US-12621565-B2 - Image capturing apparatus, and control method and storage medium for image capturing apparatus

US12621565B2US 12621565 B2US12621565 B2US 12621565B2US-12621565-B2

Abstract

An apparatus including a detecting unit configured to detect a subject from a captured image; a tracking unit configured to track the detected subject; a focus adjustment unit configured to control focus adjustment based on the captured image; and a determining unit configured to, in a case where the tracking unit is tracking a specific subject, determine if a tracking region in which the specific subject is being tracked is at an end portion of a captured image in a case in which focus adjustment is being performed in the tracking region and a focus adjustment mode in which focus adjustment is not performed when a subject is not being tracked has been set.

Inventors

Shun Nakamura

Assignees

CANON KABUSHIKI KAISHA

Dates

Publication Date: 20260505
Application Date: 20240131
Priority Date: 20230202

Claims (20)

1 . An apparatus comprising: at least one process and a memory coupled to the at least one processor storing instructions that, when executed by the at least one processor, cause the at least one processor to function as: a detecting unit configured to detect a subject from a captured image; a tracking unit configured to track the detected subject; a focus adjusting unit configured to control focus adjustment based on the captured image; and a determining unit configured to determine whether or not a tracking region in which a predetermined subject is being tracked is at an end portion of a captured image when a focal adjustment mode is set, wherein the focal adjustment mode is a mode in which focus adjustment is performed in the tracking region when the predetermined subject is being tracked by the tracking unit, and focal adjustment is not performed when the predetermined subject is not being tracked, wherein the tracking unit releases a tracking state in a case in which the determining unit has determined that the tracking region is at an end portion of a captured image.
2 . The apparatus according to claim 1 , wherein in a case where it is determined that the tracking region is at an end portion of a captured image, and where a part that is included in a larger detected part is detected as a detected part of the specific subject that is being tracked, the tracking unit does not release the tracking state.
3 . The apparatus according claim 1 , wherein in a case where it is determined that the tracking region is at an end portion of a captured image, and where a size in a screen of the subject being tracked is larger than a predetermined size, the tracking unit does not release the tracking state.
4 . The apparatus according claim 1 , wherein in a case where it is determined that the tracking region is at an end portion of a captured image, the tracking unit does not release the tracking state during a period in which a predetermined amount of time passes since a state in which the detecting unit does not detect as subject has changed to a state in which the detecting unit does detect a subject.
5 . The apparatus according to claim 1 , wherein in a case where it is determined that the tracking region is at an end portion of a captured image, and the specific subject is a person, and a direction in a screen of the tracking region that the determining unit determined is at an end portion of a captured image is the direction of the head of the person, the tracking unit does not release the tracking state.
6 . The apparatus according to claim 1 , wherein in a case where it is determined that the tracking region is at an end portion of a captured image, and tracking is being performed due to a user operation to the apparatus, the tracking unit does not release the tracking state.
7 . The apparatus according to claim 1 , wherein the at least one processor further functions as a subject registering unit that is able to register a subject in the apparatus; wherein in a case it is determined that the tracking region is at an end portion of a captured image, and a subject that was registered by the subject registering unit is being tracked, the tracking unit does not release the tracking state.
8 . The apparatus according to claim 1 , wherein after release of the tracking state has been performed, in a case in which the determining unit no longer determines that the tracking region is at an end portion of a captured image, the tracking unit once again performs tracking of the specific subject.
9 . The apparatus according to claim 1 , wherein in a case where the tracking region runs into an end of an angle of view, or where the tracking region protrudes from a predetermined region that has been set within a captured image by a predetermined amount or more, the determining unit determines that the tracking region is at an end portion of a captured image.
10 . The apparatus according to claim 1 , wherein in a case where a next position of the tracking region that is predicted based on past positions of the tracking region protrudes from a predetermined region that has been set in a captured image by a predetermined amount or more, the determining unit determines that the tracking region is at an end portion of a captured image.
11 . An apparatus comprising: at least one processor and a memory coupled to the at least one processor storing instructions that, when executed by the at least one processor, cause the at least one processor to function as: a detecting unit configured to detect a subject from a captured image; a tracking unit configured to track the detected subject; a focus adjusting unit configured to control focus adjustment based on the captured image; a determining unit configured to determine whether or not a tracking region in which a predetermined subject is being tracked is at an end portion of a captured image when a focal adjustment mode is set, wherein the focal adjustment mode is a mode in which focus adjustment is performed in the tracking region when the predetermined subject is being tracked by the tracking unit, and focal adjustment is not performed when the predetermined subject is not being tracked, wherein the focus adjusting unit changes a focus adjustment operation in a case in which the determining unit has determined that the tracking region is at an end portion of a captured image.
12 . The apparatus according to claim 11 , wherein in a case where it is determined that the tracking region is at an end portion of a captured image, the focus adjusting unit prohibits focus adjustment in an infinite direction.
13 . The apparatus according to claim 11 , wherein in a case it is determined that the tracking region is at an end portion of a captured image, the focus adjusting unit makes a speed of focus adjustment slower.
14 . The apparatus according to claim 11 , wherein in a case where it is determined that the tracking region is at an end portion of a captured image, the focus adjusting unit makes a period of time in which switching from a state in which focus adjustment is stopped to a state in which focus adjustment is executed longer.
15 . The apparatus according to claim 11 , wherein in a case it is determined that the tracking region is at an end portion of a captured image, the focus adjusting unit prioritizes use of a focus adjustment position that is in the same direction as the direction of the tracking region in a captured image from when the determining unit determined that the tracking region is at an end portion of a captured image.
16 . The apparatus according to claim 11 , wherein in a case it is determined that the tracking region is at the end portion of the captured image, and that corresponds to any of a case where a part that is included in a larger detected part is detected as a detected part of the subject that is being tracked, a case in which a size of the subject being tracked in a screen is larger than a predetermined size, a case in which it is a period until a predetermined amount of time has passed since a state in which the detecting unit does not detect a subject has changed to a state in which the detecting unit does detected a subject, a case in which the specific subject is a person and a direction in a screen of the tracking region that the determining unit has determined is at an end portion of a captured image is the direction of the head of the person, a case in which tracking is being performed due to a user operation to the apparatus, or a case where a subject was registered by a subject registering unit is being tracked, the focus adjusting unit does not perform changes to focus adjustment operations.
17 . The apparatus according to claim 11 , wherein in a case where the tracking region is running into an end of an angle of view, or in a case where the tracking region protrudes from a predetermined region that has been set within a captured image by a predetermined amount or more, the determining unit determines that the tracking region is at an end portion of a captured image.
18 . The apparatus according to claim 11 , wherein in a case where a next position of the tracking region that is predicted based on past positions of the tracking region protrudes from a predetermined region that has been set in a captured image by a predetermined amount or more, the determining unit determines that the tracking region is at an end portion of a captured image.
19 . The apparatus according to claim 11 , further comprising a sensor configured to output a plurality of images by receiving luminous fluxes that have passed through different pupil regions of an optical system, and wherein the at least one processor further functions as a focus detecting unit configured to detect a defocus amount from the plurality of images.
20 . A method for an apparatus comprising: detecting a subject from a captured image; tracking the subject that was detected during the detecting; controlling focus adjustment based on the captured image; determining whether or not a tracking region in which a predetermined subject is being tracked is at an end portion of a captured image when a first focal adjustment mode is set, wherein the first focal adjustment mode is a mode in which focus adjustment is performed in the tracking region when the predetermined subject is being tracked, and focal adjustment is not performed when the predetermined subject is not being tracked; and releasing a tracking state in a case in which it has been determined that the tracking region is at an end portion of a captured image.

Description

BACKGROUND Technical Field The aspect of the embodiments relates to a focus adjustment technology for an image capturing apparatus. Description of Related Art When a subject is brought into focus using autofocus (referred to below as “AF”) in an image capturing apparatus, there are cases in which a focus control occurs that was not intended by the photographer. For example, in a case in which AF is being performed for a specific subject that was detected by the image capturing apparatus, when the subject that is detected leaves the frame to outside of the image capturing screen, there is a need to maintain the focus state from when they left the frame, and to not perform AF on a different subject such as, for example, the background. In relation to this need, there is a technology that performs a limited AF, such that AF is performed when a subject has been detected, and AF is not performed when a subject is not detected. However, even in cases in which the subject that has been detected has left the frame, the range finding position for the AF has not left the frame and is still stopped within the image capturing screen, and therefore, there are cases in which an incorrect AF is performed on the background or the like that is included in the AF range finding range, and the focus state from when the subject left the frame cannot be maintained. Japanese Patent Application Laid-Open No. 2009-271557 discloses a technique for controlling shifts in focus by controlling the AF speed such that it becomes slow until it can be determined that the subject does not exist within the screen when a state in which the subject can be detected has changed to a state in which the subject cannot be detected. However, in the technology that has been disclosed in Japanese Patent Application Laid-Open No. 2009-271557, regardless of whether or not a subject exists inside of the screen and the subject can be detected, in cases in which a different subject is included in the AF range finding range, there is a possibility that a shift in the focus cannot be controlled. SUMMARY An apparatus comprises at least one process and a memory coupled to the at least one processor storing instructions that, when executed by the at least one processor, cause the at least one processor to function as: a detection unit configured to detect a subject from a captured image; a tracking unit configured to track the detected subject; a focus adjustment unit configured to control focus adjustment based on the captured image; and a determining unit configured to determine whether or not a tracking region in which a predetermined subject is being tracked is at an end portion of a captured image when a focal adjustment mode is set, wherein the focal adjustment mode is a mode in which focus adjustment is performed in the tracking region when the predetermined subject is being tracked by the tracking unit, and focal adjustment is not performed when the predetermined subject is not being tracked, wherein, in a case in which the determining unit has determined that the tracking region is at an end portion of an image, the tracking unit releases a tracking state. Further features of the disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a configuration of an image capturing apparatus. FIGS. 2A and B are diagrams explaining an image capturing element. FIG. 3 is a diagram showing an AF region that is used in focus detection processing. FIGS. 4A to 4C are diagrams showing a pair of image signals that are obtained from an AF region. FIGS. 5A and 5B are diagrams explaining the relationship between a shift amount and a correlation amount for a pair of image signals. FIGS. 6A and 6B are diagrams explaining the relationship between a shift amount and a correlation amount for a pair of image signals. FIG. 7 is a flowchart showing video image capturing processing. FIG. 8 is a flowchart showing subject tracking state setting processing. FIG. 9 is a flowchart showing focus shift suppression determination processing in a First Embodiment. FIG. 10 is a flowchart showing AF processing. FIG. 11 is a flowchart showing AF execution processing. FIGS. 12A to 12C are diagrams explaining an AF mode. FIGS. 13A to 13C are diagrams explaining undesirable focus shift in a mode that performs AF at the time of subject tracking. FIGS. 14A to 14C are diagrams explaining focus control in the First Embodiment. FIG. 15 is a diagram showing one example of a captured image for a case in which a size of a subject tracking region is equal to or greater than a predetermined size. FIGS. 16A and 16B are diagrams explaining a subject tracking command from a user. FIG. 17 is a flowchart showing focus shift suppression determination processing in a Second Embodiment. FIGS. 18A to 18C are diagrams explaining pupil detection. FIGS. 19A to 19C are diagrams explaining