Image processing apparatus, imaging apparatus, and method of controlling image processing apparatus

1. An image processing apparatus comprising:

a memory;

at least one processor, the processor executing the following functions in accordance with a program stored in the memory;

an acquisition unit configured to acquire a first image captured with a first exposure time and a second image captured with a second exposure time shorter than the first exposure time;

a determination unit configured to change either the first image or the second image as an image to be used for the calculation of a motion vector in accordance with a result of a detection of flicker based on the first image and the second image; and

a calculation unit configured to calculate a motion vector based on said image.

2. The image processing apparatus according to claim 1 , wherein the determination unit determines the first image as said image to be used for the calculation of the motion vector and does not determine the second image as said image to be used for the calculation of the motion vector, if the flicker is detected.

3. The image processing apparatus according to claim 1 , wherein, if the flicker is not detected, the determination unit determines said image to be used for the calculation of the motion vector based on a focal length or an angular velocity indicating shaking applied to the image processing apparatus.

4. The image processing apparatus according to claim 3 , wherein, if the focal length is equal to or larger than a threshold value in the case where the flicker is not detected, the determination unit determines the first image and the second image as images to be used for the calculation of the motion vector, and

wherein, if the focal length is not equal to or larger than the threshold value and the angular velocity is not equal to or larger than a threshold value in the case where the flicker is not detected, the determination unit determines the second image as said image to be used for the calculation of the motion vector.

5. The image processing apparatus according to claim 4 ,

wherein, even in a case where the focal length is not equal to or larger than the threshold value, if the angular velocity is equal to or larger than the threshold value, the determination unit determines the first image and the second image as images to be used for the calculation of the motion vector.

6. The image processing apparatus according to claim 1 ,

wherein, if the first image and the second image are determined as images to be used for the calculation of the motion vector, the calculation unit increases a gain of the second image so that the first image and the second image have the same brightness, and calculates the motion vector.

7. The image processing apparatus according to claim 3 , wherein, if the focal length is equal to or larger than a threshold value in a case where the flicker is not detected, the determination unit determines the first image and the second image as images to be used for the calculation of the motion vector, and

wherein, if the focal length is not equal to or larger than the threshold value and the angular velocity is not equal to or larger than the threshold value in a case where the flicker is not detected, the determination unit determines either the first image or the second image as said image to be used for the calculation of the motion vector depending on a contrast of an object.

8. The processing apparatus according, to claim 7 ,

wherein, if the angular velocity is equal to or larger than the threshold value even in a case where the focal length is not equal to or larger than the threshold value, the determination unit determines the first image and the second image as images to be used for the calculation of the motion vector.

9. The image processing apparatus according to claim 7 ,

wherein, if the first image and the second image are determined as ages to be used for the calculation of the notion vector, the calculation unit increases a gain of the second image or decreases a gain of the first image so that the first image and the second image have the same brightness, depending on the contrast of an object, and calculates the motion vector.

10. An imaging apparatus comprising:

a memory;

at least one processor, the processor executing the following functions in accordance with a program stored in the memory;

an acquisition unit configured to acquire a first image captured with a first exposure time and a second image captured with a second exposure time shorter than the first exposure time;

a determination unit configured to change either the first image or the second image as an image to be used for the calculation of a motion vector, in accordance with a result of a detection of flicker based on the first image and the second image; a calculation unit configured to calculate a motion vector based on said image; and

an image-capturing unit configured to alternately capture the first image and the second image;

wherein, if the first image and the second image are used for the calculation of the motion vector, the calculation unit calculates the motion vector based on the first image and the second image that have been captured continuously.

11. A control method of an image processing apparatus comprising:

acquiring a first image captured with a first exposure time and a second image captured with a second exposure time shorter than the first exposure time;

changing either the first image or the second image as an image to be used for the calculation of a motion vector depending on a result of a detection of flicker based on the first image and the second image; and

calculating the motion vector based on said image.