Methods and systems for display source light management with rate change control

1. A method for modifying a display source light illumination level, said method comprising:

a) determining a relative source light parameter representing the relative amount that a source light level can be reduced with adequate compensation through brightness preservation processing, where said brightness preservation processing is based upon an effectiveness of brightness preservation process that is based upon the content of an input image;

b) determining a display power difference value;

c) determining a previous frame peak source light illumination level; and

d) modifying said previous frame peak source light illumination level with said relative source light parameter and said display power difference value, thereby creating a current-frame modified source light illumination level.

2. A method for modifying a display source light illumination level, said method comprising:

a) determining a relative source light parameter representing the relative amount that a source light level can be reduced with adequate compensation through brightness preservation processing, where said brightness preservation processing is based upon an effectiveness of brightness preservation process that is based upon the content of an input image;

b) determining a display power target value;

c) determining actual display power value;

d) subtracting said actual display power value from said display power target value, thereby creating a power difference value;

e) multiplying said power difference value by a rate control parameter, thereby creating a power adjustment;

f) determining a previous frame peak source light illumination level;

g) adding said power adjustment to said previous frame peak source light illumination level, thereby creating a current frame peak source light illumination level;

h) ensuring that said current frame peak source light illumination level falls within an allowable range defined by a minimum limit and a maximum limit; and

i) multiplying said current frame peak source light illumination level by said relative source light parameter, thereby creating a current-frame modified source light illumination level.

3. A method as described in claim 2 wherein said display target power value is a source light illumination level target.

4. A method as described in claim 2 wherein said actual display power value is an actual source light illumination level.

5. A method as described in claim 2 wherein said display target power value is a power consumption target.

6. A method as described in claim 2 wherein said actual display power value is an actual battery power consumption value.

7. A method as described in claim 2 wherein said relative source light parameter is selected based on image percentiles.

8. A method as described in claim 2 wherein said rate control parameter is a variable that is dependent on current frame image content.

9. A method as described in claim 2 wherein said rate control parameter is a variable that is dependent on scene cut detection.

10. A method for modifying a display source light illumination level, said method comprising:

a) determining a relative source light parameter representing the relative amount that a source light level can be reduced with adequate compensation through brightness preservation processing of a current image frame, where said brightness preservation processing is based upon an effectiveness of brightness preservation process that is based upon the content of an input image;

b) analyzing current-frame image content of said current image frame;

c) determining a rate control parameter based on said current image frame content;

d) determining a display power target value;

e) determining actual display power value;

f) subtracting said actual display power value from said display power target value, thereby creating a power difference value;

g) multiplying said power difference value by said rate control parameter, thereby creating a power adjustment;

h) determining a previous frame peak source light illumination level;

i) adding said power adjustment to said previous frame peak source light illumination level, thereby creating a current frame peak source light illumination level;

j) ensuring that said current frame peak source light illumination level falls within an allowable range defined by a minimum limit and a maximum limit; and

k) multiplying said current frame peak source light illumination level by said relative source light parameter, thereby creating a modified source light illumination level.

11. A method as described in claim 10 wherein said display target power value is a source light illumination level target.

12. A method as described in claim 10 wherein said actual display power value is an actual source light illumination level.

13. A method as described in claim 10 wherein said display target power value is a power consumption target.

14. A method as described in claim 10 wherein said actual display power value is an actual battery power consumption value.

15. A method as described in claim 10 wherein said relative source light parameter is selected based on image percentiles.

16. A method as described in claim 10 wherein said rate control parameter is a variable that is dependent on scene cut detection.

17. A method as described in claim 16 wherein said rate control parameter has a value of 1 when a scene cut is detected in said current frame.

18. A method as described in claim 10 further comprising analyzing previous-frame image content for a previous frame.

19. A method as described in claim 18 wherein said determining a rate control parameter also comprises said analyzing previous frame image content.

20. A method as described in claim 19 wherein said analyzing current-frame image content and said analyzing previous-frame image content comprises scene cut detection.

21. A system for modifying a display source light illumination level, said system comprising:

a) a relative parameter receiver for receiving a relative source light parameter representing the relative amount that a source light level can be reduced with adequate compensation through brightness preservation processing, where said brightness preservation processing is based upon an effectiveness of brightness preservation process that is based upon the content of an input image;

b) a target receiver for receiving a display power target value;

c) a sensor for sensing an actual display power value;

d) a difference calculator for subtracting said actual display power value from said display power target value, thereby creating a power difference value;

e) a product calculator for multiplying said power difference value by a rate control parameter, thereby creating a power adjustment;

f) a buffer for storing a previous frame peak source light illumination level;

g) a sum calculator for adding said power adjustment to said previous frame peak source light illumination level, thereby creating a current frame peak source light illumination level;

h) a limit processor for ensuring that said current frame peak source light illumination level falls within an allowable range defined by a minimum limit and a maximum limit; and

i) a modified level calculator for multiplying said current frame peak source light illumination level by said relative source light parameter, thereby creating a modified source light illumination level.