Image processing apparatus, image capturing apparatus, image processing method, and storage medium

1. An image processing apparatus comprising:

one or more processors; and

at least one memory storing instructions which, when executed by the one or more processors, cause the image processing apparatus to:

specify, based on a first instruction from a user, a subject of interest within a parallax image obtained by performing image capturing from a plurality of different viewpoints;

notify a user of a capability to refocus on the specified subject of interest in an image to be generated by performing image combination processing using the parallax image; and

if a second subject of interest within a parallax image obtained by performing image capturing from a plurality of different viewpoints is specified based on a second instruction from the user after the subject of interest is specified by the user, simultaneously notify the user of a capability to refocus on the specified subject of interest and a capability to refocus on the second specified subject of interest in the image to be generated by performing image combination processing using the parallax image.

2. The image processing apparatus according to claim 1 , wherein the at least one memory stores further instructions which, when executed by the one or more processors, cause the image processing apparatus to:

generate a display image indicating the capability to refocus on the specified subject of interest in an image to be generated by performing image combination processing using parallax image; and

notify the user of the capability to refocus by displaying the display image,

wherein the display image is an image including a first image including an image of the subject of interest and is also an image indicating a capability to refocus on the subject of interest in a second image that is generated from the parallax image and differs from the first image.

3. The image processing apparatus according to claim 2 , wherein the display image is an image in which a display indicating a capability to refocus on the subject of interest in the second image is superimposed on the first image.

4. The image processing apparatus according to claim 2 , wherein the second image is generated by the image combination processing using the parallax image.

5. The image processing apparatus according to claim 2 , wherein the at least one memory stores further instructions which, when executed by the one or more processors, cause the image processing apparatus to derive a focus control range in the image combination processing; and

generate the display image based on the derived focus control range.

6. The image processing apparatus according to claim 5 , wherein the at least one memory stores further instructions which, when executed by the one or more processors, cause the image processing apparatus to derive the focus control range in accordance with an angle of view of the parallax image.

7. The image processing apparatus according to claim 5 , wherein the focus range derivation unit derives the focus control range in accordance with a resolution in the image generated by the image combination processing.

8. The image processing apparatus according to claim 5 , further comprising a determination unit configured to determine a focused state of the subject of interest based on the derived focus control range,

wherein the generation unit generates the display image based on a determination result of the determination unit.

9. The image processing apparatus according to claim 8 , wherein the determination unit determines whether it is possible to generate an image focused on the subject of interest by the image combination processing, and

the display image is an image indicating whether it is possible to generate an image focused on the subject of interest by the image combination processing.

10. The image processing apparatus according to claim 8 , further comprising a distance derivation unit configured to derive a distance to the subject of interest, wherein the determination unit determines a focused state of the subject of interest based on the distance to the subject of interest derived by the distance derivation unit and the focus control range derived by the focus range derivation unit.

11. The image processing apparatus according to claim 10 , wherein the parallax image is configured by a plurality of single-viewpoint images captured from each of the viewpoints, and

the distance derivation unit derives the distance to the subject of interest by performing stereo matching between the plurality of single-viewpoint images.

12. The image processing apparatus according to claim 2 , wherein the parallax image is configured by a plurality of single-viewpoint images captured from each of the viewpoints, and

the first image is one of the plurality of single-viewpoint images.

13. The image processing apparatus according to claim 2 , wherein the parallax image is configured by a plurality of single-viewpoint images captured from each of the viewpoints, and

the first image is a combined image obtained by combining the plurality of single-viewpoint images.

14. The image processing apparatus according to claim 1 , wherein the specification unit derives a distance of a subject space using the parallax image and specifies the subject of interest based on the derived distance of the subject space.

15. The image processing apparatus according to claim 1 , wherein the at least one memory stores further instructions which, when executed by the one or more processors, cause the image processing apparatus to notify the user of the capability to refocus by using sound.

16. The image processing apparatus according to claim 1 , wherein the at least one memory stores further instructions which, when executed by the one or more processors, cause the image processing apparatus to notify the user of the capability to refocus by using vibration.

17. The image processing apparatus according to claim 1 , wherein the at least one memory stores further instructions which, when executed by the one or more processors, cause the image processing apparatus to notify the user of the capability to refocus by using light.

18. The image processing apparatus according to claim 1 , wherein the at least one memory stores further instructions which, when executed by the one or more processors, cause the image processing apparatus to notify the user of a change in the capability to refocus.

19. An image capturing apparatus comprising the image processing apparatus according to claim 2 .

20. The image capturing apparatus according to claim 19 , wherein the image capturing apparatus has a live view function, and the display image is an image displayed by the live view function.

21. An image processing method comprising the steps of:

specifying, based on a first instruction from a user, a first subject of interest within a parallax image obtained by performing image capturing from a plurality of different viewpoints;

notifying a user of a capability to refocus on the first specified subject of interest in an image generated by performing image combination processing using the parallax image;

specifying, based on a second instruction from the user, a second subject of interest within the parallax image obtained by performing image capturing from a plurality of different viewpoints after the first subject of interest is specified by the user;

simultaneously notifying the user of a capability to refocus on the first specified subject of interest and a capability to refocus on the second specified subject of interest in the image to be generated by performing image combination processing using the parallax image.

22. A non-transitory computer readable storage medium storing a program for causing a computer to perform the image processing method according to claim 21 .