JP2023077931A - Imaging apparatus, and control method, program and storage medium thereof - Google Patents

Abstract

To provide an imaging apparatus that can focus on an object matching intention of a user in AF control in imaging a moving image.SOLUTION: An imaging apparatus comprises: a viewpoint determination section that determines a viewpoint in a subject field; a focus detection section that acquires a pair of focus detection signals from a subject image passing through different pupil areas of an imaging optical system, and detects a defocus amount of a subject on the basis of the pair of focus detection signals; and a control section that controls a position of a focus lens for the viewpoint to be a position of a proximate end within a subject field depth or its neighborhood on the basis of the defocus amount of the viewpoint acquired by the focus detection section.SELECTED DRAWING: Figure 10

Description

The present invention relates to focus adjustment technology in an imaging device.

AF (autofocus) control in an imaging device is generally performed by selecting an object to be focused and driving a focus lens based on the defocus amount detected for the object.

Face priority AF and close distance priority AF are typical methods of selecting an object to be focused. Face priority AF is a method of driving a focus lens using a defocus amount of a face detected using a method such as template matching. On the other hand, the closest object priority AF is a method of setting a plurality of focus detection frames within a screen and driving the focus lens using the defocus amount of the focus detection frames corresponding to the closest subject.

By the way, in recent years, there are an increasing number of users who take videos of themselves while introducing products and distributing videos. In this product introduction, scenes can be roughly divided into the following three scenes as shown in FIGS.
(a) A scene in which only the introducer is photographed (b) A scene in which the product is displayed in front of the product (c) A scene in which the product is used For each of the above scenes, the subject to be focused on differs, and is common. In (a), it is considered that the focus should be on the introducer, (b) on the product to be introduced, and (c) on the introducer. It is also possible to keep all subjects in focus by always narrowing down the shooting aperture and widening the depth of field. may be required.

JP 2014-235224 A

However, with the above-described conventional method of selecting a target to be focused on, there are cases where it is not possible to focus on a subject desired to be focused on in each scene of the product introduction video. When performing AF control with face-priority AF, the product cannot be brought into focus in the above case (b). Further, in the case of (c) above, in the close distance priority AF, the introducer cannot be brought into focus.

To address these problems, Japanese Patent Laid-Open No. 2002-200001 discloses a technique for focusing on a position where the maximum number of detected subjects is within the depth of field. However, the technique disclosed in Japanese Patent Laid-Open No. 2002-200010 aims at focusing on many subjects regardless of the subject, so it cannot guarantee that the main subject will be in focus.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and its object is to provide an imaging apparatus capable of focusing on an object that matches the user's intention in AF control in moving image shooting.

An image pickup apparatus according to the present invention includes point-of-interest determination means for determining a point of interest in an object field, and a pair of focus detection signals obtained from an object image that has passed through different pupil regions of an imaging optical system. focus detection means for detecting the defocus amount of the object based on the detection signal; and a control means for controlling the position of the focus lens so that it is at or near the near end.

According to the present invention, it is possible to focus on an object that matches the user's intention in AF control in moving image shooting.

1 is a block diagram showing the configuration of an imaging device according to a first embodiment of the present invention; FIG. FIG. 4 is a diagram showing the arrangement of pixels in an image sensor; 4 is a flowchart showing imaging processing; 4 is a flowchart showing video shooting processing; 4 is a flowchart showing focus detection processing; The figure which shows the scene classification of a product introduction video. 4 is a flowchart showing processing of face-priority AF. FIG. 10 is a diagram showing the depth of field when conventional AF is performed at the time of product introduction; 4 is a flowchart showing processing of close distance priority AF. 4 is a flowchart showing intra-face-depth AF processing according to the first embodiment; 4 is a flowchart showing reference point determination processing; FIG. 10 is a diagram showing an error case during reference point determination processing; 4 is a flowchart showing focus point determination processing. FIG. 7 is a diagram showing the depth of field when intra-face-depth AF is performed at the time of product introduction according to the first embodiment; 9 is a flowchart showing intra-face-depth AF processing according to the second embodiment; FIG. 11 is a diagram showing the depth of field when intra-face-depth AF is performed at the time of product introduction in the second embodiment; 11 is a flowchart showing intra-face-depth AF processing according to the third embodiment; FIG. 11 is a diagram showing the depth of field when intra-face-depth AF is performed at the time of product introduction according to the third embodiment;

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. In addition, the following embodiments do not limit the invention according to the scope of claims. Although multiple features are described in the embodiments, not all of these multiple features are essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
FIG. 1 is a block diagram showing the configuration of an imaging device 100 according to the first embodiment of the invention.

An imaging apparatus 100 of this embodiment is configured to include a lens unit 101 and a camera body 102 . A lens control unit 117 that controls the overall operation of the lens unit 101 and a camera control unit 141 that controls the overall operation of the imaging apparatus 100 including the lens unit 101 communicate with each other through terminals provided on the lens mount. It is possible.

First, the configuration of the lens unit 101 will be described. A photographing lens (imaging optical system) 111 includes a fixed lens 112 , a diaphragm 113 , and a focus lens 114 . A diaphragm control unit 115 drives the diaphragm 113 to adjust the aperture diameter of the diaphragm 113 and adjust the amount of light during photographing. The focus control unit 116 determines the drive amount for driving the focus lens 114 based on the amount of focus shift of the photographing lens 111 . The focus is adjusted by driving the focus lens 114 . AF control is realized by movement control of the focus lens 114 by the focus control unit 116 . The focus lens 114 is a lens for focus adjustment, and although it is simply shown as a single lens in FIG. 1, it is usually composed of a plurality of lenses. A diaphragm drive unit 115 and a focus control unit 116 are controlled by a lens control unit 117 .

A light flux incident through the optical member of the photographing lens 111 forms an image on the light receiving surface of the imaging element 121 and is converted into an electric signal by the imaging element 121 . The imaging device 121 is composed of a CCD or CMOS sensor having a large number of photoelectric conversion elements for converting a subject image (optical image) into signal charges. The signal charge accumulated in each photoelectric conversion element is sequentially read out from the imaging device 121 as a voltage signal corresponding to the signal charge by a driving pulse output from the timing generator 122 .

The CDS/AGC/AD converter 123 performs correlated double sampling for removing reset noise, adjusts the sensor gain, and digitizes the signals on the imaging signal and the focus detection signal read out from the imaging element 121. . The CDS/AGC/AD converter 123 outputs the imaging signal to the imaging signal processing unit 124 and the signal for focus detection of the imaging plane phase difference method to the focus detection signal processing unit 125 . In this embodiment, a system using the imaging plane phase difference method for focus detection will be described, but the focus detection method is not limited to this, and any method may be used as long as it is a phase difference method.

The focus detection signal processing unit 125 sets and arranges a focus detection area for focus detection within the imaging screen. Then, the focus detection signal processing unit 125 performs a correlation operation on the two image signals for focus detection output from the CDS/AGC/AD converter 123, and calculates the amount of image shift and reliability information (degree of coincidence of two images). , two-image steepness).

The imaging signal processing unit 124 stores the imaging signal output from the CDS/AGC/AD converter 123 in the SDRAM 136 via the bus 131 . The image signal stored in the SDRAM 136 is read by the display control section 132 via the bus 131 and displayed on the display section 133 . Also, in the operation mode for recording the imaging signal, the image signal stored in the SDRAM 136 is recorded in the recording medium 135 by the recording medium control section 134 .

The ROM 137 stores control programs executed by the camera control unit 141 and various data necessary for control. ing.

The switch SW1 (139) is a switch for performing shooting standby operations such as AF (autofocus) and AE (automatic exposure control). It is a switch to do.

The camera control unit 141 determines the lens drive amount based on the defocus amount output from the focus detection signal processing unit 125 and the reliability of the defocus amount. The lens driving amount is transmitted to the lens control unit 117 and transmitted to the focus control unit 116, thereby realizing AF. In addition, based on an instruction from the operator or the magnitude of the pixel signal of the image data temporarily stored in the SDRAM 136, the storage time of the image sensor 121, the gain setting value of the CDS/AGC/AD converter 123, and the timing are changed. Determine the settings for the generator 122 .

Next, the configuration of the imaging device 121 will be described with reference to FIG. A pixel array of the imaging device 121 is shown in FIG.

In FIG. 2, a pixel array 200 is configured by arranging unit pixels 201 in a matrix. A microlens 202 is arranged in each unit pixel 201 . Photodiodes (PDs) 203 a and 203 b are photoelectric conversion elements, and these two PDs form a unit pixel 201 arranged under a single microlens 202 . By adopting this configuration, the PDs 203a and 203b have a pupil division function, and can acquire separate images of the same object having different phases, which have passed through different pupil regions of the imaging optical system. These two separate images of the same object having a phase difference are called an A image and a B image, and the PD 203a constitutes the A image photoelectric conversion unit, and the PD 203b constitutes the B image photoelectric conversion unit.

Next, processing performed by the camera body 102 will be described. The camera control unit 141 performs the following processes according to an imaging processing program, which is a computer program stored in the ROM 137 .

FIG. 3 is a flowchart showing the procedure of photographing processing of the camera body 102. As shown in FIG. S means step.

In S301, the camera control unit 141 performs initialization processing such as camera settings, and advances the processing to S302.

In S302, the camera control unit 141 determines whether the shooting mode of the camera body 101 is the moving image shooting mode or the still image shooting mode. proceed.

In S303, the camera control unit 141 performs moving image shooting processing and advances the processing to S305. In S304, the camera control unit 141 performs still image shooting processing and advances the processing to S305. In this embodiment, a detailed description of the still image shooting process will be omitted. The moving image shooting process of S303 will be described later with reference to FIG.

In S305, the camera control unit 141 determines whether or not the shooting process has been stopped. If not stopped, the process proceeds to S306, and if stopped, the shooting process ends. When the shooting process is stopped means when the power of the camera body 102 is turned off, when an operation other than shooting is performed, such as camera user setting processing, playback processing for checking captured images/videos, etc. is.

In S306, the camera control unit 141 determines whether the shooting mode has been changed. If changed, the camera control unit 141 returns the process to S301, performs initialization processing, and then performs imaging processing in the changed shooting mode. On the other hand, if the shooting mode has not been changed, the camera control unit 141 returns the processing to S302 and continues the processing in the current shooting mode.

Next, the moving image shooting process performed in S303 of FIG. 3 will be described using the flowchart of FIG.

In S401, the camera control unit 141 determines whether or not the moving image recording switch is turned on. If it is turned on, the process proceeds to S402, and if it is not turned on, the process proceeds to S405.

In S402, the camera control unit 141 determines whether or not moving image recording is currently being performed. Recording is stopped and the process proceeds to S405. In the present embodiment, moving image recording is started and stopped each time the moving image recording switch is pressed. It is okay to stop.

In S405, the camera control unit 141 performs focus detection processing, and advances the processing to S406. The focus detection process is performed by the camera control unit 141 and the focus detection signal processing unit 125 to acquire defocus information and reliability information by imaging plane phase difference AF. will be described later.

In S406, the camera control unit 141 determines whether or not the moving image recording mode is the review mode. If the review mode is set, the process proceeds to S408. Here, the review mode is a mode specialized for video recording in which products are introduced through video distribution, etc. In this embodiment, by switching on/off the review mode, the focus detection processing method, which will be described later, is switched. .

In S407, the camera control unit 141 receives the result of the focus detection processing in S405 and performs face priority AF. The details of the face priority AF will be described with reference to the flowchart of FIG.

In S408, the camera control unit 141 receives the result of the focus detection processing in S405 and performs intra-face-depth AF processing, which is a characteristic processing of the present embodiment. The intra-face-depth AF is AF processing exclusively for the review mode, and the details will be described with reference to the flowchart of FIG. 10 . The camera control unit 141 ends the moving image shooting process after completing the processes of S407 and S408.

Next, the focus detection processing of S405 in FIG. 4 will be described with reference to FIG.

First, in S501, the camera control unit 141 sets a plurality of focus detection areas within an arbitrary range within the image sensor 121, and advances the process to S502.

In S502, the camera control unit 141 acquires a pair of image signals (images A and B) for focus detection from the image sensor 121 for the focus detection area set in S501, and advances the process to S503.

In S503, the camera control unit 141 performs row averaging processing in the vertical direction on the pair of image signals acquired in S502, and then advances the processing to S504. The processing in S503 can reduce the influence of noise on the image signal.

In S504, the camera control unit 141 performs filter processing for extracting signal components in a predetermined frequency band from the vertical row averaged signal in S503, and then advances the processing to S505. In this embodiment, a low-pass filter that extracts low-pass components of a signal and a high-pass filter that extracts high-pass components are used. Three or more types of filters, such as addition, may be used.

In S505, the camera control unit 141 calculates the correlation amount from the signal filtered in S504, and advances the process to S506.

In S506, the camera control unit 141 calculates the correlation change amount from the correlation amount calculated in S505, and advances the process to S507.

In S507, the camera control unit 141 calculates the image shift amount from the correlation change amount calculated in S506, and advances the process to S508.

In S508, the camera control unit 141 multiplies the image shift amount by a conversion coefficient to convert it into a defocus amount, and advances the process to S509. This conversion coefficient is stored in the camera according to the zoom lens position, the aperture value, and the image height of the imaging plane.

In S509, the camera control unit 141 determines the reliability indicating how reliable the defocus amount calculated in S508 is, and advances the process to S510. Reliability is determined by estimating the standard deviation of the defocus amount based on the evaluation values calculated in the processing of S505 and S506 and setting stepwise thresholds for the standard deviation. However, the reliability determination method is not limited to this method, and other methods may be used.

After completing S509, the camera control unit 141 advances the process to S510, and determines whether or not all the focus detection areas set in S501 have been processed. If the processing has not been completed for all focus detection areas, the camera control unit 141 returns the processing to S502 and performs the processing for the next focus detection area. If the camera control unit 141 determines in S510 that processing has been completed for all focus detection areas, it ends the focus detection processing.

Next, the AF processing of S407 and S408 will be described. Before describing the processing flowchart, first, a scene in which the review mode is used will be described with reference to FIG.

As described in Background Art, FIGS. 6(a), 6(b), and 6(c) show representative scenes in a product introduction video, and each means the following.
(a) A scene in which only the main person is photographed (b) A scene in which a product is displayed in front to introduce the product (c) A scene in which the product is used In this embodiment, a scene in which cosmetics are introduced will be described as an example. Reference numeral 601 indicates an introducer who introduces products, and reference numeral 602 indicates products to be introduced. Further, reference numeral 603 indicates cosmetics, and reference numeral 604 indicates a hand mirror. The object to be focused on differs for each scene. In (a), since the introducer is speaking, the introducer 601 is considered to be the focus. In (b), since the product is to be emphasized, the product 602 is considered to be in focus. In (c), it is desired to focus on the introducer 601 because it is desired to emphasize how the makeup changes.

Next, a description will be given of the fact that, with conventional AF processing (face-priority AF, closest-priority AF), there are cases where an object to be focused on is not brought into focus in these scenes.

First, the processing of face-priority AF in S407 and problems when face-priority AF is used in a product introduction video will be described with reference to the flowchart of FIG. 7 and FIG. Note that in the present embodiment, the face priority AF in S407 is executed when the review mode is not selected in S406.

In S407, when face priority AF is started, the camera control unit 141 advances the process to S701 and performs face detection processing (subject detection processing). In the face detection process, a template matching method is applied to the imaging signal output from the imaging signal processing unit 124 to detect the position of the face on the imaging plane.

In S702, the camera control unit 141 determines whether or not a face was detected in S701. If a face was detected, the process proceeds to S703, and if a face was not detected, the process proceeds to S708.

In S703, the camera control unit 141 performs pupil detection processing. Pupil detection processing is also performed by a method similar to that of S701, and the position of the pupil on the imaging plane is detected. Note that the detection processing of S701 and S703 is not limited to template matching, and may be performed by another method such as deep learning.

In S704, the camera control unit 141 determines whether or not a pupil has been detected by the pupil detection processing in S703. .

In S705, the camera control unit 141 determines the lens position indicated by the defocus amount of the area close to the detected pupil position among the focus detection areas set in S501 as the target position of the focus lens position.

In S706, the camera control unit 141 drives the focus lens to the target position, and ends the face-priority AF processing.

On the other hand, in S707, the camera control unit 141 sets the lens position indicated by the defocus amount of the area within the face detection range in the focus detection area set in S501 as the target position of the focus lens. Then, in S706, the focus lens is driven to the target position.

In S708, the camera control unit 141 sets the lens position indicated by the defocus amount of the area corresponding to the closest subject among the plurality of focus detection areas set in S501 as the target position of the focus lens. Then, in S706, the focus lens is driven to the target position. Here, when selecting the focus detection area corresponding to the closest object in S708, the area near the center image height may be prioritized or the area near the center may be limited. Also, even if a face or eyes cannot be detected, if a conspicuous area on the imaging plane can be determined based on the color information of the imaging signal output from the imaging signal processing unit 124, that area is prioritized. may

Next, FIG. 8A will be used to explain how the AF operation is performed when a moving image of a product is photographed in accordance with the face-prioritized AF processing procedure described with reference to FIG.

In FIG. 8, reference numeral 801 denotes an imaging device, which photographs an introducer 601 and products 602 (603, 604). A thick dashed line 802 indicates the focus lens position calculated by the defocus amount of the face (or pupil) of the introducer 601, and hereinafter this focus lens position is defined as a reference point. A thick dashed line 803 indicates the focus lens position calculated from the defocus amount of the product 602 (603, 604), and hereinafter this focus lens position is defined as the focus point. A dashed-dotted line 804 indicates the focus lens position after AF processing, which is the same position as the thick dashed line 802 as a result of AF processing in the processing flow of face priority AF in S407. Reference numerals 805 and 806 denote the closest end and infinite end of the depth of field determined by the aperture 113, and the subject existing between the positions indicated by 805 and 806 is within the depth of field. Therefore, it can be said that the image is in focus.

In the case of FIG. 8A, since the reference point 802 exists within the depth of field, the face (pupils) of the introducer 601 is in focus, but the point of interest 803 is located outside the depth of field. Therefore, the product 602 is out of focus. In other words, the face-priority AF cannot satisfy the requirement shown in FIG. 6B to focus on the product.

Next, the processing of the closest object priority AF and the problem when the object introduction moving image uses the closest object priority AF will be described with reference to FIGS. 9 and 8B. First, the close distance priority AF process will be described with reference to the flowchart of FIG.

First, in S901, the camera control unit 141 sets the lens position indicated by the defocus amount of the area corresponding to the closest subject among the plurality of focus detection areas set in S501 as the target position of the focus lens.

In S902, the camera control unit 141 drives the focus lens toward the target position. In S901, similarly to S708 of the face-priority AF processing flow in FIG. 7, the center area information and color information may be used to change the focus detection area selection method.

Next, with reference to FIG. 8(b), a problem when the close distance priority AF processing is used in the product introduction video will be described. In FIG. 8B, the target point 803 is the target for outputting the closest defocus amount, so the focus lens position 804 is at the same position as the target point 803, and the product 602 is in focus. However, as a result, the reference point 802 is out of the depth of field (range between reference numerals 805 and 806), and the face (eyes) of the introducer 601 is out of focus. That is, the close distance priority AF cannot satisfy the requirement shown in FIG. Note that, in FIG. 6A, since the reference point and the point of interest match, the introducer 601 can be brought into focus even in the processing of the close distance priority AF.

As described above, it can be seen that the face priority AF and the close distance priority AF, which are conventional AF processes, cannot satisfy the focus requirements required for each scene of the product introduction video. In order to solve these problems, the intra-face-depth AF is performed in the present embodiment. Next, the intra-face-depth AF processing and the focus position in the product introduction video will be described with reference to FIGS. 10 to 13. FIG.

In FIG. 10, when intra-face-depth AF processing is started, the camera control unit 141 advances the processing to S1001 to perform reference point determination processing. As described above, the reference point indicates the focus lens position calculated based on the defocus amount of the introducer's face (pupils), and the details of the reference point determination process will be described later with reference to FIG. 11 .

In S1002, the camera control unit 141 performs focus point determination processing. As described above, the focus point indicates the focus lens position calculated from the defocus amount of the product, and the details of the focus point determination process will be described later with reference to FIG. 13 .

In S1003, the camera control unit 141 determines whether or not the reference point could be determined in S1001. If the reference point could be determined, the process proceeds to S1004. .

In S1004, the camera control unit 141 sets the target position of the focus lens to the lens position where the point of interest is closest to the depth of field (closest end or its vicinity). Here, when the reliability of the defocus amount determined in S509 is low, it is assumed that the error in the defocus amount is large. Therefore, the focus lens may be controlled so that the closest depth of field comes to a position on the close side by a predetermined amount with respect to the point of interest. By performing such processing, it is possible to keep the product within the depth of field even if there is an error in the defocus amount. Also, if the lens continues to move from the reference point in the close-up direction so that the point of interest is in focus, if the reference point is within the depth of field, the focus lens continues to move and the reference point is the depth of field. If it does not enter, the movement of the focus lens is stopped. Alternatively, if the lens continues to move from the reference point in the close-up direction so that the point of interest is in focus, if the reference point is within the depth of field, the focus lens continues to move and the reference point is the depth of field. If it is no longer within , the diaphragm 113 may be controlled so that the reference point and the point of interest are within the depth of field.

In S1005, the camera control unit 141 processes the target position of the focus lens as the point of interest.

After the target position of the focus lens is determined in S1004, in S1006, the camera control unit 141 changes the target position of the focus lens to the reference point if the target position of the focus lens is on the infinity side of the reference point. The purpose of this process is that it is common to bring the product before the introducer in the product introduction video.

In S1007, the camera control unit 141 drives the focus lens toward the target position determined in S1005 and S1006, and ends the process.

Next, reference point determination processing will be described using the flowchart of FIG. 11 .

When the reference point determination process is started, the camera control unit 141 advances the process to S1101 and performs face detection processing. The method of face detection processing is the same processing as in S701 described above.

In S1102, the camera control unit 141 determines whether or not the same face as the face previously selected as the reference point (last detected face) was detected in S1101, and if detected, advances the process to S1103. , if not detected, the process proceeds to S1110. Whether or not the faces are the same can be determined using an image matching method or the like, but the method is not limited to this method, and any method that can confirm matching of faces may be used. By determining whether the faces are the same, even if there are third parties 1201 and 1202 in addition to the introducer 601 as shown in FIG. 12A, the introducer can maintain the same reference point without switching.

In S1103, the camera control unit 141 sets the same person's face as the face previously selected as the reference point as the main face. In S1104, the camera control unit 141 performs pupil detection processing on the main face.

In S1105, the camera control unit 141 determines whether or not the pupil of the main face could be detected in S1104. If the pupil could be detected, the process proceeds to S1106. proceed.

In S1106, the camera control unit 141 sets the reference point to the focus lens position determined by the defocus amount of the focus detection area at the pupil position detected in S1104. In S1107, the camera control unit 141 sets the focus lens position determined by the defocus amount within the face detection range as the reference point.

In S1108, the camera control unit 141 saves the reference point. In S1109, the camera control unit 141 saves the main face selected as the reference point and ends the process.

If the same face as the previous reference point was not detected in S1102, in S1110 the camera control unit 141 determines whether or not the main face was saved in S1109 within a predetermined past time from the present. If the main face is saved, the camera control unit 141 advances the process to S1111 and determines the previously saved reference point as the reference point. Then, in S1112, the reference point is saved (maintained for a predetermined period of time). By performing the processing of S1102, S1110, and S1111, as shown in FIG. A reference point can be maintained.

On the other hand, if the main face is not saved in S1110, the camera control unit 141 advances the process to S1113, and in S1101 determines whether or not one or more faces have been detected after a predetermined time has elapsed. If one or more faces have been detected, the camera control unit 141 advances the process to S1114 and updates the face closest to the center image height as the main face. This is a process of switching the main face because the person who was the main face was not detected for a predetermined time or longer. After that, the camera control unit 141 advances the processing to S1104 and performs the same processing as the above-described processing.

If no face is detected in S1113, the camera control unit 141 advances the processing to S1115, and ends the reference point determination processing without determining the reference point.

Next, the focus point determination processing of S1002 will be described using the flowchart of FIG.

When the focus point determination process is started, the camera control unit 141 advances the process to S1301 and determines whether or not the user has specified a focus point. As a method for the user to specify the point of interest, there is a method of specifying an object by touching the LV (live view) screen of a touch panel, or specifying coordinates on the LV screen with a dial or the like. However, the present embodiment is not limited to these methods, and any method that can specify the point of interest may be used.

If there is user designation in S1301, the camera control unit 141 advances the processing to S1302, and if there is no user designation, advances the processing to S1303.

In S1302, the camera control unit 141 sets the point of interest to the lens position indicated by the defocus amount of the user-designated coordinates, and ends the process. In S1303, the camera control unit 141 ends the process by setting the point of interest to the lens position indicated by the defocus amount of the closest subject.

FIG. 14 shows (a) a scene in which there is no product, (b) a scene in which the product is close to the introducer, and (c) a scene in which the product is far from the introducer. First, since there is no product in FIG. 14A, the reference point 802 and the point of interest 803 are at the same position. Since the focus lens position is not driven to the infinity side from the reference point 802 by S1006, the focus lens position in FIG.

In FIG. 14B, since the product 602 exists, the point of interest is the position indicated by 803 . In this case, the processing in S1004 controls the focus lens so that the point of interest 803 overlaps the closest position 805 in the depth of field. With this control, both the reference point 802 and the target point 803 are positioned within the depth of field (the range between the positions indicated by 805 and 806) in FIG. can meet.

In FIG. 14C, similarly to FIG. 14B, the focus lens is controlled so that the point of interest 803 overlaps the closest position 805 in the depth of field, so the focus lens position is indicated by 804. position. As a result, in FIG. 6B, even when the product and the introducer are far apart, the requirements for the focus position can be satisfied. Also, in FIG. 14C, the reference point 802 is out of the depth of field, so it is out of focus. The blur amount of the person's face (pupils) can be minimized.

As described above, by performing intra-face-depth AF processing according to the present embodiment, it is possible to focus on an object that the introducer wants to focus on in each scene of the product introduction video shown in FIG. Become.

(Second embodiment)
A second embodiment of the present invention will be described below. First, differences between the present embodiment and the first embodiment will be described. The difference between the first embodiment and the second embodiment lies in the processing contents of intra-face-depth AF.

In the first embodiment, priority is given to focusing on the product, but in the second embodiment, when the product is held in front, priority is given to focusing on the face (eyes), always Make sure the reference point is within the depth of field. Details of the second embodiment will be described below.

The configuration of the imaging apparatus in this embodiment is the same as the configuration in FIG. 1 described in the first embodiment, so description thereof will be omitted. 2 to 13 except for FIG. 10 are the same as those of the first embodiment, so the description is omitted.

The intra-face-depth AF processing of the second embodiment will be described with reference to the flowchart of FIG. 15 and FIG. Since S1001 to S1007 are the same as those in the flowchart of FIG. 10 of the first embodiment, description thereof will be omitted.

After the reference point is determined in S1003, the camera control unit 141 advances the processing to S1501 and determines whether both the reference point and the point of interest are within the depth of field. If the camera control unit 141 determines that both points are within the depth of field, the process proceeds to S1004, and if it is determined that both points are not within the depth of field, the process proceeds to S1502.

In S<b>1502 , the camera control unit 141 sets the target position of the focus lens to the focus lens position where the reference point is the most infinite depth of field. At this time, if the reliability of the defocus amount determined in S509 is low, the focus lens is controlled so that the maximum infinity of the depth of field comes to the infinity side of the reference point by a predetermined amount, taking into consideration the error in the defocus amount. You may By performing such processing, even if there is an error in the defocus amount, it is possible to fit the introducer's face (pupils) within the depth of field.

In S1503, a warning is displayed on the LV (live view) screen to notify the introducer that the product is out of focus. At this time, the introducer may be suggested to narrow down the diaphragm 113 to widen the depth of field, or to pull the product toward the introducer and move it to a position within the depth of field.

Next, the AF operation of the second embodiment will be described using FIG. When a product 602 is placed in front of an introducer as shown in FIG. 16A, the focus lens position is set to 804 with the lens position matching the infinity 806 as the limit so that the reference point 802 fits within the depth of field. position control. By controlling in this way, it is possible to always keep the face (eyes) of the introducer in focus. On the other hand, since the closest end of the depth of field is the position indicated by reference numeral 805, the product 602 is out of focus.

In this case, in this embodiment, as shown in 1601 in FIG. 16B, by displaying a warning display notifying that the product is out of focus, the introducer is instructed to focus on the product. It is possible to encourage action.

(Third embodiment)
A third embodiment of the present invention will be described below. First, differences between the present embodiment and the first embodiment will be described. The difference between the first embodiment and the third embodiment lies in the processing contents of intra-face-depth AF.

In the first embodiment, priority is given to focusing on the product, but in the third embodiment, when the product is placed in front of the introducer, by controlling the diaphragm 113, the reference point and the Control is performed so that both points of interest are within the depth of field. Details of the third embodiment will be described below.

The configuration of the imaging apparatus in this embodiment is the same as the configuration in FIG. 1 described in the first embodiment, so description thereof will be omitted. 2 to 13 except for FIG. 10 are the same as those of the first embodiment, so the description is omitted.

The intra-face-depth AF processing of the third embodiment will be described with reference to the flowchart of FIG. 17 and FIG. Since S1001 to S1007 are the same as those in the flowchart of FIG. 10 of the first embodiment, description thereof will be omitted.

After the reference point is determined in S1003, the camera control unit 141 advances the processing to S1501 and determines whether or not both the reference point and the point of interest are within the depth of field determined by the aperture value set by the user. do. If the camera control unit 141 determines that both points are within the depth of field, the process advances to S1701, and if it is determined that the points are not within the depth of field, the process advances to S1702. In S1701 and S1702, the aperture value of the aperture 113 is set by another method.

In S1701, the camera control unit 141 sets the aperture 113 to the aperture value set by the user, and advances the processing to S1004. On the other hand, in S1702, the camera control unit 141 sets the aperture 113 so that both the reference point and the point of interest are within the depth of field, and advances the process to S1004. By performing the process of S1702, it is possible to bring both the introducer's face (pupils) and the product into focus.

Next, the contents of the processing shown in FIG. 17 will be described with reference to FIG. FIG. 18(a) is a scene in which the introducer is close to the product, and FIG. 18(b) is a scene in which the introducer is far from the product.

In FIG. 18A, the reference point 802 and the point of interest 803 fall within the depth of field (the range between the positions indicated by 805 and 806) according to the aperture value set by the user. The focus lens is driven to a focus lens position 804 where the point of interest and the closest point 805 of the depth of field overlap. In FIG. 18B, the reference point 802 and the point of interest 803 do not fall within the depth of field of the aperture value set by the user. Therefore, by narrowing down the diaphragm 113 and widening the depth of field (the range between the positions indicated by 805 and 806), control is performed so that the reference point 802 and the target point 803 are within the depth of field.

By controlling in this way, even when the product is placed in front, it is possible to focus on both the introducer's face (eyes) and the product while opening the aperture value 113 to the minimum.

(Other embodiments)
In addition, the present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in the computer of the system or apparatus reads the program. It can also be realized by executing processing. It can also be implemented by a circuit (eg, ASIC) that implements one or more functions.

The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the claims are appended to make public the scope of the invention.

101: lens unit, 102: camera body, 111: photographing lens, 112: fixed lens, 113: aperture, 114: focus lens, 115: aperture control unit, 116: focus control unit, 117: lens control unit, 121: imaging element 141: camera control unit

Claims (16)

Point-of-interest determination means for determining a point of interest in the field;
focus detection means for acquiring a pair of focus detection signals from a subject image that has passed through different pupil regions of an imaging optical system and detecting a defocus amount of the subject based on the pair of focus detection signals;
Control for controlling the position of the focus lens based on the defocus amount of the point of interest obtained by the focus detection means so that the point of interest is positioned at or near the closest end within the depth of field. means and
An imaging device comprising: 2. The imaging apparatus according to claim 1, wherein said focus point determination means determines said focus point according to a user's designation. 3. The image pickup apparatus according to claim 1, wherein the point-of-interest determination means determines the position of the object that indicates the closest defocus amount as a result of focus detection by the focus detection means, as the point-of-interest. The control means further includes determination means for determining the reliability of the defocus amount, and the control means determines that, when the reliability of the defocus amount is lower than a predetermined amount, the position shifted from the point of interest to the close side by a predetermined amount is the subject. 4. The imaging apparatus according to any one of claims 1 to 3, wherein the position of the focus lens is controlled so as to be positioned at the closest end within the depth of field. imaging means for imaging a subject; subject detection means for detecting the subject based on the image data output from the imaging means; and a reference point based on the defocus amount of the subject obtained by the focus detection means. and reference point determination means for determining the depth of field, wherein the control means controls the position of the focus lens so that the position of the reference point is the infinite end within the depth of field. Item 5. The imaging device according to any one of Items 1 to 4. 6. The image pickup apparatus according to claim 5, wherein, when the subject detection means detects the same subject as the previous time, the reference point determining means determines the position of the same subject as the previous time as the reference point. 7. The imaging apparatus according to claim 5, wherein said reference point determining means maintains the reference point determined based on the last detected subject for a predetermined time. 8. The method according to any one of claims 5 to 7, wherein said reference point determining means determines that said reference point does not exist when said object detecting means does not detect a subject within a predetermined time period. imaging device. 9. The method according to claim 8, wherein when the reference point determination means determines that there is no reference point, the control means controls the position of the focus lens so that the position of the point of interest is focused. The imaging device described. When a plurality of subjects are detected by the subject detection means after a predetermined period of time has elapsed, the reference point determination means preferentially sets the position of the subject near the center of the imaging surface as the reference point. The imaging device according to any one of claims 5 to 9. The control means continues to move the focus lens when the focus lens is kept moving from the reference point in a close-up direction so as to bring the focus point into focus, and when the reference point is within the depth of field. 11. The imaging apparatus according to any one of claims 5 to 10, wherein said focus lens is stopped when said reference point is no longer within the depth of field. The control means continues to move the focus lens when the focus lens is kept moving from the reference point in a close-up direction so that the point of interest is focused, and when the reference point is within the depth of field, 11. The aperture is controlled so that the reference point and the point of interest are within the depth of field when the reference point is no longer within the depth of field. The imaging device according to . 13. The apparatus according to any one of claims 5 to 12, further comprising display means for displaying a warning when the reference point enters the depth of field and the target point does not enter the depth of field. The imaging device described. A point-of-interest determination step of determining a point of interest in the field;
a focus detection step of acquiring a pair of focus detection signals from a subject image that has passed through different pupil regions of an imaging optical system, and detecting a defocus amount of the subject based on the pair of focus detection signals;
Control for controlling the position of the focus lens so that the point of interest is at or near the closest end within the depth of field, based on the defocus amount of the point of interest obtained in the focus detection step. process and
A control method for an imaging device, comprising: A program for causing a computer to execute each step of the control method according to claim 14. 15. A computer-readable storage medium storing a program for causing a computer to execute each step of the control method according to claim 14.

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