WO2022209342A1

WO2022209342A1 - Imaging device, focus control method, and program

Info

Publication number: WO2022209342A1
Application number: PCT/JP2022/005343
Authority: WO
Inventors: 良能佐藤; 良知山蔦
Original assignee: ソニーグループ株式会社
Priority date: 2021-03-30
Filing date: 2022-02-10
Publication date: 2022-10-06

Abstract

This imaging device comprises: a distance determination unit that determines a distance to a subject; and an autofocus processing unit that performs autofocus control on the subject being an object to be focused, and in response to an object switching operation by a user, switches the object to be focused to another subject determined to have a distance different from that of the current subject being the object to be focused by the distance determination unit.

Description

IMAGING DEVICE, FOCUS CONTROL METHOD, AND PROGRAM

This technology relates to imaging devices, focus control methods, and programs, and particularly to autofocus control.

When an imaging device such as a still camera or a video camera is used to capture an image, the object to be captured is focused. They are manual focus, in which a target subject is focused on by a user who operates the camera, and autofocus, in which the camera automatically focuses.

Patent Document 1 below discloses a technique related to autofocus control.

JP 2020-156814

By the way, when the imaging apparatus automatically performs the focusing operation as autofocus control, the subject desired by the user is not necessarily focused. Also, when it is desired to execute the autofocus operation by targeting another object, it is necessary to turn off the autofocus once and then apply the autofocus again. For example, in motor sports or track and field events, it is assumed that the subject always needs to be in focus. When the leading runner changes during the race, it is necessary to turn off the autofocus control up to that point and execute the autofocus control again targeting the new leading subject.
Due to such circumstances, it is possible that the switching of the autofocus control target takes time and the shutter chance for capturing a still image is missed. Also, even in the case of moving image pickup, a state may occur in which appropriate focus control cannot be performed.

Therefore, in the present disclosure, regarding autofocus control, a technique is proposed that allows the user to easily switch the subject to be controlled.

An imaging device according to the present technology includes a distance determination unit that determines a distance to a subject, performs autofocus control on a subject set as a focus target, and selects a focus target according to a user's target switching operation. and an autofocus processing unit for switching to another object determined by the distance determination unit to be at a different distance from the current focus target object.
For example, the distance determination unit determines the distance (depth) from the imaging device of the subject included in the captured image and the distance relationship between the subjects. The autofocus processing unit switches the focus target to a subject at a different distance by a target switching operation. In other words, the subject to be autofocused can be switched between subjects having a positional relationship in the front-rear direction (depth direction) as viewed from the imaging device.

1 is a perspective view of an imaging device according to an embodiment of the present technology; FIG. FIG. 3 is an explanatory diagram of a panel surface of the imaging device according to the embodiment; 1 is a block diagram of an imaging device according to an embodiment; FIG. 7 is a flowchart of focus target switching processing according to the first embodiment; FIG. 10 is an explanatory diagram of focus target switching processing according to the first embodiment; 4 is an explanatory diagram of an AF area frame according to the embodiment; FIG. 10 is a flowchart of focus target switching processing according to the second embodiment. FIG. 10 is an explanatory diagram of a focus target switching process according to the second embodiment; FIG. 11 is a flowchart of focus target switching processing according to the third embodiment; FIG. FIG. 11 is an explanatory diagram of focus target switching processing according to the third embodiment; FIG. 16 is a flowchart of focus target switching processing according to the fourth embodiment; FIG. FIG. 14 is a flowchart of focus target switching processing according to the fifth embodiment; FIG.

Hereinafter, embodiments will be described in the following order.
<1. Configuration of Imaging Device>
<2. First Embodiment>
<3. Second Embodiment>
<4. Third Embodiment>
<5. Fourth Embodiment>
<6. Fifth Embodiment>
<7. Summary and Modifications>

First, the meaning of some terms used in this disclosure will be provided.
"Image" is used as a term including both "still image" and "moving image".
“Distance” and “depth” refer to the distance from the imaging device 100 to the subject measured by the imaging device 100 . That is, it is the distance in the depth direction of the captured image.
Terms related to distance such as “near”, “closest”, “far”, and “farthest” are used to mean close to the imaging device 100 or far from the imaging device 100 .
Regarding the anteroposterior relationship of the subject, terms such as “front”, “front”, and “front side” indicate the side closer to the imaging apparatus 100 , and “back”, “back”, “back side” and the like indicate the side farther from the imaging device 100 .
Further, therefore, "the head" among the subjects means the one closest to the imaging device 100. In FIG.

<1. Configuration of Imaging Device>
A configuration example of an imaging apparatus 100 according to an embodiment will be described with reference to FIGS. 1 to 3. FIG.
FIG. 1 is a perspective view of an imaging device 100. FIG. FIG. 2 is an explanatory diagram of the panel surface side of the imaging device 100. As shown in FIG. For example, the imaging device 100 is a so-called digital still camera, and can perform both still image imaging and moving image imaging by switching imaging modes.

Note that the imaging apparatus 100 of the present embodiment is not limited to a digital still camera, and may be a video camera mainly used for capturing moving images, a camera capable of capturing only still images, or a camera capable of capturing only moving images. may be Of course, a commercial camera used in a broadcasting station or the like may also be used.

In the image pickup apparatus 100, a lens barrel 102 is attached to a body housing 101 that constitutes a camera body.
When configured as a so-called lens-interchangeable camera, the lens barrel 102 is detachable from the main housing 101 so that the lens can be replaced.
In some cases, the lens barrel 102 cannot be attached to and detached from the body housing 101 . For example, a configuration example in which the lens barrel 102 is fixed to the main body housing 101, or a state in which the lens barrel 102 is retracted and stored in front of the main body housing 101 as a retractable type, and a state in which the lens barrel 102 protrudes and becomes available for use. There is a configuration example for

A display panel 41 such as a liquid crystal display (LCD) or an organic EL (Electro-Luminescence) display is provided on the panel surface of the imaging device 100 on the user side, as shown in FIG.

A display unit formed using an LCD, an organic EL display, or the like is also provided as the viewfinder 42 . The viewfinder 42 is, for example, an electronic viewfinder (EVF). However, an optical view finder (OVF) may be used, or a hybrid view finder (HVF) using a transmissive liquid crystal may be used.

The user can view images and various information through the display panel 41 and viewfinder 42 . In this example, the imaging device 100 is provided with both the display panel 41 and the viewfinder 42, but the present invention is not limited to this. Either or both of the display panel 41 and the viewfinder 42 may be detachable.

Various operators 43 are provided on the body housing 101 of the imaging device 100 .
For example, as the manipulator 43, various types of manipulators such as keys, dials, press/rotate composite manipulators, etc. are provided to realize various operating functions. For example, menu operation, reproduction operation, mode selection operation, focus operation, zoom operation, selection operation of parameters such as shutter speed and F number, etc. are possible.

Although a detailed description of each operator 43 is omitted, two custom buttons 43C1 and 43C2 are provided as one of the operators 43 in this embodiment. The custom buttons 43C1 and 43C2 are also called assignable buttons, to which predetermined operation functions are assigned in the initial state, and to which the user can assign arbitrary operation functions.
Note that the number of custom buttons is not limited to two, and may be one or three or more.

A cross key 43J is provided as one of the operators 43. The cross key 43J can be pressed in the center, up, down, left, and right, and is used for cursor operation, enter operation, and the like.

FIG. 3 shows the internal configuration of the imaging apparatus 100 including the lens barrel 102. As shown in FIG.
Note that FIG. 3 shows an example in which the imaging apparatus 100 is divided into a main housing 101 and a lens barrel 102 .

The imaging device 100 includes an imaging device (image sensor) 12, a camera signal processing unit 13, a recording control unit 14, a display unit 15, an output unit 16, an operation unit 17, a sensor unit 18, a camera control unit 30, It has a memory unit 33 .
Also, the lens barrel 102 has a lens system 21 , a lens system drive section 22 and a lens barrel control section 23 .

The lens system 21 in the lens barrel 102 includes lenses such as a zoom lens and a focus lens, and an iris (diaphragm mechanism). Light (incident light) from a subject is guided through the lens system 21 and condensed on the imaging device 12 .

The imaging element 12 is configured as, for example, a CCD (Charge Coupled Device) type, a CMOS (Complementary Metal Oxide Semiconductor) type, or the like.
The image pickup device 12 performs, for example, CDS (Correlated Double Sampling) processing, AGC (Automatic Gain Control) processing, etc. on electrical signals obtained by photoelectrically converting received light, and further performs A/D (Analog/Digital) processing. Perform conversion processing. Then, the imaging signal as digital data is output to the camera signal processing section 13 and the camera control section 30 in the subsequent stage.

The camera signal processing unit 13 is configured as an image processing processor such as a DSP (Digital Signal Processor). The camera signal processing unit 13 performs various kinds of signal processing on digital signals (captured image signals) sent from the image sensor 12 . Specifically, the camera signal processing unit 13 performs processing such as correction processing between R, G, and B color channels, white balance correction, aberration correction, shading correction, and the like. The camera signal processing unit 13 also performs YC generation processing for generating (separating) a luminance (Y) signal and color (C) signal from R, G, and B image data, processing for adjusting luminance and color, Each processing such as correction and gamma correction is performed.

Furthermore, the camera signal processing unit 13 may perform conversion to the final output format by performing resolution conversion processing, codec processing for encoding for recording or communication, and the like. The image data converted into the final output format is transferred to the recording control section 14 and the output section 16 . By outputting the image data to the display unit 15 , the image is displayed on the display panel 41 and the viewfinder 42 .

The camera signal processing unit 13 also performs image plane phase difference detection processing for autofocus (hereinafter also referred to as "AF") control. As one method for detecting the in-focus state, one pixel forming an image in the image sensor 12 is known as a photodiode (hereinafter sometimes referred to as "PD") divided pixel. The PD divided pixels are configured by arranging a pair of PD pixels divided into left and right. The image plane phase difference detection process is a process of performing phase difference detection from the output values of the left PD pixel and the right PD pixel of the PD divided pixels provided in the image sensor 12 . Note that a pair of left and right metal shielded pixels may be used instead of the PD divided pixels.

The recording control unit 14 performs recording and reproduction on a recording medium such as a non-volatile memory. The recording control unit 14 performs processing for recording image files such as moving image data and still image data, thumbnail images, and the like on a recording medium, for example.
Various actual forms of the recording control unit 14 are conceivable. For example, the recording control unit 14 may be configured as a flash memory built in the imaging device 100 and its writing/reading circuit, or may be a recording medium detachable from the imaging device 100, such as a memory card (portable flash memory, etc.). ) by a card recording/reproducing unit that performs recording/reproducing access. Moreover, it may be implemented as an HDD (Hard Disk Drive) or the like as a form incorporated in the imaging apparatus 100 .

The display unit 15 is a display unit that provides various displays to the photographer, and specifically shows the display panel 41 and the viewfinder 42 shown in FIG.
The display unit 15 executes various displays on the display screen based on instructions from the camera control unit 30 . For example, the display unit 15 displays a reproduced image of image data read from the recording medium by the recording control unit 14 . The display unit 15 is supplied with image data of a captured image whose resolution has been converted for display by the camera signal processing unit 13 , and the display unit 15 responds to an instruction from the camera control unit 30 to display an image of the captured image. Display based on data. That is, through image display is performed.
Further, the display unit 15 displays various operation menus, icons, messages, etc., that is, as a GUI (Graphical User Interface) on the screen based on instructions from the camera control unit 30 .

The output unit 16 performs wired or wireless data communication and network communication with external devices. For example, the captured image data (still image file or moving image file) is transmitted and output to an external display device, recording device, reproducing device, information processing device, or the like.
The output unit 16 is a network communication unit, and performs communication via various networks such as the Internet, a home network, and a LAN (Local Area Network), and transmits and receives various data to and from servers, terminals, etc. on the network. You may do so.

The operation unit 17 collectively indicates an input device for the user to perform various operation inputs. Specifically, the operation unit 17 is composed of various operators 43 (including custom buttons 43C1 and 43C2 and a cross key 43J) provided on the main body housing 101 and detection circuits for the operators 43 . A user's operation is detected by the operation unit 17 , and a signal corresponding to the input operation is sent to the camera control unit 30 .

As the operation unit 17, not only the operator 43 but also a touch panel may be used. For example, a touch panel may be formed on the display panel 41 and various operations may be made possible by operating the touch panel using icons, menus, or the like displayed on the display panel 41 .
Alternatively, the operation unit 17 may detect a user's tap operation or the like using a touch pad or the like.
Furthermore, the operation unit 17 may be configured as a reception unit for an external operation device such as a separate remote controller.

The camera control unit 30 is composed of a microcomputer (arithmetic processing unit) equipped with a CPU (Central Processing Unit).

The memory unit 33 stores information and the like that the camera control unit 30 uses for processing. The illustrated memory unit 33 includes, for example, ROM (Read Only Memory), RAM (Random Access Memory), flash memory, and the like.

The RAM in the memory unit 33 is used as a work area for the CPU of the camera control unit 30 to perform various data processing, and is used for temporary storage of data, programs, and the like. The ROM and flash memory (nonvolatile memory) in the memory unit 33 store an OS (Operating System) for the CPU to control each unit, content files such as image files, application programs for various operations, and firmware. etc.
The memory unit 33 may be a memory area built into the microcomputer chip as the camera control unit 30, or may be configured by a separate memory chip.

The camera control unit 30 executes a program stored in the ROM of the memory unit 33, flash memory, or the like, thereby controlling the imaging apparatus 100 and the lens barrel 102 as a whole.
For example, the camera control unit 30 controls the shutter speed of the image sensor 12, instructs various signal processing in the camera signal processing unit 13, performs image capturing and recording operations in response to user operations, reproduces recorded image files, and provides a user interface. Controls the operation of each necessary part. As for the lens system 21, the camera control unit 30 performs zoom lens control, F-number change according to the user's setting operation, auto iris control for automatically controlling the F-number, and the like.

In the case of the present embodiment, the camera control section 30 has functions as the AF processing section 31 and the distance determination section 32 by means of software programs, for example.

The AF processing unit 31 performs autofocus control to automatically focus on a target subject. Specifically, based on the defocus amount calculated by the camera signal processing unit 13, drive control of the focus lens in the lens system 21 is performed via the lens barrel control unit 23 to execute the AF operation.
The AF processing unit 31 performs such AF control on the subject set as the focus target when the user instructs the AF operation. As a result, the in-focus state of the subject to be focused is maintained.
Further, as a so-called tracking AF, processing for maintaining the focused state while tracking a specific subject is also performed. Therefore, subject recognition processing may also be performed by image analysis. For example, face recognition processing, object recognition processing using semantic segmentation technology, and the like are sequentially performed to determine the subject. By recognizing the subject for each frame of the captured image or for each intermittent frame, the position of the subject within the image plane can be confirmed and tracking AF processing can be performed.

The distance determination unit 32 determines the distance to each subject shown in the captured image, and determines the distance relationship between each subject, that is, the front-back relationship, which is the relationship in the perspective direction from the imaging device 12. .
For this reason, the distance determination unit 32 can generate depth map information for an image, for example, and determine the distance of each subject. A depth map is data indicating the distance of each pixel from the imaging device 100 to the subject. For example, by converting the defocus amount calculated by the camera signal processing unit 13 into the subject distance based on the conditions of the optical system and the imaging device, a depth map representing the subject distance distribution can be obtained. By generating such a depth map in a necessary range such as the entire image or the range of an AF area frame 50 to be described later, the distance and distance relationship between each subject can be determined.
In addition, not the entire captured image or the entire AF area frame 50, but only areas such as faces, bodies, animals, and objects obtained by the above-described face recognition processing and object recognition processing have distance information, and background information is provided. etc. may be a depth map without distance information.
In the case of the present embodiment, it is only necessary to be able to determine distance information for at least a subject that can be an AF target. , and distance information of subjects significant as AF targets.

The sensor unit 18 comprehensively indicates various sensors mounted on the imaging device.
For example, when an IMU (inertial measurement unit) is mounted as the sensor unit 18, an angular velocity (gyro) sensor with three axes of pitch, yaw, and roll detects angular velocity, and an acceleration sensor detects acceleration. be able to.
As the sensor unit 18, for example, a position information sensor, an illuminance sensor, a distance measuring sensor, etc. may be mounted. For example, the camera control unit 30 generates the above-described depth map and distance information for each subject based on the detection value of a distance measuring sensor such as a TOF (Time of Flight) method, so that the distance and anteroposterior relationship of each subject can be determined. can be

When the lens barrel 102 is attached to the body housing 101, the camera control unit 30 communicates with the lens barrel control unit 23 and issues various instructions.
In the lens barrel 102, a lens barrel controller 23, for example, a microcomputer is mounted, and various data communications are possible with the camera controller 30. FIG. For example, the camera control unit 30 instructs the lens barrel control unit 23 to drive the zoom lens, the focus lens, the iris (aperture mechanism), and the like. The lens barrel control section 23 controls the lens system driving section 22 in accordance with these drive instructions to cause the lens system 21 to operate.

The lens system driving unit 22 is provided with, for example, a motor driver for a zoom lens driving motor, a motor driver for a focus lens driving motor, a motor driver for an iris motor, and the like.
These motor drivers apply drive currents to the corresponding drivers according to instructions from the lens barrel control unit 23 to move the focus lens and the zoom lens, open and close the aperture blades of the iris, and the like.

Although FIG. 3 shows the internal configuration of the imaging device 100 in which the lens barrel 102 is separate from the main housing 101 and detachable, the lens-integrated imaging device 100 can be considered to have substantially the same configuration. However, in that case, the camera control section 30 may have the control function of the lens barrel control section 23 .

<2. First Embodiment>
Processing according to the first embodiment will be described with reference to FIGS. 4 and 5. FIG. The processing example of each embodiment described below is the processing of the camera control section 30 executed by the functions of the AF processing section 31 and the distance determination section 32 .

FIG. 4 shows an example of processing when an AF operation is being performed on a certain subject to be focused in response to, for example, a user's half-pressing of the shutter button. In step S101, the camera control unit 30 executes AF processing. That is, it is control processing for driving the focus lens based on the defocus amount detected in the area of the object to be focused.

In step S102, the camera control unit 30 determines whether or not it is time to end the AF processing due to some trigger. For example, if it is determined that the AF operation has ended due to an operation change such as the end of the user's half-pressing, release, mode change, or the like, the camera control unit 30 advances to step S107, cancels the AF control, and ends the AF operation.

During execution of the AF operation, the camera control unit 30 monitors the target switching operation in step S103.
The target switching operation is a user operation for instructing the AF processing unit 31 to switch the focus target to another subject determined by the distance determination unit 32 to be at a different distance from the current focus target subject.
For example, assume that the custom button 43C1 is assigned as an operator for the target switching operation. For example, the custom button 43C1 may be assigned to the target switching operation in the initial state, or may be assigned to the custom button 43C1 by the user's setting operation. Of course, custom button 43C2 may be used.
For example, if one push operation of the custom button 43C1 is the target switching operation, the camera control unit 30 monitors one push operation of the custom button 43C1 in step S103.

For example, when a target switching operation is detected as a push operation of the custom button 43C1, the camera control unit 30 proceeds to step S104, and the subject currently being subjected to AF, that is, the subject currently being focused is the closest within the AF area. It is determined whether or not the object is a close object.
If the object is the closest object, the camera control unit 30 continues the AF operation for that object in step S106. to change the focus target to the subject.

Here is a specific example. FIG. 5A shows an image of a track and field runner taken from the front. For example, the user can set the AF area frame 50 within the screen of the display unit 15 such as the display panel 41 . Alternatively, the AF area frame 50 may be fixedly set, or may be automatically variably set.
This AF area frame 50 is a display indicating that the inside of the frame is the AF area. The AF area is an area in which the subject within the area is the focus target of the AF operation.

For example, FIG. 6 shows various AF area frames 50 .
As the AF area frame 50, S size, M size, L size, landscape size, free size, etc. can be selected as shown in the example of FIG. The user may select one of the AF area frames 50 according to the shooting scene, or, for example, select a free size and set an arbitrary area as the AF area frame 50 by performing a range specifying operation.
For example, when photographing track and field runners with the angle of view shown in FIG. 5A, a horizontally long size AF area frame 50 should be used so that subjects suitable for AF, in this case the faces of each athlete, are included. is preferred.
Alternatively, the camera control unit 30 may automatically set an appropriate AF area by face recognition or object recognition without user selection.

In the example of FIG. 5A, the subjects H1, H2, and H3 are shown as three runners, and the display of the focus frame 51 is superimposed on the subject H1. This indicates that the AF operation is being performed with the subject H1 as the focus target.

In step S104 of FIG. 4, the camera control unit 30 uses the function of the distance determination unit 32 to determine whether the subject currently being focused in the AF operation is the closest within the AF area indicated by the AF area frame 50. Determine whether or not there is In the case of the example of FIG. 5A, it is determined whether or not the subject H1 to be focused is the nearest runner, that is, the runner in the lead.

When the object H1 to be focused is the closest object, the camera control unit 30 proceeds to step S106 and maintains the focus object without switching. In other words, even if there is a target switching operation, the focus target is not switched. Then, the process returns to step S101. In this case, the camera control section 30 continues the AF control for the subject H1 that was targeted for focusing.

On the other hand, when a subject in the AF area other than the subject H1 to be focused, for example, the subject H2 is the closest, the camera control unit 30 proceeds to step S105 and switches the focus target to the subject H2. Then, the camera control unit 30 returns to step S101, and starts AF control for the new subject H2 to be focused. FIG. 5B shows that the focus frame 51 is switched to the subject H2, and the AF operation is performed with the subject H2 as the focus target.

Therefore, when the user performs the target switching operation by pushing the custom button 43C1 or the like, the camera control unit 30 performs AF control with the subject at the front at that time as the focus target.
For example, after that, when the user performs the target switching operation when the subject H3 comes to the front, the focusing target is switched in the process of step S105, so that the focus frame 51 shifts to the subject H3 as shown in FIG. 5C. The state is switched, and the AF operation is performed with the subject H3 as the focus target.

As described above, in the first embodiment, each time the user performs the target switching operation, the AF operation is performed while switching (or maintaining) the focus target of the closest subject within the AF area. become.
In a motor sport or a track and field event, when the user wants to keep the subject in focus at all times, in normal AF operation, the user stops the AF operation once at the timing when the leading object changes, and then restarts the AF operation. There is a need to do. Due to such a time lag in operation, a photo opportunity may be missed, and a desired subject may not be successfully selected as an AF target.
On the other hand, in the first embodiment, for example, one action of pushing the custom button 43C1 once can switch the focus target of the AF operation to the first subject, which is extremely convenient for the user.

Note that there is a function of setting AF sensitivity as a function for facilitating switching of AF targets.
The setting of AF sensitivity is a function of adjusting the degree of maintenance of the focused object by setting the level of sensitivity. When the AF sensitivity is low, when another subject comes ahead of the first captured subject, the first captured subject tends to remain in focus. Conversely, when the AF sensitivity is high, when another subject comes in front of the first captured subject, the focused subject tends to shift to the subject in front.
However, even if the AF sensitivity is set to the highest sensitivity state, a slight difference in distance does not cause the switching of the focus target, and even when the switching occurs, a time lag may occur.
In that respect, switching the focus target based on distance information at the time of the user's target switching operation as in the first embodiment is necessary to realize AF operation in accordance with the user's intention. , is more favorable.

In the first embodiment, the focus target is switched to the closest subject within the AF area in accordance with the target switching operation. to the farthest object in the AF area.
In addition, the focus target is switched to the closest (or farthest) subject within the AF area, but without setting the AF area, the closest (or farthest) subject can be selected within the range of the entire screen of the captured image. ) can also be considered.

<3. Second Embodiment>
A second embodiment will be described with reference to FIGS. 7 and 8. FIG. This is an example corresponding to the user's target switching operation during tracking AF.

FIG. 7 shows an example of processing when a tracking AF operation is being performed on a subject set as a focus target, for example, by a predetermined user operation.
In step S201, the camera control unit 30 executes tracking AF processing. That is, there is tracking processing for a subject to be focused, and control processing for driving the focus lens based on the defocus amount detected for the subject area.

In step S202, the camera control unit 30 determines whether or not the timing for ending the tracking AF process has come due to some trigger. For example, if it is determined that the tracking AF ends due to the user's operation, the disappearance of the subject due to the movement of the subject out of the frame, or other causes, the camera control unit 30 advances to step S207, cancels the tracking AF control, and ends the tracking AF operation. Let

During execution of the tracking AF operation, the camera control unit 30 monitors the target switching operation in step S203. For example, it is the operation of the custom button 43C1 as described above.
For example, if a target switching operation is detected as a push operation of the custom button 43C1, the camera control unit 30 proceeds to step S204, and the subject that is currently being tracked by AF, that is, the subject that is currently being focused is within the AF area. It is determined whether or not the object is the closest object.

FIG. 8A shows an image of a track and field runner. In this example as well, the subjects H1, H2, and H3 are photographed as three runners, and the display of the focus frame 51 indicating the tracking target is superimposed on the subject H1.
For example, as for the tracking AF control, until then, AF control was performed based on the defocus amount of the area of the subject H1 while tracking the subject H1 in the image regardless of the order of the race.

In step S204 of FIG. 7, it is determined whether or not the subject H1 to be focused in the tracking AF is the closest runner, that is, the leading runner.

When the subject H1 to be focused is the closest subject, the camera control unit 30 proceeds to step S206 and maintains the focus target without switching. That is, even if there is a target switching operation, the process returns to step S201 without switching the focus target. In this case, the camera control unit 30 continues the tracking AF control for the subject H1 that was targeted for focusing.

On the other hand, when a subject in the AF area other than the subject H1 to be focused, for example, the subject H2 is the closest, the camera control unit 30 proceeds to step S205 and switches the focus target to the subject H2. Then, the camera control unit 30 returns to step S201 and starts the tracking AF control for the new object H2 to be focused. FIG. 8B shows that the focus frame 51 is switched to the subject H2, and the tracking AF operation is performed with the subject H2 as the focus target.

Therefore, when the user performs the target switching operation by pushing the custom button 43C1 or the like, the camera control unit 30 performs tracking AF control with the subject at the front at that time as the focus target.

As described above, in the second embodiment, each time the user performs the target switching operation, the tracking AF operation is performed while the focus target of the tracking AF operation is switched (or maintained) to the first subject. become.

Even when tracking AF is used, when tracking cannot be completed or when changing to tracking of another subject, the user must select the subject to be tracked again and perform the AF operation again. There is For example, an operation of selecting a subject again and performing AF again during one race scene is highly difficult as an operation, and there is a risk of loss of photographing opportunities.
Being able to switch the focus target of the tracking AF with one action operation as in the second embodiment is extremely convenient for the user.
In addition, even if the tracking AF does not work well and the background is still captured, it is possible to immediately change the tracking target to the one in front.
As a use case, it is suitable when you want to focus on a specific player in a race or the like, but want to shoot the moment the leading player reaches the finish line. If the user performs the target switching operation at the moment immediately before the goal of the leading player, the leading player can be captured by the tracking AF instead of the player that has been the focus target of the tracking AF.

As a modified example, a processing example of switching the focus target of the tracking AF to the farthest subject in accordance with the target switching operation is also conceivable.

In the case of tracking AF, the subject to be tracked is not necessarily within a specific area in the image. You may make it switch to the object of the nearest (or farthest) among them.

<4. Third Embodiment>
A third embodiment will be described with reference to FIGS. 9 and 10. FIG. This is an example in which, for example, by toggling the custom button 43C1 or the like, the focus target is switched in order from the subject within the AF area to the one with the shortest distance.

Similar to FIG. 4, FIG. 9 shows an example of processing when an AF operation is being performed on a certain subject to be focused.
In step S301, the camera control unit 30 executes AF processing.
In step S302, the camera control unit 30 determines whether or not it is time to end the AF process. If it is determined to end AF, the camera control unit 30 proceeds to step S307, cancels the AF control, and ends the AF operation.

During execution of the AF operation, the camera control unit 30 monitors the target switching operation in step S303.
For example, when a target switching operation is detected as a push operation of the custom button 43C1, the camera control unit 30 advances to step S304, and the subject currently being AF-ing, that is, the subject currently being focused is the closest within the AF area. It is determined whether or not the object is a close object.

If the subject to be focused is not the closest subject within the AF area, the camera control unit 30 advances to step S305 to set the subject to be focused within the AF area to the front or rear of the subject currently being focused. Switch to the previous object in terms of direction order. Then, the camera control unit 30 returns to step S301, and starts AF control for the new subject to be focused.

When the subject to be focused is the closest subject in the AF area, the camera control unit 30 proceeds from step S304 to step S306 and switches the focus target to the farthest subject in the AF area. Then, the camera control unit 30 returns to step S301, and starts AF control for the new subject to be focused.

As a result, each time the user performs a target switching operation as a push operation of the custom button 43C1, the focus target is switched to the front side in order, and if the subject is the closest, the focus target is the closest. You will be returned to the subject behind you.
For example, it is assumed that the distance relationships among subjects H1, H2, and H3 in FIGS. 10A, 10B, and 10C are H1<H2<H3. In other words, it is assumed that the subject H3 is the farthest from the imaging device 100 and the subject H1 is the closest to the imaging device 100 .

In this case, when the target switching operation is performed in the state of FIG. 10A in which the subject H3 is the focus target, the state is switched to the state in which the subject H2, which is immediately ahead, is the focus target, as shown in FIG. 10B. Further, when the target switching operation is performed, the state is switched to a state in which the subject H1 immediately ahead is set as the focus target as shown in FIG. 10C. Further, when the target switching operation is performed, since the subject H1 up to that point is the closest subject, the state is switched to the state in which the farthest subject H3 is set as the focus target as shown in FIG. 10A.

With such an operation function, the user can extremely easily select an AF focus target when he/she wants to set an arbitrary subject as the focus target. In particular, by using the toggle operation, the user can perform the push operation the required number of times until the desired subject becomes the focus target.

As a modification, for example, the process of step S306 in FIG. 9 may be a process of maintaining the closest object. In other words, switching is disabled from the closest subject. The focus target is switched sequentially from the rear to the front, but when the closest subject is in focus, the focus target cannot be switched even if the target switching operation is performed. This is an example of processing. This is an example of processing that meets the need to switch the focus target only in the direction of approaching the imaging device 100 .

In addition, the process of sequentially switching the focus target to the front side each time the target switching operation is performed, as in FIG. 9 or the modified example described above, can also be applied to switching the focus target in the tracking AF operation.

<5. Fourth Embodiment>
A fourth embodiment will be described with reference to FIG. This is an example in which, for example, by toggle operation of the custom button 43C1 or the like, the focus target is switched in order from the farthest subject in the AF area.

In FIG. 11, the same step numbers are assigned to the same processes as in FIG. 9 to avoid redundant description.
In this case, the camera control unit 30 monitors the target switching operation in step S303 while the AF operation is being performed. . In step S314, the camera control unit 30 determines whether or not the subject currently being focused is the farthest subject within the AF area.

If the subject to be focused is not the farthest subject in the AF area, the camera control unit 30 advances to step S315 to set the subject to be focused in the AF area to the front or rear of the subject currently being focused. Switch to the next subject in the order of direction. Then, the camera control unit 30 returns to step S301, and starts AF control for the new subject to be focused.

When the subject to be focused is the farthest subject in the AF area, the camera control unit 30 proceeds from step S314 to step S316 and switches the focus target to the closest subject in the AF area. Then, the camera control unit 30 returns to step S301, and starts AF control for the new subject to be focused.

As a result, each time the user performs an object switching operation as a push operation of the custom button 43C1, the object to be focused is sequentially switched to the rear side, and if the object is the farthest, the object to be focused is the maximum. It will be returned to the close subject.
Therefore, in the case of FIGS. 10A, 10B, and 10C described above, each time the target switching operation is performed, switching is performed in the reverse order of FIGS. 10C, 10B, 10A, 10C, . go.

As a modification, for example, the process of step S316 in FIG. 11 may be a process of maintaining the farthest subject. In other words, switching is disabled from the farthest subject. The focus target is switched sequentially from the front side to the rear, but when the farthest subject is in focus, the focus target cannot be switched even if the target switching operation is performed. This is an example of processing. This is an example of processing that meets the need to switch the focus target only toward a distance from the imaging apparatus 100 .

In addition, the process of sequentially switching the focus target to the rear side each time the target switching operation is performed, as in FIG. 11 or the modified example described above, can also be applied to the switching of the focus target in the tracking AF operation.

<6. Fifth Embodiment>
A fifth embodiment will be described with reference to FIG. This is an example of processing in which the processing of FIGS. 9 and 11 are combined. In FIG. 12, the same steps as those in FIGS. 9 and 11 are given the same step numbers to avoid overlapping explanations.

In this case, two manipulators in the imaging device 100 are assigned as manipulators for the target switching operation.
For example, the custom button 43C1 is assigned to a forward target switching operation (hereinafter referred to as "forward operation"), and the custom button 43C2 is assigned to a backward target switching operation (hereinafter referred to as "backward operation").
Alternatively, one of the upward operation and the downward operation of the cross key 43J may be forward operation, and the other may be backward operation. Further, one of the left operation and right operation of the cross key 43J may be forward operation, and the other may be backward operation.
Further, as two dedicated keys, an operator 43 for front operation and rear operation may be provided, or an operator capable of lever operation corresponding to front and rear may be provided.

The camera control unit 30 monitors forward operation in step S320 and monitors rearward operation in step S321 during AF execution.
When the forward operation is detected, the camera control unit 30 proceeds from step S320 to step S304, and proceeds to step S305 or step S306 depending on whether or not the current subject to be focused is the closest in the AF area. move on. That is, as described with reference to FIG. 9, the process of sequentially switching the focus target to the subject in front is performed.
When the rearward operation is detected, the camera control unit 30 proceeds from step S321 to step S314, and proceeds to step S315 or step S316 depending on whether or not the current subject to be focused is the farthest in the AF area. move on. That is, as described with reference to FIG. 11, the process of sequentially switching the focus target to the rear subject is performed.

By performing such processing, the user can arbitrarily switch the focus target to the front side or the rear side by, for example, operating the custom buttons 43C1 and 43C2, and the AF operation can be switched to the desired subject. You will be able to do it more smoothly.

The modifications described in the third and fourth embodiments can also be applied to the fifth embodiment.

<7. Summary and Modifications>
The following effects are obtained in the above embodiment.
The image capturing apparatus 100 according to the first to fifth embodiments includes a distance determination unit 32 that determines the distance to the subject, performs AF control on the subject that is the focus target, and responds to the user's target switching operation. Accordingly, an AF processing unit 31 is provided for switching the focus target to another subject determined by the distance determination unit 32 to be at a different distance from the current focus target subject.
In some cases, the user may want to switch the AF target to a subject at a different position in the depth direction as viewed from the imaging apparatus 100. In that case, the user normally terminates the AF operation once, selects a new subject, and performs AF. An operation is performed to turn on the action. However, there are many cases in which focusing on a new subject is not successful, and it is possible that a photo opportunity may be missed due to delays. On the other hand, according to the processing of the embodiment, the focus target for the AF operation can be switched to a different subject in the depth direction only by the target switching operation, so that extremely easy and convenient operability for the user can be provided. become a thing.
In particular, by responding to the target switching operation, the AF target subject can be switched at the timing requested by the user, so switching the AF focus target according to the user's intention is extremely easy. It is especially suitable for shooting dynamic subjects.

As described in the first embodiment, the AF processing unit 31 switches the focus target among the subjects in the AF area set as the area in the captured image in response to the target switching operation. Sometimes.
As a result, the focus target of the AF operation is switched only between subjects captured within the AF area frame 50 in the captured image. For example, even if an object or the like that is not of interest appears in other parts of the screen, particularly in the near side, it is possible to prevent that object or the like from being focused. Therefore, depending on the switching of the focus target by the target switching operation, it is easier for the user to correctly switch to the subject that the user wants to switch to.

In the first embodiment, an example has been described in which the AF processing unit 31 switches the focus target to the subject determined by the distance determination unit 32 to be the closest distance in accordance with the target switching operation.
As a result, it is possible to provide a convenient function for a use case in which the closest subject is to be the AF target. For example, in track and field competitions and other races, even in cases where the leading (closest) subject as seen from the imaging device 100 changes, it is possible to easily focus on the leading subject.

In the third embodiment, the AF processing unit 31 selects the focus target in accordance with the target switching operation so that the order of the distance relationship determined by the distance determination unit 32 is one more than the current focus target subject. An example of switching to a subject on the near side has been described.
As a result, the AF target subject can be sequentially switched to the subject closer to the imaging apparatus 100 by the target switching operation, and various shooting scenes can be flexibly handled.
This is particularly convenient when you want to switch from shooting a subject in the back to a subject in the front. Alternatively, it is also useful for getting out of a state in which AF was performed with an undesired subject as the focus target.

In the third embodiment, when the object to be focused is the closest object at the time of the object switching operation, the focus object is switched to the farthest object.
As a result, the AF target subject is sequentially switched to the subject closer to the imaging device 100 by the target switching operation, and then the closest subject is returned to the farthest subject. That is, the in-focus object is repeatedly switched from the rear object to the front object in order. Therefore, the user can easily select any subject as a focus target with one operation.

In the fourth embodiment, the AF processing unit 31 selects the focus target in accordance with the target switching operation so that the order of the distance relationship determined by the distance determination unit 32 is one more than the current focus target subject. An example of switching to a subject on the far side has been described.
As a result, the AF target subject can be sequentially switched to the subject farther from the imaging apparatus 100 by the target switching operation, and various shooting scenes can be flexibly handled. This is particularly convenient when you want to switch from shooting a subject in front of you to a subject in the back. Alternatively, it is also useful for getting out of a state in which AF was performed with an undesired subject as the focus target.

In the fourth embodiment, when the object to be focused is the farthest object at the time of the object switching operation, the focus object is switched to the closest object.
As a result, the AF target subject is sequentially switched to a subject farther from the imaging apparatus 100 by the target switching operation, and then the farthest subject is followed by the closest subject. That is, the in-focus object is repeatedly switched from the front object to the rear object in order. Therefore, the user can easily select any subject as a focus target with one operation.

In the second embodiment, the AF processing unit 31 performs tracking AF control to bring the subject in focus while tracking the subject to be focused, and in the tracking AF control, the focus target is changed according to the target switching operation. Here is an example of switching.
This makes it possible to easily switch the focus target of the AF operation even when executing the tracking AF. For example, while tracking AF is being performed on a specific player, it is possible to easily switch the focus target of the tracking AF to the leading player at the moment of a goal.
Note that the processing of the third, fourth, and fifth embodiments can also be applied to switching the focus target of tracking AF. As a result, even during the tracking AF, the subject to be tracked and focused can be switched smoothly at any timing.

In the embodiment, an example is given in which the target switching operation is an operation of one action of the operator provided on the main housing 101 .
For example, one-time push operation of a button operator, one-time operation of a lever operator, one-time touch operation of a touch operator, and so on, by performing a target switching operation with one action, the focus target of the AF operation is changed. Since it can be switched, the user can quickly select an AF target according to the situation of the subject at the time of shooting.
Note that the target switching operation may be a one-action operation of an operator provided on the lens barrel 102 .

In the embodiment, an example is given in which the target switching operation is an operation of one operator such as the custom button 43C1.
For example, an operation for sequentially switching the focus target to a subject in front as in the third embodiment or an operation for sequentially switching to a subject in the rear as in the fourth embodiment can be performed using a single operator. It is realized by toggle operation. As a result, the user can easily switch the focus target at desired timing with one operator, and usability is improved.

In the fifth embodiment, as an operator for the target switching operation, a first operator (for example, the custom button 43C1 ) and a second operator (for example, custom button 43C2) for instructing switching of the focus target to a subject farther away than the current focus target subject. Then, the AF processing unit 31 switches the focus target to a subject determined to be closer than the current subject by the distance determination unit 32 according to the operation of the first operator, , the focus target is switched to a subject determined by the distance determination unit 32 to be at a greater distance than the current subject.
By providing two operators, the user can use the operators properly to arbitrarily designate a subject on the far side or a subject on the near side to switch the focus target. As a result, a desired subject can be set as an AF target more quickly.

In the embodiment, the example in which the custom button 43C1 (or 43C2) is provided as an operator capable of selectively setting the operation function as the target switching operation has been described.
This allows the user to arbitrarily make settings for the target switching operation, increasing the degree of freedom of use.
In addition, when a plurality of custom buttons are provided, such as the custom buttons 43C1 and 43C2, the user can select which custom button is to be used as the operator for the target switching operation, and can match the mode of use of the user. It is also possible to select not to perform the target switching operation.

In each embodiment, it is assumed that the target switching operation is performed by an operator such as a key. may be performed.

It has been described that the AF area indicated by the AF area frame 50 in the embodiment can be changed by user operation (see FIG. 6).
The user can select the AF area frame 50 from among a plurality of ones or freely set it. Accordingly, it is possible to set the AF area frame 50 in which the target switching operation can be effectively used, according to the type of subject and shooting scene. When the AF area frame 50 is appropriate, the focus target can be appropriately switched between target subjects.

The processing of switching the subject to be focused during the AF operation and the tracking AF operation described in each embodiment can be applied to both still image capturing and moving image capturing.

The program of the embodiment is a program that causes a CPU, a DSP, or a device including these to execute the processes shown in FIGS. 4, 7, 9, 11, or 12, for example.
That is, the program of the embodiment performs distance determination processing for determining the distance to the subject, performs AF control on the subject set as the focus target, and determines the focus target according to the user's target switching operation. A program for causing an information processing apparatus to perform AF processing for switching to another subject determined by distance determination processing to be at a different distance from the current focus target subject.

With such a program, the imaging device 100 of the present disclosure can be easily realized using an information processing device. For example, by installing such a program in an information processing device such as a smart phone, a tablet terminal, or a personal computer equipped with an image capturing function, it becomes possible to realize the operation functions described in the embodiment when capturing an image.

Such a program can be recorded in advance in a HDD (Hard Disk Drive) as a recording medium built in equipment such as a computer device, or in a ROM or the like in a microcomputer having a CPU.
Alternatively, a flexible disc, a CD-ROM (Compact Disc Read Only Memory), an MO (Magneto Optical) disc, a DVD (Digital Versatile Disc), a Blu-ray disc (Blu-ray Disc (registered trademark)), a magnetic disc, a semiconductor memory, It can be temporarily or permanently stored (recorded) in a removable recording medium such as a memory card. Such removable recording media can be provided as so-called package software.
In addition to installing such a program from a removable recording medium to a personal computer or the like, it can also be downloaded from a download site via a network such as a LAN (Local Area Network) or the Internet.

It should be noted that the effects described in this specification are merely examples and are not limited, and other effects may also occur.

Note that the present technology can also adopt the following configuration.
(1)
a distance determination unit that determines the distance to the subject;
Autofocus control is performed on the subject that is the focus target, and the focus target is determined to be at a different distance from the current focus target subject by the distance determination unit in accordance with the target switching operation by the user. An imaging device comprising: an autofocus processing unit that switches to another subject.
(2)
The autofocus processing unit switches a focus target among subjects in an autofocus area set as a region in the captured image in response to the target switching operation. Device.
(3)
The imaging apparatus according to (1) or (2) above, wherein the autofocus processing section switches the focus target to the subject determined to be the closest distance by the distance determination section in accordance with the target switching operation.
(4)
The autofocus processing unit, in accordance with the target switching operation, sets the focus target to the side one closer to the current focus target subject in the order of the distance relationship determined by the distance determination unit. The imaging apparatus according to (1) or (2) above, wherein switching to a subject is performed.
(5)
The autofocus processing unit switches the focus target to the farthest subject when the current focus target subject is the closest subject during the target switching operation. Imaging device.
(6)
In accordance with the target switching operation, the autofocus processing unit sets the focus target to the side farther by one than the current focus target subject in the order of the distance relationship determined by the distance determination unit. The imaging apparatus according to (1) or (2) above, wherein switching to a subject is performed.
(7)
The above-mentioned (6), wherein the autofocus processing unit switches the focus target to the closest subject when the current focus target subject is the farthest subject during the target switching operation. Imaging device.
(8)
The autofocus processing unit is
Tracking autofocus control is performed to bring the subject in focus while tracking the subject, and in the tracking autofocus control, the focus target is switched in accordance with the target switching operation. (1) to (7) above The imaging device according to any one of 1.
(9)
The imaging apparatus according to any one of (1) to (8) above, wherein the target switching operation is one action operation of an operator provided on a housing.
(10)
The imaging apparatus according to any one of (1) to (9) above, wherein the target switching operation is an operation of one operator.
(11)
As an operator for the target switching operation,
a first operator for instructing switching of the focus target to a subject closer to the subject than the current focus target;
a second operator for instructing switching of the focus target to a subject farther away than the current focus target subject;
The autofocus processing unit is
switching a focus target to a subject determined by the distance determination unit to be closer than the current subject in response to the operation of the first operator;
The imaging device according to any one of (1) to (9) above, in which the focus target is switched to the subject determined to be farther than the current subject by the distance determination unit in accordance with the operation of the second operator. .
(12)
The imaging apparatus according to any one of (1) to (10) above, further comprising an operator capable of selectively setting an operation function as the target switching operation.
(13)
The imaging device according to (2) above, wherein the autofocus area is changeable by a user operation.
(14)
distance determination processing for determining the distance to the subject;
Autofocus control is performed on the subject that is the focus target, and the focus target is determined to be at a different distance from the current focus target subject by the distance determination process according to the target switching operation by the user. Autofocus processing to switch to another subject,
A focus control method performed by the imaging device.
(15)
distance determination processing for determining the distance to the subject;
Autofocus control is performed on the subject that is the focus target, and the focus target is determined to be at a different distance from the current focus target subject by the distance determination process according to the target switching operation by the user. Autofocus processing to switch to another subject,
A program that causes an information processing device to execute

12 image sensor 13 camera signal processing unit 18 sensor unit 30 camera control unit 31 AF processing unit 32 distance determination unit 41 display panel 43 operator 43C1, 43C2 custom button 43J cross key 50 AF area frame 51 focus frame 100 imaging device 101 main housing body 102 lens barrel

Claims

a distance determination unit that determines the distance to the subject;
Autofocus control is performed on the subject that is the focus target, and the focus target is determined to be at a different distance from the current focus target subject by the distance determination unit in accordance with the target switching operation by the user. An imaging device comprising: an autofocus processing unit that switches to another subject.
The imaging apparatus according to claim 1, wherein the autofocus processing unit switches a focus target among subjects within an autofocus area set as a region within the captured image in response to the target switching operation. .
The imaging apparatus according to claim 1, wherein the autofocus processing section switches the focus target to the subject determined to be the closest distance by the distance determining section in accordance with the target switching operation.
The autofocus processing unit, in accordance with the target switching operation, sets the focus target to the side one closer to the current focus target subject in the order of the distance relationship determined by the distance determination unit. The imaging device according to claim 1, wherein the imaging device is switched to a subject.
The imaging according to claim 4, wherein the autofocus processing unit switches the focus target to the farthest subject when the current focus target subject is the closest subject during the target switching operation. Device.
In accordance with the target switching operation, the autofocus processing unit sets the focus target to the side farther by one than the current focus target subject in the order of the distance relationship determined by the distance determination unit. The imaging device according to claim 1, wherein the imaging device is switched to a subject.
The imaging according to claim 6, wherein the autofocus processing unit switches the focus target to the closest subject when the current focus target subject is the farthest subject during the target switching operation. Device.
The autofocus processing unit is
2. The imaging apparatus according to claim 1, wherein tracking autofocus control is performed to bring the subject in focus while tracking the subject to be focused, and in the tracking autofocus control, the focus target is switched according to the target switching operation. .
The imaging apparatus according to claim 1, wherein the target switching operation is one action operation of an operator provided on a housing.
The imaging apparatus according to claim 1, wherein the target switching operation is an operation of one operator.
As an operator for the target switching operation,
a first operator for instructing switching of the focus target to a subject closer to the subject than the current focus target;
a second operator for instructing switching of the focus target to a subject farther away than the current focus target subject;
The autofocus processing unit is
switching a focus target to a subject determined by the distance determination unit to be closer than the current subject in response to the operation of the first operator;
2. The imaging apparatus according to claim 1, wherein a focus target is switched to a subject determined by the distance determination unit to be farther than the current subject according to the operation of the second operator.
The imaging apparatus according to claim 1, further comprising an operator capable of selectively setting an operation function as the target switching operation.
The imaging device according to claim 2, wherein the autofocus area is changeable by user operation.
distance determination processing for determining the distance to the subject;
Autofocus control is performed on the subject that is the focus target, and the focus target is determined to be at a different distance from the current focus target subject by the distance determination process according to the target switching operation by the user. Autofocus processing to switch to another subject,
A focus control method performed by the imaging device.
distance determination processing for determining the distance to the subject;
Autofocus control is performed on the subject that is the focus target, and the focus target is determined to be at a different distance from the current focus target subject by the distance determination process according to the target switching operation by the user. Autofocus processing to switch to another subject,
A program that causes an information processing device to execute