JP5583465B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging apparatus that controls the amount of auxiliary light applied to a subject when shooting a moving image.

  2. Description of the Related Art Conventionally, a method for capturing a moving image using an auxiliary light source such as an LED, a video light, or a strobe device is known. As a result, it is possible to perform photographing with appropriate brightness. However, if the auxiliary light source is always caused to emit light during long-time photographing, there is a problem that the battery runs out in a short time.

  Patent Document 1 discloses a technique for measuring the amount of peripheral light and controlling the light emission amount of the strobe device in accordance with the measured peripheral light amount. According to this technology, it is possible to perform moving image shooting with appropriate brightness while suppressing battery consumption.

JP 2005-348014 A

  However, in the conventional technology, the amount of light emitted from the strobe device is determined by the amount of peripheral light, so even if there is no characteristic subject, if the amount of peripheral light is small, the amount of light emitted by the strobe device increases and the battery consumption increases. There was a problem of becoming.

  An object of the present invention is to provide a technique for appropriately controlling the light emission amount of auxiliary light based on the detection result of a subject of interest in a moving image.

An imaging device according to an aspect of the present invention is an imaging device capable of capturing a moving image, and includes a target subject detection unit that detects a target subject in a moving image, a light emitting unit that emits auxiliary light, and a video capturing. And a light emission amount control unit that controls a light emission amount of the light emitting unit based on a detection result of the target subject by the target subject detection unit, and the light emission amount control unit detects the target subject by the target subject detection unit. If the target subject is not detected by the target subject detection unit, the light emission amount of the light emitting unit is increased when the target subject detection unit does not detect the target subject. The light emission amount of the part is reduced or stopped .

  According to the present invention, by controlling the light emission amount of the auxiliary light based on the detection result of the subject of interest in the moving image, it is possible to shoot a moving image with appropriate brightness while suppressing the battery consumption amount. Can do.

It is a block diagram which shows the structure of the digital still camera which is an imaging device in one Embodiment. It is a flowchart which shows the main processing flow performed with the digital still camera which is an imaging device in one Embodiment. It is a flowchart which shows the detail of a live view display, video recording, and image processing. It is a flowchart which shows the detail of a reproduction | regeneration process. It is a flowchart which shows the detail of light emission amount control processing.

  FIG. 1 is a block diagram illustrating a configuration of a digital still camera that is an imaging apparatus according to an embodiment. The digital still camera shown in FIG. 1 includes a camera body 1, an interchangeable lens 2, and an auxiliary light source 3.

  The interchangeable lens 2 includes a lens 1010, a flash memory 1011, a microcomputer 1012, a driver 1013, and a diaphragm 1014. The interchangeable lens 2 is communicably connected to the camera body 1 via the I / F 999.

  The auxiliary light source 3 includes a light 1020 and a light emission controller 1021, and is connected to the camera body 1 via the I / F 998 so as to be communicable. In the present embodiment, the auxiliary light source 3 is configured to be separable from the camera body 1, but may be configured to be integrated with the camera body 1.

  The camera body 1 includes a mechanical shutter 101, an image sensor 102, an analog processing unit 103, an analog / digital conversion unit 104 (hereinafter referred to as A / D conversion unit 104), a bus 105, an SDRAM 106, and an image processing unit 107. An AE processing unit 108, an AF processing unit 109, an image compression / decompression unit 110, a memory interface 111 (hereinafter referred to as a memory I / F 111), a recording medium 112, an LCD driver 113, an LCD 114, and a microcomputer 115. An operation unit 116, a flash memory 117, a subject detection unit 118, a histogram calculation unit 119, and a histogram change detection unit 120.

  The lens 1010 focuses the optical image of the subject on the image sensor 102. The lens 1010 may be a single focus lens or a zoom lens.

  The microcomputer 1012 is connected to the I / F 999, the flash memory 1011 and the driver 1013. The microcomputer 1012 reads and writes information stored in the flash memory 1011 and controls the driver 1013. Information stored in the flash memory 1011 includes data on the focal length of the interchangeable lens 2 and the like.

  The microcomputer 1012 can further communicate with the microcomputer 115 via the I / F 999, transmits various information to the microcomputer 115, and receives information such as an aperture value from the microcomputer 115.

  In response to an instruction from the microcomputer 1012, the driver 1013 drives the lens 1010 to change the focal length and focus position, and drives the aperture 1014. The aperture 1014 is provided in the vicinity of the lens 1010 and adjusts the amount of light of the subject.

  The auxiliary light source 3 includes a light 1020 and a light emission controller 1021. The light 1020 is, for example, a video light, and can emit light and irradiate auxiliary light toward the subject to forcibly increase the amount of light of the subject. The light emission controller 1021 controls turning on / off of the light 1020 and the amount of emitted light based on an instruction input from the microcomputer 115 via the I / F 998.

  The mechanical shutter 101 is driven in response to an instruction from the microcomputer 115 to control the time for exposing the subject to the image sensor 102.

  The image sensor 102 is an image sensor in which a Bayer array color filter is arranged in front of a photodiode constituting each pixel. The Bayer array has a line in which R pixels and G (Gr) pixels are alternately arranged in a horizontal direction, and a line in which G (Gb) pixels and B pixels are alternately arranged, and the two lines are further divided. It is configured by alternately arranging in the vertical direction. The imaging element 102 receives the light collected by the lens 1010 by a photodiode that constitutes a pixel and performs photoelectric conversion, and outputs the amount of light to the analog processing unit 103 as a charge amount. The image sensor 102 may be a CMOS type or a CCD type.

  The analog processing unit 103 performs waveform shaping on the electrical signal (analog image signal) read from the image sensor 102 while reducing reset noise and the like, and further increases the gain so that the target brightness is obtained. . The A / D conversion unit 104 converts the analog image signal output from the analog processing unit 103 into a digital image signal (hereinafter referred to as image data).

  A bus 105 is a transfer path for transferring various data generated in the digital camera to each unit in the digital camera. The bus 105 includes an A / D conversion unit 104, an SDRAM 106, an image processing unit 107, an AE processing unit 108, an AF processing unit 109, an image compression / decompression unit 110, a memory I / F 111, an LCD driver 113, and the like. The microcomputer 115, the subject detection unit 118, the histogram calculation unit 119, and the histogram change detection unit 120 are connected.

  The image data output from the A / D conversion unit 104 is temporarily stored in the SDRAM 106 via the bus 105. The SDRAM 106 is a storage unit that temporarily stores various data such as image data obtained by the A / D conversion unit 104 and image data processed by the image processing unit 107 and the image compression / decompression unit 110.

  The image processing unit 107 performs various image processing such as white balance correction processing, synchronization processing, and noise reduction processing on the image data read from the SDRAM 106. The image data after each processing is performed by the image processing unit 107 is stored in the SDRAM 106.

  The AE processing unit 108 calculates subject luminance from the image data. The data for calculating the subject brightness may be an output of a dedicated photometric sensor. The AF processing unit 109 extracts a high-frequency component signal from the image data, and acquires a focus evaluation value by AF (Auto Focus) integration processing.

  The subject detection unit 118 performs image processing by the image processing unit 107, reads image data stored in the SDRAM 106, analyzes the image data, and detects a target subject in the image. The subject of interest is a subject that the photographer is expected to pay attention at the time of photographing, and is, for example, a person or an animal. Detection of a subject of interest such as a person or an animal can be performed by a known method such as pattern matching. The detection result of the subject of interest is sent to the microcomputer 115.

  A histogram calculation unit 119 performs image processing by the image processing unit 107, reads image data stored in the SDRAM 106, and creates histogram data of image feature amounts. In the present embodiment, histogram data corresponding to the luminance distribution of the image is created, and the created histogram data is transmitted to the histogram change detection unit 120. In the present embodiment, a luminance histogram is created as the histogram of the feature amount of the image. For example, when the image data is composed of RGB data, each of the RGB histograms can be created. In other words, the histogram of the feature amount of the image is not limited to the luminance histogram.

  The histogram change detection unit 120 receives the histogram data transmitted from the histogram calculation unit 119 and compares it with the histogram data received so far, thereby detecting the amount of change in the histogram data. The detection result of the change amount of the histogram data is sent to the microcomputer 115.

  When still image data is recorded, the image compression / decompression unit 110 reads the image data from the SDRAM 106, compresses the read image data according to the JPEG compression method, and temporarily stores the compressed JPEG image data in the SDRAM 106. The microcomputer 115 creates a JPEG file by adding a JPEG header necessary for constructing a JPEG file to the JPEG image data stored in the SDRAM 106, and sends the created JPEG file via the memory I / F 111. To the recording medium 112.

  The image compressing / decompressing unit 110 also reads out the moving image data from the SDRAM 106 when recording the moving image data. The compressed moving image data is temporarily stored in the SDRAM 106 after being compressed according to the H.264 system. The image compression / decompression unit 110 further performs a process of decompressing (decompressing) the compressed data based on a command from the microcomputer 115.

  The recording medium 112 is, for example, a recording medium including a memory card that can be attached to and detached from the camera body 1, but is not limited thereto.

  The LCD driver 113 displays an image on the LCD 114. Display of images includes display of moving images such as REC view display that displays image data immediately after shooting for a short time, playback display of a JPEG file recorded on the recording medium 112, and live view display. When reproducing the compressed data recorded on the recording medium 112, the image compression / decompression unit 110 reads out the compressed data recorded on the recording medium 112, performs decompression (decompression) processing, and then temporarily decompresses the decompressed data. It is stored in the SDRAM 106. The LCD driver 113 reads the decompressed data from the SDRAM 106, converts the read data into a video signal, and then outputs it to the LCD 114 for display.

  The microcomputer 115 having a function as a control unit comprehensively controls various sequences of the digital camera body 1. In particular, the microcomputer 115 is based on the subject detection result sent from the subject detection unit 115, the detection result of the change amount of the histogram data sent from the histogram change detection unit 120, or both detection results. , A light emission instruction for the light 1020 is issued to the light emission controller 1021 via the I / F 998. An operation unit 116 and a flash memory 117 are connected to the microcomputer 115.

  The operation unit 116 is an operation member such as a power button, a release button, a moving image button, a playback button, and various input keys. When one of the operation members of the operation unit 116 is operated by the user, the microcomputer 115 executes various sequences according to the user's operation. The power button is an operation member for instructing power on / off of the digital camera. When the power button is pressed, the power of the digital camera is turned on. When the power button is pressed again, the digital camera is turned off. The release button has a two-stage switch of a first release switch and a second release switch. When the release button is pressed halfway and the first release switch is turned on, the microcomputer 115 performs a shooting preparation sequence such as AE processing and AF processing. Further, when the release button is fully pressed and the second release switch is turned on, the microcomputer 115 performs shooting by executing a shooting sequence.

  The playback button is a button for causing the LCD 114 to display a still image or a moving image obtained by shooting.

  The movie button is a button for starting and ending movie shooting. Since the moving image is not yet shot in the initial state, when the moving image button is pressed in this state, moving image shooting starts. When the moving image button is pressed during moving image shooting, moving image shooting ends. Therefore, each time the moving image button is pressed, the start and end of moving image shooting are repeated alternately.

  The flash memory 117 stores various parameters necessary for the operation of the digital camera such as a white balance gain, a color matrix coefficient, and a low-pass filter coefficient according to the white balance mode, and a manufacturing number for specifying the digital still camera. ing. The flash memory 117 also stores various programs executed by the microcomputer 115. The microcomputer 115 reads parameters necessary for various sequences from the flash memory 117 according to a program stored in the flash memory 117, and executes each process.

  FIG. 2 is a flowchart illustrating a main processing flow performed by a digital still camera which is an imaging apparatus according to an embodiment. When the user presses the power button to turn on the digital still camera, the microcomputer 115 starts the process of step S201.

  In step S201, the recording flag is initialized to off, a time counter described later is set to 0, and a dimming flag described later is initialized to off. The recording flag is a flag that is turned on during moving image shooting and turned off when no moving image is shot.

  In step S202, it is determined whether or not the playback button has been operated by the user. If it is determined that the play button has been operated, the process proceeds to step S203. If it is determined that the play button has not been operated, the process proceeds to step S204.

  In step S203, processing for reproducing a still image or a moving image obtained by shooting is performed. Details of the reproduction process will be described later with reference to FIG.

  In step S204, it is determined whether or not the video button has been operated by the user. If it is determined that the movie button has been operated, the process proceeds to step S205. If it is determined that the movie button has not been operated, the process proceeds to step S208.

  In step S205, the recording flag is reversed, and the process proceeds to step S206. As described above, every time the video button is pressed, the video recording start and end are alternately repeated. Therefore, in this step, if the recording flag is off, it is on, and if it is on, Turn off and invert the recording flag.

  In step S206, it is determined whether the recording flag is on. If it is determined that the recording flag is off, the process proceeds to step S208. If it is determined that the recording flag is on, the process proceeds to step S207.

  In step S207, a time counter described later is set to 0, and a dimming flag described later is set to OFF, and the process proceeds to step S208.

  In step S208, it is determined whether the recording flag is on. If it is determined that the recording flag is on, the process proceeds to step S214.

  If it is determined in step S214 that moving image recording is in progress, image processing and image compression are performed on the image data of the moving image based on the image signal from the image sensor 102, and then recorded on the recording medium 112. If it is determined that the moving image recording is not in progress, a live view display for determining a subject composition and shutter timing in still image shooting is performed. Details of live view display, moving image shooting, and image processing in step S214 will be described later with reference to FIG.

  On the other hand, if it is determined in step S208 that the recording flag is off, the process proceeds to step S209. In step S209, it is determined whether or not the user has pressed the release button halfway to turn on the first release switch. If it is determined that the first release switch is turned on, the process proceeds to step S210.

  In step S210, AF processing is performed. Specifically, first, the AF processing unit 109 calculates a focus evaluation value. The microcomputer 115 issues a command for driving the lens 1010 to the driver 1013 based on the focus evaluation value. Based on this command, the driver 1013 drives the lens 1010 to change the focal length and the focus position.

  If the first release switch is not turned on in step S209, or if the first release switch remains on, the process proceeds to step S211. In step S211, it is determined whether or not the user has fully pressed the release button to turn on the second release switch. If it is determined that the second release switch is turned on, the process proceeds to step S212. If it is determined that the second release switch is not turned on, the process proceeds to step S214.

  In step S212, the light 1020 of the auxiliary light source 3 is turned off. That is, the microcomputer 115 sends an instruction to turn off the light 1020 to the light emission controller 1021 via the I / F 998. Based on this turn-off instruction, the light emission controller 1021 turns off the light 1020. Note that when the light 1020 is off, the off state is maintained.

  In step S213, still image shooting and image processing are performed. Since still image shooting and image processing for image data obtained by shooting are known processing, detailed description thereof is omitted here.

  In step S215, it is determined whether the power of the digital still camera is turned off. If it is determined that the power is not turned off, the process returns to step S202, and the above-described processing is performed. On the other hand, when the power button is pressed by the user and the power is turned off, the process of the flowchart is ended.

  As described above, in the main flow in the present embodiment, the still image shooting mode is set in the initial setting. In this state, steps S202 → S204 → S208 → S209 → S211 → S214 → S215 → S202 are sequentially executed. Perform live view display. If the release button is pressed halfway during live view display, an AF operation is performed in step S210. If the release button is fully pressed, a still image is shot in step S213. When the moving image button is pressed, the recording flag is turned on in step S205, and moving image shooting is continued by repeatedly executing steps S208, S214, S215, S202, S204, and S208. When the moving image button is pressed again in this state, the recording flag is turned off in step S205, and the flow returns to the still image flow described above.

  FIG. 3 is a flowchart showing details of the process in step S214 of the flowchart shown in FIG. 2, that is, live view display / moving image capturing / image processing.

  In step S310, AE processing is performed. Specifically, the AE processing unit 108 calculates subject brightness, and refers to the exposure condition determination table stored in the flash memory 117 based on the calculated subject brightness, so that the ISO sensitivity at the time of shooting, the aperture The amount of auxiliary light emitted and the shutter speed are determined.

  In step S320, shooting is performed. The shooting (moving image shooting) is the same as a conventionally used method. That is, shooting is performed by controlling a so-called electronic shutter based on the determined aperture, shutter speed, and ISO sensitivity.

  In step S330, various image processes are performed on the image data (Bayer data) obtained in step S320 to perform development processing for conversion into luminance (Y) and color difference (Cb, Cr) signal data.

  In step S340, the LCD driver 113 displays image data on the LCD 114.

  In step S350, it is determined whether a moving image is being recorded. If the recording flag is off, it is determined that the moving image is not being recorded, and the process proceeds to step S390. In step S390, the light 1020 of the auxiliary light source 3 is turned off. That is, the microcomputer 115 sends an instruction to turn off the light 1020 to the light emission controller 1021 via the I / F 998. Based on this turn-off instruction, the light emission controller 1021 turns off the light 1020. Note that when the light 1020 is off, the off state is maintained.

  On the other hand, if it is determined in step S350 that the recording flag is on and the moving image is being recorded, the process proceeds to step S360. In step S360, a moving image file is generated and recorded on the recording medium 112. That is, the image compression / decompression unit 110 compresses the image data according to the format of the moving image file, adds predetermined header information, and generates a moving image file. The compression format of the moving image file includes “H.264”, “Motion JPEG”, “MPEG”, and the like. Then, the generated moving image file is recorded on the recording medium 112 via the memory I / F 111.

  In step S370, it is determined whether the auxiliary light source 3 is attached to the camera body 1. When the auxiliary light source 3 is attached to the camera body 1, the microcomputer 115 can communicate with the light emission controller 1021 via the I / F 998. Therefore, the microcomputer 115 transmits a signal to the light emission controller 1021. If there is a response from the light emission controller 1021, the microcomputer 115 determines that the auxiliary light source 3 is attached to the camera body 1, and proceeds to step S380. On the other hand, if there is no response from the light emission controller 1021, it determines with the auxiliary light source 3 not being attached to the camera main body 1, and complete | finishes the process of this flowchart.

  In step S380, the light emission amount of the light 1020 of the auxiliary light source 3 is controlled. Details of the light emission amount control of the light 1020 will be described later with reference to FIG.

  FIG. 4 is a flowchart showing details of the process in step S203 of the flowchart shown in FIG. 2, that is, the reproduction process.

  In step S400, an image file to be displayed on the LCD 114 is determined based on the operation of the operation unit 116 by the user. When the user presses the play button, the moving image file and still image file recorded on the recording medium 112 are displayed as a list (thumbnail display) on the LCD 114. For video files, the first frame image is displayed as a thumbnail. The user selects a file to be displayed on the LCD 114 by operating a cross key included in the operation unit 116. The selected file is determined as an image file to be displayed on the LCD 114.

  In step S410, it is determined whether or not the image file determined in step S400 is a moving image file. If it is determined that the file is not a moving image file but a still image file, the process proceeds to step S480.

  In step S480, the image compression / decompression unit 110 acquires the image data to be displayed on the LCD 114 by selecting and expanding the still image file determined in step S400 from the files recorded on the recording medium 112. .

  In step S490, the LCD driver 113 causes the LCD 114 to display the image data acquired in step S480.

  On the other hand, if it is determined in step S410 that the image file determined in step S400 is a moving image file, the process proceeds to step S420. In step S420, information on the number of frames included in the header information of the moving image file is acquired.

  In step S430, a parameter N for counting the number of frames is set to an initial value of 1.

  In step S440, the image compression / decompression unit 110 selects the moving image file determined in step S400 from the files recorded in the recording medium 112, and performs a process of expanding the Nth frame image data.

  In step S450, the LCD driver 113 causes the LCD 114 to display the Nth frame image data acquired in step S440.

  In step S460, 1 is added to parameter N, and the process proceeds to step S470.

  In step S470, it is determined whether or not the parameter N is larger than the number of frames of the moving image file. If it is determined that the parameter N is equal to or less than the number of frames of the moving image file, the process returns to step S440, the image data of the next frame is expanded (step S440), and displayed on the LCD 114 (step S450). On the other hand, when it is determined that the parameter N is larger than the number of frames of the moving image file, the reproduction process is terminated.

  FIG. 5 is a flowchart showing details of the process in step S380 of the flowchart shown in FIG. 3, that is, the light emission amount control process.

  In step S500, a histogram corresponding to the feature amount of the image is created for the most recent image data obtained by moving image shooting. Specifically, the histogram calculation unit 119 reads the latest image data obtained by moving image shooting from the SDRAM 106, and calculates a luminance histogram as a histogram of the feature amount of the read image data.

  In step S510, the subject detection unit 118 reads the latest image data obtained by moving image shooting from the SDRAM 106, and analyzes the read image data to detect a subject of interest such as a person or an animal.

  In step S520, it is determined whether or not the subject of interest has been detected by the subject detection unit 118 as a result of the processing of step S510. If it is determined that the subject of interest has been detected, the process proceeds to step S530.

  In step S530, the average brightness of the area in which the subject of interest is detected is obtained out of the entire area of the image, and the light is selected so that the brightness of the subject of interest becomes an appropriate brightness based on the obtained brightness. The amount of emitted light 1020 is controlled. That is, the microcomputer 115 calculates a light emission amount for setting the brightness of the subject of interest to an appropriate brightness, and transmits information on the calculated light emission amount to the light emission controller 1021 via the I / F 998. The light emission controller 1021 adjusts the light emission amount of the light 1020 based on the received light emission amount.

  In step S540, the dimming flag is turned off. In step S610, which will be described later, a light reduction process for gradually reducing the light emission amount of the light 1020 is performed. The dimming flag is a flag for determining whether or not to perform the dimming process of the light 1020.

  On the other hand, if it is determined in step S520 that the subject of interest has not been detected, the process proceeds to step S550. In step S550, it is determined whether the light emission amount of the light 1020 is the maximum, or whether the dimming flag is on. If it is determined that the light emission amount of the light 1020 is not the maximum and the dimming flag is off, the process proceeds to step S560.

  In step S560, in order to detect the subject of interest on the image, the light emission amount of the light 1020 is slightly increased, and the process proceeds to step S540. Specifically, the microcomputer 115 obtains a light emission amount obtained by increasing the current light emission amount by a predetermined amount, and transmits information on the obtained light emission amount to the light emission controller 1021 via the I / F 998. The light emission controller 1021 changes the light emission amount of the light 1020 based on the received light emission amount. In the process of step S560, that is, the process of slightly increasing the light emission amount of the light 1020, the target subject is detected in the image while the light emission amount of the light 1020 is less than the maximum value and the dimming flag is off. Until then.

  In step S550, instead of determining whether or not the light emission amount of the light 1020 is the maximum, it may be determined whether or not the light emission amount of the light 1020 is a predetermined amount less than the maximum value. In this case, the process of slightly increasing the light emission amount of the light 1020 is continued until the target subject is detected in the image while the light emission amount of the light 1020 is less than the predetermined amount and the dimming flag is off. Done.

  On the other hand, if it is determined in step S550 that the light emission amount of the light 1020 is the maximum, or if it is determined that the dimming flag is on, the process proceeds to step S570. In step S570, the histogram change detection unit 120 detects the change amount of the histogram calculated in step S500, and determines whether or not the detected change amount is equal to or greater than a predetermined amount. This determination is performed in order to detect a change in the subject in the image. Accordingly, the predetermined amount as the threshold is set so that a change in the image due to the slight increase or decrease in the light 1020 is not detected as a change in the subject in the image. If it is determined that the amount of change in the histogram is greater than or equal to the predetermined amount, the process proceeds to step S580, and if it is determined that it is less than the predetermined amount, the process proceeds to step S590.

  In step S580, the time counter for measuring the time when the amount of change in the histogram is determined to be less than the predetermined amount is reset, and the process proceeds to step S540.

  In step S590, a time counter for measuring the time when the amount of change in the histogram is determined to be less than the predetermined amount is counted up.

  In step S600, it is determined whether a predetermined time (for example, several seconds) has elapsed based on the count value of the time counter. If it is determined that the predetermined time has not elapsed, the process proceeds to step S540. If it is determined that the predetermined time has elapsed, the process proceeds to step S610.

  In step S610, it is determined that there is no subject that needs to be irradiated with auxiliary light in the moving image being shot, and it is determined that light emission of the light 1020 is unnecessary, and the light emission amount of the light 1020 is slightly reduced. Specifically, the microcomputer 115 obtains a light emission amount obtained by reducing the current light emission amount by a predetermined amount, and transmits information on the obtained light emission amount to the light emission controller 1021 via the I / F 998. The light emission controller 1021 changes the light emission amount of the light 1020 based on the received light emission amount. In the process of step S610, that is, the process of slightly reducing the light emission amount of the light 1020, the subject of interest is detected in the image or the amount of change in the histogram is determined until the light emission amount of the light 1020 becomes zero. It is continuously performed until it is determined that the amount is not less than the fixed amount.

  In step S620, the dimming flag is turned on and the light emission amount control is terminated.

  As described above, according to the imaging apparatus in one embodiment, the subject of interest in the moving image is detected, and the light emission amount of the light 1020 is controlled based on the detection result of the subject of interest. It is possible to shoot moving images with appropriate brightness while suppressing consumption.

  In addition, when the target subject is detected, the light emission amount of the light 1020 is controlled so that the detected exposure of the target subject is appropriate, so that the target subject can be imaged with appropriate brightness. .

  Further, when the target subject is not detected, the light emission amount of the light 1020 is increased. When the target subject is not detected even when the light emission amount of the light 1020 reaches a predetermined amount, the light emission amount of the light 1020 is increased. Will decrease. Thus, until the light emission amount of the light 1020 reaches a predetermined amount, the light emission amount of the light 1020 is increased so that the subject of interest can be detected in the image, and the light emission amount of the light 1020 reaches the predetermined amount. Then, it can be determined that there is no subject of interest in the image and the light 1020 does not need to be emitted, and the amount of emitted light can be reduced to reduce the amount of battery consumption.

  In addition, according to the imaging device in one embodiment, since the change in the feature amount of the image obtained by imaging is detected and the light emission amount of the light 1020 is controlled based on the detection result of the feature amount change, The amount of light emitted from the light 1020 at the time of moving image capturing can be appropriately controlled according to the change in the subject. Furthermore, by calculating the feature amount of the image as a histogram, it is possible to reliably detect a change in the subject in the image.

  In addition, according to the imaging apparatus of the embodiment, when the target subject is not detected, the light emission amount of the light 1020 is increased, and the target subject is detected even if the light emission amount of the light 1020 reaches a predetermined amount. If the change in the histogram of the feature amount of the image is less than the predetermined change, the light emission amount of the light 1020 is decreased. Thereby, after the light emission amount of the light 1020 reaches a predetermined amount, it is more accurately determined whether or not the light 1020 needs to emit light. Consumption can be reduced.

  In the description of the embodiment described above, hardware processing is assumed as processing performed by the imaging apparatus, but it is not necessary to be limited to such a configuration. For example, a configuration in which processing is performed separately by software is also possible. In this case, the imaging apparatus includes a main storage device such as a CPU and a RAM, and a computer-readable storage medium in which a program for realizing all or part of the above processing is stored. Here, this program is called an imaging program. Then, the CPU reads out the imaging program stored in the storage medium and executes information processing / calculation processing, thereby realizing the same processing as that of the imaging device described above.

  Here, the computer-readable recording medium refers to a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, and the like. Further, the imaging program may be distributed to a computer via a communication line, and the computer that has received the distribution may execute the imaging program.

  The present invention is not limited to the above-described embodiment, and various modifications and applications can be made without departing from the gist of the present invention. For example, the light 1020 used at the time of moving image capturing is not limited to a video light, and any light source such as an LED that can irradiate auxiliary light.

  In step S610 of the flowchart shown in FIG. 5, the light emission amount of the light 1020 is slightly reduced, but the light emission of the light 1020 may be stopped.

DESCRIPTION OF SYMBOLS 1 ... Camera body 2 ... Interchangeable lens 3 ... Auxiliary light source 101 ... Mechanical shutter 102 ... Imaging element 103 ... Analog processing part 104 ... Analog / digital conversion part 114 ... LCD
115 ... Microcomputer 118 ... Subject detection unit 119 ... Histogram calculation unit 120 ... Histogram change detection unit 1020 ... Light 1021 ... Light emission controller

Claims (6)

An imaging device capable of capturing moving images,
A subject-of-interest detector that detects a subject of interest in a moving image;
A light emitting section for emitting auxiliary light;
A light emission amount control unit that controls a light emission amount of the light emitting unit based on a detection result of the target subject by the target subject detection unit when capturing a moving image;
With
The light emission amount control unit increases the light emission amount of the light emitting unit when the target subject is not detected by the target subject detection unit, and even if the light emission amount of the light emitting unit reaches a predetermined amount, the light emission amount control unit If the target subject is not detected by the target subject detection unit, the light emission amount of the light emitting unit is decreased or stopped,
An imaging apparatus characterized by that. A feature amount change detection unit that detects a change in the feature amount of the image obtained by imaging;
The light emission amount control unit based on the detection result of the change in the feature amount by the feature amount change detecting unit, the imaging apparatus according to claim 1, characterized in that to control the light emission amount of the light-emitting portion. A histogram calculation unit that calculates the feature amount of the image as a histogram;
The imaging apparatus according to claim 2 , wherein the feature amount change detection unit calculates a change in the histogram calculated by the histogram calculation unit as a change in the feature amount of the image. The imaging apparatus according to claim 3 , wherein the histogram calculation unit calculates a histogram of luminance of the image as a histogram of the feature amount of the image. An imaging device capable of capturing moving images,
A subject-of-interest detector that detects a subject of interest in a moving image;
A light emitting section for emitting auxiliary light;
A light emission amount control unit that controls a light emission amount of the light emitting unit based on a detection result of the target subject by the target subject detection unit when capturing a moving image;
A feature amount change detection unit that detects a change in the feature amount of an image obtained by imaging;
With
The light emission amount control unit increases the light emission amount of the light emitting unit when the target subject is not detected by the target subject detection unit, and even if the light emission amount of the light emitting unit reaches a predetermined amount, the light emission amount control unit When the target subject is not detected by the target subject detection unit and the change amount of the histogram of the feature amount of the image is less than a predetermined change amount, the light emission amount of the light emitting unit is decreased or stopped. An imaging apparatus characterized by that. The light emission amount control unit, at the time of imaging of the still image, the imaging apparatus according to any one of claims 1 to 5, characterized in that to stop the emission of the auxiliary light by the light emitting portion.