Method for producing a color image and imaging device employing same

• US 8,860,751 B2
• Filed: 12/03/2012
• Issued: 10/14/2014
• Est. Priority Date: 09/01/2009
• Status: Active Grant

• Current Assignee: Entertainment Experience LLC
• Original Assignee: Entertainment Experience LLC
• Inventors: Sullivan, James R., Heckman, Rodney L.
• Primary Examiner(s): Sajous, Wesner
• Application Number:
  US13/692,066
• Publication Number:
  US 20130093783A1
• Time in Patent Office: 680 Days
• Field of Search: 345/36, 345 38- 39, 345 46- 50, 345/52, 345/63, 345 76- 77, 345 83-889, 348/68, 348/101, 348253-254, 348255-258, 348268-270, 348/552, 348/557, 348/577, 348602-603, 348630-631, 348/655, 348/687, 348/730, 348/739, 348750-751, 348761-761, 358518-520, 358/516, 358523-525, 382/162, 382/167, 382/254, 382/274, 382/276
• US Class Current: 345/601
• CPC Class Codes: G06F 1/3265 Power saving in display device
• CPC Class Codes: G06T 11/001 Texturing; Colouring; Generation of texture or colour inpainting G06T5/77
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2330/023 using energy recovery or conservation
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/06 using colour palettes, e.g. look-up tables

Abstract

A method of producing a color image using a display comprised of pixels comprising red, green and blue primary color subpixels. The method comprises reducing the color gamut and increasing the brightness of the image relative to a base level, decreasing power to the display to reduce the brightness of the image, restoring color to the image to approximately the base level by modifying image pixel data using a three-dimensional lookup table to produce output image pixel data, and communicating the output image pixel data to the display. The display may be an LCD display, an LED display, an OLED display, a plasma display, and a DMD projector. Reducing the color gamut and increasing the brightness of the image may be accomplished by adding white to the image. The white may be added adaptively according to an algorithm by which the amount of white added decreases with increasing color saturation.

Claims

1. A method of producing a color image using a display device comprised of pixels comprising red, green and blue primary color subpixels, the method comprising:

a) increasing the brightness of the image relative to a base level by changing display device primary colors, thereby changing the color gamut of the display device;

b) decreasing power to the display device to reduce the brightness of the image;

c) restoring color to the image to approximately the base level by modifying image pixel data using a three-dimensional lookup table to produce output image pixel data; and

d) communicating the output image pixel data to the display device to produce the color image;

wherein decreasing power to the display device reduces the brightness of the image to a level brighter than the base level.

2. The method of claim 1, further comprising adding white to the image to reduce the color gamut and increase the brightness of the image.

3. The method of claim 2, wherein white is added by a white subpixel.

4. The method of claim 2, wherein white is added to at least one of the primary color subpixels.

5. The method of claim 2, wherein white is added to two of the three primary color subpixels.

6. The method of claim 2 wherein white is added to the three primary color subpixels.

7. The method of claim 6, wherein white is added to the three primary color subpixels in unequal amounts.

8. The method of claim 6 wherein white is added adaptively according to an algorithm by which the amount of white added decreases with increasing color saturation.

9. The method of claim 8, wherein the algorithm by which the amount of white added decreases with increasing color saturation includes a Gaussian function that defines the decrease in white with increasing color saturation.

10. The method of claim 8, wherein the algorithm is used to determine the values in the three-dimensional lookup table.

11. The method of claim 8, wherein a plurality of images are produced using the display device, and wherein the algorithm includes determining the amount of white to add to each image pixel and the amount of the decrease in power for each image pixel.

12. The method of claim 8, wherein the algorithm includes determining the amount of white added for each individual pixel.

13. The method of claim 12, wherein the algorithm includes determining the amount of white added for each individual red, green and blue primary color subpixel.

14. The method of claim 2, wherein white is added to the subpixels during a portion of a pixel exposure time.

15. The method of claim 2, wherein white is added from a second source that is separate from a first source providing the red, green and blue primary color subpixels.

16. The method of claim 15, wherein the display device is an LCD display device comprising a first backlight as the first source, and a second backlight as the second source.

17. The method of claim 2 wherein the display device is an LCD display device, and the white is added to each pixel by a white subpixel.

18. The method of claim 1, wherein the display device is one of an LCD display device, an LED display device, an OLED display device, a plasma display device, and a DMD projector.

19. The method of claim 1, wherein decreasing power to the display device reduces the brightness of the image to approximately the base level.

20. The method of claim 1, wherein memory colors are preserved in the color image.

21. The method of claim 1, wherein restoring the color of the image includes correcting the white point of the display device to a white point of a color standard.

22. The method of claim 1, wherein the restoring the color of the image is performed in the IPT uniform hue color space.

23. The method of claim 1, wherein the values in the three-dimensional look-up table are determined by using a visual model of the human visual system.

24. The method of claim 23, wherein the values in the three-dimensional look-up table are determined using chromatic adaptation of the human visual system.

25. A method of producing a color image using a display device comprised of pixels comprising red, green and blue primary color subpixels, the method comprising:

a) increasing the brightness and reducing the color saturation of the image relative to a base level by adding white to the image pixels;

b) decreasing power to the display device to reduce the brightness of the image;

c) restoring the color saturation of the image to approximately the base level by modifying image pixel data using a three-dimensional lookup table to produce output image pixel data; and

d) communicating the output image pixel data to the display device to produce the color image;

wherein decreasing power to the display device reduces the brightness of the image to a level brighter than the base level.

26. The method of claim 25, wherein white is added by a white subpixel.

27. The method of claim 25, wherein white is added to at least one of the primary color subpixels.

28. The method of claim 25, wherein white is added to two of the three primary color subpixels.

29. The method of claim 25 wherein white is added to the three primary color subpixels.

30. The method of claim 29, wherein white is added to the three primary color subpixels in unequal amounts.

31. The method of claim 29 wherein white is added adaptively according to an algorithm by which the amount of white added decreases with increasing color saturation.

32. The method of claim 31, wherein the algorithm by which the amount of white added decreases with increasing color saturation includes a Gaussian function that defines the decrease in white with increasing color saturation.

33. The method of claim 31, wherein the algorithm is used to determine the values in the three-dimensional lookup table.

34. The method of claim 31, wherein a plurality of images are produced using the display device, and wherein the algorithm includes determining the amount of white to add to each image pixel and the amount of the decrease in power for each image.

35. The method of claim 31, wherein the algorithm includes determining the amount of white added for each individual pixel.

36. The method of claim 35, wherein the algorithm includes determining the amount of white added for each individual red, green and blue primary color subpixel.

37. The method of claim 25, wherein white is added to the subpixels during a portion of a pixel exposure time.

38. The method of claim 25, wherein white is added from a second source that is separate from a first source providing the red, green and blue primary color subpixels.

39. The method of claim 38, wherein the display device is an LCD display device comprising a first backlight as the first source, and a second backlight as the second source.

40. The method of claim 25 wherein the display device is an LCD display device, and the white is added to each pixel by a white subpixel.

41. The method of claim 25, wherein the display device is one of an LCD display device, an LED display device, an OLED display device, a plasma display device, and a DMD projector.

42. The method of claim 25, wherein decreasing power to the display device reduces the brightness of the image to approximately the base level.

43. The method of claim 25, wherein the restoring the color of the image is performed in the IPT uniform hue color space.

44. The method of claim 25, wherein the values in the three-dimensional look-up table are determined by using a visual model of the human visual system.

45. The method of claim 44, wherein the values in the three-dimensional look-up table are determined using chromatic adaptation of the human visual system.

46. The method of claim 25, wherein memory colors are preserved in the color image.

47. The method of claim 25, wherein restoring the color of the image includes correcting the white point of the display device to a white point of a color standard.