Method and apparatus for initiating subsequent exposures based on determination of motion blurring artifacts

• US 7,639,888 B2
• Filed: 11/10/2004
• Issued: 12/29/2009
• Est. Priority Date: 11/10/2004
• Status: Expired due to Fees

• Current Assignee: FotoNation Limited (Adeia Inc.)
• Original Assignee: FotoNation Ireland Limited (Adeia Inc.)
• Inventors: Corcoran, Peter, Steinberg, Eran, Prilutsky, Yury
• Primary Examiner(s): Mehta; Bhavesh M
• Assistant Examiner(s): BLOOM, NATHAN J
• Application Number:
  US10/985,650
• Publication Number:
  US 20060098237A1
• Time in Patent Office: 1,875 Days
• Field of Search: 382/107, 348/208.99, 348/208.1, 348/208.4, 348/208.14, 348/208.16
• US Class Current: 382/255
• CPC Class Codes: H04N 23/63 by using electronic viewfinders
• 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 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6811 based on the image signal
• CPC Class Codes: H04N 23/6812 based on additional sensors, e.g. acceleration sensors
• CPC Class Codes: H04N 23/682 Vibration or motion blur correction

Abstract

A digital image acquisition system includes a portable apparatus for capturing digital images and a digital processing component for detecting, analyzing, invoking subsequent image captures and informing the photographer regarding motion blur, and for reducing camera motion blur in an image captured by the apparatus. The digital processing component operates by comparing the image with at least one other image, for example a preview image, of nominally the same scene taken outside the exposure period of the main image. In one embodiment the digital processing component identifies at least one feature in a single preview image which is relatively less blurred than the corresponding feature in the main image, calculates a point spread function (PSF) in respect of such feature, and initiates a subsequent capture if determined that the motion blur exceeds a certain threshold. In another embodiment the digital processing determines the degree of blur by analyzing the motion blur in the captured image itself, and initiates a subsequent capture if determined that the motion blur exceeds a certain threshold. Such real time analysis may use the auto focusing mechanism to qualitatively determine the PSF.

Claims

1. A digital image acquisition system, comprising an apparatus for capturing digital images and a digital processing component for initiating a new image capture upon determining that a threshold camera motion blur has occurred in a captured digital image based on a comparison of image data of a captured digital image and one or more relatively low resolution reference images each acquired with a same sensor, such that at least a same portion of said same sensor captures at least a portion of said image data of each of said captured digital image and said one or more relatively low resolution reference images within a temporal range that includes an exposure period of the captured digital image, and times proximately before and after said exposure period, and of nominally the same scene as that of the captured digital image, and wherein said image data of said captured digital image and said one or more relatively low resolution reference images comprises said captured image and at least one of the one or more relatively low resolution reference images taken outside the exposure period of said captured image, and wherein said digital processing component is arranged first to align at least portions of the image data of said captured digital image and said one or more relatively low resolution reference images, and then to compare the image data of said captured digital image and said one or more relatively low resolution reference images for determining a camera motion blur function, and to determine whether to de-blur said captured image depending on whether the camera motion blur function indicates that sufficient or insufficient blur exists.

2. A system according to claim 1, wherein the determining that a threshold camera motion blur has occurred is based on determining a motion blur function.

3. A system according to claim 2 wherein the camera motion blur function is mathematically defined as a point spread function (PSF).

4. A system according to claim 2, wherein said digital processing component further de-blurs the captured image using said determined camera motion blur function.

5. A system according to claim 1, wherein at least one of the sets of image data that are compared comprises a preview image.

6. A system according to claim 1, wherein a first set of image data is compared to a second set of image data comprising a lower pixel resolution than the first set and wherein said digital processing component is arranged to match the pixel resolutions of the first and second image data sets.

7. A system according to claim 6, wherein said digital processing component is arranged to match the pixel resolutions of the first and second image data sets by at least one of up-sampling the first image data set and sub-sampling the second image data set.

8. A system according to claim 1, wherein the alignment is a global, alignment on entire or substantially entire images.

9. A system according to claim 1, wherein said digital processing component uses the captured image and a single reference image as the image data sets that are compared, and determines a motion blur function based on the comparison.

10. A system according to claim 9, wherein said digital processing component identifies at least one characteristic of the reference image which is relatively less blurred than the corresponding characteristic of the captured image, and calculates said blur function in respect of said characteristic.

11. A system according to claim 10, wherein said digital processing component de-blurs the captured image by de-convolving the captured image using the blur function.

12. A system according to claim 1, wherein said digital processing component uses the captured image and multiple reference images taken at successive points in time.

13. A system according to claim 12, wherein said digital processing component calculates a trajectory of at least one characteristic in the reference images, extrapolates such characteristic on to the captured image, and calculates a motion blur function in respect of said characteristic.

14. A system according to claim 13, wherein said digital processing component de-blurs the captured image by dc-convolving the captured image using the blur function.

15. A system according to claim 1, wherein said digital processing component is configured to inform the photographer if it determines that the captured image is blurred.

16. A system according to claim 1, wherein said digital image acquisition system comprises a portable digital camera comprising a single sensor for capturing said at least two sets of image data.

17. A system as claimed in claim 16, wherein said digital processing component is located in said portable digital camera.

18. A system according to claim 1, wherein said digital image acquisition system comprises a combination of a portable digital camera and an external processing device, wherein said camera comprises a single sensor for capturing said at least two sets of image data.

19. A system as claimed in claim 17, wherein said digital processing component is located in said external processing device.

20. A system as in claim 1, wherein said at least two image data sets comprise said captured image and a reference image taken outside the exposure period of said captured image, and wherein said system comprises a single sensor for capturing said at least two sets of image data.

21. A system as in claim 20, wherein said digital image capturing apparatus is configured to capture a reference image before said exposure period of said captured image.

22. A system according to claim 20 wherein the digital processing component determines a camera motion blur function based on the comparison, wherein the camera motion blur function is mathematically defined as a point spread function (PSF).

23. A system according to claim 22, wherein said digital processing component is configured to further de-blur the captured image using said determined camera motion blur function.

24. A system according to claim 22, wherein the reference image comprises a preview image.

25. A system according to claim 20, wherein the reference image comprises a lower pixel resolution than the captured image, and wherein said digital processing component is arranged to match the pixel resolutions of the captured image and the reference image.

26. A system according to claim 25, wherein said digital processing component is arranged to match the pixel resolutions of the captured image and the reference mage by at least one of up-sampling the reference image and sub-sampling the captured image.

27. A system according to claim 20, wherein said digital processing component is arranged to align at least portions of the captured image and the reference image.

28. A system according to claim 20, wherein the motion blur determining is performed in real time relative to the capturing of the digital image.

29. A system according to claim 1, wherein said apparatus comprises an image sensor component and said at least two sets of image data are acquired by said same image sensor component.

30. A system according to claim 29, wherein said apparatus further comprises an optical system and said at least two sets of image data are acquired along said same optical path.

31. In a digital image acquisition system including an apparatus having a processor, lens and image sensor for capturing digital images, a method comprising using said processor in initiating a new image capture upon determining that a threshold camera motion blur has occurred in a captured digital image based on a comparison of image data of a captured digital image and one or more relatively low resolution reference images each acquired with a same sensor, such that at least a same portion of said same sensor captures at least a portion of said image data of each of said captured image and said one or more relatively low resolution references images, within a temporal range that includes an exposure period of the captured digital image, and times proximately before and after said exposure period, and of nominally the same scene as that of the captured digital image, and wherein said image data of said captured image and said one or more relatively low resolution references images comprises said captured image and at least one of said one or more relatively low resolution reference images taken outside the exposure period of said captured image, and wherein said digital processing component is arranged first to align at least portions of the image data of said captured digital image and said one or more relatively low resolution reference images, and then to compare the image data of said captured digital image and said one or more relatively low resolution reference images for determining a camera motion blur function, and to determine whether to de-blur said captured image depending on whether the camera motion blur function indicates that sufficient or insufficient blur exists.

32. A method according to claim 31, wherein said reference image is taken before said exposure period of said captured image.

33. A method according to claim 31, wherein the determining comprises matching pixel resolutions of the reference and captured images by at least one of up-sampling a reference image and sub-sampling the captured image.

34. A method according to claim 31, further comprising identifying at least one characteristic of the reference image which is relatively less blurred than the corresponding characteristic of the captured image, and calculating a motion blur function in respect of said characteristic.

35. A method according to claim 31, further comprising calculating a trajectory of at least one characteristic in the reference image, extrapolating such characteristic onto the captured image, and calculating a motion blur function in respect of said characteristic.

36. A method according to claim 31, further comprising determining a camera motion blur function based on said comparison, and wherein the camera motion blur function comprises a point spread function (PSF).

37. A method according to claim 31, further including de-blurring the captured image using said determined camera motion blur function.

38. A method according to claim 37, wherein the de-blurring comprises de-convolving the captured image using the blur function.

39. A method according to claim 31, further including informing the photographer when the captured image is determined to be blurred.

40. A method according to claim 31, further including transferring the at least two images from the digital image capturing apparatus to an external processing device for determining a motion blur function.

41. A method according to claim 31, wherein the motion blur determining is performed in real time relative to the capturing of the digital image.

42. A method according to claim 31, further comprising acquiring images corresponding to said at least two image data sets with a same image sensor component.

43. A method according to claim 42, wherein said capturing of said images occurs along a same optical path.

44. One or more processor-readable storage devices having digital code embedded therein for programming one or more processors to perform a camera motion blur determining method that comprises capturing digital images, and initiating a new image capture upon determining that a threshold camera motion blur has occurred in a captured digital image based on a comparison of image data of the captured digital image and one or more relatively low resolution reference images each acquired with a same sensor, such that at least a same portion of said same sensor captures at least a portion of said image data of each of said captured digital image and said one or more relatively low resolution reference images, within a temporal range that includes an exposure period of the captured digital image, and times proximately before and after said exposure period, and of nominally the same scene as that of the captured digital image, and wherein said image data of said captured digital image and said one or more relatively low resolution reference images comprises said captured image and at least one of said one or more reference images taken outside the exposure period of said captured image, and wherein said digital processing component is arranged first to align at least portions of the image data of said captured digital image and said one or more relatively low resolution reference images, and then to compare the image data of said captured digital image and said one or more relatively low resolution reference images for determining a camera motion blur function, and to determine whether to de-blur said captured image depending on whether the camera motion blur function indicates that sufficient or insufficient blur exists.

45. The one or more storage devices of claim 44, wherein said reference image is taken before said exposure period of said captured image.

46. The one or more storages devices of claim 44, wherein the determining comprises matching pixel resolutions of the reference and captured images by at least one of up-sampling a reference image and sub-sampling the captured image.

47. The one or more storage devices of claim 44, the method further comprising identifying at least one characteristic of the reference image which is relatively less blurred than the corresponding characteristic of the captured image, and calculating a camera motion blur function in respect of said characteristic.

48. The one or more storage devices of claim 44, the method further comprising calculating a trajectory of at least one characteristic in the reference image;

extrapolating such characteristic onto the captured image, and calculating a camera motion blur function in respect of said characteristic.

49. The one or more storage devices of claim 44, the method further comprising determining a camera motion blur function, and wherein the camera motion blur function comprises a point spread function (PSF).

50. The one or more storage devices of claim 49, further including de-blurring the captured image using said determined camera motion blur function.

51. The one or more storage devices of claim 50, wherein the de-blurring comprises de-convolving the captured image using the blur function.

52. The one or more storage devices of claim 44, the method further including informing the photographer when the captured image is determined to be blurred.

53. The one or more storage devices of claim 44, the method further including transferring the at least two images from the digital image capturing apparatus to an external processing device for determining a motion blur function.

54. The one or more storage devices of claim 44, wherein the motion blur determining is performed in real time relative to the capturing of the digital image.

55. The one or more storage devices of claim 44, the method further comprising acquiring images corresponding to said at least two image data sets with a same image sensor component.

56. The one or more storage devices of claim 55, wherein said capturing of said images occurs along a same optical path.