DYNAMIC COMPENSATION OF DISPLAY BACKLIGHT BY ADAPTIVELY ADJUSTING A SCALING FACTOR BASED ON MOTION

• US 20110032430A1
• Filed: 08/06/2009
• Published: 02/10/2011
• Est. Priority Date: 08/06/2009
• Status: Active Grant

• Current Assignee: North Star Innovations Inc. (Wi-LAN Inc.)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: He, Zhongli, Prieto, Yolanda
• Granted Patent: US 8,325,280 B2
• Time in Patent Office: Days
• US Class Current: 348/687
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/106 Determination of movement vectors or equivalent parameters within the image
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: H04N 21/4318 by altering the content in the rendering process, e.g. blanking, blurring or masking an image region image enhancement or restoration in general G06T5/00
• CPC Class Codes: H04N 21/44008 involving operations for analysing video streams, e.g. detecting features or characteristics in the video stream arrangements characterised by components specially adapted for monitoring, identification or recognition of video in broadcast systems H04H60/59
• CPC Class Codes: H04N 21/4436 Power management, e.g. shutting down unused components of the receiver power management in computer systems G06F1/3203; hibernate or awake process in computer systems G06F9/4418
• CPC Class Codes: H04N 5/144 Movement detection for video coding H04N19/503; analysis of motion in general G06T7/20
• CPC Class Codes: H04N 5/57 Control of contrast or brightness

Abstract

A video adjustment system for processing video information is disclosed which includes a motion analyzer and an adjustment module. The motion analyzer determines a motion level metric of the video information based on at least one motion parameter. The adjustment adjusts an initial dynamic light scaling factor to provide an adjusted dynamic light scaling factor based on the motion level. The dynamic light scaling factor may be used for luminance compensation and backlight display scaling. The motion level may be based on any type of motion information, such as motion vector information or information indicating a scene change. A distortion module may perform a distortion evaluation of the video information for calculating the initial scaling factor. Alternatively, the distortion module may include a memory which stores predetermined scaling factors based on statistical distortion level characterization.

Claims

1. A video adjustment system for processing video information, comprising:

a motion analyzer which determines a motion level metric of the video information based on at least one motion parameter; and

an adjustment module which adjusts an initial dynamic light scaling factor to provide an adjusted dynamic light scaling factor based on said motion level.

2. The video adjustment system of claim 1, wherein said motion analyzer determines said motion level metric based on motion vector information.

3. The video adjustment system of claim 1, wherein said motion analyzer determines said motion level metric based on detecting a scene change.

4. The video adjustment system of claim 1, wherein said motion analyzer determines said motion level metric based on a percentage of intraframe coded video blocks of a video frame.

5. The video adjustment system of claim 1, wherein said adjustment module determines said adjusted dynamic light scaling factor based on a power level.

6. The video adjustment system of claim 1, wherein said adjustment module subtracts an incremental scaling value from said initial dynamic light scaling factor if motion is above a predetermined threshold or if a scene change is detected.

7. The video adjustment system of claim 1, further comprising a distortion module which performs distortion evaluation of the video information for calculating said initial dynamic light scaling factor based on a target distortion metric.

8. The video adjustment system of claim 1, wherein said distortion module comprises a memory which stores a plurality of predetermined scaling factors based on statistical distortion level characterization in which one of said plurality of predetermined scaling factors is selected as said initial dynamic light scaling factor by a target distortion metric.

9. An electronic video device, comprising:

a video processing system which provides motion information associated with video information;

a video adjustment system which determines a dynamic light scaling factor based on a target distortion metric and said motion information; and

a display system which displays adjusted video information which is adjusted based on said dynamic light scaling factor.

10. The electronic video device of claim 9, wherein said video adjustment system comprises:

a distortion module which determines an initial dynamic light scaling factor for said video information based on said target distortion metric;

a motion analyzer which determines a motion metric of said video information based on said motion information; and

an adjustment module which provides an adjusted dynamic light scaling factor based on said initial dynamic light scaling factor and said motion metric.

11. The electronic video device of claim 10, further comprising:

a controller which provides a power level value; and

wherein said adjustment module determines said adjusted dynamic light scaling factor by subtracting a factor of said power level value and said motion metric from said initial scaling factor.

12. The electronic video device of claim 9, wherein said motion information comprises motion vector information.

13. The electronic video device of claim 9, wherein said motion information comprises an indication of a scene change.

14. The electronic video device of claim 9, wherein said display system comprises:

a luminance compensator which adjusts luminance of said video information based on said dynamic light scaling factor; and

a backlight unit which adjusts backlight power based on said dynamic light scaling factor.

15. The electronic video device of claim 9, wherein said video adjustment system comprises a lookup table of stored scaling factors predetermined by statistical distortion level characterization of test images.

16. A method of processing video information, comprising:

determining a motion level of the video information; and

adjusting an initial dynamic light scaling factor to provide an adjusted dynamic light scaling factor based on the motion level.

17. The method of claim 16, further comprising determining a distortion level of the video information and providing the initial dynamic light scaling factor to achieve a target distortion level.

18. The method of claim 16, wherein said determining a motion level comprises measuring displacement of motion vector information.

19. The method of claim 16, wherein said determining a motion level comprises measuring a relative amount of intraframe coded information.

20. The method of claim 16, further comprising:

determining available power; and

wherein said adjusting an initial dynamic light scaling factor comprises providing the adjusted dynamic light scaling factor based on the initial dynamic light scaling factor, the motion level, and available power.

21. The method of claim 16, further comprising compensating luminance of the video information using the adjusted dynamic light scaling factor.

22. The method of claim 16, further comprising scaling a backlight of a display using the adjusted dynamic light scaling factor.