RGBW SENSOR ARRAY

• US 20110102638A1
• Filed: 10/11/2010
• Published: 05/05/2011
• Est. Priority Date: 03/05/2007
• Status: Active Grant

• Current Assignee: FotoNation Limited (Adeia Inc.)
• Original Assignee: Tessera Technologies Ireland Limited (Adeia Inc.)
• Inventors: Susanu, George, Petrescu, Stefan, Capata, Adrian, Nanu, Florin, Corcoran, Peter
• Granted Patent: US 8,878,967 B2
• Time in Patent Office: Days
• US Class Current: 348/239
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/10144 Varying exposure
• CPC Class Codes: G06T 5/009 Global, i.e. based on properties of the image as a whole applied in cameras using an electronic image sensor H04N23/80, H04N23/70
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/92 based on global image properties
• CPC Class Codes: H04N 23/843 Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 25/133 including elements passing panchromatic light, e.g. filters passing white light
• CPC Class Codes: H04N 25/589 with different integration times, e.g. short and long exposures

Abstract

A color filter enhancement method for a portable digital image acquisition device includes digitally exposing color pixels of a color sensor array for a first digital exposure duration and digitally exposing white pixels of a color sensor array for a second digital exposure time shorter than the first digital exposure duration. A color filter enhanced digital image is generated using data from both the color pixels exposed for the first digital exposure duration and the white pixels exposed for the second digital exposure duration.

Claims

1. A color filter enhancement method for a portable digital image acquisition device, comprising:

using optics, a color sensor array and a processor to acquire and process digital images;

obtaining a first relatively underexposed and sharp image of a scene (“

sharp image”

) by exposing a first set of pixels of the sensor array;

obtaining a second relatively well exposed and blurred image of the same scene (“

blurred image”

) by exposing a second set of pixels of the sensor array for a longer duration than the sharp image, and wherein the second set of pixels interleaves the first set of pixels; and

applying color or luminance information, or both, from the blurred image to the sharp image, thereby constructing a color-enhanced and/or luminance-enhanced version of the sharp image.

2. The method of claim 1, wherein obtaining the blurred image comprises digitally exposing color pixels of the sensor array for a first digital exposure duration;

and wherein obtaining the sharp image comprises digitally exposing white pixels of the sensor array for a second digital exposure time shorter than the first digital exposure duration.

3. The method of claim 2, wherein the constructing of the color-enhanced and/or luminance-enhanced version of the sharp image comprises using data from both the color pixels exposed for the first digital exposure duration and the white pixels exposed for the second digital exposure duration.

4. The method of any of claims 2, wherein the digitally exposing of the color pixels and the white pixels for different exposure times comprises clocking the color pixels and the white pixels independently.

5. The method of any of claims 2, wherein the digitally-exposing of the color pixels and the white pixels for different exposure times comprises including sensor data over different temporal ranges.

6. The method of claim 5, wherein the different temporal ranges are overlapping.

7. The method of claim 6, wherein a first temporal range corresponding to the digitally-exposing of the color pixels comprises an entire second temporal range corresponding to the digitally-exposing of the white pixels.

8. The method of claim 2, wherein the color pixels comprise greater motion blurring effect than the white pixels due to the color pixels being digitally-exposed for a longer duration than the white pixels, and the method further comprises compensating blurring in the color pixels using less-blurred data from the white pixels.

9. The method of claim 2, wherein at least a segment of the exposure periods of the sharp and blurred images temporally overlap.

10. The method of claim 1, wherein the second digital exposure time comprises not more than half of the first digital exposure time.

11. The method of claim 1, wherein the second digital exposure time comprises approximately a third of the first digital exposure time.

12. The method of claim 1, wherein the color sensor array comprises a CMOS-based sensor.

13. The method of claim 1, further comprising storing, transmitting, or displaying the color-enhanced and/or luminance-enhanced version of the sharp image, or a further processed version, or combinations thereof.

14. The method of claim 1, wherein at least a segment of the exposure periods of the sharp and blurred images temporally overlap.

15. A portable digital image acquisition device, comprising:

optics and a color sensor array for acquiring a color digital image;

a processor;

one or more processor-readable media having code embedded therein for programming the processor to perform a color filter enhancement method that comprises the following;

obtaining a first relatively underexposed and sharp image of a scene (“

sharp image”

) by exposing a first set of pixels of the sensor array;

obtaining a second relatively well exposed and blurred image of the same scene (“

blurred image”

) by exposing a second set of pixels of the sensor array for a longer duration than the sharp image, and wherein the second set of pixels interleaves the first set of pixels; and

applying color or luminance information, or both, from the blurred image to the sharp image, thereby constructing a color-enhanced and/or luminance-enhanced version of the sharp image.

16. The device of claim 15, wherein obtaining the blurred image comprises digitally exposing color pixels of the sensor array for a first digital exposure duration;

and

wherein obtaining the sharp image comprises digitally exposing white pixels of the sensor array for a second digital exposure time shorter than the first digital exposure duration.

17. The device of claim 16, wherein the constructing of the color-enhanced and/or luminance-enhanced version of the sharp image comprises using data from both the color pixels exposed for the first digital exposure duration and the white pixels exposed for the second digital exposure duration.

18. The device of any of claims 16, wherein the digitally exposing of the color pixels and the white pixels for different exposure times comprises clocking the color pixels and the white pixels independently.

19. The device of any of claims 16, wherein the digitally-exposing of the color pixels and the white pixels for different exposure times comprises including sensor data over different temporal ranges.

20. The device of claim 19, wherein the different temporal ranges are overlapping.

21. The device of claim 20, wherein a first temporal range corresponding to the digitally-exposing of the color pixels comprises an entire second temporal range corresponding to the digitally-exposing of the white pixels.

22. The device of claim 16, wherein the color pixels comprise greater motion blurring effect than the white pixels due to the color pixels being digitally-exposed for a longer duration than the white pixels, and the method further comprises compensating blurring in the color pixels using less-blurred data from the white pixels.

23. The device of claim 16, wherein at least a segment of the exposure periods of the sharp and blurred images temporally overlap.

24. The device of claim 15, wherein the second digital exposure time comprises not more than half of the first digital exposure time.

25. The device of claim 15, wherein the second digital exposure time comprises approximately a third of the first digital exposure time.

26. The device of claim 15, wherein the color sensor array comprises a CMOS-based sensor.

27. The device of claim 15, wherein the method further comprises storing, transmitting, or displaying the color-enhanced and/or luminance-enhanced version of the sharp image, or a further processed version, or combinations thereof.

28. The device of claim 15, wherein at least a segment of the exposure periods of the sharp and blurred images temporally overlap.

29. One or more processor-readable media having code embedded therein for programming the processor to perform a color filter enhancement method that comprises:

obtaining a first relatively underexposed and sharp image of a scene (“

sharp image”

) by exposing a first set of pixels of the sensor array;

obtaining a second relatively well exposed and blurred image of the same scene (“

blurred image”

) by exposing a second set of pixels of the sensor array for a longer duration than the sharp image, and wherein the second set of pixels interleaves the first set of pixels; and

applying color or luminance information, or both, from the blurred image to the sharp image, thereby constructing a color-enhanced and/or luminance-enhanced version of the sharp image.

30. The one or more processor-readable media of claim 29, wherein obtaining the blurred image comprises digitally exposing color pixels of the sensor array for a first digital exposure duration;

and

wherein obtaining the sharp image comprises digitally exposing white pixels of the sensor array for a second digital exposure time shorter than the first digital exposure duration.

31. The one or more processor-readable media of claim 30, wherein the constructing of the color-enhanced and/or luminance-enhanced version of the sharp image comprises using data from both the color pixels exposed for the first digital exposure duration and the white pixels exposed for the second digital exposure duration.

32. The one or more processor-readable media of claim 30, wherein the digitally exposing of the color pixels and the white pixels for different exposure times comprises clocking the color pixels and the white pixels independently.

33. The one or more processor-readable media of claim 30, wherein the digitally-exposing of the color pixels and the white pixels for different exposure times comprises including sensor data over different temporal ranges.

34. The one or more processor-readable media of claim 33, wherein the different temporal ranges are overlapping.

35. The one or more processor-readable media of claim 34, wherein a first temporal range corresponding to the digitally-exposing of the color pixels comprises an entire second temporal range corresponding to the digitally-exposing of the white pixels.

36. The one or more processor-readable media of claim 30, wherein the color pixels comprise greater motion blurring effect than the white pixels due to the color pixels being digitally-exposed for a longer duration than the white pixels, and the method further comprises compensating blurring in the color pixels using less-blurred data from the white pixels.

37. The one or more processor-readable media of claim 30, wherein at least a segment of the exposure periods of the sharp and blurred images temporally overlap.

38. The one or more processor-readable media of claim 29, wherein the second digital exposure time comprises not more than half of the first digital exposure time.

39. The one or more processor-readable media of claim 29, wherein the second digital exposure time comprises approximately a third of the first digital exposure time.

40. The one or more processor-readable media of claim 29, wherein the color sensor array comprises a CMOS-based sensor.

41. The one or more processor-readable media of claim 29, wherein the method further comprises storing, transmitting, or displaying the color-enhanced and/or luminance-enhanced version of the sharp image, or a further processed version, or combinations thereof.

42. The one or more processor-readable media of claim 29, wherein at least a segment of the exposure periods of the sharp and blurred images temporally overlap.