Method and system for adaptive color and contrast for display devices

1. A method for automatically and adaptively controlling contrast and color of a display device, comprising:

computing a normalized histogram of a current image;

computing degrees of correlation between the normalized histogram and a number of template histograms;

sorting the template histograms based upon the associated degrees of correlation;

selecting a number of the best correlated template histograms based on the sorting;

associating each of the selected template histograms with a corresponding transfer function;

blending the transfer functions to form a blended transfer function; and

applying the blended transfer function to the current image.

2. The method of claim 1 , wherein the current image is a video frame V n , included in a video formed of a number L video frames.

3. The method as recited in claim 2 , further comprising:

applying the blended transfer function to video frames V n+1 to video frame V n+k .

4. The method of claim 3 , further comprising:

averaging the normalized histogram with a previous number M normalized histograms each of which is associated with a particular video frame.

5. The method of claim 1 , further comprising:

if none of the degrees of correlation is greater than a predetermined threshold value, then applying only a default transfer function to the current image.

6. The method of claim 1 , wherein the histogram is normalized to a predefined range.

7. The method of claim 1 , further comprising:

analyzing the pixel luma distribution, by collection and analysis of pixel luma distribution using multiple bands; and

generating a luma and a chroma control response.

8. The method of claim 7 in which the multiple bands include overlapping bands.

9. The method of claim 8 that collects pixel luma distribution information using bin counters for each band.

10. The method of claim 9 in which the collection of pixel luma distribution information is limited to a user-definable region in the display.

11. The method of claim 10 in which the application of automatic and adaptive contrast and color control is to a user-definable region in the display.

12. The method of claim 10 in which an optimal contrast control response is generated by analysis of the actual luma distribution followed by blending of user defined contrast control responses.

13. The method as recited in claim 1 , wherein the computing a degree of correlation between the normalized histogram and a template histogram comprises:

determining an absolute difference of the heights of each bin of the template histogram and the normalized histogram; and

adding the absolute differences together.

14. The method as recited in claim 13 , wherein the best correlation is the lowest value of the adding.

15. The method of claim 1 in which RGB, YUV, YCrCb, YPrPb or any other color domain are utilized.

16. The method of claim 15 in which analog or digital displays are utilized.

17. The method of claim 2 wherein the histogram for a particular frame is stored in a memory.

18. Computer program product for automatically and adaptively controlling contrast and color of a display device, comprising:

computer code for computing a normalized histogram of a current image;

computer code for computing degrees of correlation between the normalized histogram and a number of template histograms;

computer code for sorting the template histograms based upon the associated degrees of correlation;

computer code for selecting a number of the best correlated template histograms based on the sorting;

computer code for associating each of the selected template histograms with a corresponding transfer function;

computer code for blending the transfer functions to form a blended transfer function;

computer code for applying the blended transfer function to the current image; and

computer readable medium for storing the computer code.

19. The computer program product of claim 18 , wherein the current image is a video frame V n , included in a video formed of a number L video frames.

20. The computer program product as recited in claim 19 , further comprising:

computer code for applying the blended transfer function to video frames V +1 to video frame V n+k .

21. The computer program product of claim 20 , further comprising:

computer code for averaging the normalized histogram with a previous number M normalized histograms each of which is associated with a particular video frame.

22. The computer program product of claim 18 , further comprising:

computer code for applying only a default transfer function to the current image if none of the degrees of correlation is greater than a predetermined threshold value.

23. The computer program product of claim 18 , wherein the histogram is normalized to a predefined range.

24. The computer program product of claim 18 , further comprising:

computer code for analyzing the pixel luma distribution, by collection and analysis of pixel luma distribution using multiple bands; and

computer code for generating a luma and a chroma control response.

25. The computer program product of claim 24 in which the multiple bands include overlapping bands.

26. The computer program product of claim 25 that collects pixel luma distribution information using bin counters for each band.

27. The computer program product of claim 26 in which the collection of pixel luma distribution information is limited to a user-definable region in the display.

28. The computer program product of claim 27 in which the application of automatic and adaptive contrast and color control is to a user-definable region in the display.

29. The computer program product of claim 27 in which an optimal contrast control response is generated by analysis of the actual luma distribution followed by blending of user defined contrast control responses.

30. The computer program product as recited in claim 18 , wherein the computing a degree of correlation between the normalized histogram and a template histogram comprises:

computer code for determining an absolute difference of the heights of each bin of the template histogram and the normalized histogram; and

computer code for adding the absolute differences together.

31. The computer program product as recited in claim 30 , wherein the best correlation is the lowest value of the adding.

32. The computer program product of claim 18 in which RGB, YUV, YCrCb, YPrPb or any other color domain are utilized.

33. The computer program product of claim 32 in which analog or digital displays are utilized.

34. The computer program product of claim 19 wherein the histogram for a particular frame is stored in a memory.

35. An apparatus for automatically and adaptively controlling contrast and color of a display device, comprising:

means for computing a normalized histogram of a current image;

means for computing degrees of correlation between the normalized histogram and a number of template histograms;

means for sorting the template histograms based upon the associated degrees of correlation;

means for selecting a number of the best correlated template histograms based on the sorting;

means for associating each of the selected template histograms with a corresponding transfer function;

means for blending the transfer functions to form a blended transfer function; and

means for applying the blended transfer function to the current image.