Nonlinear signal scaling for display device power saving

• US 10,186,232 B2
• Filed: 08/01/2016
• Issued: 01/22/2019
• Est. Priority Date: 08/01/2016
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Huang, Ai-Mei, Dai, Min
• Primary Examiner(s): Flora, Nurun N
• Application Number:
  US15/224,817
• Publication Number:
  US 20180033397A1
• Time in Patent Office: 904 Days
• Field of Search: None
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2330/023 using energy recovery or conservation
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/2011 by amplitude modulation
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• 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 5/10 Intensity circuits

Abstract

Techniques are described in which pixel intensity values of a display of a computing device may be nonlinearly scaled down to reduce the power consumption of the display. The computing device may determine a compressed pixel brightness range for the display. The computing device may determine a set of initial scaled pixel intensity levels based at least in part on the compressed pixel intensity range. The computing device may determine a set of scaled pixel intensity values based at least in part on an estimated power consumption value associated with the set of initial scaled pixel intensity levels. The computing device may scale the pixel brightness of pixels of the display from one of a plurality of pixel intensity levels to a corresponding scaled pixel intensity level of the set of scaled pixel intensity levels.

Claims

1. A method comprising:

determining, by at least one processor, a compressed pixel intensity range for a plurality of pixel intensity levels of a display device based at least in part on a target power scaling value, wherein the target power scaling value is associated with a target power consumption of the display device to display an image;

determining, by the at least one processor, a set of initial scaled pixel intensity levels for the plurality of pixel intensity levels based at least in part on the compressed pixel intensity range;

determining, by the at least one processor, an estimated power consumption value, wherein the estimated power consumption value is associated with an estimated power consumption of the display device to display the image according to the set of initial scaled pixel intensity levels;

determining, by the at least one processor, a set of scaled pixel intensity levels based at least in part on a ratio of the target power scaling value to the estimated power consumption value; and

scaling a pixel intensity of each of a plurality of pixels of the display device from one of the plurality of pixel intensity levels to a corresponding scaled pixel intensity level of the set of scaled pixel intensity levels to display, by the display device, the image according to the set of scaled pixel intensity levels.

2. The method of claim 1, wherein determining the set of initial scaled pixel intensity levels further comprises:

determining a contrast enhancement index for each of the plurality of pixel intensity levels to display, by the display device, the image according to the scaled pixel intensity level based at least in part on a frequency of the respective pixel intensity level within output colors of the plurality of pixels of the display device; and

determining the set of initial scaled pixel intensity levels based at least in part on the contrast enhancement index for each of the plurality of pixel intensity levels.

3. The method of claim 2, wherein determining the set of initial scaled pixel intensity levels further comprises:

determining a contrast for each initial scaled pixel intensity level of the set of initial scaled pixel intensity levels based at least in part on the contrast enhancement index for a corresponding intensity level of the plurality of intensity levels.

4. The method of claim 3, wherein determining the set of scaled pixel intensity levels further comprises:

determining the contrast for each scaled pixel intensity level of the set of scaled pixel intensity levels based at least in part on the target power scaling value, the estimated power consumption value, and the contrast enhancement index for the corresponding pixel intensity level of the plurality of pixel intensity levels.

5. The method of claim 1, wherein determining the compressed pixel intensity range for the plurality of pixel intensity levels of the display device further comprises:

determining a power consumption value associated with a maximum pixel intensity level out of the plurality of pixel intensity levels;

scaling the power consumption value according to the target power scaling value; and

determining a maximum pixel intensity level for the compressed pixel intensity range based at least in part on the scaled power consumption value.

6. The method of claim 1, wherein each of the plurality of pixel intensity levels for the display device comprises a value component of a hue-saturation-value (HSV) color space.

7. The method of claim 1, wherein the display device comprises an organic light-emitting-diode (OLED) display device.

8. A computing device comprising:

a display; and

at least one processor configured to;

determine a compressed pixel intensity range for a plurality of pixel intensity levels of the display based at least in part on a target power scaling value, wherein the target power scaling value is associated with a target power consumption of the display to display an image;

determine a set of initial scaled pixel intensity levels for the plurality of pixel intensity levels based at least in part on the compressed pixel intensity range;

determine an estimated power consumption value, wherein the estimated power consumption value is associated with an estimated power consumption of the display to display the image according to the set of initial scaled pixel intensity levels;

determine a set of scaled pixel intensity levels based at least in part on a ratio of the target power scaling value to the estimated power consumption value; and

scale a pixel intensity of each of a plurality of pixels of the display from one of the plurality of pixel intensity levels to a corresponding scaled pixel intensity level of the set of scaled pixel intensity levels to display, by the display, the image according to the set of scaled pixel intensity levels.

9. The computing device of claim 8, wherein the at least one processor is further configured to:

determine a contrast enhancement index for each of the plurality of pixel intensity levels to display, by the display, the image according to the scaled pixel intensity level based at least in part on a frequency of the respective pixel intensity level within output colors of the plurality of pixels of the display; and

determine the set of initial scaled pixel intensity levels based at least in part on the contrast enhancement index for each of the plurality of pixel intensity levels.

10. The computing device of claim 9, wherein the at least one processor is further configured to:

determine a contrast for each initial scaled pixel intensity level of the set of initial scaled pixel intensity levels based at least in part on the contrast enhancement index for a corresponding intensity level of the plurality of intensity levels.

11. The computing device of claim 10, wherein the at least one processor is further configured to:

determine the contrast for each scaled pixel intensity level of the set of scaled pixel intensity levels based at least in part on the target power scaling value, the estimated power consumption value, and the contrast enhancement index for the corresponding pixel intensity level of the plurality of pixel intensity levels.

12. The computing device of claim 8, wherein at least one processor is further configured to:

determine a power consumption value associated with a maximum pixel intensity level out of the plurality of pixel intensity levels;

scale the power consumption value according to the target power scaling value; and

determine a maximum pixel intensity level for the compressed pixel intensity range based at least in part on the scaled power consumption value.

13. The computing device of claim 8, wherein each of the plurality of pixel intensity levels for the display comprises a value component of a hue-saturation-value (HSV) color space.

14. The computing device of claim 8, wherein the display comprises an organic light-emitting-diode (OLED) display device.

15. A non-transitory computer-readable storage medium storing instructions that, when executed, cause at least one processor to:

determine a compressed pixel intensity range for a plurality of pixel intensity levels of a display device based at least in part on a target power scaling value, wherein the target power scaling value is associated with a target power consumption of the display device to display an image;

determine a set of initial scaled pixel intensity levels for the plurality of pixel intensity levels based at least in part on the compressed pixel intensity range;

determine an estimated power consumption value, wherein the estimated power consumption value is associated with an estimated power consumption of the display device to display the image according to the set of initial scaled pixel intensity levels;

determine a set of scaled pixel intensity levels based at least in part on a ratio of the target power scaling value to the estimated power consumption value; and

scale a pixel intensity of each of a plurality of pixels of the display device from one of the plurality of pixel intensity levels to a corresponding scaled pixel intensity level of the set of scaled pixel intensity levels to display, by the display device, the image according to the set of scaled pixel intensity levels.

16. The non-transitory computer-readable storage medium of claim 15, wherein the instructions further cause the at least one processor to:

determine a contrast enhancement index for each of the plurality of pixel intensity levels to display, by the display device, the image according to the scaled pixel intensity level based at least in part on a frequency of the respective pixel intensity level within output colors of the plurality of pixels of the display device; and

determine the set of initial scaled pixel intensity levels based at least in part on the contrast enhancement index for each of the plurality of pixel intensity levels.

17. The non-transitory computer-readable storage medium of claim 16, wherein the instructions further cause the at least one processor to:

determine a contrast for each initial scaled pixel intensity level of the set of initial scaled pixel intensity levels based at least in part on the contrast enhancement index for a corresponding intensity level of the plurality of intensity levels.

18. The non-transitory computer-readable storage medium of claim 17, wherein the instructions further cause the at least one processor to:

determine the contrast for each scaled pixel intensity level of the set of scaled pixel intensity levels based at least in part on the target power scaling value, the estimated power consumption value and the contrast enhancement index for the corresponding pixel intensity level of the plurality of pixel intensity levels.

19. The non-transitory computer-readable storage medium of claim 15, wherein the instructions further cause the at least one processor to:

determine a power consumption value associated with a maximum pixel intensity level out of the plurality of pixel intensity levels;

scale the power consumption value according to the target power scaling value; and

determine a maximum pixel intensity level for the compressed pixel intensity range based at least in part on the scaled power consumption value.

20. The non-transitory computer-readable storage medium of claim 15, wherein each of the plurality of pixel intensity levels for the display device comprises a value component of a hue-saturation-value (HSV) color space.

21. An apparatus comprising:

means for determining a compressed pixel intensity range for a plurality of pixel intensity levels of a display device based at least in part on a target power scaling value, wherein the target power scaling value is associated with a target power consumption of the display device to display an image;

means for determining a set of initial scaled pixel intensity levels for the plurality of pixel intensity levels based at least in part on the compressed pixel intensity range;

means for determining an estimated power consumption value, wherein the estimated power consumption value is associated with an estimated power consumption of the display device to display the image according to the set of initial scaled pixel intensity levels;

means for determining a set of scaled pixel intensity levels based at least in part on a ratio of the target power scaling value to the estimated power consumption value; and

means for scaling a pixel intensity of each of a plurality of pixels of the display device from one of the plurality of pixel intensity levels to a corresponding scaled pixel intensity level of the set of scaled pixel intensity levels to display, by the display device, the image according to the set of scaled pixel intensity levels.

22. The apparatus of claim 21, wherein the means for determining the set of initial scaled pixel intensity levels further comprises:

means for determining a contrast enhancement index for each of the plurality of pixel intensity levels to display, by the display device, the image according to the scaled pixel intensity level based at least in part on a frequency of the respective pixel intensity level within output colors of the plurality of pixels of the display device; and

means for determining the set of initial scaled pixel intensity levels based at least in part on the contrast enhancement index for each of the plurality of pixel intensity levels.

23. The apparatus of claim 22, wherein the means for determining the set of initial scaled pixel intensity levels further comprises:

means for determining a contrast for each initial scaled pixel intensity level of the set of initial scaled pixel intensity levels based at least in part on the contrast enhancement index for a corresponding intensity level of the plurality of intensity levels.

24. The apparatus of claim 23, wherein the means for determining the set of scaled pixel intensity levels further comprises:

means for determining the contrast for each scaled pixel intensity level of the set of scaled pixel intensity levels based at least in part on the target power scaling value, the estimated power consumption value, and the contrast enhancement index for the corresponding pixel intensity level of the plurality of pixel intensity levels.

25. The apparatus of claim 21, wherein the means for determining the compressed pixel intensity range for the plurality of pixel intensity levels of the display device further comprises:

means for determining a power consumption value associated with a maximum pixel intensity level out of the plurality of pixel intensity levels;

means for scaling the power consumption value according to the target power scaling value; and

means for determining a maximum pixel intensity level for the compressed pixel intensity range based at least in part on the scaled power consumption value.

26. The apparatus of claim 21, wherein each of the plurality of pixel intensity levels for the display device comprises a value component of a hue-saturation-value (HSV) color space.