Image capture apparatus and control method therefor
An amount of change between images is calculated based on a motion vector between images obtained by an image sensor and on shake information related to a shake in a rotational direction around at least an axis perpendicular to an optical axis of an imaging optical system. Then, based on a shake correction amount determined based on the shake information and the amount of change, an image obtained by the image sensor is geometrically deformed. The amount of change is a shake component of the image capture apparatus in a direction perpendicular to the optical axis, and is calculated after cancelling at least one of a change between images caused by the shake in the rotational direction included in the shake information and a change between images caused by an influence of a difference between exposure periods of the image sensor.
1. An image capture apparatus comprising:
a detection unit configured to detect a motion vector between images obtained by an image sensor;
an obtaining unit configured to obtain shake information related to a shake in a rotational direction around an axis perpendicular to an optical axis of an imaging optical system;
a calculation unit configured to calculate an amount of change between the images based on the shake information and on the motion vector;
a determination unit configured to determine a shake correction amount based on the shake information and on the amount of change; and
a deformation unit configured to geometrically deform an image obtained by the image sensor based on the shake correction amount, wherein
the calculation unit calculates a shake component of the image capture apparatus in a direction perpendicular to the optical axis as the amount of change, after cancelling a change between images caused by an influence of a difference between exposure periods of the image sensor included in the motion vector, based on the shake information.
2. The image capture apparatus according to claim 1 , wherein
if the shake information does not include information related to a shake in a rotational direction around the optical axis, the calculation unit further calculates, after cancelling the deformation, a shake component of the image capture apparatus in the rotational direction around the optical axis as the amount of change.
3. The image capture apparatus according to claim 1 , wherein
the calculation unit calculates the amount of change, after further cancelling a change between images caused by optical aberration of the imaging optical system included in the motion vector.
4. The image capture apparatus according to claim 3 , wherein
the calculation unit cancels the change between the images caused by the optical aberration using a geometric deformation parameter corresponding to a parameter for the imaging optical system.
5. The image capture apparatus according to claim 1 , further comprising
an optical anti-shake function configured to reduce a shake of an image by driving an optical correction element in a direction different from the optical axis, wherein
the calculation unit calculates the shake component after removing an influence of the reduction of the shake by the optical anti-shake function on a change between images.
6. The image capture apparatus according to claim 1 , wherein
the shake information is based on an output of a sensor that measures a rotation amount of the image capture apparatus around a yaw axis and a pitch axis.
7. The image capture apparatus according to claim 1 , wherein
the shake component of the image capture apparatus in the direction perpendicular to the optical axis is a shake component caused by a translational motion of the image capture apparatus.
8. The image capture apparatus according to claim 1 , wherein
the image sensor is a CMOS image sensor, and the change between the images caused by the influence of the difference between the exposure periods of the image sensor is a rolling shutter distortion.
9. A control method for an image capture apparatus, comprising:
a detection step of detecting a motion vector between images obtained by an image sensor;
an obtainment step of obtaining shake information related to a shake in a rotational direction around an axis perpendicular to an optical axis of an imaging optical system;
a calculation step of calculating an amount of change between the images based on the shake information and on the motion vector;
a determination step of determining a shake correction amount based on the shake information and on the amount of change; and
a deformation step of geometrically deforming an image obtained by the image sensor based on the shake correction amount, wherein
in the calculation step, a shake component of the image capture apparatus in a direction perpendicular to the optical axis is calculated as the amount of change, after cancelling a change between images caused by an influence of a difference between exposure periods of the image sensor included in the motion vector, based on the shake information.
10. A non-transitory computer-readable storage medium storing a program for causing a computer included in an image capture apparatus to execute a -control method for the image capture apparatus comprising:
a detection step of detecting a motion vector between images obtained by an image sensor;
an obtainment step of obtaining shake information related to a shake in a rotational direction around an axis perpendicular to an optical axis of an imaging optical system;
a calculation step of calculating an amount of change between the images based on the shake information and on the motion vector;
a determination step of determining a shake correction amount based on the shake information and on the amount of change; and
a deformation step of geometrically deforming an image obtained by the image sensor based on the shake correction amount, wherein
in the calculation step, a shake component of the image capture apparatus in a direction perpendicular to the optical axis is calculated as the amount of change, after cancelling a change between images caused by an influence of a difference between exposure periods of the image sensor included in the motion vector, based on the shake information.
11. An image capture apparatus comprising:
a detection unit configured to detect a motion vector between images obtained by an image sensor;
an obtaining unit configured to obtain shake information related to a shake in a rotational direction around an axis perpendicular to an optical axis of an imaging optical system;
a calculation unit configured to calculate an amount of change between the images based on the shake information and on the motion vector;
a determination unit configured to determine a shake correction amount based on the shake information and on the amount of change; and
a deformation unit configured to geometrically deform an image obtained by the image sensor based on the shake correction amount, wherein
the calculation unit calculates a shake component of the image capture apparatus in a direction perpendicular to the optical axis as the amount of change, after cancelling a change between images caused by optical aberration of the imaging optical system.
12. A control method for an image capture apparatus comprising:
detecting a motion vector between images obtained by an image sensor;
obtaining shake information related to a shake in a rotational direction around an axis perpendicular to an optical axis of an imaging optical system;
calculating an amount of change between the images based on the shake information and on the motion vector;
determining a shake correction amount based on the shake information and on the amount of change; and
geometrically deforming an image obtained by the image sensor based on the shake correction amount, wherein
in the calculating, a shake component of the image capture apparatus in a direction perpendicular to the optical axis is calculated as the amount of change, after cancelling a change between images caused by optical aberration of the imaging optical system.
13. A non-transitory computer-readable storage medium storing a program for causing a computer included in an image capture apparatus to execute a control method for an image capture apparatus comprising:
detecting a motion vector between images obtained by an image sensor;
obtaining shake information related to a shake in a rotational direction around an axis perpendicular to an optical axis of an imaging optical system;
calculating an amount of change between the images based on the shake information and on the motion vector;
determining a shake correction amount based on the shake information and on the amount of change; and
geometrically deforming an image obtained by the image sensor based on the shake correction amount, wherein
in the calculating, a shake component of the image capture apparatus in a direction perpendicular to the optical axis is calculated as the amount of change, after cancelling a change between images caused by optical aberration of the imaging optical system.