IMAGE CAPTURE APPARATUS AND CONTROL METHOD THEREFOR

• US 20150022678A1
• Filed: 07/11/2014
• Published: 01/22/2015
• Est. Priority Date: 07/16/2013
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Tsubaki, Hidetoshi
• Granted Patent: US 9,392,176 B2
• Time in Patent Office: Days
• US Class Current: 348/208.5
• CPC Class Codes: H04N 23/6811 based on the image signal
• CPC Class Codes: H04N 23/687 by shifting the lens or sensor position

Abstract

An image capture apparatus has an image sensor and an optical anti-shake mechanism that reduces a shake of a captured image by driving an optical correction element in a different direction from an optical axis of an imaging optical system in accordance with a detected shake. Reference coordinates for geometric deformation processing applied to the captured image are determined based on an amount and direction of a movement of the optical correction element. The geometric deformation processing is applied to the captured image using these reference coordinates and an amount of geometric deformation based on the detected shake. Coordinates of the captured image corresponding to an intersection of the optical axis and the image sensor before the optical correction element is moved through the driving are determined as the reference coordinates.

Claims

1. An image capture apparatus with an optical anti-shake mechanism that reduces a shake of a captured image by driving an optical correction element in a different direction from an optical axis of an imaging optical system in accordance with a detected shake, the image capture apparatus comprising:

an image sensor;

a determination unit configured to determine reference coordinates for geometric deformation processing applied to the captured image based on an amount and direction of a movement of the optical correction element; and

a deformation processing unit configured to apply the geometric deformation processing to the captured image using the reference coordinates determined by the determination unit and an amount of geometric deformation based on the detected shake, wherein

the determination unit determines, as the reference coordinates for the geometric deformation processing, coordinates of the captured image corresponding to an intersection of the optical axis and the image sensor before the optical correction element is moved through the driving.

2. The image capture apparatus according to claim 1, wherein

the determination unit obtains the amount and the direction of the movement of the anti-shake element by way of measurement.

3. The image capture apparatus according to claim 1, wherein

the determination unit obtains the amount and the direction of the movement of the anti-shake element using control information for the anti-shake element in the optical anti-shake mechanism.

4. The image capture apparatus according to claim 1, wherein

the geometric deformation processing is for performing one or more of rolling shutter distortion correction, correction of planar rotation or projection, and skew correction.

5. The image capture apparatus according to claim 1, wherein

the deformation processing unit applies geometric deformation processing of a correction amount corresponding to a difference between an amount of the detected shake and an amount of a shake reduced by the optical anti-shake mechanism.

6. The image capture apparatus according to claim 1, further comprising

an estimation unit configured to detect a motion vector or corresponding point between images captured at different time points, wherein

the deformation processing unit applies the geometric deformation processing using an amount of geometric deformation based on information of the motion vector or the corresponding point detected by the estimation unit if reliability of the detected motion vector or corresponding point is not determined to be low, and applies the geometric deformation processing using the reference coordinates and the amount of geometric deformation based on the detected shake if the reliability of the detected motion vector or corresponding point is determined to be low.

7. A control method for an image capture apparatus having an image sensor and an optical anti-shake mechanism that reduces a shake of a captured image by driving an optical correction element in a different direction from an optical axis of an imaging optical system in accordance with a detected shake, the control method comprising:

a determination step of determining reference coordinates for geometric deformation processing applied to the captured image based on an amount and a direction of a movement of the optical correction element; and

a deformation processing step of applying the geometric deformation processing to the captured image using the reference coordinates determined in the determination step and an amount of geometric deformation based on the detected shake, wherein

the determination step determines, as the reference coordinates for the geometric deformation processing, coordinates of the captured image corresponding to an intersection of the optical axis and the image sensor before the optical correction element is moved through the driving.