Image pickup apparatus, image pickup system, method of controlling image pickup apparatus, and non-transitory computer-readable storage medium

• US 9,565,353 B2
• Filed: 09/12/2014
• Issued: 02/07/2017
• Est. Priority Date: 09/18/2013
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Nishigori, Hidetoshi
• Primary Examiner(s): FOSSELMAN, JOEL W
• Application Number:
  US14/484,531
• Publication Number:
  US 20150077621A1
• Time in Patent Office: 879 Days
• Field of Search: 348/349, 396/104
• US Class Current: 1/1
• 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 processor performing the functions of a focus detention unit, a determination unit, a calculation unit and a control unit, wherein

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

the determination unit is configured to determine an object image in an image based on the image signal;

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

the control unit is configured to perform in-focus control based on the in-focus position calculated by the calculation unit,

wherein the calculation unit is configured to, when the determination unit determines that a plural object images exist in the image based on the image signal and each of the in-focus positions of the plural object images is within a predetermined range, adjust the in-focus position to perform the in-focus control so as to focus on one of the plural object images, and

wherein the calculation unit is configured to, when the determination unit determines that the plural object images exist in the image based on the image signal and each of the in-focus positions of the plural object images is not in the predetermined range , adjust the in-focus position to perform the in-focus control based on each of the in-focus positions of the plural object images that is in the predetermined range and also based on each of the in-focus positions of the plural object images not in the predetermined range.

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

the determination unit is configured to determine a position of the object image existing in the image based on the image signal and the number of the plural object images, and

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

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 image based on the image signal 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 image based on the image signal 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 image exists in the image based on the image signal, adjust the in-focus position so as to focus on the one object image.

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 image based on the image signal, 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 image based on the image signal to an in-focus position at a peripheral portion of the image based on the image signal.

7. The image pickup apparatus according to claim 1,

wherein the calculation unit is configured to set an average value of the in-focus positions of the plural object images as the final in-focus position to perform the in-focus control.

8. 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 image, depending on a shooting mode set by a photographer.

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

the determination unit is configured to determine a size of the object image in the image based on the image signal, and

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

10. The image pickup apparatus according to claim 9,

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 image.

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

the determination unit is configured to determine whether a previously registered object image exists among the plural object images existing in the image based on the image signal, and

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

12. The image pickup apparatus according to claim 1,

wherein the object image is a person'"'"'s face.

13. 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 image in an image based on the image signal,

a calculation unit configured to calculate an in-focus position based on information of the object image 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,

wherein the calculation unit is configured to, when the determination unit determines that a plural object images exist in the image based on the image signal and each of the in-focus positions of the plural object images is within a predetermined range, adjust the in-focus position to perform the in-focus control so as to focus on one of the plural object images, and

wherein the calculation unit is configured to, when the determination unit determines that the plural object images exist in the image based on the image signal and each of the in-focus positions of the plural object images is not in the predetermined range, adjust the in-focus position to perform the in-focus control based on each of the in-focus positions of the plural object images that is in the predetermined range and also based on each of the in-focus positions of the plural object images not in the predetermined range.

14. 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 image in an image based on the image signal;

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

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

wherein in the step of calculating the in-focus position, when in the step of determining the object image, it is determined that a plural object images exist in the image based on the image signal and each of the in-focus positions of the plural object images is within a predetermined range, the in-focus position to perform the in-focus control so as to focus on one of the plural object images is adjusted, and

wherein in the step of calculating the in-focus position, when in the step of determining the object image, it is determined that the plural object images exist in the image based on the image signal and each of the in-focus positions of the plural object images is not in the predetermined range, the in-focus position to perform the in-focus control is adjusted based on each of the in-focus positions of the plural object images that is in the predetermined range and also based on each of the in-focus positions of the plural object images not in the predetermined range.

15. The method according to claim 14, wherein:

a position of the object image existing in the image based on the image signal and the number of the plural object images are determined in the step of determining the object image, and

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

16. 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 image in an image based on the image signal;

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

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

wherein in the step of calculating the in-focus position, when in the step of determining the object image, it is determined that a plural object images exist in the image based on the image signal and each of the in-focus positions of the plural object images is within a predetermined range, the in-focus position to perform the in-focus control so as to focus on one of the plural object images is adjusted, and

wherein in the step of calculating the in-focus position, when in the step of determining the object image, it is determined that the plural object images exist in the image based on the image signal and each of the in-focus positions of the plural object images is not in the predetermined range, the in-focus position to perform the in-focus control is adjusted based on each of the in-focus positions of the plural object images that is in the predetermined range and also based on each of the in-focus positions of the plural object images not in the predetermined range.

17. The non-transitory computer-readable storage medium according to claim 16, wherein:

a position of the object image existing in the image based on the image signal and the number of the plural object images are determined in the step of determining the object image, and

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