Electronic apparatus and control method of the same

Abstract

To effectively use a pre-capture function while suppressing power consumption.SOLUTION: An electronic apparatus includes: operation means of outputting a first operation instruction for instructing photographing preparation and a second operation instruction for instructing recording of a photographed image; acquisition means of repeatedly acquiring determination information for estimating the level of possibility of the output of the second operation instruction; storage means of temporarily holding image data output from imaging means during the output of the first operation instruction; controlling means of, during the output of the first operation, performing control of the image data by the imaging means and holding the image data in the storage means by first control in the case where the estimated level is a first level, and performing the control by second control for reducing power consumption compared to the first control in the case where the estimated level is a second level; and recording means of recording the image data of an image photographed by the imaging means in accordance with the instruction in the case where the second operation instruction is output and the image data held by the storage means at the timing nearest to the instructed timing in a recording medium.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an electronic device and a control method thereof, and more particularly to a photography control technique in an electronic device. [Background technology]

[0002] Conventionally, in electronic devices with an imaging function such as a digital camera, there has been a time lag between when a photographer presses the release button of the camera to give an instruction to shoot and when the shooting and recording actually starts, which has sometimes prevented the photographer from capturing the image he or she desires.

[0003] In response to this, Patent Document 1 proposes a camera equipped with a pre-capture function. The pre-capture function is a function that repeatedly captures images while the release button is pressed down to the first position, so that a predetermined number of images of the same quality as still images are stored in buffer memory. Then, when the release button is pressed down to the second position, the images stored in the buffer memory and the image captured at the time the release button was pressed down to the second position are stored in recording media.

[0004] By using such a pre-capture function, it is possible to photograph and record from the moment the photographer issues a photographing instruction, thereby enabling the photographer to obtain the image he or she desires. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-252804 Summary of the Invention [Problem to be solved by the invention]

[0006] However, while the pre-capture function disclosed in Patent Document 1 is effective when the photographer has a strong intention to shoot, such as by staring intently at the subject and aiming for the right timing to shoot, continued shooting wastes power when the photographer has a weak intention to shoot, such as by looking away from the subject. On the other hand, if the photographer waits without using the pre-capture function, there is a risk that the scene to be shot will be missed due to a time lag, and the desired image will not be obtained, so it is desirable to keep the pre-capture function running.

[0007] The present invention has been made in consideration of the above problems, and has as its object to make it possible to effectively use the pre-capture function while suppressing power consumption. [Means for solving the problem]

[0008] In order to achieve the above object, the electronic device of the present invention has an operation means for outputting a first operation instruction instructing preparation for shooting and a second operation instruction instructing recording of a shot image, an acquisition means for repeatedly acquiring judgment information for estimating the level of possibility that the second operation instruction will be output, a storage means for temporarily storing image data output from an imaging means while the first operation instruction is being output, a control means for controlling the imaging means to shoot the image data and store it in the storage means while the first operation instruction is being output, by performing a first control if the level estimated based on the judgment information is a first level, and by performing a second control that reduces power consumption more than the first control if the level is a second level lower than the first level, and a recording means for recording, when the second operation instruction is output, image data of an image shot by the imaging means in accordance with the instruction and image data stored in the storage means at a timing immediately prior to the timing of the instruction, on a recording medium. [Effects of the Invention]

[0009] According to the present invention, it is possible to effectively use the pre-capture function while suppressing power consumption. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing an example of the hardware configuration of an imaging apparatus according to an embodiment of the present invention. [Figure 2] 4 is a flowchart showing a shooting process of the imaging device according to the first embodiment. [Figure 3] 5 is a flowchart showing pre-capture photography control according to the first embodiment. [Figure 4] 5A and 5B are explanatory diagrams illustrating detection of the direction of the line of sight by the photographer sensing unit according to the first and second embodiments. [Figure 5] 10 is a flowchart showing pre-capture photography control according to the second embodiment. [Figure 6] 10 is a flowchart showing pre-capture photography control according to the third embodiment. [Figure 7] 13A and 13B are explanatory diagrams illustrating detection of the direction of the line of sight by a photographer sensing unit according to the third embodiment. [Figure 8] 10 is a flowchart showing a processing operation of an imaging apparatus according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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.

[0012] 1 is a block diagram showing the hardware configuration of an image capturing device 100 according to an embodiment of the present invention. Note that image capturing device 100 may be any electronic device equipped with a camera function, such as a digital camera or digital video camera, a camera-equipped mobile phone, a camera-equipped computer, a game console, or the like.

[0013] The control unit 101 is configured with at least one processor and controls the overall operation of the imaging device 100. The control unit 101 reads a program for controlling the imaging device 100 from the memory unit 108 and loads a part of the program into the system memory unit 106, thereby controlling the entire imaging device 100.

[0014] The power supply control unit 102 is composed of a battery detection circuit, protection circuit, DC-DC converter, LDO regulator, etc., and converts the power supplied from the power supply unit 103 into a voltage suitable for each electronic device constituting the image capture device 100 and supplies it. The power supply control unit 102 also has functions such as detecting whether a battery is installed, the battery type, and the remaining charge, and protecting load circuits connected to the power supply circuit by cutting off the power supply when an overcurrent is detected. Furthermore, the power supply control unit 102 has a power detection circuit that can detect the amount of power supplied to each unit in the image capture device 100.

[0015] The power supply unit 103 is composed of a secondary battery such as a NiCd battery, a NiMH battery, or a Li battery, an AC adapter, etc. It also has a circuit for acquiring the remaining battery power, and can notify the acquired remaining battery power to the control unit 101 via communication.

[0016] The operation unit 104 has operation members for inputting various operation instructions to the control unit 101. The operation unit 104 is configured using any one of a switch, a dial, a touch panel, a voice recognition device, etc., or a combination thereof. The release button, which is one of the operation members of the operation unit 104, is configured as a two-stage switch consisting of a first release switch and a second release switch. When the first release switch is pressed down to the first stage (e.g., halfway down), it turns on, and a first operation instruction instructing preparation for shooting is output to the control unit 101. When the second release switch is pressed down to the second stage (e.g., fully down), it turns on, and a second operation instruction instructing recording of the captured image is output to the control unit 101. Note that in the present invention, the operation member that outputs the first operation instruction and the second operation instruction is not limited to the release button, and may be configured to output the first operation instruction and the second operation instruction.

[0017] The recording unit 105 includes a system memory unit 106 and an external recording unit 107. The system memory unit 106 is composed of RAM or the like, and is used to expand programs read from the memory unit 108 and constants, variables, and the like for the operation of the control unit 101. The system memory unit 106 also sequentially and temporarily stores image data of images (hereinafter referred to as "pre-capture images") obtained by repeatedly performing pre-capture shooting, which captures images of the same or similar quality as the images obtained by the actual shooting, before the actual shooting. Once a predetermined number of pre-capture images have been stored, the oldest pre-capture image among the stored images is deleted, and a new pre-capture image is stored. The external recording unit 107 is a removable recording medium such as a semiconductor memory, and records image data of the pre-capture images and images obtained by the actual shooting.

[0018] The memory unit 108 is composed of an electrically erasable and storable non-volatile memory, a ROM, etc., and stores constants, programs, etc. for the operation of the control unit 101. The programs referred to here include programs for executing the processes shown in the flowcharts described later in this embodiment.

[0019] The imaging unit 109 is composed of an imaging element such as a CMOS sensor or a CCD, and performs imaging based on instructions from the control unit 101, and transmits information about the acquired image (image data, etc.) to the control unit 101.

[0020] The display unit 110 has a liquid crystal device, a speaker, etc. that displays operating status and messages such as characters, images, and sounds in accordance with the execution of a program in the control unit 101, and is composed of a combination of an EVF, LCD, LED, sound-generating elements, etc.

[0021] The photographer sensing unit 111 detects status information (determination information) of the photographer and notifies the control unit 101 of the detected status information of the photographer. The photographer sensing unit 111 is configured by one or a combination of an in-camera capable of capturing an image of the photographer, a camera shake detection sensor capable of detecting the amount of camera shake of the photographer, a grip sensor capable of detecting whether the photographer is holding the imaging device 100, and the like.

[0022] First Embodiment Hereinafter, the photographing process in the first embodiment by the imaging device 100 having the above configuration will be described with reference to Fig. 2. The process of the flowchart in Fig. 2 starts when the control unit 101 detects a first operation instruction output by the photographer pressing the first release switch of the operation unit 104.

[0023] In S201, the control unit 101 performs pre-capture shooting and temporarily stores the obtained pre-capture image in the system memory unit 106. Note that, as a default, pre-capture shooting is performed in a first shooting state, which will be described later.

[0024] Next, in S202, pre-capture shooting control is performed. The pre-capture shooting control will now be described with reference to the flowchart of FIG.

[0025] In S301, the photographer sensing unit 111 acquires status information of the photographer and outputs it to the control unit 101. In the first embodiment, the photographer sensing unit 111 has an inner camera that can capture an image of the photographer himself, and captures an image of the photographer with the inner camera to detect the gaze of the photographer as status information of the photographer.

[0026] In S302, the control unit 101 determines whether to output a first pre-capture control instruction or a second pre-capture control instruction to the imaging unit 109 based on the photographer status information acquired by the photographer sensing unit 111, and outputs the determined control instruction. If the control unit 101 outputs the first pre-capture control instruction to the imaging unit 109, the process proceeds to S303, and if the control unit 101 outputs the second pre-capture control instruction, the process proceeds to S304.

[0027] The determination performed in S302 will now be described with reference to FIG. As shown in Fig. 4, the photographer sensing unit 111 is installed on the rear surface of the imaging device 100 and has an in-camera capable of capturing an image of the photographer himself / herself. The photographer's gaze information is acquired from an image captured by the in-camera as status information of the photographer. As shown in Fig. 4(a), when the control unit 101 detects a gaze direction in which the photographer is looking at the display unit 110 on the rear surface of the imaging device 100 from an image captured by the in-camera, the control unit 101 infers that the photographer has an intention to take a photograph (high likelihood of issuing a command to take a photograph), and notifies the imaging unit 109 of a first pre-capture control instruction. On the other hand, when the control unit 101 cannot detect a gaze direction in which the photographer is looking at the display unit 110 on the rear surface of the imaging device 100 as shown in Fig. 4(b), the control unit 101 infers that the photographer has little intention to take a photograph (low likelihood of issuing a command to take a photograph), and notifies the imaging unit 109 of a second pre-capture control instruction.

[0028] In S303, the image capture unit 109 receives a first pre-capture control instruction and operates in a first image capture state, and in S304, the image capture unit 109 receives a second pre-capture control instruction and operates in a second image capture state. Here, the second image capture state is an image capture state in which at least one pre-capture image capture parameter, such as the frame rate during pre-capture image capture, the recording image quality, or the number of pre-capture images retained, is reduced compared to the first image capture state. By controlling in this way, pre-capture image capture can be performed while reducing the power consumption of the image capture device 100 when the photographer's intention in capturing the image is low.

[0029] When the frame rate is reduced, the number of images captured per unit time can be reduced, which reduces power consumption of the imaging unit 109, which captures pre-capture images and transfers them to the control unit 101, the control unit 101 which processes the transferred pre-capture images, and the external recording unit 107, which records images after actual shooting (described later).

[0030] When the recording image quality is reduced, the image size read out per frame from the imaging unit 109 can be reduced. Therefore, similar to the case where the number of images taken per unit time is reduced, the power consumption of the imaging unit 109, the control unit 101, and the external recording unit 107 can be reduced.

[0031] In addition, if the number of pre-capture images held is reduced, the number of pre-capture images held in the system memory unit 106 can be reduced, thereby reducing the power consumption when temporarily recording to the external recording unit 107.

[0032] After transitioning to the first imaging state in S303, the control unit 101 instructs the photographer sensing unit 111 to operate in power saving mode in S305. On the other hand, after transitioning to the second imaging state in S304, the control unit 101 instructs the photographer sensing unit 111 to operate in normal mode in S306.

[0033] In the power saving mode, the frame rate and / or resolution of the photographer sensing unit 111 is reduced to reduce the power consumption of the photographer sensing unit 111. When the photographer sensing unit 111 is driven in the power saving mode, the performance of estimating the photographer's state is reduced, but since the pre-capture shooting parameters are set by the photographer in the first imaging state, the shooting performance of the pre-capture shooting is not impaired. Therefore, in the first imaging state, the photographer sensing unit 111 is driven in the power saving mode, and reducing the power consumption of the photographer sensing unit 111 is prioritized over the performance of estimating the photographer's state.

[0034] On the other hand, in the second imaging state, if a transition from a low to a high shooting intention is detected, it is necessary to immediately transition to the first imaging state, restore the pre-capture shooting parameters, and perform pre-capture shooting. Therefore, in the second imaging state, the photographer sensing unit 111 is driven in normal mode, and the ability to estimate the photographer's state is prioritized over the power consumption of the photographer sensing unit 111. This completes the processing related to the pre-capture photography control, and the process proceeds to S203 in FIG.

[0035] In S203, the control unit 101 determines whether a first operation instruction has been output by the photographer pressing the first release switch of the operation unit 104. If the first operation instruction has been output, the process proceeds to S205, and if the first operation instruction has not been output, the process proceeds to S204.

[0036] In S204, the control unit 101 erases the pre-capture image temporarily recorded in the system memory unit 106, and ends the process.

[0037] In S205, the control unit 101 determines whether a second operation instruction has been output by the photographer pressing the second release switch of the operation unit 104. If the second operation instruction has not been output, the process returns to S201 and the above-described processing is repeated. As a result, pre-capture shooting is repeatedly performed while the first operation instruction is being output before actual shooting is performed. In this case, pre-capture shooting is performed in either the first shooting state or the second shooting state set in S202.

[0038] As described above, a predetermined number of pre-capture images, starting with the most recently captured image, are temporarily stored in the system memory unit 106. The number of pre-capture images temporarily stored can be changed as needed, for example, to the number that fills the system memory unit 106, a predetermined number, or a number set by the photographer.

[0039] On the other hand, if the second operation instruction has been output, the process proceeds to S206, and the control unit 101 controls the imaging unit 109 to perform actual shooting. Note that actual shooting is different from pre-capture shooting and refers to normal single-shot shooting, in which one image is captured.

[0040] In S207, the control unit 101 records, in the external recording unit 107, the pre-capture image captured immediately before the second operation instruction was output, and the actual captured image acquired in S206, among the pre-capture images stored in the system memory unit 106. Note that the number of pre-capture images recorded together with the actual captured image is not limited to one, and multiple images may be recorded. In this case, it is preferable to record the pre-capture images captured closest to the output of the second operation instruction. After saving, all pre-capture images stored in the system memory unit 106 are erased. Note that this erasure process may be performed after the second operation instruction is no longer output.

[0041] In S208, the control unit 101 determines whether a second operation instruction has been output by the photographer pressing the second release switch of the operation unit 104. If the second operation instruction has been output, the process proceeds to S209, and if the second operation instruction has not been output, the process proceeds to S211.

[0042] In S209, the control unit 101 controls the imaging unit 109 to perform actual photographing. In S210, the control unit 101 records the actual photographed image acquired in S209 in the external recording unit 107, and then returns to S208 to repeat the above-described processing.

[0043] On the other hand, in S211, the control unit 101 determines whether a first operation instruction has been output by the photographer pressing the first release switch of the operation unit 104. If the first operation instruction has been output, the process returns to S201 and the above-described processing is repeated. If the first operation instruction has not been output, the processing ends.

[0044] As described above, according to the first embodiment, when the photographer's photographic intent is estimated to be weak based on the photographer's status information, the pre-capture photographing parameters are changed to reduce at least one of the frame rate, recording image quality, number of retained pre-capture images, etc. This allows for power-saving operation. On the other hand, when the photographer's photographic intent is estimated to be strong, the photographer can obtain the image he or she desires by performing pre-capture photographing as before.

[0045] <Second embodiment> Next, a description will be given of the photographing process by the imaging device 100 in a second embodiment of the present invention. Note that the basic flow of the photographing process in this embodiment is the same as that in the first embodiment described with reference to Fig. 2, but the content of the pre-capture photographing control performed in S202 is different. Therefore, the pre-capture photographing control in this embodiment will be described below.

[0046] FIG. 5 is a flowchart showing the pre-capture photography control performed in S202 of FIG. 2 in the second embodiment.

[0047] First, in S501, the photographer sensing unit 111 acquires status information of the photographer and outputs it to the control unit 101. Note that here too, the status information of the photographer is obtained by capturing an image of the photographer using the in-camera provided in the photographer sensing unit 111 and detecting the gaze of the photographer.

[0048] In S502, the control unit 101 infers whether the photographer's photographic intention is strong based on the photographer's state information acquired by the photographer sensing unit 111 as described above with reference to Fig. 4. If it is inferred that the photographer's photographic intention is strong, the pre-capture photographing control ends and the process proceeds to S203 in Fig. 2. On the other hand, if it is inferred that the photographer's photographic intention is not strong (low), the process proceeds to S503.

[0049] In S503, the control unit 101 determines whether a predetermined time has elapsed since the control unit 101 estimated in S502 that the photographer's shooting intention was low. If the predetermined time has elapsed, the process proceeds to S504, and if the predetermined time has not elapsed, the process proceeds to S505.

[0050] In S504, the control unit 101 deletes the pre-capture image temporarily stored in the system memory unit 106. For example, if a period of about 5 seconds has passed during which the photographer has little intention to take a photograph, the control unit 101 determines that the pre-capture image temporarily stored in the system memory unit 106 is unnecessary.

[0051] Next, in S505, the control unit 101 determines whether a first operation instruction has been output by the photographer pressing the first release switch of the operation unit 104. If the first operation instruction has been output, the process proceeds to S506, and if the first operation instruction has not been output, the subroutine related to pre-capture shooting control is terminated and the process proceeds to S204 in Fig. 2. Then, in S204, if S504 has not been passed (i.e., if the first operation instruction has not been output within a predetermined time), the pre-capture image temporarily held in the system memory unit 106 is erased, and the process then terminates.

[0052] In S506, the control unit 101 determines whether a second operation instruction has been output by the photographer pressing the second release switch on the operation unit 104. If a second operation instruction has been output, the subroutine related to pre-capture shooting control ends, and the process proceeds to S206 in Fig. 2. Note that if the pre-capture image has been erased in S504, after the actual shooting in S206, only the actual shot image is recorded in the external recording unit 107 in S207.

[0053] On the other hand, if the second operation instruction is not output in S506, the process returns to S501 and repeats the above-described process. In this way, by returning to S501, only the first operation instruction is output, and while the photographer's photographic intention is estimated to be low in S502, the photographer's photographic intention is repeatedly estimated without performing pre-capture photography.

[0054] Also, even if the photographer's photographic intent is estimated to be low, if it is re-estimated in S502 that the photographer's photographic intent is high, the process proceeds to S203 and subsequent steps in Fig. 2, and if NO in S205 (only the first operation instruction is output), the process returns to S201 and pre-capture shooting is performed. In this way, while only the first operation instruction is output, pre-capture shooting can be temporarily suspended while the photographer's photographic intent is low.

[0055] As described above, according to the second embodiment, when it is estimated that the photographer's intentions are low based on the photographer's state information, pre-capture shooting is temporarily suspended, thereby enabling operation in a power-saving manner.

[0056] <Third embodiment> Next, a description will be given of the photographing process by the imaging device 100 according to the third embodiment of the present invention. Note that the basic flow of the photographing process in this embodiment is the same as that in the first embodiment described with reference to Fig. 2, but the content of the pre-capture photographing control performed in S202 is different. Therefore, the pre-capture photographing control in this embodiment will be described below.

[0057] FIG. 6 is a flowchart showing the pre-capture photography control performed in S202 of FIG. 2 in the third embodiment.

[0058] First, in S601, the photographer sensing unit 111 acquires status information of the photographer and outputs it to the control unit 101. In S602, the control unit 101 calculates the gaze angle θ of the photographer with respect to the imaging device 100 based on the status information of the photographer sent from the photographer sensing unit 111. Note that the method for detecting the gaze angle θ of the photographer is not particularly limited, and for example, the angle can be estimated using a pre-trained model such as deep learning. In this case, for example, image data captured by the in-camera can be used as input data, and a learning model learned from gaze angle information with respect to the imaging device can be used as training data.

[0059] Next, in the processes of S603 to S605, the obtained line-of-sight angle θ is determined in stages, for example, as shown in Fig. 7. Here, as an example, the determination is performed using threshold values ​​θ1, θ2, and θ3 (θ1<θ2<θ3).

[0060] In S603, the control unit 101 determines whether the angle θ calculated in S602 is θ≦θ1. If θ≦θ1, the process proceeds to S606, and if not, the process proceeds to S604.

[0061] In S604, the control unit 101 determines whether the angle θ calculated in S602 is θ1<θ≦θ2. If θ1<θ≦θ2, the process proceeds to S607, and if not, the process proceeds to S605.

[0062] In S605, the control unit 101 determines whether the angle θ calculated in S602 is θ2<θ≦θ3. If θ2<θ≦θ3, the process proceeds to S608, and if not, the process proceeds to S609.

[0063] In S606, the control unit 101 sets the frame rate of the pre-capture shooting to 60 fps for the imaging unit 109. In S607, the control unit 101 sets the frame rate of the pre-capture shooting to 30 fps for the imaging unit 109. In S608, the control unit 101 sets the frame rate of the pre-capture shooting to 24 fps for the imaging unit 109. In S609, the control unit 101 sets the image capturing unit 109 so that the frame rate of pre-capture shooting is 12 fps.

[0064] When any one of the processes in S606 to S609 is completed, the pre-capture shooting control ends and the process proceeds to S203 in FIG.

[0065] In the third embodiment, the frame rate is changed by dividing the line of sight angle θ into four stages, but the number of stages is not limited to four. The frame rate can also be set as appropriate.

[0066] Furthermore, in the above example, a case was described in which the frame rate is changed depending on the angle of the photographer's line of sight, but the present invention is not limited to this. For example, power saving can be achieved by gradually changing the resolution or the number of pre-capture images retained.

[0067] As described above, according to the third embodiment, by gradually changing the pre-capture shooting parameters in accordance with the photographer's state information and shooting intention, it is possible to operate with less power consumption when it is estimated that the photographer has less intention to shoot. On the other hand, it is possible to more easily obtain the photographer's desired image when it is estimated that the photographer has more intention to shoot.

[0068] <Fourth embodiment> Next, the photographing process by the image capturing device 100 in the fourth embodiment will be described with reference to FIG.

[0069] In S801, the control unit 101 acquires state information of the photographer from the photographer sensing unit 111 and infers whether the photographer has any intention to take a photograph. The method for inferring the photographer's intention to take a photograph is not particularly limited, and may be, for example, as described in the first embodiment with reference to FIG. 4, or may be inferred based on the amount of camera shake by the photographer or whether the photographer is holding the imaging device 100. If it is inferred that the photographer has any intention to take a photograph, the process proceeds to S802. If it is inferred that the photographer has little intention to take a photograph, the process of S801 is repeated.

[0070] In S802, the control unit 101 issues an instruction to start pre-capture shooting to the imaging unit 109, and starts pre-capture shooting. At this time, the frame rate at which pre-capture shooting is performed is set to a first frame rate. The first frame rate is set to a frame rate that can also handle fast subject shooting, such as 60 fps. While pre-capture shooting is being performed, as described above, pre-capture images are temporarily stored in the system memory unit 106 up to a predetermined number.

[0071] In S803, the control unit 101 determines whether a first operation instruction has been output by the photographer pressing the first release switch of the operation unit 104. If the first operation instruction has been output, the process proceeds to S809, and if the first operation instruction has not been output, the process proceeds to S804.

[0072] In S804, the control unit 101 determines whether a predetermined time T1 has elapsed since the start of pre-capture shooting without the first operation instruction being output. If the predetermined time T1 has not elapsed, the process proceeds to S807, and if the predetermined time T1 has elapsed, the process proceeds to S805.

[0073] In S805, pre-capture shooting is performed at the second frame rate. At this time, if pre-capture shooting is performed at the first frame rate, the setting is changed to the second frame rate. Here, if the first frame rate is 60 fps, the second frame rate is set to a value slower than the first frame rate, such as 30 fps.

[0074] Next, in S806, the control unit 101 determines whether a predetermined time T2 has elapsed since the start of pre-capture shooting without the first release switch being pressed, and if the predetermined time T2 has not elapsed, proceeds to S807, and if the predetermined time T2 has elapsed, proceeds to S808.

[0075] In S807, similarly to S801, it is inferred whether the photographer had any intention to take the photograph. If it is inferred that there was an intention to take the photograph, the process returns to S803 and repeats the above process, and if it is inferred that there was little intention to take the photograph, the process proceeds to S808.

[0076] In S808, the control unit 101 deletes all pre-capture images temporarily stored in the system memory unit 106, issues an instruction to end pre-capture photography to the imaging unit 109, and ends the process.

[0077] The operations of S804 to S808 are controls intended to stop pre-capture shooting after determining that gaze detection by the photographer sensing unit 111 is accidental and is likely not due to an intention to take a photograph. Even if gaze detection by the photographer sensing unit 111 in S801 determines that there is an intention to take a photograph and pre-capture shooting is started, if a predetermined time T1 has passed without any operation for taking a photograph, such as pressing the first release button, it is determined that there is doubt as to whether there is an intention to take a photograph, and the frame rate is lowered to reduce power consumption. If the elapsed time exceeds a predetermined time T2, it is determined that there is little intention to take a photograph, and pre-capture shooting is stopped, thereby further reducing power consumption.

[0078] In this way, the predetermined time T1 is a time for determining whether there is any suspicion of an intention to take a photograph, and T2 is set to an elapsed time sufficient to determine that there is no intention to take a photograph. For example, T1 may be set to 10 seconds and T2 may be set to 30 seconds. Furthermore, if the photographer sensing unit 111 detects that the photographer's gaze detection has been released before the predetermined times T1 and T2 have elapsed (YES in S807), the process transitions to S808 at that point, and pre-capture shooting ends.

[0079] The predetermined times T1 and T2 may be changed depending on the stability of the imaging device 100 (e.g., handheld or tripod-mounted shooting). The imaging device 100 may be equipped with an acceleration sensor to detect the magnitude of vibration of the imaging device 100, or a mechanical switch attached to the tripod may be used to determine whether the imaging device 100 is attached to a tripod or handheld. When determining based on the magnitude of vibration, if the vibration is smaller than a predetermined value (high stability), it is determined to be tripod-mounted shooting, and if the vibration is larger than a predetermined value (low stability), it is determined to be handheld shooting. Furthermore, when using tripod-mounted shooting, the photographer may be far away from the imaging device 100. If the photographer intends to take a photograph, they must approach the imaging device 100 to operate the operation unit 104 and take a photograph, which takes time. Therefore, the predetermined times T1 and T2 may be set longer for tripod-mounted shooting than for handheld shooting.

[0080] On the other hand, if it is determined in S803 that the first operation instruction has been output, then in S809 the control unit 101 determines whether a second operation instruction has been output by the photographer pressing the second release switch of the operation unit 104. If the second operation instruction has been output, the process proceeds to S206, and if the second operation instruction has not been output, the process returns to S803 and the above-described processing is repeated.

[0081] The processes in S206 to S211 are the same as those described above with reference to FIG. 2, and therefore will not be described here. In a scene where the subject is being searched for away from the imaging device 100, such as with tripod shooting, if the subject is found and then the first shooting instruction is issued, it is necessary to move to the camera, and there is a possibility that the subject will be missed in the meantime. On the other hand, if pre-capture shooting is always performed, power consumption will be wasted when there is no intention to shoot.

[0082] In contrast, according to the fourth embodiment, pre-capture is started in response to a presumption that there is an intention to shoot based on the detection result of the photographer sensing unit 111. This makes it possible to prevent missed shots due to a delay in the first shooting instruction, and also makes it possible to reduce power consumption in scenes where there is little intention to shoot.

[0083] In the first to fourth embodiments, it is assumed that the photographer's state information is the gaze of the photographer detected by capturing an image of the gaze of the photographer using the in-camera of the photographer sensing unit 111, but the present invention is not limited to this. For example, a configuration in which the in-camera detects the orientation of the photographer's face or body may be used. Furthermore, the photographer sensing unit 111 can be applied to any type of sensor, such as a camera shake detection sensor capable of detecting the amount of camera shake of the photographer, or a grip sensor capable of detecting whether the photographer is holding the imaging device, which can detect the photographer's state information.

[0084] <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.

[0085] 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. [Explanation of symbols]

[0086] 100: imaging device, 101: control unit, 102: power supply control unit, 103: power supply unit, 104: operation unit, 105: recording unit, 106: system memory unit, 107: external recording unit, 108: memory unit, 109: imaging unit, 110: display unit, 111: photographer sensing unit

Claims

1. A camera having a control means for controlling, in response to a second instruction for recording a captured image, to record in a recording means first image data output from a first imaging means and second image data of a plurality of frames output from the first imaging means before the first image data is captured, The electronic device according to claim 1, wherein the control means detects a state of a photographer and performs control to change at least a frame rate or a resolution of the second image of the plurality of frames in accordance with the detected state of the photographer.

2. The electronic device described in Claim 1, characterized in that the state of the photographer is detected based on image data captured by a second imaging means for photographing the photographer.

3. The electronic device described in Claim 1, characterized in that the state of the photographer is at least one of the angles of the photographer's line of sight, face, and body.

4. The electronic device described in Claim 1, characterized in that the control means temporarily stores in memory the second image data of the multiple frames output from the first imaging means while a first instruction instructing preparation for shooting is output, and in response to the second instruction, controls the first image data and the second image data to be recorded in the recording means.

5. An electronic device having a control means for controlling, in response to a second instruction for recording a captured image, to record in a recording means first image data output from a first imaging means and second image data of a plurality of frames output from the first imaging means before the first image data is captured, The electronic device is characterized in that the control means detects the stability of the electronic device and controls to change at least the frame rate or resolution of the second image of the multiple frames in accordance with the detected stability of the electronic device.

6. The electronic device described in Claim 5, characterized in that the detection of the stability of the electronic device is performed by detecting whether or not the electronic device is attached to a tripod.

7. The electronic device described in Claim 5, characterized in that the detection of the stability of the electronic device is performed by detecting vibrations of the electronic device.

8. The electronic device described in Claim 5, characterized in that the control means temporarily stores in memory the second image data of the multiple frames output from the first imaging means while a first instruction instructing preparation for shooting is output, and controls the first image data and the second image data to be recorded in the recording means in response to the second instruction.

9. A control process for controlling, in response to a second instruction for recording a captured image, to record in a recording means first image data output from a first imaging means and second image data of a plurality of frames output from the first imaging means before the first image data is captured, A control method for an electronic device, characterized in that the control step detects a state of a photographer and controls to change at least a frame rate or a resolution of the second image of the multiple frames in accordance with the detected state of the photographer.

10. A control process for controlling an electronic device to record in a recording means first image data output from a first imaging means and second image data of a plurality of frames output from the first imaging means before the first image data is captured, in response to a second instruction for recording a captured image, A control method for an electronic device, characterized in that in the control process, the stability of the electronic device is detected, and at least the frame rate or resolution of the second image of the multiple frames is changed depending on the detected stability of the electronic device.

11. A program for causing a computer to function as each of the means of the electronic device according to any one of claims 1 to 8.

12. A computer-readable storage medium storing the program according to claim 11.

Images