IMAGE PICKUP APPARATUS, IMAGE PICKUP SYSTEM, METHOD OF CONTROLLING IMAGE PICKUP APPARATUS, AND NON-TRANSITORY COMPUTER-READABLE STORAGE MEDIUM

• US 20150077621A1
• Filed: 09/12/2014
• Published: 03/19/2015
• Est. Priority Date: 09/18/2013
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Nishigori, Hidetoshi
• Granted Patent: US 9,565,353 B2
• Time in Patent Office: Days
• US Class Current: 348/349
• CPC Class Codes: H04N 23/61 based on recognised objects
• CPC Class Codes: H04N 23/67 Focus control based on electronic image sensor signals

Abstract

An image pickup apparatus includes an image pickup element configured to perform photoelectric conversion on an optical image obtained through an image pickup optical system to generate an image signal, a focus detection unit configured to perform focus detection based on the image signal, a determination unit configured to determine an object in a screen, a calculation unit configured to calculate an in-focus position based on information of the object determined by the determination unit, and a control unit configured to perform the in-focus control based on the in-focus position calculated by the calculation unit.

Claims

1. An image pickup apparatus comprising:

an image pickup element configured to perform photoelectric conversion on an optical image obtained through an image pickup optical system to generate an image signal;

a focus detection unit configured to perform focus detection based on the image signal;

a determination unit configured to determine an object in a screen;

a calculation unit configured to calculate an in-focus position based on information of the object determined by the determination unit; and

a control unit configured to perform in-focus control based on the in-focus position calculated by the calculation unit.

2. The image pickup apparatus according to claim 1, wherein:

the determination unit is configured to determine a position of the object existing in the screen and the number of the objects, and

the calculation unit is configured to adjust the in-focus position based on the position of the object and the number of the objects.

3. The image pickup apparatus according to claim 1, wherein the calculation unit is configured to adjust a difference between an imaging position of the image pickup optical system as the in-focus position in the screen and a position of the image pickup element, the difference being caused by a curvature of field of the image pickup optical system.

4. The image pickup apparatus according to claim 1, wherein the calculation unit is configured to adjust a difference between an imaging position of the image pickup optical system as the in-focus position in the screen and a position of the image pickup element, the difference being caused by inclination of the image pickup element with respect to the image pickup optical system.

5. The image pickup apparatus according to claim 1, wherein the calculation unit is configured to, when the determination unit determines that only one object exists in the screen, adjust the in-focus position so as to focus on the one object.

6. The image pickup apparatus according to claim 1, wherein the calculation unit is configured to, when the determination unit determines that no object exists in the screen, adjust a difference between an imaging position of the image pickup optical system and a position of the image pickup element so as to move the in-focus position in a direction from an in-focus position at a central portion of the screen to an in-focus position at a peripheral portion of the screen.

7. The image pickup apparatus according to claim 1, wherein the calculation unit is configured to, when the determination unit determines that the objects exist in the screen and each of the in-focus positions of the objects is within a predetermined range, adjust the in-focus position so as to focus on one of the objects.

8. The image pickup apparatus according to claim 1, wherein the calculation unit is configured to, when the determination unit determines that the objects exist in the screen and each of the in-focus positions of the objects is not in a predetermined range, adjust a final in-focus position based on each of the in-focus positions of the objects.

9. The image pickup apparatus according to claim 8, wherein the calculation unit is configured to set an average value of the in-focus positions of the objects as the final in-focus position.

10. The image pickup apparatus according to claim 1, wherein the calculation unit is configured to determine whether to calculate the in-focus position based on information of the object, depending on a shooting mode set by a photographer.

11. The image pickup apparatus according to claim 1, wherein:

the determination unit is configured to determine a size of the object in the screen, and

the calculation unit is configured to adjust the in-focus position depending on the size of the object.

12. The image pickup apparatus according to claim 11, wherein the calculation unit is configured to change weighting of an adjustment amount of the in-focus position depending on the size of the object.

13. The image pickup apparatus according to claim 1, wherein:

the determination unit is configured to determine whether a previously registered object exists among the objects existing in the screen, and

the calculation unit is configured to adjust the in-focus position so as to focus on the previously registered object when the previously registered object exists in the screen.

14. The image pickup apparatus according to claim 1, wherein the object is a person'"'"'s face.

15. An image pickup system comprising:

an image pickup optical system; and

an image pickup apparatus,

wherein the image pickup apparatus includes

an image pickup element configured to perform photoelectric conversion on an optical image obtained through the image pickup optical system to generate an image signal,

a focus detection unit configured to perform focus detection based on the image signal,

a determination unit configured to determine an object in a screen,

a calculation unit configured to calculate an in-focus position based on information of the object determined by the determination unit, and

a control unit configured to perform in-focus control based on the in-focus position calculated by the calculation unit.

16. A method of controlling an image pickup apparatus, the method comprising the steps of:

performing photoelectric conversion on an optical image obtained through an image pickup optical system to generate an image signal;

performing focus detection based on the image signal;

determining an object in the screen;

calculating an in-focus position based on information of the object; and

performing in-focus control based on the in-focus position.

17. The method according to claim 16, wherein:

a position of the object existing in the screen and the number of the objects are determined in the step of determining the object, and

the in-focus position is adjusted depending on the position of the object and the number of the objects in the step of calculating the in-focus position.

18. A non-transitory computer-readable storage medium storing a program which causes a computer to execute a method of controlling an image pickup apparatus, the method comprising:

performing photoelectric conversion on an optical image obtained through image pickup optical system to generate an image signal;

performing focus detection based on the image signal;

determining an object in a screen;

calculating an in-focus position based on information of the object; and

performing in-focus control based on the in-focus position.

19. The non-transitory computer-readable storage medium according to claim 18, wherein:

a position of the object existing in the screen and the number of the objects are determined in the step of determining the object, and

the in-focus position is adjusted depending on the position of the object and the number of the objects in the step of calculating the in-focus position.