Image capture apparatus and control method therefor

• US 9,001,225 B2
• Filed: 10/14/2013
• Issued: 04/07/2015
• Est. Priority Date: 10/22/2012
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Watanabe, Takeshi, Miyasako, Kenichi
• Primary Examiner(s): Ho, Tuan
• Assistant Examiner(s): CAMARGO, MARLY S.B.
• Application Number:
  US14/053,055
• Publication Number:
  US 20140111658A1
• Time in Patent Office: 540 Days
• Field of Search: 348/208.99, 348/208.1, 348/208.3, 348/208.4, 348/208.6, 348/208.11, 348/208.12, 348/208.13, 348/222.1, 348/345, 396/52, 382/255, 382/107, 382/261, 382/263, 382/264, 375/240.16, 375/240.22
• US Class Current: 348/208.99
• CPC Class Codes: G02B 27/646 compensating for small deviations, e.g. due to vibration or shake movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68
• 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
• CPC Class Codes: H04N 23/683 performed by a processor, e.g. controlling the readout of an image memory

Abstract

An image capture apparatus comprises a first shake detection unit configured to detect a shake of the image capture apparatus, a rotational shake calculation unit configured to calculate a rotational shake amount, a second shake detection unit configured to detect the shake of the image capture apparatus, a translational shake calculation unit configured to calculate a translational shake amount, a correction amount calculation unit configured to calculate, based on the rotational shake amount and the translational shake amount, a correction amount for correcting image blurring, and a correction unit configured to correct the image blurring, wherein the rotational shake calculation unit calculates a first translational motion component and perspective component, and wherein the correction amount calculation unit calculates a second translational motion component.

Claims

1. An image capture apparatus comprising:

a first shake detection unit configured to detect a shake of said image capture apparatus;

a rotational shake calculation unit configured to calculate a rotational shake amount based on an output of said first shake detection unit;

a second shake detection unit configured to detect the shake of said image capture apparatus by a method different from that of said first shake detection unit;

a translational shake calculation unit configured to calculate a translational shake amount based on the output of said first shake detection unit and an output of said second shake detection unit;

a correction amount calculation unit configured to calculate, based on the rotational shake amount and the translational shake amount, a correction amount for correcting image blurring of an image; and

a correction unit configured to correct the image blurring based on a calculation result of said correction amount calculation unit,

wherein said rotational shake calculation unit calculates a first translational motion component and perspective component using the rotational shake amount, and the first translational motion component is a translational motion component of image blurring generated in a captured image due to a rotational shake, and

wherein said correction amount calculation unit calculates a second translational motion component based on the first translational motion component and the translational shake amount, and the second translational motion component is a translational motion component of image blurring generated in the captured image due to the rotational shake and a translational shake.

2. The apparatus according to claim 1,

wherein said second shake detection unit serves as a motion vector detection unit configured to detect a motion vector between two images forming a moving image, and

wherein said translational shake calculation unit calculates the translational shake amount by subtracting a value based on the output of said shake detection unit from a value based on a motion vector.

3. The apparatus according to claim 1, further comprising

an optical correction unit configured to optically correct the image blurring generated in the captured image due to the shake,

wherein said correction amount calculation unit calculates, based on the output of said shake detection unit, a correction amount for optically correcting a translational motion component of the image blurring generated in the captured image due to the shake, and calculates, based on the rotational shake amount, the translational shake amount, and the correction amount for optically correcting the translational motion component, the translational motion component of the image blurring generated in the captured image.

4. The apparatus according to claim 3,

wherein said second shake detection unit serves as a motion vector detection unit configured to detect a motion vector between two images forming a moving image, and

wherein said translational shake calculation unit calculates the translational shake amount generated in the captured image due to a translation of said image capture apparatus by adding the motion vector to a result obtained by converting translational motion optically corrected by said optical correction unit into a moving amount on an imaging plane, and subtracting, from the addition result, a result obtained by calculating the translational motion component of the image generated in the captured image based on the rotational shake amount.

5. The apparatus according to claim 1,

wherein said correction amount calculation unit calculates a translational motion component for final correction by adding a result obtained by calculating the translational motion component generated in the captured image based on the rotational shake amount to the calculation result of said translational shake calculation unit, and subtracting, from the addition result, a result obtained by converting translational motion optically corrected by said optical correction unit into a moving amount on an imaging plane.

6. The apparatus according to claim 1,

wherein said rotational shake calculation unit includes a restriction unit configured to restrict an output according to the rotational shake amount.

7. The apparatus according to claim 1,

wherein said rotational shake calculation unit includes a control unit configured to restrict an output of the rotational shake amount according to a correction amount of translational motion generated in the captured image based on the rotational shake amount among deformation components calculated by said correction amount calculation unit.

8. The apparatus according to claim 6,

wherein said rotational shake calculation unit includes a control unit configured to restrict an output of the rotational shake amount according to a correction amount of a perspective component generated in the captured image based on the rotational shake amount among deformation components calculated by said correction amount calculation unit.

9. The apparatus according to claim 6,

wherein said rotational shake calculation unit includes a high-pass filter, and limits the rotational shake amount to be output by changing a cutoff frequency of said high-pass filter.

10. The apparatus according to claim 6,

wherein said rotational shake calculation unit includes an integrator, and limits the rotational shake amount to be output by changing a time constant of said integrator.

11. A control method for an image capture apparatus, comprising:

a first shake detection step of detecting a shake of the image capture apparatus;

a rotational shake calculation step of calculating a rotational shake amount based on an output in the first shake detection step;

a second shake detection step of detecting the shake of the image capture apparatus by a method different from that in the first shake detection step;

a translational shake calculation step of calculating a translational shake amount based on the output in the first shake detection step and an output in the second shake detection unit;

a correction amount calculation step of calculating, based on the rotational shake amount and the translational shake amount, a correction amount for correcting image blurring of an image; and

a correction step of correcting the image blurring based on a calculation result in the correction amount calculation step,

wherein in the rotational shake calculation step, a first translational motion component and perspective component are calculated using the rotational shake amount, and the first translational motion component is a translational motion component of image blurring generated in a captured image due to a rotational shake, and

wherein in the correction amount calculation step, a second translational motion component is calculated based on the first translational motion component and the translational shake amount, and the second translational motion component is a translational motion component of image blurring generated in the captured image due to the rotational shake and a translational shake.