Image processing apparatus and method of controlling the same

Patent metadata

Field	Value
Publication number	US-11546502-B2
Application number	US-202117405167-A
Country	US
Kind code	B2
Filing date	Aug 18, 2021
Priority date	Sep 14, 2020
Publication date	Jan 3, 2023
Grant date	Jan 3, 2023

Abstract

An image processing apparatus is operable to determine a focus target area of an image capturing apparatus. The apparatus comprises: an obtainment unit configured to obtain a first area to be a focus target in a first image captured by the image capturing apparatus at a first point in time, a detection unit configured to detect a second area to be a focus target candidate from a second image captured by the image capturing apparatus at a second point in time succeeding a first point in time; and a determination unit configured to determine, based on the first area and the second image, a focus target area in the second image from among one or more partial areas in the second area.

First claim

What is claimed is:

1. An image processing apparatus operable to determine a focus target area of an image capturing apparatus, the image processing apparatus comprising:
one or more processors; and
a memory for storing instructions to be executed by the one or more processors, wherein, when the instructions stored in the memory are executed by the one or more processors, the image processing apparatus functions as:
an obtainment unit configured to obtain a first area to be a focus target in a first image captured by the image capturing apparatus at a first point in time;
a detection unit configured to detect a second area to be a focus target candidate from a second image captured by the image capturing apparatus, the second image being captured by the image capturing apparatus at a second point in time succeeding the first point in time; and
a determination unit configured to determine, based on the first area and the second image, a focus target area in the second image from among one or more partial areas in the second area.

2. The image processing apparatus according to claim 1 , wherein, when the instructions stored in the memory are executed by the one or more processors, the image processing apparatus further functions as:
a depth information obtainment unit configured to obtain depth information for each area of an image captured by the image capturing apparatus, and
wherein the determination unit determines, based on depth information that corresponds to the first area and depth information that corresponds to the second area, the focus target area in the second image.

3. The image processing apparatus according to claim 1 , wherein
the determination unit determines, based on a difference in depth calculated according to depth information that corresponds to the first area and depth information that corresponds to the second area, the focus target area.

4. The image processing apparatus according to claim 3 , wherein
the determination unit determines, from among the one or more partial areas, a partial area for which a difference between a depth of the first area and a depth of the partial area is smaller than a predetermined threshold as the focus target area.

5. The image processing apparatus according to claim 4 , wherein
the determination unit, in a case where there are a plurality of partial areas for which a difference with respect to the depth of the first area is less than a predetermined value, determines, from among the plurality of partial areas, a partial area whose area is relatively large or depth is relatively small as the focus target area.

6. The image processing apparatus according to claim 2 , wherein
the depth information is based on a distance between the image capturing apparatus and a subject or a phase difference of incident light on an image capturing element of the image capturing apparatus.

7. The image processing apparatus according to claim 1 , wherein
the detection unit detects, in the second image, an area having an image feature that is similar to an image feature extracted from the first area as the second area.

8. The image processing apparatus according to claim 7 , wherein
the obtainment unit obtains a specific portion of a person or object as the first area, and
the detection unit detects a portion that is the same as the specific portion as the second area.

9. The image processing apparatus according to claim 8 , wherein
the obtainment unit obtains the specific portion of the person or object as the first area, and
the detection unit, in a case where the portion that is the same as the specific portion cannot be detected, detects a portion that is different from the specific portion as the second area.

10. The image processing apparatus according to claim 1 , wherein, when the instructions stored in the memory are executed by the one or more processors, the image processing apparatus further functions as:
an extraction unit configured to extract, from the second area, one or more partial areas that meets a predetermined condition, and
wherein the determination unit determines the focus target area in the second image from among the one or more partial areas extracted by the extraction unit.

11. The image processing apparatus according to claim 10 , wherein
the extraction unit extracts, from the second area, an area whose depth indicated by depth information that corresponds to the second image is included in a predetermined range as the one or more partial areas.

12. The image processing apparatus according to claim 10 , wherein
the extraction unit, based on a depth of field when the image capturing apparatus captured the second image, changes the predetermined condition of the one or more partial areas.

13. The image processing apparatus according to claim 1 , wherein
the determination unit, based on a plurality of criteria, determines the focus target area in the second image, and
the plurality of criteria include respective criteria for a similarity between the first area and the second area and an area of the one or more partial areas.

14. The image processing apparatus according to claim 13 , wherein
the determination unit changes the plurality of criteria of the focus target area based on an elapsed time from the first point in time.

15. The image processing apparatus according to claim 1 , wherein
the second area is an area that indicates a head portion and/or a torso portion of a person.

16. The image processing apparatus according to claim 1 , wherein
the determination unit preferentially determines, from among the one or more partial areas, a partial area whose area is larger than a predetermined value as the focus target area in the second image.

17. A method of controlling an image processing apparatus operable to determine a focus target area of an image capturing apparatus, the method comprising:
obtaining a first area to be a focus target in a first image captured by the image capturing apparatus at a first point in time;
detecting a second area to be a focus target candidate from a second image captured by the image capturing apparatus, the second image being captured by the image capturing apparatus at a second point in time succeeding the first point in time; and
determining, based on the first area and the second image, a focus target area in the second image from among one or more partial areas in the second area.

18. A non-transitory computer-readable recording medium storing a program that causes a computer to function as an image processing apparatus operable to determine a focus target area of an image capturing apparatus, the image processing apparatus comprising:
one or more processors; and
a memory for storing instructions to be executed by the one or more processors, wherein, when the instructions stored in the memory are executed by the one or more processors, the image processing apparatus functions as:
an obtainment unit configured to obtain a first area to be a focus target in a first image captured by the image capturing apparatus at a first point in time;
a detection unit configured to detect a second area to be a focus target candidate from a second image captured by the image capturing apparatus, the second image being captured by the image capturing apparatus at a second point in time succeeding the first point in time; and
a determination unit configured to determine, based on the first area and the second image, a focus target area in the second image from among one or more partial areas in the second area.

Assignees

• Canon Kk

Inventors

• Aoba Masato
• Takeuchi Koichi

Classifications

• H04N23/611

  where the recognised objects include parts of the human body · CPC title

• H04N23/672 Primary

  based on the phase difference signals · CPC title

• G03B13/36

  Autofocus systems · CPC title

• H04N23/959

  by adjusting depth of field during image capture, e.g. maximising or setting range based on scene characteristics · CPC title

• H04N23/635

  Region indicators; Field of view indicators · CPC title