Method of determining PSF using multiple instances of a nominally similar scene

• US 7,636,486 B2
• Filed: 11/10/2004
• Issued: 12/22/2009
• 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:
  US10/985,657
• Publication Number:
  US 20060098890A1
• Time in Patent Office: 1,868 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: G06T 2207/20201 Motion blur correction
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening
• 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 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 de-convolves the main image using the PSF. In another embodiment, the digital processing component calculates a trajectory of at least one feature in a plurality of preview images, extrapolates such feature on to the main image, calculates a PSF in respect of the feature, and de-convolves the main image using the PSF. In another embodiment the digital processing unit after determining the degree of blur notifies the photographer of the existing blur or automatically invokes consecutive captures.

Claims

1. A digital image acquisition system comprising an apparatus for capturing digital images and a digital processing component for determining a camera motion blur function in a captured digital image based on a comparison of at least two sets of image data, including at least one relatively low resolution reference image, each acquired with a same sensor, such that at least a same portion of said same sensor captures at least a portion of each of said at least two sets of image data, 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 at least two sets of image data comprise said at least one relatively low resolution reference image, or at least one processed version of said at least one reference image taken outside the exposure period of said captured digital image and modified pursuant to processing including aligning or matching pixel resolution of said at least two sets of image data, or both, and wherein said digital processing component is arranged to compare the at least two sets of image data for determining said camera motion blur function in said captured digital image, and to determine to de-blur said captured digital image only when the camera motion blur function indicates that sufficient blur exists within the captured digital image.

2. A system according to claim 1 wherein the camera motion blur function is mathematically defined as a point spread function (PSF).

3. A system according to claim 1, wherein said digital processing component further de-blurs the captured image using said determined camera motion blur function.

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

5. A system according to claim 1, wherein said digital processing component is arranged to match the pixel resolutions of the at least two sets of image data.

6. A system according to claim 5, 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.

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

8. 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.

9. A system according to claim 8, 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.

10. A system according to claim 9, wherein said digital processing component de-blurs the captured image by de-convolving the captured image using the blur function.

11. 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.

12. A system according to claim 11, 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 said blur function in respect of said characteristic.

13. A system according to claim 12, wherein said digital processing component de-blurs the captured image by de-convolving the captured image using the blur function.

14. 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.

15. A system of according to claim 14, wherein the digital image capturing apparatus is configured to capture another image if the digital processing component determines that the captured image is blurred.

16. A system of according to claim 1, wherein the digital image capturing apparatus is configured to capture another image if the digital processing component determines that the captured image is blurred.

17. 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.

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

19. 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.

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

21. A system as in claim 1, 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 1 wherein the camera motion blur function is mathematically defined as a point spread function (PSF).

23. A system according to claim 1, 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 1, wherein the reference image comprises a preview image.

25. A system according to claim 1, 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 1, wherein said motion blur function determining occurs in real-time relative to the image capture.

28. 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.

29. A system according to claim 28, wherein said apparatus further comprises an optical system and said at least two sets of image data are acquired along said same optical path.

30. In a digital image acquisition system including an apparatus for capturing digital images, including a lens, an image sensor and a processor, a method comprising programming said processor with program code embedded within a computer readable medium, and using said processor in determining a camera motion blur function in a captured digital image based on a comparison of at least two images each acquired with a same sensor, including at least one relatively low resolution reference image, such that at least a same portion of said same sensor captures at least a portion of each of said at least two sets of image data, 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 at least two sets of image data comprise said at least one relatively low resolution reference image, or at least one processed version of said at least one reference image taken outside the exposure period of said captured digital image and modified pursuant to processing including aligning or matching pixel resolution of said at least two sets of image data, or both, and wherein said digital processing component is arranged to compare the at least two sets of image data for determining said camera motion blur function in said captured digital image, and to determine to de-blur said captured digital image only when the camera motion blur function indicates that sufficient blur exists within the captured digital image.

31. A method according to claim 30, wherein said reference image is taken before said exposure period of said captured image.

32. A method according to claim 30, 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.

33. A method according to claim 30, 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 said blur function in respect of said characteristic.

34. A method according to claim 30, further comprising calculating a trajectory of at least one characteristic in the reference image, extrapolating such characteristic onto the captured image, and calculating said blur function in respect of said characteristic.

35. A method according to claim 30, wherein the camera motion blur function comprises a point spread function (PSF).

36. A method according to claim 30, further including de-blurring the captured image using said determined camera motion blur function.

37. A method according to claim 36, wherein the de-blurring comprises de-convolving the captured image using the blur function.

38. A method according to claim 30, further including informing the photographer when the captured image is determined to be blurred.

39. A method according to claim 30, further including transferring the at least two images from the digital image capturing apparatus to an external processing device for determining the motion blur function.

40. A method according to claim 30, wherein the motion blur function determining is performed in real time relative to the capturing of the digital image.

41. method according to claim 30, further comprising acquiring images corresponding to said at least two image data sets with a same image sensor component.

42. A method according to claim 41, wherein said capturing of said images occurs along a same optical path.

43. One or more processor-readable storage devices having digital code embedded therein for programming one or more processors to perform a camera motion blur function determining method that comprises capturing digital images, and determining a camera motion blur function in a captured digital image based on a comparison of at least two images each acquired with a same sensor, such that at least a same portion of said same sensor captures at least a portion of each of said at least two sets of image data, 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 at least two sets of image data comprise at least one relatively low resolution reference image, or at least one processed version of said at least one reference image taken outside the exposure period of said captured digital image and modified pursuant to processing including aligning or matching pixel resolution of said at least two sets of image data, or both, and wherein said digital processing component is arranged to compare the at least two sets of image data for determining said camera motion blur function in said captured digital image, and to determine to de-blur said captured digital image only when the camera motion blur function indicates that sufficient blur exists within the captured digital image.

44. The one or more storage devices of claim 43, wherein said reference image is taken before said exposure period of said captured image.

45. The one or more storages devices of claim 43, 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.

46. The one or more storage devices of claim 43, 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 said blur function in respect of said characteristic.

47. The one or more storage devices of claim 43, 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 said blur function in respect of said characteristic.

48. The one or more storage devices of claim 43, wherein the camera motion blur function comprises a point spread function (PSF).

49. The one or more storage devices of claim 43, further including de-blurring the captured image using said determined camera motion blur function.

50. The one or more storage devices of claim 49, wherein the de-blurring comprises de-convolving the captured image using the blur function.

51. The one or more storage devices of claim 43, the method further including informing the photographer when the captured image is determined to be blurred.

52. The one or more storage devices of claim 43, the method further including transferring the at least two images from the digital image capturing apparatus to an external processing device for determining the motion blur function.

53. The one or more storage devices of claim 43, wherein the motion blur function determining is performed in real time relative to the capturing of the digital image.

54. The one or more storage devices of claim 43, the method further comprising acquiring images corresponding to said at least two image data sets with a same image sensor component.

55. The one or more storage devices of claim 54, wherein said capturing of said images occurs along a same optical path.