JP2018180111A - Imaging device, method for controlling the same, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device for imaging a subject to be tracked, in which the performance of tracking the subject is maintained and power consumption is suppressed by a tracking control sequence that corresponds to the remaining life of a battery.SOLUTION: An imaging device 1 detects a subject around by a search while changing the direction of imaging, and images the subject to be tracked. A system control unit 10 controls the drive of a pan-tilt mechanism unit that changes the direction of imaging by a motor-operated universal head control unit 20, and also controls an angular field of view by zoom control. A tracked subject detection unit 22 detects the subject to be tracked. The zoom lens position and the control position of the pan-tilt mechanism unit are changed so that the image of a detected subject is at a prescribed position and in prescribed size within the imaged angular field of view. A remaining battery life detection unit 21 detects the remaining battery life of the imaging device 1. A system control unit 10 changes a zoom control range in accordance with the present remaining life of battery and thereby changes a subject tracking control sequence.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for detecting and searching for a surrounding subject while changing the shooting direction by pan and tilt operations, and for shooting while tracking the detected subject.

  As an imaging device having a function of tracking an object in a shooting screen, there is, for example, a device which attaches a camera to a camera platform and controls the panning operation and tilting operation of the camera platform by motor drive. Further, by using the camera having the zooming function, the user can track the subject while adjusting the zooming so that the size of the subject image in the shooting screen becomes a desired size. On the other hand, since the size of a battery is also reduced with the recent miniaturization of an imaging device, for example, when a large amount of power is consumed to drive an imaging optical system, the power supply voltage drops. In order to reduce the possibility of the system down of the imaging device, reduction of power consumption is an important issue.

  Patent Document 1 discloses a technique for reducing the power consumption of an imaging device having a tracking function. When the camera platform is driven by a battery, the control circuit on the camera platform side is set to give priority to the panning operation. In this setting, even when the panning operation and the tilting operation are simultaneously instructed, the panning motor drive circuit operates only in response to the panning operation signal, and the tilting motor drive circuit is stopped. Furthermore, when only the tilting operation is commanded, the panning motor drive circuit is stopped and only the tilting motor drive circuit is operated. As a result, since the panning operation period and the tilting operation period do not overlap, the power consumption does not overlap and the power consumption is reduced to about half. The maximum current value of the battery is approximately halved, allowing the use of a small capacity battery. In the device disclosed in Patent Document 2, switching between two different power consumption modes is possible in order to reduce the tracking performance as much as possible while suppressing the power consumption. When transitioning to the power saving mode, processing for fixing the pan / tilt operation at a predetermined position and processing for setting a long cycle for detecting an object are performed.

JP-A-7-63299 Unexamined-Japanese-Patent No. 2007-49362

In the technique disclosed in Patent Document 1, the tracking performance of the subject and the operation of the camera platform are not particularly associated with each other, so it is considered that suppressing power consumption while maintaining the tracking performance of the subject. Not. Further, in the technology disclosed in Patent Document 2, when shifting to the power saving mode, the position of the pan / tilt operation is fixed at a predetermined position. Therefore, it can not be said that the tracking performance of the subject can be sufficiently secured in the power saving mode. In addition, even if setting is made to extend the cycle of subject detection, there is no effect of suppressing power consumption during tracking control of the subject. Patent Document 1 and Patent Document 2 do not particularly mention the difference in the remaining battery level for each imaging device when tracking the same subject using a plurality of imaging devices capable of tracking control.
An object of the present invention is to suppress power consumption of an imaging device while maintaining tracking performance of an object.

  An imaging apparatus according to an embodiment of the present invention controls a zoom unit that changes a focal length of an imaging optical system, an object detection unit that detects an object to be tracked, and a drive unit that changes the zoom unit and a photographing direction. Accordingly, the control unit performs control for tracking the subject detected by the subject detection unit, and battery remaining amount detection unit for detecting the remaining amount of the battery which is the power supply of the drive unit. The control means acquires information on the remaining battery level detected by the remaining battery level detection means, and controls the zoom means in a first control range when the remaining battery level is greater than a threshold, and the battery When the remaining amount is equal to or less than the threshold value, control of the zoom means is performed in a second control range which is changed to the wide angle side with respect to the first control range.

  According to the imaging device of the present invention, power consumption of the imaging device can be suppressed while maintaining the tracking performance of the subject.

FIG. 1 is a block diagram showing a system configuration of a digital camera according to an embodiment of the present invention. It is a figure which shows the detailed structure of the system control part in this embodiment, and a motor-driven pan-head mechanism part. FIG. 6 is a diagram showing pan and tilt driving of the digital camera according to the embodiment of the present invention. 5 is a flowchart of a tracking control sequence of the digital camera according to the first embodiment. It is a figure which shows typically the relationship between the digital camera which concerns on 2nd Embodiment, and another imaging device. It is a flowchart of the tracking control sequence of the digital camera which concerns on 2nd Embodiment. It is a flowchart which shows the process following FIG.

  Embodiments of the present invention will be described with reference to the drawings. In the following embodiments, a digital camera will be described as an example of an imaging device according to the present invention, but the present invention is not limited to this, and can be applied to various imaging devices such as mobile phones with a camera.

First Embodiment
FIG. 1 is a block diagram showing an example of a system configuration of a digital camera as an imaging apparatus according to the present embodiment. The imaging apparatus 1 includes an electric pan head mechanism unit 20, and can control the imaging direction. The imaging optical system 2 includes a zoom lens 2a, a focus lens 2b, an aperture shutter unit 2c, and the like. An imaging element 4 is disposed on the optical axis 3 of the imaging optical system 2, and photoelectrically converts an optical image formed by the imaging optical system 2 to output an electrical signal. The A / D converter 5 converts an analog signal output from the imaging device 4 into a digital signal. The image processing unit 6 performs predetermined pixel interpolation processing, color conversion processing, gamma processing, and the like on the output signal of the A / D converter 5. Further, the image processing unit 6 performs predetermined arithmetic processing using captured image data, and the system control unit 10 controls the exposure control unit 7 and the focus control unit 8 based on the obtained result. That is, the system control unit 10 performs AE (automatic exposure) processing, AF (auto focus) processing of a contrast method, and the like. Furthermore, the image processing unit 6 performs predetermined arithmetic processing using captured image data, and performs AWB (auto white balance) processing based on the obtained arithmetic result.

  The output signal of the A / D converter 5 is written to the internal memory 11 via the image processing unit 6 or directly. The image signal written in the internal memory 11 is read out by the D / A converter 12, converted into an analog signal, and output to the image display unit 13. The image display unit 13 includes a liquid crystal display device or the like, and displays an image on the screen according to the output signal of the D / A converter 12. The image display unit 13 realizes an electronic view finder function by sequentially displaying captured image data. Further, the image display unit 13 displays various menu items related to various settings of the imaging device 1, photographing conditions such as zoom magnification, exposure setting, and the like. The user can operate the operation unit 14 while viewing the display screen to change the setting of the designated item.

  The compression / decompression unit 16 reads the image data stored in the internal memory 11, compresses or expands the image data by adaptive discrete cosine transform (ADCT) or the like, and writes the processed image data in the internal memory 11 again. The internal memory 11 has a sufficient storage capacity to store data of a predetermined number of still images and moving images of a predetermined time. The internal memory 11 can also be used as a work area of the system control unit 10.

  The exposure control unit 7 controls the aperture shutter unit 2c. The focus control unit 8 controls the focus lens 2b. The zoom control unit 9 controls the zooming operation by moving the zoom lens 2 a to change the focal length of the imaging optical system 2. The zoom control unit 9 can obtain information of the focal length corresponding to the position of the zoom lens 2a. Each of the control units 7 to 9 performs operation control in charge of each according to a control command of the system control unit 10. The system control unit 10 is a control center unit of the imaging device 1 and includes a CPU (central processing unit). The memory 17 stores constants, variables, programs and the like for the operation of the system control unit 10.

  The operation unit 14 is a switch, a dial, a touch panel, a voice recognition device, or the like used when the user instructs the system control unit 10 to perform various operations. In the present embodiment, the operation unit 14 includes a switch for switching the mode, a zoom operation lever, a menu button, a set button, and the like. A still image shooting and a moving image shooting can be selected by the shooting mode switching switch. Further, it is possible to select whether or not to perform tracking imaging by switching the tracking imaging mode.

  The release switch 15 is an operation member for inputting a photographing instruction from the user. The release switch 15 has a two-stage switch configuration, and the user performs a half-press operation on the first stage when performing still image shooting manually. At this time, the first switch (denoted as SW1) is turned on, and a shooting preparation instruction is issued. The system control unit 10 controls imaging preparation operations such as AF processing and AE processing. Next, when the user performs a full-press operation on the second stage, the second switch (denoted as SW2) is turned on, and a photographing instruction is issued. The system control unit 10 drives the diaphragm shutter unit 2 c via the exposure control unit 7, and performs control of acquiring image data by the imaging device 4.

  When the system control unit 10 receives an imaging instruction, the system control unit 10 places the imaging device 4 in an accumulation state, and performs an exposure operation of the imaging device 4 by opening and closing a shutter mechanism included in the aperture shutter unit 2c. The shutter mechanism unit returns to the closed state, and after the charge accumulation of the imaging device 4 is completed, the system control unit 10 reads the accumulated charge as a signal. The system control unit 10 performs a series of development processing and image processing on the signal read from the imaging device 4 using the A / D converter 5, the image processing unit 6, the compression / decompression unit 16 and the internal memory 11. Generate image data. The generated image data is recorded on the recording medium 18 as data of an image file. The recording medium 18 is a hard disk, a flash memory or the like, and has a capacity sufficient for recording a plurality of pieces of image data. The communication unit 19 is a communication module with which the imaging device 1 communicates with another imaging device, and more specifically, is configured by a wireless local area network (LAN) unit.

  The motor-driven pan-head mechanism 20 is a mechanism for changing the shooting direction of the imaging apparatus 1 into a panning direction (horizontal and horizontal directions) and a tilting direction (vertical and vertical directions). The imaging direction of the imaging device 1 on the camera platform can be changed by drive control of the motor. The battery remaining amount detection unit 21 detects the remaining amount of a battery (not shown) that operates the imaging device 1. The power supplied by the battery is consumed by the drive of the motorized pan head mechanism unit 20 and the entire imaging process.

  The tracking subject detection unit 22 acquires image data from the internal memory 11 and detects a subject to be tracked. In the following, processing for detecting a subject person as a tracking target based on face information (shapes and positional relationships of organs such as eyes, nose, and mouth) of a specific individual registered in advance, an example of so-called face detection processing will be described. explain. The face detection process is a process of detecting a face area present in a captured image by a predetermined algorithm. For example, the tracking subject detection unit 22 extracts face information from a rectangular partial area in a captured image, and compares the face information with face information of a tracking target person registered in advance. If the correlation amount between the two is larger than the threshold, the partial region is determined to be the face region of the person to be tracked. The determination process is repeatedly performed while variously changing the combination of the size of the partial area, the arrangement position, and the arrangement angle, and the face area of the person to be tracked is detected. The tracking subject detection unit 22 can detect the size and position of the tracking target subject area based on the face area. Furthermore, subject information such as presence / absence of movement of the subject and movement speed can be acquired by calculating a motion vector related to the detected subject region.

  Further, the tracking subject detection unit 22 detects a subject distance for the detected subject region. The subject distance is distance information or information (evaluation value, defocus amount, etc.) corresponding to the distance information between the imaging device 1 and the subject. In the present embodiment, as an example, a method of detecting the subject distance according to the evaluation value obtained from the contrast distribution of the image will be described. In the subject distance detection process, a process of acquiring image data as needed while changing the position of the focus lens 2b over the entire drivable range at an arbitrary timing is performed, and the contrast evaluation value in the subject region in the image Is calculated. The tracking subject detection unit 22 determines the subject distance of the detected subject based on the transition of the contrast evaluation value of the subject area. In the application of the present invention, the method of detecting the subject information and the method of detecting the subject distance are not limited. For example, the communication unit 19 communicates with a communication device possessed by an object to be tracked (hereinafter, also referred to as a tracking object), and detects object information and an object distance. Alternatively, the subject distance can be detected based on the phase difference or the defocus amount of a plurality of image signals acquired by a distance measurement sensor (focus detection unit) using a phase difference method or a pupil division type imaging device.

  FIG. 2 is a block diagram showing the detailed configuration of the system control unit 10 and the electric camera platform mechanism unit 20 in the present embodiment. The electric camera platform mechanism unit 20 includes a tracking control unit 30 that performs tracking control of an object, and a pan and tilt mechanism unit that is drive-controlled by the tracking control unit 30. The panning control unit 33 and the panning motor 35 drive the panning operation, and the tilting control unit 34 and the tilting motor 36 drive the tilting operation.

  The tracking control unit 30 controls the entire tracking control of the electric camera platform mechanism unit 20. The tracking control unit 30 controls panning control and tilting control in accordance with a control command from the system control unit 10, and performs power supply control to the panning motor 35 and the tilting motor 36. The tracking control unit 30 performs tracking control of the tracking object when the user selects to perform tracking imaging with the operation unit 14 and the tracking object is detected by the tracking object detection unit 22. . For example, the panning control unit 33 and the tilting control unit 34 perform control of positioning the detected tracking target subject image at the center of the screen in accordance with the movement of the tracking subject. The panning control unit 33 controls the rotation of the panning motor 35 in order to give movement of the imaging device 1 in the panning direction. The tilting control unit 34 controls the rotation of the tilting motor 36 in order to give movement of the imaging device 1 in the tilting direction.

  Next, with reference to FIG. 3, the drive of the imaging device 1 by the electric camera platform mechanism 20 will be described in detail. FIG. 3A is a schematic view showing the appearance of the imaging device 1. FIG. 3 (B) is a plan view for explaining the panning drive, and FIG. 3 (C) is a side view for explaining the tilting drive.

  In the panning operation, as shown in FIG. 3B, the imaging apparatus 1 is rotated clockwise and counterclockwise about the rotation axis 300 by the electric camera platform mechanism 20. Thereby, the imaging | photography range of the imaging device 1 changes along a left-right (horizontal) direction. Further, in the tilting operation, as shown in FIG. 3C, the imaging apparatus 1 is tilted in the elevation angle direction and the depression angle direction about the rotation axis 301 by the electric camera platform mechanism 20. Thereby, the imaging | photography range of the imaging device 1 changes along an up-down (vertical) direction. In the subject tracking operation of the imaging device 1, it is possible to make the photographing direction follow the movement of the tracking target by the combination of the panning drive and the tilting drive.

  A subject tracking sequence of the imaging device 1 in the present embodiment will be described with reference to the flowchart of FIG. 4. A program for performing the following processing is stored in the memory 17, and read and executed by the system control unit 10.

  When the power is turned on, the imaging apparatus 1 performs various initialization processes and the like, and then waits for an operation instruction by the operation of the operation unit 14. In step S <b> 401, the system control unit 10 determines whether the user operates the operation unit 14 and a subject tracking execution instruction has been issued. If it is determined that a subject tracking execution instruction has been issued, the process advances to step S402. If there is no subject tracking execution instruction, the determination process of step S401 is continued.

  In S402, a subject search process is performed. The system control unit 10 instructs the motor-driven panhead mechanism unit 20 to move in the panning direction and the tilting direction, and performs control to change the imaging direction of the imaging device 1. At the same time, the tracking object detection unit 22 acquires captured image data and executes object detection processing of a tracking target. The system control unit 10 continues the instruction of the drive control of the motor-driven panhead mechanism unit 20 until the predetermined threshold time elapses. When a tracking subject is detected or a predetermined threshold time has elapsed, the system control unit 10 stops the drive control of the electric camera platform mechanism unit 20.

  In step S403, the system control unit 10 determines whether the tracking subject has been detected by the subject searching process in step S402. If it is determined that the tracking subject has been detected, the process proceeds to S404. On the other hand, if the tracking subject can not be detected, the process returns to S402 and continues.

  At S404, tracking subject detection unit 22 calculates the size of the detected tracking subject image on the shooting screen, and system control unit 10 determines that the tracking subject image has a predetermined size based on the size of the tracking subject image. The zoom lens position (initial position) is determined. In the present embodiment, as the predetermined size related to the tracking subject image, the size in which the face area of the tracking subject is contained in the shooting screen and the face area is maximized is set. However, the application of the present invention is not limited to this, and it may be set to any size.

  In step S405, the system control unit 10 performs control of moving the zoom lens 2a to the zoom lens position determined in step S404 via the zoom control unit 9. In the next S406, subject tracking control starts for the detected tracking subject. The tracking control here includes panning control and tilting control, and zoom control for driving the zoom lens 2a by determining the zoom lens position so that the image area of the tracking target has a predetermined size. That is, the panning control unit 33 and the tilting control unit 34 perform drive control in accordance with the movement of the tracking subject. At the same time, a process of calculating the size of the tracking subject image in the shooting screen is performed, the zoom lens position at which the tracking subject image becomes a predetermined size is determined, and zoom control is performed. The subject tracking control is continuously performed until the time of pause or stop.

  In step S407, the system control unit 10 stores the panning control position, the tilting control position, and the zoom lens position at that point in time as position information of the tracking subject. With respect to these pieces of position information, information for a predetermined time is acquired and stored in the memory 17.

  In S408, the system control unit 10 acquires the current battery remaining amount from the battery remaining amount detecting unit 21 and compares it with "Threshold 1" which is a first predetermined threshold. A determination process is performed to determine whether the current battery remaining amount is equal to or less than threshold 1. If the current battery remaining amount is equal to or less than threshold 1, the process proceeds to step S409. On the other hand, when the current battery remaining amount is larger than the threshold 1, the process proceeds to S413.

  In step S409, the system control unit 10 temporarily stops tracking control on the detected tracking subject. In S410, the system control unit 10 determines the zoom control range when the battery remaining amount is equal to or less than the threshold 1. The zoom control range is determined based on information indicating the transition of the position of the tracking object, that is, the temporal change amount of the position of the tracking object. When the amount of change in the position of the tracking object is large, control is performed to change the zoom lens position to a wider angle side. When the amount of change in the position of the tracking object is small, the amount of displacement when changing the zoom lens position to the wide angle side can be reduced. Specifically, first, based on the position information of the tracking subject for a predetermined period of time stored in the memory 17 in S407, a process of determining the telephoto limit of the zoom control is performed. For example, by calculating the average position of the panning control position of the tracking subject for a predetermined time and the average position of the tilting control position of the tracking object for a predetermined time, center coordinates of each position are calculated. Then, the first position at which the absolute value difference based on the center coordinates of the panning control position of the tracking subject for a predetermined time is maximum and the center coordinates of the tilting control position of the tracking subject for a predetermined time A second position at which the absolute value difference is maximized is calculated. The system control unit 10 calculates the moving range of the subject from the first and second positions, calculates the zoom lens position which can put the moving range in the same screen, and sets this position as the limit position on the telephoto side. Decide as.

  Next, the system control unit 10 calculates the zoom lens position on the wide-angle side from the limit value of the size of the object area in the image that the tracking object detection unit 22 can detect as a tracking object. Decide as. In step S411, the system control unit 10 causes the zoom control unit 9 to move the zoom lens 2a to the telephoto limit position determined in step S410. In S412, the tracking control for the tracking subject, which has been temporarily stopped in S409, is resumed. Note that zoom control in the following tracking control is performed within the zoom control range determined in S410.

  In step S413, the system control unit 10 determines whether subject tracking control can be continued. If it is determined that the subject tracking control can not be continued, the process advances to step S414. If it is determined that the subject tracking control can be continued, the process returns to step S407 to continue the process. In step S414, the system control unit 10 stops tracking control on the detected tracking subject. Thereafter, the process returns to S402 and continues.

  In the present embodiment, when the battery remaining amount becomes equal to or less than the threshold during the subject tracking control, the zoom control range changed to the wide angle side than the zoom control range when the battery remaining amount is larger than the threshold is set and zoom control is performed. Is done. In other words, if the remaining battery level falls below the threshold during subject tracking control, the zoom lens position at which the tracking subject falls within the angle of view is calculated based on the panning and tilting control amount for a predetermined time, and the telephoto side A process is performed to determine the limit position of. By limiting the zoom control range and setting it to the wider angle side, the number of times of panning control and tilting control and the drive amount can be reduced while capturing the image of the tracking object in the screen, so power consumption can be saved. is there.

  Furthermore, in the present embodiment, when the battery remaining amount falls below the threshold during subject tracking control, the tracking subject detection unit 22 calculates the limit zoom lens position at which the tracking subject can be detected, and sets it as the limit position on the wide angle side. , To limit the control range of the zoom. This limitation can reduce the number of times of panning control and tilting control and the amount of driving while reducing the possibility that the tracking subject can not be detected, and therefore power consumption can be reduced.

  According to the present embodiment, it is possible to achieve both the reduction of the power consumption of the imaging device and the followability of the subject tracking control. In an imaging apparatus that detects surrounding objects while changing the imaging direction by panning and tilting operations and follows the detected tracking object, imaging is suitable for tracking control according to the remaining battery capacity of the imaging apparatus A sequence can be provided.

Second Embodiment
Next, a second embodiment of the present invention will be described. By using the code | symbol already used about the component similar to 1st Embodiment in this embodiment, those detailed description is abbreviate | omitted and a difference is mainly demonstrated.

  FIG. 5 is a diagram schematically showing the relationship between the imaging device 1 of the present embodiment and a plurality of imaging devices 500 to 504 existing around it. The imaging device 1 includes a communication unit 19 and has a wireless LAN function. The imaging devices 500 to 504 are peripheral imaging devices provided with a wireless LAN function as in the imaging device 1. In the following description, the number of imaging devices in the vicinity is five, but the number of imaging devices does not matter.

  The imaging device 1 and the imaging devices 500 to 504 around it belong to the same wireless LAN network 505 and can perform data communication with each other. For example, the imaging devices 1,500 to 504 acquire the remaining battery amount information by the respective remaining battery amount detectors, and broadcast the respective remaining battery amount information on the wireless LAN network 505. The imaging device 1 can grasp the remaining battery charge information of the surrounding imaging devices 500 to 504 in real time or at regular time intervals by receiving the broadcasted battery residual charge information.

In the present embodiment, the imaging devices 1 and 500 to 504 can share the following information on the wireless LAN network 505.
Installation position information of each imaging device Information of shooting direction (hereinafter referred to as reference shooting direction) when panning control and tilting control are not performed in each imaging device.

  The method of sharing the installation position information and the information of the reference imaging direction on the wireless LAN network 505 does not matter. For example, data of the installation position of each imaging device and the reference imaging direction may be stored in advance in a memory in the device. Alternatively, calibration may be performed with respect to the installation position and the reference imaging direction based on the detection result when a specific reference object is detected at the time of activation of each imaging device. Further, the communication unit 19 can acquire the battery remaining amount information and the subject position information from another imaging device at a predetermined cycle set in advance. The predetermined cycle is determined by a cycle (for example, an imaging cycle or the like) in which the position information of the tracking subject is updated in each imaging device.

  The subject tracking operation of the imaging device 1 according to the present embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 and FIG. 7 are flowcharts showing the tracking control sequence of the imaging device 1. A program for executing the following processing is stored in the memory 17 and executed by the system control unit 10. When the power is turned on, the imaging apparatus 1 performs various initialization processes and the like, and then waits for an operation instruction by the operation of the operation unit 14. The processes in steps S601 to S603 are the same as the processes in steps S401 to S403 in FIG.

  In step S604, the imaging apparatus 1 acquires the installation position, the panning control position when the tracking subject is detected in step S603, the reference photographing position of the tilting control position, and the subject distance calculated by the tracking subject detection unit 22. Using these pieces of information, the imaging device 1 calculates position information on the three-dimensional coordinates of the tracking subject (hereinafter referred to as subject position information), and broadcasts it on the wireless LAN network 505.

  In step S605, the imaging device 1 receives the position information that the imaging devices 500 to 504 calculate and broadcast on the wireless LAN network 505 as in step S604. The position information is position information (hereinafter referred to as other subject position information) on the three-dimensional coordinates of the subject which the imaging devices 500 to 504 are to track, and is received through the wireless LAN network 505. The processes of S606 to S608 are the same as the processes of S404 to S406 in FIG. 4, and thus the detailed description will be omitted.

  In step S609, the system control unit 10 of the imaging device 1 acquires current battery remaining amount information from the battery remaining amount detecting unit 21. In step S610, the imaging device 1 broadcasts the current remaining battery amount acquired in step S609 on the wireless LAN network 505 as data on the remaining battery amount information of the imaging device 1. In step S611, the imaging device 1 receives the remaining battery charge information (hereinafter, referred to as other battery remaining charge information) of the surrounding imaging devices 500 to 504 broadcast on the wireless LAN network 505.

  In step S612, the imaging device 1 determines the most remaining battery level on the basis of the other battery level information received through the wireless LAN network 505 in step S611, and determines this as the other battery maximum level. The process advances to step S613 in FIG. 7, and the imaging device 1 compares the other battery maximum remaining amount determined in step S612 with the remaining amount of battery of the imaging device 1 acquired in step S609 (hereinafter also referred to as own battery remaining amount). A determination process is performed as to whether the other battery maximum remaining amount is equal to or more than the battery remaining amount of the imaging device 1. If the other battery maximum remaining amount is equal to or more than the own battery remaining amount, the process proceeds to step S614. On the other hand, if the other battery maximum remaining amount is smaller than the own battery remaining amount, the process proceeds to S620.

The imaging device 1 compares the difference between the other battery maximum remaining amount determined in S614 and the battery remaining amount of the imaging device 1 acquired in S609 with a predetermined threshold (hereinafter referred to as threshold 2). Determine the relationship. If it is determined that the difference between the other battery maximum remaining amount and the own battery remaining amount is equal to or greater than the threshold 2, the process proceeds to step S615. On the other hand, when it is determined that the difference between the other battery maximum remaining amount and the own battery remaining amount is smaller than the threshold 2, the process proceeds to S621.
In step S615, the imaging device 1 determines whether the zoom lens position is fixed at a predetermined position in step S618 described later. If it is determined that the zoom lens position is fixed at the predetermined position, the process advances to step S621. If it is determined that the zoom lens position is not fixed at the predetermined position, the process proceeds to step S616. In S616, the imaging device 1 pauses tracking control on the detected tracking subject.

  In step S617, the system control unit 10 of the imaging device 1 performs drive control to change the zoom lens position to a predetermined position. In the present embodiment, the predetermined position is described as the position at the wide-angle end (Wide end) as an example of the zoom lens position at which the amount of control for panning control and tilting control decreases. In S618, setting processing is performed to fix the zoom lens position in tracking control to the zoom lens position in drive control of S617. In the present embodiment, a process of temporarily fixing the zoom lens position is described as an example of limiting the zoom control range, but a predetermined range in which the zoom control range is limited (for example, a range set in advance with a predetermined position as a center) It may be limited to Note that until the fixed setting of the zoom lens position is canceled in S620 described later, the zoom control in the following tracking control is performed at the zoom lens position by the drive control in S617 (that is, the zoom drive by the tracking control is Not).

  In step S619, the imaging device 1 resumes tracking control on the detected tracking subject. In S620, the imaging device 1 cancels the fixed setting of the zoom lens position performed in S618.

  In step S621, the imaging device 1 broadcasts subject position information on the wireless LAN network 505. In step S 622, the imaging apparatus 1 receives other subject position information from the wireless LAN network 505. In step S623, the system control unit 10 of the imaging device 1 determines whether subject tracking control can be continued. If it is determined that the subject tracking control can not be continued, the process advances to step S624. On the other hand, when it is determined that the subject tracking control can be continued, the process returns to S609 of FIG. 6 to continue the process.

  Here, if the zoom lens position is fixed at the wide-angle end position in S615, the tracking subject detection unit 22 can detect the tracking subject as a tracking subject, and the tracking subject is smaller than the limit of the size of the subject area in the shooting screen. The size of the area of may be reduced. If the area of the tracking subject becomes excessively small, the subject tracking control may not be able to be continued. Therefore, the imaging device 1 calculates the position of the tracking object in the imaging device 1 from the other object position information received through the wireless LAN network 505 in S622. The position of the tracking object is a position of the tracking object in the imaging device 1 which is relatively calculated from the other object position information, and is referred to as a relative object position. In the present embodiment, in the imaging device 1 and the imaging devices 500 to 504 in the vicinity thereof, respective installation positions (for example, latitude and longitude and altitude) and a reference imaging direction (for example, azimuth angle) are acquired. These pieces of information can be shared by a plurality of imaging devices on the wireless LAN network 505. Each imaging device can calculate the position on the three-dimensional coordinate of the tracking subject based on the own device. Therefore, the imaging device obtains the installation position of the other imaging device and the position information of the tracking object on the three-dimensional coordinates, thereby calculating the relative object position relative to the own device by general coordinate calculation. It can be decided. If it is determined in S623 that the tracking control can be continued for the calculated relative object position, the imaging device 1 returns to S609 and continues the process. On the other hand, when it is determined that the subject tracking control can not be continued, the process proceeds to S624, the imaging apparatus 1 stops the tracking control for the detected tracking subject, and then returns to S602 to continue the process.

  In the present embodiment, while the imaging device 1 is performing tracking control, the maximum battery remaining amount of the imaging devices 500 to 504 therearound is larger than the battery remaining amount of the imaging device 1, and the difference is A determination is made as to whether the threshold value is 2 or more. When this condition is satisfied, the zoom lens position of the imaging device 1 is fixed at a predetermined position (for example, the wide-angle end position), so the number of times and driving amount of panning control and tilting control of the imaging device 1 can be reduced. it can. By suppressing the power consumption of the imaging device 1, it is possible to prevent the battery remaining amount of the imaging device 1 from becoming zero quickly as compared with the surrounding imaging devices 500 to 504.

  Furthermore, also in the imaging devices 500 to 504 in the vicinity, similarly to the imaging device 1, processing for comparing the respective battery remaining amounts with the maximum battery remaining amounts of the other imaging devices is performed. Since the tracking control can be continued while maintaining the battery remaining amount in all the imaging devices uniform, it is possible to prevent that only the battery remaining amount of any imaging device quickly becomes zero. Further, in the present embodiment, it is possible to share, via the wireless LAN network 505, the position information of the tracking subject being tracked by the imaging device 1 and the imaging devices 500 to 504 around it. Accordingly, even when the zoom lens position is fixed at a predetermined position in an imaging device, subject tracking control can be continued.

  In the present embodiment, the other battery maximum remaining amount with the largest remaining amount of battery is determined based on the battery remaining amount information of the surrounding imaging devices 500 to 504, and the other battery maximum remaining amount and the battery remaining amount of the imaging device 1 Perform processing to compare with. However, the present invention is not limited to this, and a process of calculating the average value of the battery remaining amount from the battery remaining amount information of the surrounding imaging devices 500 to 504 and comparing the average value with the battery remaining amount of the imaging device 1 You may go.

Other Embodiments
Although the above-mentioned embodiment demonstrated the example which uses a wireless LAN unit as a communication means, it is not necessarily limited to this, You may use other communication systems, such as a wired LAN and a mobile telephone network. Further, the means for changing the imaging direction of the imaging device 1 is not limited to the configuration in which the motorized pan head mechanism 20 is included in the device, and any mechanical portion capable of changing the imaging direction of the imaging device 1 may be used. May be For example, as a configuration that does not have the motorized panhead mechanism in the device, there is a configuration in which the imaging apparatus is attached to the motorized panhead mechanism.

  The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or storage medium, and one or more processors in a computer of the system or apparatus read and execute the program. Can also be realized. It can also be implemented by a circuit (eg, an ASIC) that implements one or more functions.

DESCRIPTION OF SYMBOLS 1 imaging device 2 imaging optical system 2a zoom lens 4 imaging device 9 zoom control part 10 system control part 19 communication part 20 electric pan head mechanism part 21 battery residual amount detection part 22 tracking object detection part

Claims (15)

Zoom means for changing the focal length of the imaging optical system;
An object detection unit that detects an object to be tracked;
A control unit that performs control of tracking the subject detected by the subject detection unit by controlling the zoom unit and a drive unit that changes the shooting direction;
Battery remaining amount detecting means for detecting a remaining amount of a battery which is a power source of the driving means;
The control means acquires information on the remaining battery level detected by the remaining battery level detection means, and controls the zoom means in a first control range when the remaining battery level is greater than a threshold, and the battery An image pickup apparatus characterized in that the control of the zoom means is performed in a second control range which is changed to the wide angle side of the first control range when the remaining amount is equal to or less than a threshold.   The imaging apparatus according to claim 1, wherein the control unit limits a control range of the zoom unit when the battery remaining amount is equal to or less than a threshold.   3. The image pickup apparatus according to claim 2, wherein the control means determines a limit position on the telephoto side of the zoom means when the battery remaining amount is equal to or less than a threshold.   4. The image pickup apparatus according to claim 3, wherein the control means calculates the movement range of the subject to be tracked which is detected by the subject detection means to determine the limit position. Comprising the drive means;
The driving unit includes a first driving unit that changes the imaging direction to the first direction, and a second driving unit that changes the imaging direction to the second direction.
The control means performs the first position information of the subject acquired by the subject detection means when controlling the first drive means, and the subject detection when performing control of the second drive means. 5. The image pickup apparatus according to claim 4, wherein the moving range of the subject is calculated from second position information of the subject acquired by the means.   The first and second position information is information indicating the transition of the position of the object to be tracked, and the control means calculates an average position of control positions of the first and second drive means. The imaging apparatus according to claim 5, wherein the first and second position information as a reference is acquired.   The control means determines the limit position on the wide-angle side of the zoom means by the limit value of the size of the subject area in the image which can be detected by the subject detection means when the battery remaining amount is equal to or less than a threshold. The imaging device according to any one of claims 1 to 6, wherein The apparatus further comprises: a battery remaining amount information indicating a battery remaining amount of an imaging device other than the imaging device, and communication means for acquiring position information of an object tracked by the other imaging device.
The control means compares the battery remaining amount indicated by the battery remaining amount information acquired by the communication means with the battery remaining amount detected by the battery remaining amount detecting means, and sets the control range of the zoom means to The imaging device according to any one of claims 1 to 7, characterized in that a process of changing is performed.   9. The imaging apparatus according to claim 8, wherein the communication unit acquires the battery remaining amount information and the position information of the subject in a preset cycle. The communication means and the control means select, as the maximum battery remaining amount, the battery remaining amount having the largest battery remaining amount among the battery remaining amounts indicated by the plurality of battery remaining amount information acquired from the other imaging device Or calculating an average value of the remaining battery charge indicated by the plurality of remaining battery charge information,
The control means has a battery remaining amount detected by the battery remaining amount detecting means smaller than the maximum battery remaining amount or an average value, and a battery remaining amount detected by the battery remaining amount detecting means and the maximum battery 10. The image pickup apparatus according to claim 8, wherein the position of the zoom means is limited when the difference between the remaining amount or the average value is larger than a threshold.   11. The image pickup apparatus according to claim 10, wherein, when limiting the position of the zoom means, the control means performs control to fix the position at the position of the wide angle end.   The control unit cancels the restriction on the position of the zoom unit when the maximum battery remaining amount or the average value is smaller than the battery remaining amount detected by the battery remaining amount detecting unit. 10. The imaging device according to 10.   The control means performs tracking control of the subject by calculating the position of the subject to be tracked from the position information of the subject acquired by the communication means while limiting the position of the zoom means. The imaging device according to any one of claims 10 to 12. A control method executed by an imaging apparatus that performs tracking control of an object,
Detecting an object to be tracked;
Detecting the remaining amount of the battery;
And a tracking control process in which the control unit performs control to track the detected subject by controlling the zoom unit that changes the focal length of the imaging optical system and the drive unit that changes the imaging direction.
In the tracking control step, the control means controls the zoom means in the first control range when the detected remaining amount of the battery is larger than the threshold, and the remaining amount of the battery is equal to or less than the threshold And controlling the zoom unit in a second control range which is changed to a wider angle side than the first control range. A program causing a computer of an imaging device to execute each process according to claim 14.

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