Imaging apparatus, control method, and program

Abstract

To reduce power consumption while enabling rapid switching of display to an EVF.SOLUTION: An imaging apparatus includes motion detection means for detecting motion occurring in the imaging apparatus, first imaging means for imaging the front direction of the imaging apparatus, second imaging means for imaging the rear direction of the imaging apparatus, a first display device provided on the rear side of the imaging apparatus for displaying a first image acquired by the first imaging means, face detection means for detecting faces included in a second image acquired by the second imaging means, and control means for controlling the operation of the first display device and the face detection means. The control means causes the face detection means to start detecting faces in response to the motion detection means detecting a predetermined movement of the imaging apparatus, and starts preparatory processing related to display preparation of the first display device under condition of the face detection means detecting a face.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an imaging device, a control method, and a program, and more particularly to a display control technique for an electronic viewfinder. [Background technology]

[0002] Imaging devices such as digital cameras are provided with a rear monitor that displays the captured image so that the subject captured within the imaging angle of view can be confirmed, and the photographer can determine the composition of the shot while looking at the rear monitor. Meanwhile, there is also a certain demand for composing the shot using an optical viewfinder, which was the mainstream in film-based analog cameras. For this reason, some imaging devices are equipped with an electronic viewfinder (EVF) in addition to the rear monitor, and the captured image is displayed through the EVF, allowing the photographer to determine the composition in the same way as with an optical viewfinder.

[0003] However, displaying a captured image on both the rear monitor and the EVF increases the power consumption of the imaging device, which reduces the usable time of the imaging device when it is battery-powered. For this reason, there are imaging devices that are equipped with a configuration that detects when the photographer is looking into the EVF (eye proximity detection), and reduce power consumption by controlling the EVF to display the captured image only when eye proximity detection is active (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-130825 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, a proximity sensor can be used to detect eye contact as in Patent Document 1. However, if the camera mistakenly detects the photographer's finger holding the imaging device as eye contact, power consumption may not be reduced appropriately. On the other hand, the accuracy of eye contact detection can be improved by providing a camera (a so-called "in-camera") on the rear side of the imaging device and performing face detection processing on the photographer's captured images. However, since capturing images with the in-camera and then applying face detection processing to the sequentially acquired captured images increases the computational load, the display on the EVF may switch to a later time after the photographer actually places their eye on the screen. In such cases, the photographer may not be able to start composing the image at the desired timing, which can create a sense of complication for the photographer.

[0006] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide an imaging device, a control method, and a program that quickly switch the display to the EVF while reducing power consumption. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the imaging device of the present invention is an imaging device comprising: a movement detection means for detecting movement occurring in the imaging device; a first imaging means for capturing an image in the front direction of the imaging device; a second imaging means for capturing an image in the rear direction of the imaging device; a first display device provided on the rear side of the imaging device for displaying the first captured image acquired by the first imaging means; a face detection means for detecting a face included in the second captured image acquired by the second imaging means; and a control means for controlling the operation of the first display device and the face detection means, wherein the control means causes the face detection means to start face detection in response to the movement detection means detecting a predetermined movement of the imaging device, and starts preparation processing for display preparation of the first display device on the condition that a face has been detected by the face detection means. [Effects of the Invention]

[0008] With this configuration, the present invention makes it possible to reduce power consumption and quickly switch the display to the EVF. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram illustrating a hardware configuration of an image capturing apparatus 100 according to an embodiment and a modification of the present invention. [Figure 2] FIG. 1 is a diagram illustrating the detection axis of the motion sensor 109 of the imaging device 100 according to the embodiment and the modified example of the present invention. [Figure 3] 10A and 10B are diagrams illustrating swing-up movements according to the embodiment and modified examples of the present invention; [Figure 4] FIG. 10 is a diagram illustrating eye proximity detection according to an embodiment and a modification of the present invention. [Figure 5] (a) A timing chart relating to display control of a first captured image according to a conventional technique. (b) A timing chart relating to display control of a first captured image according to an embodiment and a modification of the present invention. [Figure 6] 10 is a flowchart illustrating a display switching process executed by the imaging device 100 according to the embodiment and a modification of the present invention. [Figure 7] FIG. 10 is a diagram illustrating face detection according to a first modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Embodiment] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] In the embodiment described below, the present invention is applied to an image capturing device equipped with an in-camera, a rear monitor, and an electronic viewfinder (EVF) as an example of an image capturing device. However, the present invention can be applied to any device equipped with two image capturing devices that capture images in different directions and two types of display devices.

[0012] <Hardware configuration of imaging device> The hardware configuration of the imaging device 100 according to this embodiment will be described below with reference to the block diagram of FIG.

[0013] The control unit 101 is a control device that controls the operation of each block included in the imaging device 100. The control unit 101 may be configured with at least one processor. The control unit 101 controls the operation of each block by reading out an operation program for each block from the memory unit 102, expanding it into the system memory unit 103, and executing it. The control unit 101 also includes a system timer (not shown) and is configured to be able to measure time.

[0014] The memory unit 102 is a non-volatile storage device such as a ROM or flash ROM. The memory unit 102 is configured to be electrically erasable and storeable. The memory unit 102 stores operation programs for each block of the imaging device 100 as well as information such as constants required for the operation of each block.

[0015] The system memory unit 103 is a volatile storage device such as a DRAM or SRAM. The system memory unit 103 is used not only as an area for loading the operation programs of each block of the imaging device 100, but also as an area for temporarily storing intermediate data output by each block. Such intermediate data includes captured images (captured data) output by the first imaging unit 107 and second imaging unit 108 (described below) and display images (display data) on the rear monitor 110 and the EVF 111.

[0016] The power supply control unit 104 controls the power supply to each block of the imaging device 100. The power supply control unit 104 is configured to include, for example, a battery detection circuit, a protection circuit, a DC-DC converter, an LDO regulator, etc. The imaging device 100 of this embodiment is configured to be operable by power supply from a power supply unit 105, which is a battery, and the power supply control unit 104 converts the power supplied from the power supply unit 105 to a required voltage and supplies it to each block. The power supply control unit 104 includes, for example, a power detection circuit that detects the amount of power to be supplied to each block. The power supply control unit 104 also has a battery attachment detection function, a battery type detection function, a battery remaining charge detection function, and a protection function that cuts off the power supply when an overcurrent is detected.

[0017] The power supply unit 105 is a secondary battery (battery) such as a NiCd battery, a NiMH battery, or a Li battery. The power supply unit 105 has a function of acquiring the remaining battery capacity, and can transmit the acquired remaining capacity information to the power supply control unit 104. Note that, although the present embodiment will be described assuming that the power supply unit 105 is a battery, it goes without saying that it may also be an external power supply such as an AC adapter.

[0018] The operation input unit 106 is a user input interface included in the imaging device 100. The operation input unit 106 may include operation members such as switches and dials. Furthermore, if a rear monitor 110 (described later) is configured to accept touch operations, the operation input unit 106 may include a sensor for accepting the touch operations. Furthermore, if the imaging device 100 is configured to have a voice recognition function, the operation input unit 106 may also include a voice recognition device. When the operation input unit 106 detects an operation input, it outputs a control signal corresponding to the operation input to the control unit 101. In one aspect, the operation input unit 106 includes a release switch that accepts different operation inputs by pressing the release switch in two stages with different strokes. In this case, the operation input unit 106 outputs an SW1 signal in response to a half-press operation (focus command) of the release switch, and outputs an SW2 signal in response to a full-press operation (shooting command) of the release switch, and transmits the content of each operation input to the control unit 101.

[0019] The imaging device 100 of this embodiment includes two types of imaging units. Specifically, the imaging device 100 includes a first imaging unit 107 as a first imaging means according to the present invention, and a second imaging unit 108 as a second imaging means. Each imaging unit includes an imaging element such as a CMOS sensor or a CCD, and converts an optical image formed on an imaging surface by a light beam incident via a corresponding optical system into an analog image signal to obtain a captured image. The first imaging unit 107 and the second imaging unit 108 are configured to capture images in different directions within the imaging device 100 and have different uses. In this embodiment, the first imaging unit 107 is configured to capture images in the front direction of the imaging device 100, i.e., in the direction in which the subject the photographer is attempting to photograph is located as viewed from the imaging device 100. On the other hand, the second imaging unit 108 is a so-called in-camera, configured to capture images in the rear direction of the imaging device 100, i.e., in the direction in which the photographer is located as viewed from the imaging device 100. In the following description, in order to clearly distinguish whether an image is acquired by the first imaging unit 107 or the second imaging unit 108, the image acquired by the first imaging unit 107 will be referred to as the "first captured image," and the image acquired by the second imaging unit 108 will be referred to as the "second captured image."

[0020] In the illustrated example, a lens unit 120 is shown as an optical system for forming an optical image on the image sensor of the first imaging unit 107 to clearly indicate the main imaging direction of the imaging device 100. The lens unit 120 includes, for example, a lens group and an aperture, as well as a control circuit that drives the lens and aperture for focus control and exposure control. The lens unit 120 and the imaging device 100 are electrically connected via a lens connection unit 112, and information can be communicated between the control unit 101 and a control circuit (not shown) provided in the lens unit 120.

[0021] The motion sensor 109 is a sensor that detects movement occurring in the imaging device 100. In this embodiment, the motion sensor 109 is configured to be able to detect the direction, distance, and speed of movement occurring in the imaging device 100 for each of the X, Y, and Z components defined for the imaging device 100. In this embodiment, as shown in FIG. 2, the Y axis is set in the depth direction of the optical axis of the lens connection part 112, the Z axis is set in the direction toward the top surface of the imaging device 100 (the upward direction when the imaging device 100 is held in a so-called horizontal position), and the X axis is set as the remaining axis. In the example shown in the figure, three axes of a left-handed system are set to make it easier to understand the description of the movement of the imaging device 100, but the implementation of the present invention is not limited to this.

[0022] The rear monitor 110 is a display device provided in the imaging device 100 and is used to display various types of information. The rear monitor 110 displays display data stored in the system memory unit 103. Such display data includes, for example, a menu screen related to settings of the imaging device 100 and image data stored in a recording medium 130, which will be described later. The rear monitor 110 can also provide a "live view" display by displaying a first captured image acquired by the first imaging unit 107 as a through image. The live view display allows the photographer to determine (frame) the composition to be photographed via the rear monitor 110.

[0023] The imaging device 100 of this embodiment has an electronic viewfinder (EVF) 111 in addition to the rear monitor 110, and can similarly display the first captured image. The EVF 111 may be, for example, an organic EL display device. The EVF 111 is configured so that the photographer can look into it to check the display. Like the rear monitor 110, the EVF 111 displays the first captured image acquired by the first imaging unit 107 through the display, allowing the photographer to perform so-called viewfinder photography.

[0024] As described above, the imaging device 100 of this embodiment is provided with two types of display devices for checking a captured image related to framing during shooting: the EVF 111 as a first display device according to the present invention, and the rear monitor 110 as a second display device. Both of these display devices are provided on the rear side of the imaging device 100.

[0025] <<Display Control Overview>> An overview of the display control of the first captured image executed in the shooting mode in the imaging device 100 of this embodiment having such a hardware configuration will be described.

[0026] In the shooting mode, the first captured image acquired by the first imaging unit 107 is basically displayed on the rear monitor 110, providing the photographer with a live view display. To enable the photographer to perform viewfinder shooting, the first captured image needs to be displayed on the EVF 111, but displaying the image on both the first imaging unit 107 and the second imaging unit 108 increases power consumption. For this reason, in the shooting mode of this embodiment, the power control unit 104 is basically controlled not to supply power to the EVF 111. Therefore, the control unit 101 needs to execute preparatory processing related to display preparation of the EVF 111 so that framing using the EVF 111 can be performed at a timing desired by the photographer, and further perform display control so that the first captured image is displayed.

[0027] Here, in a mode in which a proximity sensor is used to detect whether the photographer has placed their eye on the EVF 111, erroneous detection occurs as described above, making it impossible to appropriately control the operation of the EVF 111. For this reason, the imaging device 100 of this embodiment employs a method in which the photographer's face is detected based on the second captured image acquired by the second imaging unit 108 during shooting mode, and whether the photographer has placed their eye on the EVF 111 is detected based on that state.

[0028] On the other hand, the mode of monitoring the second captured image and detecting whether the photographer has placed his / her eye on the EVF 111 depending on the detection state of the photographer's face is expected to increase the computational load related to the face detection process. If the computational load increases, for example, the execution of the preparation process for the EVF 111 may be delayed because the calculation is not completed, and the first captured image may not start to be displayed on the EVF 111 when the photographer places his / her eye on the EVF 111. Furthermore, frequent execution of the face detection process may ultimately lead to increased power consumption. Therefore, the imaging device 100 of this embodiment performs the following control to reduce the computational load of the face detection process for the second captured image while quickly displaying the first captured image on the EVF 111.

[0029] (Detection of swinging up motion) First, the control unit 101 detects (movement detection) whether or not a predetermined movement (hereinafter, sometimes referred to as a swing-up movement) has occurred in relation to the stance of the imaging device 100. The control unit 101 detects whether or not a swing-up movement has occurred in the imaging device 100 based on, for example, the output of the motion sensor 109 obtained at a predetermined most recent time.

[0030] Here, detection of a swing-up motion in one embodiment will be described with reference to the drawings. In this embodiment, the control unit 101 determines that a predetermined motion has occurred when the imaging device 100 moves in the Z-axis direction at a speed exceeding a threshold.

[0031] 3(a) and 3(b) show examples of the states of the photographer and the image capture device 100 before and after a swing-up motion occurs. In the state shown in FIG. 3(a), for example, the photographer is framing the subject while checking the subject through the rear monitor 110. When the photographer desires to frame using the EVF 111, it is assumed that the photographer will quickly move (swing up) the image capture device 100 from the state shown in FIG. 3(a) to the state shown in FIG. 3(b). If the state shown in FIG. 3(a) is time t=t0 and the state shown in FIG. 3(b) is time t=t1, the control unit 101 determines whether the image capture device 100 has moved in the Z-axis direction between times t0 and t1 and whether the movement is at a speed exceeding a threshold.

[0032] The determination of whether the moving direction is the Z-axis direction is made based on whether the movement mainly occurs in the Z-axis direction from time t0 to t1. This determination is made, for example, based on the moving distance based on the output of the motion sensor 109. The moving distance s based on the motion sensor 109, for example, when the acceleration from time t0 to t1 is a, s = 1 / 2 × a × (t1 - t0) 2 can be derived by (assuming the initial velocity is 0). Note that the positional relationship before and after the movement (which was at a higher position at time t0 or t1) can be determined, for example, by the inclination of the imaging device 100.

[0033] For example, as shown in FIG. 3(c), when the imaging device 100 is positioned at position 301 at time t0 and moves to position 302 at time t1, it moves approximately 60 cm in the Z-axis direction and hardly moves in the X-axis direction. In this case, since the relationship of the Z-axis component of the movement > the X-axis component of the movement holds for the movement from position 301 to position 302, the control unit 101 determines that the moving direction of the imaging device 100 from time t0 to t1 is the Z-axis direction. Also, when the imaging device 100 is positioned at position 303 at time t0 and moves to position 302 at time t1, it moves approximately 60 cm in the Z-axis direction and approximately 30 cm in the X-axis direction. Similarly in this case, since the relationship of the Z-axis component of the movement > the X-axis component of the movement holds, the control unit 101 determines that the moving direction of the imaging device 100 from time t0 to t1 is the Z-axis direction.

[0034] On the other hand, when the imaging device 100 is positioned at position 303 at time t0 and moves to position 304 at time t1, it moves approximately 30 cm in the Z-axis direction and approximately 60 cm in the X-axis direction. In this case, since the relationship of the Z-axis component of the movement < the X-axis component of the movement clearly holds for the movement from position 303 to position 304, the control unit 101 determines that the moving direction of the imaging device 100 from time t0 to t1 is not the Z-axis direction.

[0035] Note that when the imaging device 100 is set at position 301 at time t0 and moves to position 304 at time t1, it has moved approximately 30 cm in the Z-axis direction and approximately 30 cm in the X-axis direction. In this case, although the Z-axis component and the X-axis component of the movement from position 301 to position 304 are equal, the relationship of the Z-axis component < X-axis component of the movement does not clearly hold. Therefore, in this aspect, the control unit 101 similarly determines that the movement direction of the imaging device 100 from time t0 to t1 is in the Z-axis direction.

[0036] When the movement direction of the imaging device 100 that occurs within a predetermined time is in the Z-axis direction as described above, the control unit 101 determines that there is a possibility that the photographer uses the EVF 111, and further determines whether the movement speed exceeds a threshold value. Then, when the conditions regarding the movement direction and the movement speed of the imaging device 100 that occur within a predetermined time are satisfied, the control unit 101 determines that a lifting operation has occurred.

[0037] (Photographer's face detection) When it is determined that a lifting operation has occurred, the control unit 101 further detects whether the photographer's face is included in the second captured image. That is, in the imaging device 100 of the present embodiment, the control unit 101 controls to start face detection processing for the second captured image acquired by the second imaging unit 108 on the condition that it is detected that a lifting operation has occurred.

[0038] After detecting the swing-up motion, if the photographer desires to frame using the EVF 111, it is assumed that the photographer further raises the image capture device 100 as shown in FIG. 4(a) and then brings the image capture device 100 closer to the face as shown in FIG. 4(b). At this time, the angle of view of the second image capture unit 108, indicated by the dashed-dotted line, includes the photographer's face. Therefore, as shown in the figure, the second captured images 401 and 402 acquired by the second image capture unit 108 both show the area of ​​the person's face. Here, the second captured images 401 and 402 are captured images acquired by the second image capture unit 108 when the image capture device 100 is in the state shown in FIG. 4(a) and the state shown in FIG. 4(b), respectively. As shown in the figure, if the photographer desires to frame using the EVF 111, after the photographer performs the swing-up motion, the photographer's face is captured in the second captured image, and the area of ​​the area of ​​the face further increases.

[0039] Therefore, in the face detection process that starts after detecting the swing-up motion, the control unit 101 determines whether (1) a face is captured in the second captured image, and (2) whether the face has come closer (whether the area exceeds a threshold), and then controls the display of the first captured image on the EVF 111. Here, the threshold value related to the area of ​​the face region in the second captured image for detecting that an eye has been placed close to the camera may be a fixed value determined at the time of shipment of the image capture device 100, or may be a value that can be changed arbitrarily by the user of the image capture device 100.

[0040] However, in a conventional technique in which preparation processing for the EVF 111 is started in response to detection of the photographer's eye being placed near the subject by a proximity sensor, it may not be possible to promptly display the first captured image on the EVF 111. Fig. 5(a) shows a time chart relating to display control of the EVF 111 in a conventional method. The time chart in Fig. 5(a) illustrates, in chronological order, the control content when the photographer starts the image capture device 100 in shooting mode with their eye away from the subject, then places their eye near the EVF 111 to frame and capture an image, and then turns off the power to the image capture device 100. Note that in this example, the image capture device 100 is configured to display the first captured image on only one of the rear monitor 110 or the EVF 111 in shooting mode; the first captured image is displayed on the rear monitor 110 when the photographer is away from the subject, and on the EVF 111 when the photographer is near the subject.

[0041] As shown in the figure, when the proximity sensor detects eye proximity at timing 501, the imaging device 100 executes a display switching process to switch the display of the first captured image from the rear monitor 110 to the EVF 111. In parallel with this display switching process, the control unit 101 starts preparation processing 502 for the EVF 111 from timing 501.

[0042] Here, the preparation processing 502 is a sequence up to the point where the EVF 111 is ready to be turned on. In the illustrated example, the lighting processing 502 includes processing for supplying power to start the EVF 111, executing processing related to video signal output settings and other initial settings to bring the EVF 111 into a display-ready state, and processing for starting image output to the EVF 111. When image output starts, the EVF 111 is turned on (in a display state) at timing 503, and the first captured image is displayed, allowing the photographer to view a live image via the EVF 111.

[0043] Therefore, in the conventional method in which preparation processing 502 of the EVF 111 is started in response to detection of the photographer's eye being placed near the lens by a proximity sensor, the photographer can view the live view display through the EVF 111 at timing 503. In other words, in the conventional method, the photographer cannot check the state of the subject during the period from timing 501 to timing 503.

[0044] For this reason, in the imaging device 100 of this embodiment, the control unit 101 starts preparatory processing for the EVF 111 before it becomes certain that the photographer will place his or her eye on the EVF 111. More specifically, the control unit 101 starts execution of the preparatory processing other than image output processing on the condition that a face is detected for the first time in the face detection processing that started after the swing-up motion was detected. That is, the control unit 101 controls the EVF 111 to start preparatory processing when the state shown in Fig. 3(b), in which the swing-up motion was detected, changes to the state shown in Fig. 4(a), and a face is detected for the first time in the second captured image.

[0045] 5(b), the control unit 101 can start preparatory processing 512 before timing 511 at which it is determined that the eyepiece is in the close-view state because the area of ​​the face region in the second captured image exceeds the threshold. In the example shown in the figure, preparatory processing 512 starts at timing 513, when a face is first detected in the second captured image. Therefore, the control unit 101 can start image output at timing 511 thereafter, and can display the first captured image on the EVF 111 at timing 514. In other words, according to the method of the present invention, the photographer can view the live view display through the EVF 111 at timing 514.

[0046] Furthermore, because the face detection process can impose a high computational load as described above, the control unit 101 controls the face detection process on the second captured image, which is executed in response to the detection of a swing-up motion, so that it is executed for a limited period of time. In other words, in this embodiment, the control unit 101 determines that the EVF 111 will not be used if a face is detected in the second captured image within a predetermined period of time after the swing-up motion is detected and the area of ​​the face region does not exceed a threshold. In other words, even if the control unit 101 starts preparation processing related to the first face detection, the control unit 101 ends the preparation processing and face detection processing without starting image output to the EVF 111.

[0047] 5, in order to reduce power consumption, the imaging device 100 of this embodiment will be described assuming that in shooting mode the first captured image is displayed on either the rear monitor 110 or the EVF 111. That is, when the control unit 101 causes the first captured image to be displayed on the EVF 111, the control unit 101 controls the rear monitor 110 not to display the first captured image.

[0048] <<Display switching process>> 6, a specific description will be given of the display switching process executed in the imaging device 100 of this embodiment when switching the display destination of the live view display from the rear monitor 110 to the EVF 111. The process corresponding to this flowchart can be realized by the control unit 101 reading out a corresponding processing program stored in, for example, the memory unit 102, and loading and executing the program in the system memory unit 103. This display switching process will be described as being started, for example, when the imaging device 100 is started in shooting mode.

[0049] It is assumed that, prior to executing this display switching process, the control unit 101 executes the process of initializing the register of the motion sensor 109 and the process of starting the sequential acquisition of the first captured image by the first imaging unit 107 and the sequential acquisition of the second captured image by the second imaging unit 108.

[0050] In S601, the control unit 101 executes preparation processing for the rear monitor 110, and starts displaying the first captured image on the rear monitor 110 (live view display).

[0051] In S602, the control unit 101 determines whether a swing-up motion has been detected. The determination in this step is made based on the output of the motion sensor 109 obtained in the most recent predetermined time. If the control unit 101 determines that a swing-up motion has been detected, it proceeds to S603, and if it determines that a swing-up motion has not been detected, it repeats the processing in this step.

[0052] In S603, the control unit 101 starts face detection processing for the second captured image. The control unit 101 also starts counting the time that has elapsed since the detection of the swing-up motion.

[0053] In S604, the control unit 101 determines whether a human face area has been detected in the second captured image. If the control unit 101 determines that a face area has been detected in the second captured image, the process proceeds to S605. If the control unit 101 determines that a face area has not been detected, the process proceeds to S609.

[0054] In S605, the control unit 101 starts preparation processing for the EVF 111.

[0055] In S606, the control unit 101 determines whether the area of ​​the face region included in the second captured image exceeds the threshold within a predetermined period from the detection of the swing-up motion. If the control unit 101 determines that the area of ​​the face region exceeds the threshold within the predetermined period, the control unit 101 proceeds to S607, and if the control unit 101 determines that the area of ​​the face region does not exceed the threshold within the predetermined period, the control unit 101 proceeds to S608.

[0056] In S607, the control unit 101 executes processing to switch the display destination of the first captured image from the rear monitor 110 to the EVF 111, and then completes this display switching processing.

[0057] On the other hand, if the area of ​​the face region does not exceed the threshold within the predetermined period in S606, the control unit 101 ends the face detection process started in S603 and the preparation process started in S605 in S608, and returns the process to S602.

[0058] On the other hand, if a face area is not detected in S604, the control unit 101 determines in S609 whether a predetermined period of time has elapsed since the detection of the swing-up motion. That is, in this step, the control unit 101 determines whether a predetermined period of time has elapsed without detecting a face area in the second captured image after the detection of the swing-up motion. If the control unit 101 determines that the predetermined period of time has elapsed since the detection of the swing-up motion, it proceeds to S610, and if it determines that the predetermined period of time has not elapsed, it returns to S604.

[0059] In S610, the control unit 101 ends the face detection process started in S603 and returns the process to S602.

[0060] As described above, the imaging device of this embodiment can reduce power consumption and quickly switch the display to the EVF. That is, when determining whether or not to switch the display to the EVF 111, a swing-up motion is detected as a first step, and then, using the detection of that motion as a condition, face detection is performed as a second step, so the computational load can be reduced compared to when face detection processing is always performed. Furthermore, since preparation processing is started in response to the first detection of a face area in the second step, the display can be quickly switched at the timing when the photographer actually brings his or her eye close to the EVF 111.

[0061] In the present embodiment, the second captured image is not displayed on any display device and is used only for face detection processing, but the present invention is not limited to this. For example, the second captured image may be displayed on the rear monitor 110 in a manner superimposed on the first captured image while the first captured image is being displayed on the rear monitor 110, so that the photographer can easily understand the conditions under which the display switches to the EVF 111.

[0062] In addition, although the present embodiment has been described as detecting the occurrence of a swing-up motion using the method described with reference to Fig. 3, the present invention is not limited to this. It will be readily understood that other types of movement of the image capture device 100 can be used as a trigger for starting face detection processing.

[0063] [Variation 1] In the above-described embodiment, only the photographer's face is detected in the second captured image acquired by the second imaging unit 108, but the present invention is not limited to this. For example, in a situation where another person is present behind the photographer as shown in Fig. 7(a), multiple face areas may be detected in the second captured image as shown in Fig. 7(b). When multiple face areas are detected in the second captured image in this way, the control unit 101 may identify the face area 701 with the largest area as the photographer's face area and determine whether the eye is in close proximity based on the area of ​​the face area.

[0064] [Variation 2] In the above-described embodiment, the display destination of the first captured image is switched from the rear monitor 110 to the EVF 111 on the condition that the face area of ​​the photographer is detected within a predetermined period of time from the detection of the swing-up motion and the area of ​​the face area exceeds a threshold. However, the present invention is not limited to this embodiment, and the period for determining whether a (first) face is detected to start the preparation process and the period for determining whether the area of ​​the face area exceeds a threshold may be set differently. In one embodiment, the latter determination period may be set as the elapsed time since the start of the preparation process, for example.

[0065] [Variation 3] In the above-described embodiment and modified example, a limit is placed on the period during which face detection processing is performed in order to reduce the computational load. That is, the display destination of the first captured image is switched to the EVF 111 on the condition that the area of ​​the photographer's face region exceeds a threshold within a predetermined period. However, the present invention is not limited to this. In other words, the quick switching of the display destination of the first captured image from the rear monitor 110 to the EVF 111 when the eye is placed close to the camera can be achieved as long as the preparatory processing for the EVF 111 is executed in advance. Therefore, the condition for switching the display destination of the first captured image to the EVF 111 does not have to include the condition of the detection of a swing-up motion or the elapsed time since the start of the preparatory processing.

[0066] [Other embodiments] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0067] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention.

[0068] [Summary of the embodiment and modifications] The disclosure of this specification includes the following imaging device, control method, and program. (Item 1) An imaging device, a movement detection means for detecting a movement occurring in the imaging device; a first imaging means for imaging a front direction of the imaging device; a second imaging means for imaging a rear direction of the imaging device; a first display device provided on the rear side of the imaging device and configured to display a first captured image acquired by the first imaging means; a face detection means for detecting a face included in the second captured image acquired by the second imaging means; a control means for controlling the operation of the first display device and the face detection means; and The control means causing the face detection means to start face detection in response to the movement detection means detecting a predetermined movement of the imaging device; On the condition that a face is detected by the face detection means, a preparation process relating to display preparation of the first display device is started. Control An imaging device characterized by: (Item 2) The control means controls the first display device to display the first captured image on the condition that the face detected by the face detection means has reached a predetermined state after the start of the preparation process. 2. The imaging device according to item 1, (Item 3) The predetermined state includes the area of ​​a face region in the second captured image being greater than a threshold. 3. The imaging device according to item 2, (Item 4) The predetermined state is a state in which the area of ​​the face region in the second captured image exceeds a threshold within a predetermined period after the predetermined movement is detected. 4. The imaging device according to item 2 or 3. (Item 5) The predetermined state is a state in which the area of ​​the face region in the second captured image exceeds a threshold within a predetermined period from the start of the preparation process. 4. The imaging device according to item 2 or 3. (Item 6) The control means terminates the preparation process when the face detected by the face detection means does not attain the predetermined state within the predetermined period. 6. The imaging device according to item 4 or 5, (Item 7) When a plurality of faces are detected by the face detection means, the control means determines whether the face having the largest area in the second captured image has reached the predetermined state. 7. The imaging device according to any one of items 2 to 6, characterized in that: (Item 8) a second display device provided on the rear side and displaying the first captured image; The control means controls the first display device not to display the first captured image when the first display device is caused to display the first captured image. 8. The imaging device according to any one of items 2 to 7, characterized in that: (Item 9) a second display device provided on the rear side and displaying the first captured image; The control means displaying the first captured image on the second display device during a period in which the first captured image is being acquired by the first imaging means; On the condition that the face detected by the face detection means has reached the predetermined state, the display of the first captured image is switched from the second display device to the first display device. Control 8. The imaging device according to any one of items 2 to 7, characterized in that: (Item 10) The first display device is an electronic viewfinder, and the second display device is a rear monitor. 10. The imaging device according to item 8 or 9, (Item 11) The predetermined movement is a state in which the moving direction of the imaging device is a predetermined direction and the moving speed of the imaging device exceeds a threshold. 11. The imaging device according to any one of items 1 to 10, characterized in that: (Item 12) The preparation process includes a process of supplying power to the second imaging means to start it up. 12. The imaging device according to any one of items 1 to 11, (Item 13) a movement detection means for detecting a movement occurring in the imaging device; a first imaging means for imaging a front direction of the imaging device; a second imaging means for imaging a rear direction of the imaging device; a first display device provided on the rear side of the imaging device and configured to display a first captured image acquired by the first imaging means; A control method for an imaging device having a face detection step of detecting a face included in a second captured image acquired by the second imaging means; a control step of controlling the operation of the first display device and the face detection step; and In the control step, starting the operation of the face detection step in response to the detection of a predetermined movement of the imaging device by the movement detection means; On the condition that a face is detected in the face detection step, a preparation process relating to display preparation of the first display device is started. It is controlled so that A control method comprising: (Item 14) 13. A program for causing a computer to function as a control unit of the imaging device according to any one of items 1 to 12. [Explanation of symbols]

[0069] 100: Imaging device, 101: Control unit, 104: Power supply control unit, 105: Power supply unit, 107: First imaging unit, 108: Second imaging unit, 109: Motion sensor, 110: Rear monitor, 111: Electronic viewfinder (EVF)

Claims

1. An imaging device, a movement detection means for detecting a movement occurring in the imaging device; a first imaging means for imaging a front direction of the imaging device; a second imaging means for imaging a rear direction of the imaging device; a first display device provided on a rear side of the imaging device and configured to display a first captured image acquired by the first imaging means; a face detection unit that detects a face included in the second captured image acquired by the second imaging unit; a control unit for controlling the operation of the first display device and the face detection unit; and The control means causing the face detection means to start face detection in response to the movement detection means detecting a predetermined movement of the imaging device; On the condition that a face has been detected by the face detection means, a preparation process relating to display preparation of the first display device is started. Control An imaging device characterized by:

2. The control means controls the first display device to display the first captured image on the condition that the face detected by the face detection means has reached a predetermined state after the start of the preparation process.

2. The imaging device according to claim 1.

3. The predetermined state includes the area of ​​a face region in the second captured image being greater than a threshold.

3. The imaging device according to claim 2.

4. The predetermined state is a state in which the area of ​​the face region in the second captured image exceeds a threshold within a predetermined period after the predetermined movement is detected.

3. The imaging device according to claim 2.

5. The predetermined state is a state in which the area of ​​the face region in the second captured image exceeds a threshold within a predetermined period from the start of the preparation process.

3. The imaging device according to claim 2.

6. The control means terminates the preparation process when the face detected by the face detection means does not attain the predetermined state within the predetermined period.

5. The imaging device according to claim 4.

7. When a plurality of faces are detected by the face detection means, the control means determines whether the face having the largest area in the second captured image has reached the predetermined state.

3. The imaging device according to claim 2.

8. a second display device provided on the rear side and displaying the first captured image; The control means controls the first display device not to display the first captured image when the first display device is caused to display the first captured image.

3. The imaging device according to claim 2.

9. a second display device provided on the rear side and displaying the first captured image; The control means displaying the first captured image on the second display device during a period in which the first captured image is being acquired by the first imaging means; On the condition that the face detected by the face detection means has reached the predetermined state, the display of the first captured image is switched from the second display device to the first display device. Control 3. The imaging device according to claim 2.

10. The first display device is an electronic viewfinder, and the second display device is a rear monitor.

9. The imaging device according to claim 8.

11. The predetermined movement is a state in which the moving direction of the imaging device is a predetermined direction and the moving speed of the imaging device exceeds a threshold.

2. The imaging device according to claim 1.

12. The preparation process includes a process of supplying power to the second imaging means to start it up.

2. The imaging device according to claim 1.

13. a movement detection means for detecting a movement occurring in the imaging device; a first imaging means for imaging a front direction of the imaging device; a second imaging means for imaging a rear direction of the imaging device; a first display device provided on a rear side of the imaging device and configured to display a first captured image acquired by the first imaging means; A control method for an imaging device having a face detection step of detecting a face included in the second captured image acquired by the second imaging means; a control step of controlling the operation of the first display device and the face detection step; and In the control step, starting the operation of the face detection step in response to the detection of a predetermined movement of the imaging device by the movement detection means; On the condition that a face is detected in the face detection step, a preparation process relating to display preparation of the first display device is started. It is controlled so that A control method comprising:

14. A program for causing a computer to function as a control unit of the imaging device according to any one of claims 1 to 12.

Images