Methods and Systems for Ambient-Illumination-Selective Display Backlight Modification and Image Enhancement

• US 20110074803A1
• Filed: 09/29/2009
• Published: 03/31/2011
• Est. Priority Date: 09/29/2009
• Status: Abandoned Application

• Current Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Kerofsky, Louis Joseph
• Application Number:
  US12/569,853
• Publication Number:
  US 20110074803A1
• Time in Patent Office: Days
• US Class Current: 345/589
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336

Abstract

Aspects of the present invention comprise systems and methods for determining image content characteristics, determining ambient illumination conditions, selecting an initial backlight level based on the image content characteristics and selecting a backlight compensation process to be applied to the image based on the initial backlight level. Some aspects further relate to modification of the initial backlight level based on ambient illumination conditions and some aspects further relate to modification of the image with a second process based on ambient conditions.

Claims

1. A method for enhancing image display with ambient illumination input, said method comprising:

a) determining an ambient illumination condition near a display device;

b) determining an image content characteristic for an input image to be displayed;

c) calculating an initial backlight selection based on said image content characteristic;

d) determining a brightness compensation process to compensate said input image based on said initial backlight selection;

e) applying said brightness compensation process to said input image, thereby creating a backlight compensated image;

f) modifying said initial backlight selection based on said ambient illumination condition thereby creating an ambient-adapted backlight selection; and

g) modifying said backlight compensated image with a second brightness compensation process based on said ambient illumination condition, thereby creating an ambient-adapted, backlight-compensated image.

2. A method as described in claim 1 further comprising displaying said ambient-adapted, backlight compensated image using said ambient-adapted backlight selection.

3. A method as described in claim 1 wherein said modifying said initial backlight selection comprises setting said initial backlight selection to a maximum backlight intensity when said ambient illumination condition is bright, and.

4. A method as described in claim 1 wherein said modifying said initial backlight selection comprises setting said initial backlight selection to an increased value when said ambient illumination condition is mid-range.

5. A method as described in claim 1 wherein said modifying said initial backlight selection comprises maintaining said initial backlight selection at a current value when said ambient illumination condition is dim.

6. A method as described in claim 1 wherein said image content characteristic is a histogram.

7. A method as described in claim 1 wherein said modifying said initial backlight selection comprises a perceptual white point calculation.

8. A method as described in claim 1 wherein said modifying said initial backlight selection comprises applying a temporal filter.

9. A method for enhancing image display with ambient illumination input, said method comprising:

a) determining an ambient illumination condition near a display device;

b) determining an image content characteristic for an input image to be displayed;

c) calculating an initial backlight selection based on said image content characteristic;

d) determining a brightness compensation process to compensate said input image based on said initial backlight selection;

e) applying said brightness compensation process to said input image, thereby creating a backlight compensated image;

f) modifying said initial backlight selection based on said ambient illumination condition, wherein said modifying results in an ambient-adapted backlight selection and said modifying comprises setting said initial backlight selection to a maximum backlight intensity when said ambient illumination condition is bright, setting said initial backlight selection to an increased value when said ambient illumination condition is mid-range and maintaining said initial backlight selection at a current value when said ambient illumination condition is dim.

10. A method as described in claim 9 further comprising modifying said backlight compensated image with a second brightness compensation process based on said ambient illumination condition, thereby creating an ambient-adapted, backlight-compensated image.

11. A method as described in claim 9 wherein said determining an ambient illumination condition comprises determining whether ambient luminance intensity falls within a luminance category.

12. A method as described in claim 9 wherein said determining an image content characteristic comprises determining whether a brightness characteristic of said input image falls within a brightness category.

13. A method as described in claim 9 wherein said determining a brightness compensation process comprises selecting from a plurality of tone scale curves that correspond to various combinations of values for said image content characteristic.

14. A method as described in claim 10 wherein said modifying said backlight compensated image with a second brightness compensation process based on said ambient illumination condition comprises applying a first tone scale operation to said brightness compensated image to brighten said image to a first extent when said ambient illumination condition is bright.

15. A method as described in claim 14 wherein said modifying said backlight compensated image with a second brightness compensation process based on said ambient illumination condition further comprises applying a second tone scale operation to said brightness compensated image to brighten said image to a second extent, when said ambient illumination condition is mid-range.

16. A method as described in claim 15 wherein said modifying said backlight compensated image with a second brightness compensation process based on said ambient illumination condition comprises applying a third tone scale operation to said brightness compensated image to brighten said image to a third extent when said ambient illumination condition is dim.

17. A method for enhancing image display with ambient illumination input, said method comprising:

a) determining an ambient illumination condition near a display device;

b) determining an image content characteristic for an input image to be displayed;

c) calculating an initial backlight selection based on said image content characteristic;

d) determining a brightness compensation process to compensate said input image based on said initial backlight selection;

e) applying said brightness compensation process to said input image, thereby creating a backlight compensated image;

f) modifying said initial backlight selection based on said ambient illumination condition, wherein said modifying results in an ambient-adapted backlight selection and said modifying comprises setting said initial backlight selection to a maximum backlight intensity when said ambient illumination condition is bright, setting said initial backlight selection to an increased value when said ambient illumination condition is mid-range and maintaining said initial backlight selection at a current value when said ambient illumination condition is dim; and

g) modifying said backlight compensated image based on said ambient illumination condition, thereby creating an ambient-adapted, backlight-compensated image.

18. A method as described in claim 17 wherein said modifying said backlight compensated image with a second brightness compensation process based on said ambient illumination condition comprises applying a first tone scale operation to said brightness compensated image to brighten said image to a first extent when said ambient illumination condition is bright.

19. A method as described in claim 18 wherein said modifying said backlight compensated image with a second brightness compensation process based on said ambient illumination condition comprises applying a second tone scale operation to said brightness compensated image to brighten said image to a second extent that is less bright than said first extent, when said ambient illumination condition is mid-range.

20. A method as described in claim 19 wherein said modifying said backlight compensated image with a second brightness compensation process based on said ambient illumination condition comprises avoiding modification of said backlight compensated image when said ambient illumination condition is dim.