile to a spatial filter to be inserted into each of the multiple displays, respectively, to produce a seamless tiled display image from the multiple displays.

65. The method of claim 64, further includes disposing the spatial filter anywhere in an image formation path of each of the multiple displays.

66. A display system for producing a seamless tiled display image from multiple discrete images, comprising:

multiple displays for displaying each of the multiple discrete images separately onto the display screen, the multiple displays displaying the multiple discrete images such that at least one of the multiple discrete images partially overlaps with another of the at least one multiple discrete images; and

a spatial filter, disposed in each of the multiple displays, to produce the seamless tiled display image from the multiple overlapping discrete images, wherein the spatial filter modulates a light based on a determined spatial gradient profile of each of the multiple displays, wherein the determined spatial gradient profile is based on a measured luminance profile of each of the multiple displays and a computed desired luminance profile for each of the multiple displays, respectively, wherein the spatial filter is a transmissive medium, wherein the transmissive medium is a monochrome filter tuned for a specific color in the light.

67. A display system for producing a seamless tiled display image from multiple discrete images, comprising:

multiple displays for displaying each of the multiple discrete images separately onto the display screen, the multiple displays displaying the multiple discrete images such that at least one of the multiple discrete images partially overlaps with another of the at least one multiple discrete images; and

a spatial filter, disposed in each of the multiple displays, to produce the seamless tiled display image from the multiple overlapping discrete images, wherein the spatial filter modulates a light based on a determined spatial gradient profile of each of the multiple displays, wherein the determined spatial gradient profile is based on a measured luminance profile of each of the multiple displays and a computed desired luminance profile for each of the multiple displays, respectively, wherein the spatial filter modulates the light to prevent stray light from coming from each of the projectors.

68. A display system for producing a seamless tiled display image from multiple discrete images, comprising:

multiple displays for displaying each of the multiple discrete images separately onto the display screen, the multiple displays displaying the multiple discrete images such that at least one of the multiple discrete images partially overlaps with another of the at least one multiple discrete images; and

a spatial filter, disposed in each of the multiple displays, to produce the seamless tiled display image from the multiple overlapping discrete images, wherein the spatial filter modulates a light based on a determined spatial gradient profile of each of the multiple displays, wherein the determined spatial gradient profile is based on a measured luminance profile of each of the multiple displays and a computed desired luminance profile for each of the multiple displays, respectively, and wherein the computed desired luminance comprises selecting a reference luminance from each of the multiple displays for a center region of the seamless tiled display image, and computing a fall-off luminance profile for outside the center region for each of the multiple displays using a mathematical function.

69. The display system of claim 68, wherein the center region comprises a summation of light energy at display centers of each of the multiple displays.

70. The display system of claim 68, wherein computing the fall-off profile outside the center region is based on a mathematical function.

71. The display system of claim 68, wherein the mathematical function is selected from the group consisting of a sinusoidal function, a gaussian function, and a polynomial function.

72. The display system of claim 68, wherein the computing the fall-off profile outside the center region is determined by $L$

(x,y)=Lc

[Lx,min+(1-Lx,min)

cos

(Δ



 



xDx

π

)]

[Ly,min+(1-Ly,min)

cos

(Δ



 



yDy

π

)],

where, Δ

x is a horizontal distance to a left or right edge of the center region for left fall off, D_x is a horizontal dimension of each tiled image, and L_x,min is a desired minimum luminance of the fall-off horizontally, and where Δ

y is a vertical distance to a right or left edge of the center region for right fall off, D_y is a vertical dimension of each of the tiled image, and L_y,min is a desired minimum luminance of the fall-off vertically.