Camera and method with additional evaluation image capture based on scene brightness changes

• US 20070236567A1
• Filed: 04/06/2006
• Published: 10/11/2007
• Est. Priority Date: 04/06/2006
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Eastman Kodak Company
• Inventors: Luo, Jiebo, Pillman, Bruce
• Granted Patent: US 7,903,168 B2
• Time in Patent Office: Days
• US Class Current: 348/143
• CPC Class Codes: H04N 23/631 Graphical user interfaces [GUI] specially adapted for controlling image capture or setting capture parameters
• CPC Class Codes: H04N 23/634 Warning indications
• CPC Class Codes: H04N 23/673 based on contrast or high frequency components of image signals, e.g. hill climbing method
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 23/72 Combination of two or more compensation controls
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control

Abstract

In a method and digital camera, initial evaluation images of a scene are captured with the camera. A change in scene brightness between two or more of the evaluation images is computed. When the scene brightness change is outside a predetermined brightness range, a metric of scene-to-capture mismatch in the evaluation images is determined. When the brightness change and the metric are both outside predetermined ranges, the camera is shifted to a second capture state prior to the capturing of one or more additional evaluation images. In either case, a final camera state is determined using available evaluation images and one or more final images are captured with the camera in the final camera state.

Claims

1. An imaging method for a digital camera, said method comprising the steps of:

capturing a set of evaluation images of a scene with the camera;

computing a change in scene brightness between two or more of said evaluation images;

computing a metric of scene-to-capture mismatch in said evaluation images, when said brightness change is outside a predetermined brightness range;

shifting said camera to a second capture state prior to said capturing of one or more evaluation images of said set, when said brightness change and said metric are outside respective said ranges;

determining a final camera state using said set of evaluation images;

capturing one or more final images with said camera in said final camera state.

2. The method of claim 1 further comprising maintaining said camera in an initial capture state during said capturing of all of said evaluation images, when said brightness change is in said predetermined brightness range or when said mismatch metric is in a predetermined metric range;

3. An imaging method for a digital camera, said method comprising the steps of:

capturing a plurality of initial evaluation images of a scene with the camera;

computing a change in scene brightness between two or more of said initial evaluation images;

when said brightness change is outside a predetermined brightness range, computing scene-to-capture mismatch in said initial evaluation images;

when said brightness change is outside said predetermined brightness range and said mismatch is outside a predetermined mismatch range, shifting said camera to a second capture state and capturing one or more additional evaluation images;

determining a final camera state using said evaluation images;

capturing one or more final images with said camera in said final camera state.

4. The method of claim 3 wherein said second capture state is at least partially compensatory to said mismatch.

5. The method of claim 3 wherein said determining is limited to said initial evaluation images when at least one of said brightness change and said mismatch is in the respective said range.

6. The method of claim 3 wherein said brightness change has possible values with magnitudes from zero to a maximum measurable by said camera and said predetermined brightness range is intermediate to said magnitudes.

7. The method of claim 3 wherein each said evaluation image has associated depth of field and distance range information and said computing of said mismatch further comprises assessing correspondence between said distance range information and said depth of field information.

8. The method of claim 7 wherein said second capture state is at least partially corrective of said mismatch.

9. The method of claim 7 wherein said computing of said mismatch further comprises assessing tonality accumulations in highlights and shadows of said evaluation images.

10. The method of claim 3 wherein said computing of said mismatch further comprises assessing tonality accumulations in highlights and shadows of said evaluation images.

11. The method of claim 10 wherein said second capture state is at least partially corrective of said tonality accumulations.

12. The method of claim 3 wherein each of said capture states includes settings of a plurality of:

focal length, exposure time, focus distance, aperture, white balance adjustment, and flash state.

13. The method of claim 3 wherein said evaluation and final images are frames of a continuous video stream.

14. The method of claim 3 wherein said evaluation and final images are still digital images and said method further comprises archiving said final images and deleting said evaluation images, without user intervention.

15. The method of claim 3 wherein said computing, computing, and shifting steps are free of user intervention.

16. The method of claim 15 wherein said determining step is free of user intervention.

17. The method of claim 15 wherein said determining further comprises displaying indications of a plurality of capture states inclusive of said final capture state prior to said setting, wherein said setting further comprises accepting user input designating one of said plurality of capture states as said final capture state.

18. The method of claim 17 wherein one of said capture states of said plurality is said second capture state.

19. The method of claim 18 wherein said indications are respective said evaluation images.

20. The method of claim 17 further comprising, following said shifting and prior to said determining, switching said camera to another second capture state and capturing one or more supplemental evaluation images;

and wherein said capture states of said plurality include said second capture states.

21. The method of claim 19 wherein said indications are respective said evaluation images.

32. The method of claim 16 further comprising, following said changing and prior to said evaluating, switching said camera to another second capture state and capturing one or more supplemental evaluation images.

22. A digital camera comprising:

a capture unit settable in a plurality of different capture states, said capture unit being actuable to capture a sequence of evaluation images and separately trippable to capture one or more final images, said capture unit defaulting to a predetermined one of said capture states when said capture unit is actuated;

a control unit operatively connected to said capture unit, said control unit responding when said capture unit is actuated to capture said evaluation images, said responding including;

locating one or more markers in said evaluation images, said markers each being indicative of a defect in said evaluation images, assessing brightness change in said scene using said sequence to provide an brightness change assessment, changing said camera to a second of said states and capturing one or more additional evaluation images of said scene when said brightness change assessment is outside a predetermined range, said additional evaluation images being at least partially remedial of said defect.

23. The camera of claim 22 wherein said control unit evaluates said evaluation images including said additional images, sets said camera in a final of said capture states responsive to said evaluating, and captures one or more final images with said camera in said final state when said capture unit is tripped.

24. The camera of claim 23 wherein said evaluating, setting, and capturing of said final images are without user intervention additional to the tripping of said capture unit.

25. The camera of claim 23 wherein said predetermined range has intermediate values between values in a first range and values in a second range, said values in said first range being zero or relatively small, said values in said second range being relatively large.

26. The camera of claim 23 wherein each said evaluation image of said sequence has associated depth of field information and distance range information as to one or more subjects in said scene;

said markers are mismatches between said distance range information and said depth of field information; and

said additional evaluation images each have a respective depth of field correcting said mismatches.

27. The camera of claim 22 wherein said markers are tonality accumulations in highlights and shadows of said images;

and said additional evaluation images exhibit greater tonality in one or both of said highlights and shadows.

28. The camera of claim 22 wherein each of said capture states includes settings of a plurality of:

focal length, exposure time, focus distance, aperture, white balance adjustment, and flash state.

29. The camera of claim 22 wherein said evaluation and final images are frames of a continuous video stream.

30. The camera of claim 22 further comprising memory operatively connected to said control unit;

and wherein said evaluation and final images are still digital images and said control unit archives said final images in said memory and deletes said evaluation images, without user intervention.

31. An imaging method for a digital camera, said method comprising the steps of:

capturing one or more evaluation images of a scene with the camera in an initial capture state, each said evaluation image having an associated focus distance;

providing distance range information as to one or more subjects in said images;

determining one or more mismatches between said distance range information and said depth of field;

assessing brightness change in said scene using said sequence;

when said brightness change assessment is outside a predetermined range, changing said camera to a second capture state providing an altered depth of field, and capturing one or more additional evaluation images of said scene having said altered depth of field;

evaluating said evaluation images;

setting said camera in a final capture state responsive to said evaluating; and

capturing one or more final images with said camera in said final capture state.

33. The method of claim 31 wherein said predetermined range has intermediate values between values in a first range and values in a second range, said values in said first range being zero or relatively small, said values in said second range being relatively large.

34. The method of claim 31 wherein each of said capture states includes settings of a plurality of:

focal length, exposure time, focus distance, aperture, white balance adjustment, and flash state.

35. The method of claim 31 wherein said determining, assessing, and changing steps are free of user intervention.

36. An imaging method for a digital camera, said method comprising the steps of:

capturing one or more evaluation images of a scene with the camera in an initial capture state;

locating one or more tonality accumulations in highlights and shadows of one or more of said evaluation images;

assessing brightness change in said scene using said sequence;

when said brightness change assessment is outside a predetermined range, changing said camera to a second capture state at least partially compensatory to at least one of said tonality accumulations and capturing one or more additional evaluation images of said scene with said camera in said second capture state;

evaluating said evaluation images;

setting said camera in a final state of said plurality of capture states responsive to said evaluating; and

capturing one or more final images with said camera in said final state.

37. The method of claim 36 further comprising, following said changing and prior to said evaluating, switching said camera to another second capture state and capturing one or more supplemental evaluation images.

38. The method of claim 36 wherein said predetermined range has intermediate values between values in a first range and values in a second range, said values in said first range being zero or relatively small, said values in said second range being relatively large.

39. The method of claim 36 wherein each of said capture states includes settings of a plurality of:

focal length, exposure time, focus distance, aperture, white balance adjustment, and flash state.

40. The method of claim 36 wherein said locating, assessing, and changing steps are free of user intervention.