Imaging system, method for controlling imaging system, and storage medium

Abstract

To pick up an image of a subject to be tracked under an image pickup condition as suitable as possible.SOLUTION: When the first UWB anchor 401-1 in the first imaging apparatus 100-1 communicates with the UWB tag 402 held by the subject H that can move and performs tracking of the subject H, in a case where the distance between the first UWB anchor 401-1 and the UWB tag 402 becomes equal to or greater than a predetermined distance and the distance between the second UWB anchor 401-2 in the second imaging apparatus 100-2 and the UWB tag 402 becomes less than a predetermined distance, the imaging apparatus that tracks the subject H is changed from the first imaging apparatus 100-1 to the second imaging apparatus 100-2.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an imaging system, a control method for an imaging system, and a program. [Background technology]

[0002] Normally, when an imaging device is close to a subject, the imaging device can obtain a high-quality image (video). However, when the subject moves far away, the imaging device can only capture the subject with a wide-angle composition, and the quality of the image (video) obtained by the imaging device decreases. In consideration of this point, Patent Document 1 describes a technology for capturing a tracking target subject within the angle of view using an imaging device capable of pan-tilt operation to change the imaging direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-188326 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 is a technology for tracking one subject with one imaging device, and although it is possible to track a distant subject, the subject is imaged as small, making it difficult to image the subject being tracked under suitable imaging conditions.

[0005] The present invention has been made in view of the above-mentioned problems, and has as its object to enable imaging of a subject to be tracked under imaging conditions as favorable as possible. [Means for solving the problem]

[0006] The imaging system of the present invention has a plurality of imaging devices, including a first imaging device that images a movable subject and has a first communication unit that communicates with a holding communication unit held by the subject, and a second imaging device that images the subject and is located at a different position from the first imaging device and has a second communication unit that communicates with the holding communication unit, and when the first communication unit in the first imaging device communicates with the holding communication unit to track the subject, if the distance between the first communication unit and the holding communication unit becomes equal to or greater than a predetermined distance and the distance between the second communication unit and the holding communication unit becomes less than the predetermined distance, the imaging device that tracks the subject is changed from the first imaging device to the second imaging device. [Effects of the Invention]

[0007] According to the present invention, it is possible to capture an image of a subject to be tracked under the most suitable imaging conditions possible. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of a schematic configuration of an imaging device according to a first embodiment. [Figure 2] 1 is a diagram illustrating an example of the internal configuration of an imaging device according to a first embodiment. [Figure 3] 2 is a diagram illustrating an example of the internal configuration of a UWB device used in the imaging system according to the first embodiment. FIG. [Figure 4] FIG. 4 is a sequence diagram schematically illustrating a ranging method when the UWB device shown in FIG. 3 is applied to a UWB anchor (initiator) and a UWB tag (responder). [Figure 5] 5A to 5C are diagrams illustrating an example of processing in a control method for the imaging system according to the first embodiment. [Figure 6] 10A to 10C are diagrams illustrating an example of processing in a control method for an imaging system according to a second embodiment. [Figure 7] 10A to 10C are diagrams illustrating an example of processing in a control method for an imaging system according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0010] (First embodiment) First, the first embodiment will be described.

[0011] <Configuration of imaging device> Fig. 1 is a diagram illustrating an example of a schematic configuration of an imaging device 100 according to a first embodiment. The imaging device 100 shown in Fig. 1(a) is provided with an operation member (hereinafter referred to as a "power button") that can operate a power switch, but operations such as tapping, flicking, or swiping on a touch panel may also be used). Fig. 1(b) is a diagram illustrating X, Y, and Z axes that define the installation state of each component of the imaging device 100 shown in Fig. 1(a).

[0012] As shown in FIG. 1( a ), the imaging device 100 includes a lens barrel 102 , a fixed portion 103 , a tilt rotation unit 104 , a pan rotation unit 105 , an angular velocity meter 106 , and an accelerometer 107 .

[0013] The lens barrel 102 is a housing containing an imaging unit including a lens group and an imaging element for capturing images. The imaging device 100 is provided with a rotation mechanism that can rotate the lens barrel 102 relative to the fixed unit 103. The tilt rotation unit 104 is a motor-driven mechanism that can rotate the lens barrel 102 in the pitch direction shown in FIG. 1(b). The pan rotation unit 105 is a motor-driven mechanism that can rotate the lens barrel 102 in the yaw direction shown in FIG. 1(b). Thus, the lens barrel 102 can rotate in one or more axial directions. Note that both the angular velocity meter 106 and the accelerometer 107 are mounted on the fixed unit 103 of the imaging device 100. A device shake detection unit (209 in FIG. 2) configured inside the imaging device 100 detects a shake angle associated with vibration of the imaging device 100 based on output values ​​of the angular velocity meter 106 and the accelerometer 107. The imaging device 100 then rotates the tilt rotation unit 104 and the pan rotation unit 105 based on the detected shake angle. This makes it possible to correct the shake and tilt of the lens barrel 102, which is the movable part of the imaging device 100.

[0014] Fig. 2 is a diagram showing an example of the internal configuration of the imaging device 100 according to the first embodiment. In Fig. 2, the same components as those shown in Fig. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0015] As shown in FIG. 2, imaging device 100 includes a zoom drive control unit 202, a focus drive control unit 204, and a lens barrel rotation drive unit 205 in addition to lens barrel 102, tilt rotation unit 104, and pan rotation unit 105 shown in FIG. 1. Lens barrel 102 also includes a zoom unit 201, a focus unit 203, and an imaging unit 206. As shown in FIG. 2, imaging device 100 also includes an image processing unit 207, an image encoding unit 208, a device shake detection unit 209, a first power supply unit 210, a second control unit 211, a second power supply unit 212, an audio input unit 213, and an audio processing unit 214. As shown in FIG. 2, imaging device 100 also includes a memory 215, a nonvolatile memory 216, a video output unit 217, an audio output unit 218, a recording / playback unit 220, a recording medium 221, a communication unit 222, a first control unit 223, an LED control unit 224, and a setting unit 226.

[0016] The zoom unit 201 includes a zoom lens that changes magnification. The zoom drive control unit 202 drives and controls the zoom unit 201. The focus unit 203 includes a lens that adjusts focus. The focus drive control unit 204 drives and controls the focus unit 203. The imaging unit 206 receives light incident on an imaging element through each lens group, performs analog-to-digital (A / D) conversion on charge information (image signal information) corresponding to the amount of light, generates digital image data, and outputs the digital image data to the image processing unit 207. The image processing unit 207 performs image processing such as distortion correction, white balance adjustment, and color interpolation on the digital image data acquired from the imaging unit 206, and outputs the processed digital image data to the image encoding unit 208. The image encoding unit 208 converts the digital image data output from the image processing unit 207 into a recording format such as JPEG format, and transmits the converted data to the memory 215 or the video output unit 217. The image processing unit 207 also reads out digital image data temporarily stored in the memory 215, encodes the image signal, and generates compressed image data. This compressed image data is sent to the recording / playback unit 220, for example.

[0017] The lens barrel rotation drive unit 205 drives the tilt rotation unit 104 and the pan rotation unit 105 to drive the lens barrel 102 in the tilt direction and the pan direction.

[0018] The device vibration detection unit 209 is equipped with, for example, an angular velocity meter 106 that detects the angular velocity of the imaging device 100 in three axial directions, and an accelerometer 107 that detects the acceleration of the imaging device 100 in three axial directions. The device vibration detection unit 209 calculates the rotation angle of the imaging device 100, the shift amount of the imaging device 100, etc. based on the detected signals.

[0019] The first control unit 223 is configured to include a processor (for example, a CPU, GPU, microprocessor, MPU, etc.) and a cache memory. The first control unit 223 executes various processes to control each component of the imaging device 100 and controls data transfer between each component. The non-volatile memory 216 is an electrically erasable and recordable memory (for example, Flash ROM), and stores constants, programs, etc. for the operation of the first control unit 223.

[0020] The audio input unit 213 acquires audio around the imaging device 100 as an audio signal from a microphone provided in the imaging device 100, performs analog-to-digital conversion to generate digital audio data, and outputs the audio to the audio processing unit 214. The audio processing unit 214 performs audio-related processing such as optimization processing on the digital audio data output from the audio input unit 213. The audio data processed by the audio processing unit 214 is then transmitted to and stored in the memory 215 by the first control unit 223. Furthermore, the audio input unit 213 may be configured such that multiple microphones are mounted on the imaging device 100, and the audio processing unit 214 can detect the direction of sound on a plane on which the multiple microphones are installed. The memory 215 temporarily stores image data obtained by the image processing unit 207 and audio data obtained by the audio processing unit 214.

[0021] The recording / playback unit 220 records the compressed image data generated by the image processing unit 207, other control data related to image capture, and the like, onto the recording medium 221. The recording medium 221 may be a recording medium built into the imaging device 100, or a removable recording medium. The recording medium 221 can record various types of data, such as compressed image data and compressed audio data, generated by the imaging device 100, and a medium with a larger capacity than the nonvolatile memory 216 is generally used. For example, the recording medium 221 includes any type of recording medium, such as a hard disk, optical disk, magneto-optical disk, CD-R, DVD-R, magnetic tape, nonvolatile semiconductor memory, flash memory, and the like.

[0022] Furthermore, the recording and reproducing unit 220 reads (plays back) compressed image data, compressed audio data, various data, and programs recorded on the recording medium 221. Then, the recording and reproducing unit 220 transmits the read compressed image data and compressed audio data to the first control unit 223, the image processing unit 207, and the audio processing unit 214. The image processing unit 207 and the audio processing unit 214 temporarily store the compressed image data and compressed audio data in the memory 215, decode them in a predetermined procedure, and transmit the decoded data to the video output unit 217 and the audio output unit 218.

[0023] The second control unit 211 is provided separately from the first control unit 223, which controls the entire system of the imaging device 100, and controls the power supply to the first control unit 223. The first power supply unit 210 and the second power supply unit 212 supply power for operating the first control unit 223 and the second control unit 211, respectively. When a power button provided on the imaging device 100 is pressed, power is first supplied to both the first control unit 223 and the second control unit 211, and the first control unit 223 controls the first power supply unit 210 to turn off its own power supply. Even while the first control unit 223 is not operating, the second control unit 211 continues to operate, and receives information from the device vibration detection unit 209 and the audio processing unit 214. The second control unit 211 performs a process of determining whether to activate the first control unit 223 based on various input information, and if it determines to activate the first control unit 223, it instructs the first power supply unit 210 to supply power.

[0024] The video output unit 217 consists of, for example, a video output terminal, and transmits an image signal (image data) to display a video on a connected external display or the like. The audio output unit 218 outputs, for example, a preset audio pattern from a speaker built in the imaging device 100 during shooting or the like. Also, the audio output unit 218 and the video output unit 217 may be a combined single terminal, such as a terminal like an HDMI (registered trademark) (High-Definition Multimedia Interface) terminal.

[0025] The communication unit 222 is a component for performing communication between the imaging device 100 and an external device, or between the imaging device 100 and another imaging device, etc., and transmits and receives data such as compressed image data and compressed audio data, for example. The communication unit 222 may include, for example, wireless communication devices such as UWB (Ultra-Wideband) devices, infrared communication devices, Bluetooth communication devices, wireless LAN communication devices, WirelessUSB, etc. Here, although it is said that the communication unit 222 may include various wireless communication devices, it may also be said that it may include various wireless communication modules.

[0026] The LED control unit 224 controls, for example, the LEDs provided in the imaging device 100 to light up in a preset lighting and blinking pattern during shooting or the like.

[0027] The setting unit 226 sets the shooting release conditions according to the image data acquired by the imaging unit 206. Here, the shooting release conditions are determined based on the image evaluation value. The image evaluation value is a value that serves as an index as to whether the scene captured by the imaging device 100 is a scene suitable for imaging (shooting), and is obtained based on subject face detection information, degree of eye squint, face expression, face orientation, and size of the subject within the angle of view, etc.

[0028] <Configuration of UWB Device> 3 is a diagram showing an example of the internal configuration of a UWB device 300 used in the imaging system according to the first embodiment. The UWB device 300 is a device that performs wireless communication using UWB (Ultra-Wideband) technology.

[0029] As shown in FIG. 3, the UWB device 300 includes a power supply 301, a CPU 302, an antenna control unit 1 (303), a UWB antenna 1 (304), a UWB antenna 2 (305), an antenna control unit 2 (306), a BLE antenna 307, and an acceleration sensor 308.

[0030] The power supply 301 supplies power to each component of the UWB device 300 , supplying the power necessary for the overall operation of the UWB device 300 .

[0031] The CPU 302 performs various processes and overall control of the operation of the UWB device 300. For example, the CPU 302 is responsible for logical control of the UWB device 300, and performs data processing, execution of control sequences, management of communication protocols, and the like.

[0032] Antenna control unit 1 (303) controls the output and directivity of UWB antenna 1 (304) and UWB antenna 2 (305). In UWB wireless communication, proper antenna directivity is directly related to communication quality. UWB antenna 1 (304) and UWB antenna 2 (305) transmit and receive wideband signals. UWB technology is used for high-precision location, and the antennas are specialized for transmitting and receiving short pulse signals.

[0033] The antenna control unit 2 (306) optimizes communication by adjusting the position and directivity of the BLE antenna 307. The antenna control unit 2 (306) works in cooperation with the antenna control unit 1 (303) to optimize the transmission and reception of signals throughout the UWB device 300. The BLE antenna 307 is used for pairing between UWB devices 300 and for short-range communication with nearby Bluetooth devices.

[0034] The acceleration sensor 308 detects the movement of the UWB device 300 and acquires position information and vibration information. The information acquired by this acceleration sensor 308 is used for the positioning and operation trigger of the UWB device 300.

[0035] Each component (301 - 308) of the UWB device 300 shown in FIG. 3 cooperates to realize the functions of the UWB device 300, enabling high-precision positioning and communication.

[0036] <UWB Positioning Method> FIG. 4 is a sequence diagram schematically showing the ranging method by applying the UWB device 300 shown in FIG. 3 to a UWB anchor (initiator) 401 and a UWB tag (responder) 402, respectively. In the example shown in FIG. 4, the distance is measured using the communication between the UWB anchor (initiator) 401 and the UWB tag (responder) 402.

[0037] The UWB anchor (initiator) 401 shown in FIG. 4 is the UWB device 300 on the side that transmits UWB pulses to measure the distance. Also, the UWB tag (responder) 402 shown in FIG. 4 is the UWB device 300 on the side that receives and replies to UWB pulses. The UWB anchor (initiator) 401 and the UWB tag (responder) 402 are set up as UWB devices 300 equipped with, for example, the UWB communication modules related to components 303 - 307 in FIG. 3 and the clock synchronization mechanism related to the CPU 302 in FIG. 3.

[0038] In FIG. 4, the measurement of the distance starts from the activation of the UWB anchor (initiator) 401. First, the UWB communication modules of the UWB anchor (initiator) 401 and the UWB tag (responder) 402 have the ability to generate and receive UWB pulse signals, and the clock synchronization mechanism is operating.

[0039] The UWB anchor (initiator) 401 generates a UWB pulse signal S401 and transmits it to the UWB tag (responder) 402.

[0040] The UWB tag (responder) 402 records the arrival time of the UWB pulse signal S401 and returns a response pulse signal S402 to the UWB anchor (initiator) 401.

[0041] 4, the time from when UWB anchor (initiator) 401 transmits UWB pulse signal S401 to when it receives response pulse signal S402 is defined as time T403. Also in FIG. 4, the time from when UWB tag (responder) 402 receives UWB pulse signal S401 and responds is defined as time T402. Then, UWB anchor (initiator) 401 measures the arrival time difference T401 between the UWB pulse signal S401 it transmitted and the response pulse signal S402 from UWB tag (responder) 402. Arrival time difference T401 represents the time from when UWB pulse signal S401 is transmitted from UWB anchor (initiator) 401 to UWB tag (responder) 402 and when it is received by UWB tag (responder) 402. This arrival time difference T401 is half the time it takes for the pulse signal to make a round trip. Specifically, it is expressed by the following equation (1). T401=1 / 2*(T403-T402) ···(1)

[0042] After measuring the time difference of arrival T401, the UWB anchor (initiator) 401 uses the speed of light (c) to calculate the distance from the following equation (2). Distance (d)=T401*Speed ​​of light (c) ···(2) In equation (2), the speed of light (c) is approximately 299,792,458 meters per second.

[0043] By calculating the distance shown in the above equation (2), it is possible to measure the distance between two UWB devices, the UWB anchor (initiator) 401 and the UWB tag (responder) 402.

[0044] <Method for controlling an imaging system> Fig. 5 is a diagram showing a processing example of the control method for the imaging system 10-1 according to the first embodiment. In Fig. 5, the same components as those shown in Figs. 1, 2, and 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0045] First, FIG. 5(a) will be described. In the imaging system 10-1 shown in Fig. 5(a), the subject H is a subject that holds the UWB tag 402 shown in Fig. 4 and can move within a predetermined range. An example of this subject H is a child moving around within a nursery school or the like. The imaging system 10-1 shown in Fig. 5(a) has a first imaging device 100-1 and a second imaging device 100-2 as multiple imaging devices.

[0046] The first imaging device 100-1 is an imaging device that captures an image of a movable subject H, and includes a first UWB anchor 401-1 that is a first communication unit that communicates with a UWB tag 402 that is a communication unit held by the subject H. Here, in this embodiment, the first imaging device 100-1 includes the first UWB anchor 401-1 that corresponds to the UWB anchor 401 shown in Fig. 4 as one component of the communication unit 222 shown in Fig. 2.

[0047] The second imaging device 100-2 is an imaging device that images the subject H, is placed at a position different from that of the first imaging device 100-1, and includes a second UWB anchor 401-2 that is a second communication unit that communicates with the UWB tag 402 held by the subject H. In this embodiment, the second imaging device 100-2 includes the second UWB anchor 401-2 that corresponds to the UWB anchor 401 shown in Fig. 4 as one component of the communication unit 222 shown in Fig. 2.

[0048] First, in the imaging system 10-1 shown in FIG. 5(a), a first imaging device 100-1 equipped with a first UWB anchor 401-1 tracks and automatically captures an image of a subject H holding a UWB tag 402. Also, in the imaging system 10-1 shown in FIG. 5(a), a second imaging device 100-2 equipped with a second UWB anchor 401-2 has the imaging unit 206 powered off and is in a standby state (power-saving mode). The UWB tag 402 and each of the first UWB anchor 401-1 and the second UWB anchor 401-2 periodically communicate wirelessly, so that the distance from each imaging device 100 to the subject H can be determined. Furthermore, the first imaging device 100-1 and the second imaging device 100-2 also communicate wirelessly, so that distance information between each imaging device 100 and the subject H is shared among all imaging devices 100.

[0049] Next, FIG. 5(b) will be described. Fig. 5(b) shows a state in which subject H holding UWB tag 402 has moved, as compared to Fig. 5(a). The state of imaging system 10-1 shown in Fig. 5(b) shows a case in which, as subject H moves, the distance between first imaging device 100-1 (first UWB anchor 401-1) and UWB tag 402 held by subject H becomes equal to or greater than a predetermined distance. Also, the state of imaging system 10-1 shown in Fig. 5(b) shows a case in which, as subject H moves, the distance between second imaging device 100-2 (second UWB anchor 401-2) and UWB tag 402 held by subject H becomes less than the predetermined distance.

[0050] In the state of the imaging system 10-1 shown in FIG. 5(b), the first imaging device 100-1 transmits a tracking change request signal for the subject H to the second imaging device 100-2. Upon receiving the tracking change request signal for the subject H, the second imaging device 100-2 turns on the power of the imaging unit 206 and checks whether the subject H is captured within the angle of view. If the subject H is captured within the angle of view, the second imaging device 100-2 transmits a tracking change enable signal for the subject H to the first imaging device 100-1. Thereafter, the second imaging device 100-2 tracks the subject H holding the UWB tag 402 and automatically captures an image. That is, in the imaging system 10-1 shown in FIG. 5, as the subject H moves, the imaging device tracking the subject H is changed from the first imaging device 100-1 to the second imaging device 100-2. After this change, the first image capturing device 100-1 turns off the power supply of the image capturing unit 206 and transitions to a standby state (power saving mode).

[0051] When changing the imaging device that tracks subject H from first imaging device 100-1 to second imaging device 100-2, if second imaging device 100-2 is too close to subject H, the image of the subject after the change will be too close and it will be difficult to obtain a good image (video). Therefore, as a condition for changing the imaging device that tracks subject H, in addition to the above-mentioned condition that the distance to UWB tag 402 held by subject H is less than a predetermined distance, a condition that the distance to UWB tag 402 is equal to or greater than a second predetermined distance may be considered.

[0052] In the imaging system 10-1 according to the first embodiment shown in FIG. 5, the imaging device tracking the subject H is changed from the first imaging device 100-1 to the second imaging device 100-2 as the subject H moves. Specifically, the imaging device tracking the subject H is changed to the second imaging device 100-2, whose distance to the UWB tag 402 held by the subject H is less than a predetermined distance. That is, according to the first embodiment, by dynamically changing the imaging device 100 tracking the subject H depending on the distance to the UWB tag 402 held by the subject H, the subject H can always be tracked and imaged from a close distance. This allows the subject H being tracked to be imaged under the most suitable imaging conditions possible. Furthermore, by dynamically changing the imaging device 100 tracking the subject H depending on the distance to the UWB tag 402 held by the subject H, the continuity of the subject image (video) is ensured, and the quality of the subject image (video) can be improved.

[0053] 5, the imaging system 10-1 has two imaging devices 100, but the present invention is not limited to this and may have three or more imaging devices 100. In the case of an imaging system 10-1 having three or more imaging devices 100, the imaging device 100 closest to the subject H among the imaging devices 100 that satisfy the change conditions for the imaging device that tracks the subject H described in this embodiment is set as the imaging device 100 that tracks the subject H.

[0054] (Second embodiment) Next, a second embodiment will be described. In the following description of the second embodiment, matters common to the first embodiment will be omitted, and only matters different from the first embodiment will be described.

[0055] The second embodiment differs from the first embodiment described above only in the control method of the imaging system 10, and will be described below.

[0056] <Method for controlling an imaging system> Fig. 6 is a diagram showing a processing example of a control method for the imaging system 10-2 according to the second embodiment. In Fig. 6, the same components as those shown in Figs. 1, 2, 4, and 5 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0057] In the imaging system 10-2 shown in Fig. 6(a), the second imaging device 100-2 equipped with the second UWB anchor 401-2 automatically captures an image by tracking a subject H holding a UWB tag 402. In the imaging system 10-2 shown in Fig. 6(a), the first imaging device 100-1 equipped with the first UWB anchor 401-1 has the imaging unit 206 powered off and is in a standby state (power saving mode).

[0058] In the imaging system 10-2 shown in FIG. 6(a), the second imaging device 100-2 is tracking a subject H. However, because there is an obstacle 11 between the second imaging device 100-2 and the subject H, the second imaging device 100-2 is unable to capture an image (video) of the subject H. In this manner, if the second imaging device 100-2, which is tracking the subject H, is unable to capture an image of the subject H for a certain period of time, the second imaging device 100-2 transmits a signal requesting a change in tracking of the subject H to the first imaging device 100-1. Upon receiving the signal requesting a change in tracking of the subject H, the first imaging device 100-1 turns on the power of the imaging unit 206 and checks whether the subject H is captured within the angle of view. If the subject H is captured within the angle of view, the first imaging device 100-1 transmits a signal indicating that the tracking of the subject H can be changed to the second imaging device 100-2.

[0059] 6(b), the first imaging device 100-1 tracks and automatically captures the subject H holding the UWB tag 402. That is, in the imaging system 10-2 shown in FIG. 6, the imaging device that tracks the subject H is changed from the second imaging device 100-2 to the first imaging device 100-1 depending on whether or not it is possible to capture an image of the subject H. After this change, the second imaging device 100-2 turns off the power of the imaging unit 206 and transitions to a standby state (power saving mode).

[0060] 6, in the imaging system 10-2 according to the second embodiment, if the imaging device 100 tracking the subject H is unable to capture an image of the subject H for a certain period of time, the imaging device tracking the subject H is changed to another imaging device 100 that can capture an image of the subject H. According to the second embodiment, even an imaging device 100 that is far from the subject H can reliably capture an image of the subject H, so that continuity of the image (video) of the subject being tracked can be ensured. This makes it possible to capture the subject H being tracked under imaging conditions that are as favorable as possible.

[0061] 6, the imaging system 10-2 has two imaging devices 100, but the present invention is not limited to this and may have three or more imaging devices 100. In the case of the imaging system 10-2 having three or more imaging devices 100, the imaging device 100 closest to the subject H among the imaging devices 100 that satisfy the change conditions for the imaging device that tracks the subject H described in this embodiment is set as the imaging device 100 that tracks the subject H.

[0062] (Third embodiment) Next, a third embodiment will be described. In the following description of the third embodiment, matters common to the first and second embodiments will be omitted, and only matters different from the first and second embodiments will be described.

[0063] The third embodiment differs from the first and second embodiments described above only in the control method of the imaging system 10, and will be described below.

[0064] <Method for controlling an imaging system> Fig. 7 is a diagram showing a processing example of a control method for the imaging system 10-3 according to the third embodiment. In Fig. 7, the same components as those shown in Figs. 1, 2, and 4 to 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0065] In the imaging system 10-3 shown in Fig. 7(a), the second imaging device 100-2 equipped with the second UWB anchor 401-2 automatically captures an image by tracking a subject H holding a UWB tag 402. In the imaging system 10-3 shown in Fig. 7(a), the first imaging device 100-1 equipped with the first UWB anchor 401-1 has the imaging unit 206 powered off and is in a standby state (power saving mode).

[0066] In the imaging system 10-3 shown in FIG. 7(a), the second imaging device 100-2 is tracking a subject H. However, because there is an obstacle 11 between the second imaging device 100-2 and the subject H, the second imaging device 100-2 is unable to capture an image (video) of the subject H. In this manner, when the second imaging device 100-2, which is tracking the subject H, is unable to capture an image of the subject H for a certain period of time, the second imaging device 100-2 transmits a signal requesting a change in tracking of the subject H to the first imaging device 100-1. Upon receiving the signal requesting a change in tracking of the subject H, the first imaging device 100-1 turns on the power of the imaging unit 206 and checks whether the subject H is captured within the angle of view. However, because there is also an obstacle 12 between the first imaging device 100-1 and the subject H as shown in FIG. 7(a), the first imaging device 100-1 is also unable to capture an image (video) of the subject H, and the subject H is not captured within the angle of view. In such a case, the first image capturing device 100-1 transmits a signal indicating that switching of tracking of the subject H is not possible to the second image capturing device 100-2, and then turns off the power supply of the image capturing unit 206 and transitions to the standby state (power saving mode) again.

[0067] The second imaging device 100-2, which has received the signal indicating that switching of tracking of subject H is not possible, determines that none of the imaging devices 100 can image subject H, and as shown in Figure 7(b), it also turns off the power to its imaging unit 206 and transitions to a standby state (power saving mode).

[0068] In the imaging system 10-3 shown in FIG. 7, if all of the imaging devices 100 are unable to capture an image of the subject H for a certain period of time, all of the imaging devices 100 are transitioned to a power saving mode, thereby reducing unnecessary power consumption and extending the operating time of the entire imaging system.

[0069] Furthermore, after all the imaging devices 100 have entered the power saving mode, if the UWB tag 402 moves at a certain distance or speed along with the movement of the subject H, all the imaging devices 100 turn on the power of their imaging units 206 and cancel the power saving mode. Then, the imaging devices 100 that have turned on the power of their imaging units 206 and canceled the power saving mode check whether the subject H is captured within their angle of view. If the subject H is not captured within the angle of view of any of the imaging devices 100, the imaging units 206 are again turned off and the devices are returned to the power saving mode. If the subject H is captured within the angle of view of any of the imaging devices 100, the imaging device 100 that is closest to the subject H among the imaging devices 100 capturing the subject H is set as the imaging device 100 that will track the subject H. In this case, the imaging devices 100 other than the imaging device 100 closest to the subject H are controlled to turn off the power of their imaging units 206 and return to the power saving mode.

[0070] (Other embodiments) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions. This program and a computer-readable storage medium storing the program are included in the present invention.

[0071] It should be noted that the above-described embodiments of the present invention are merely illustrative examples of the implementation of the present invention, and the technical scope of the present invention should not be construed as being limited by these. In other words, the present invention can be implemented in various forms without departing from its technical concept or main features.

[0072] The disclosure of this embodiment includes the following configuration, method, and program. [Configuration 1] a first imaging device that captures an image of a movable subject, the first imaging device including a first communication unit that communicates with a communication unit held by the subject; a second imaging device that captures an image of the subject, the second imaging device being disposed at a position different from that of the first imaging device and including a second communication unit that communicates with the holding communication unit; a plurality of imaging devices including When the first communication unit in the first imaging device communicates with the holding communication unit to track the subject, When the distance between the first communication unit and the holding communication unit becomes equal to or greater than a predetermined distance and the distance between the second communication unit and the holding communication unit becomes less than the predetermined distance, the imaging device that tracks the subject is changed from the first imaging device to the second imaging device. An imaging system characterized by: [Configuration 2] When the second imaging device cannot image the subject for a certain period of time and another imaging device among the plurality of imaging devices other than the second imaging device can image the subject, the imaging device that tracks the subject is changed from the second imaging device to the other imaging device. 2. The imaging system according to configuration 1, [Configuration 3] When the plurality of image capturing devices cannot capture an image of the subject for a certain period of time, the plurality of image capturing devices are switched to a power saving mode. 3. The imaging system according to configuration 1 or 2. [Configuration 4] When the holding and communication unit moves at a certain distance or at a certain speed along with the movement of the subject, the power saving mode of the plurality of imaging devices is cancelled. 4. The imaging system according to configuration 3. [Configuration 5] The holding communication unit, the first communication unit, and the second communication unit are configured as UWB devices. 5. The imaging system according to any one of configurations 1 to 4. [Method 1] a first imaging device that captures an image of a movable subject, the first imaging device including a first communication unit that communicates with a communication unit held by the subject; a second imaging device that captures an image of the subject, the second imaging device being disposed at a position different from that of the first imaging device and including a second communication unit that communicates with the holding communication unit; A control method for an imaging system having a plurality of imaging devices, When the first communication unit in the first imaging device communicates with the holding communication unit to track the subject, When the distance between the first communication unit and the holding communication unit becomes equal to or greater than a predetermined distance and the distance between the second communication unit and the holding communication unit becomes less than the predetermined distance, the imaging device that tracks the subject is changed from the first imaging device to the second imaging device. 10. A control method for an imaging system comprising: [Program 1] A program for causing a computer to function as the imaging system according to any one of the first to fifth aspects. [Explanation of symbols]

[0073] 10: imaging system, 100-1: first imaging device, 100-2: second imaging device, 401-1: first UWB anchor (first communication unit), 401-2: second UWB anchor (second communication unit), 402: UWB tag (holding communication unit), H: subject

Claims

1. an imaging device for imaging a movable subject, the imaging device including a first communication unit for communicating with a communication unit held by the subject; a second imaging device that captures an image of the subject, the second imaging device being disposed at a position different from that of the first imaging device and including a second communication unit that communicates with the holding communication unit; a plurality of imaging devices including When the first communication unit in the first imaging device communicates with the holding communication unit to track the subject, if the distance between the first communication unit and the holding communication unit becomes equal to or greater than a predetermined distance and the distance between the second communication unit and the holding communication unit becomes less than the predetermined distance, the imaging device that tracks the subject is changed from the first imaging device to the second imaging device. An imaging system characterized by:

2. When the second imaging device cannot image the subject for a certain period of time and another imaging device among the plurality of imaging devices other than the second imaging device can image the subject, the imaging device that tracks the subject is changed from the second imaging device to the other imaging device.

2. The imaging system according to claim 1, wherein:

3. When the plurality of image capturing devices cannot capture an image of the subject for a certain period of time, the plurality of image capturing devices are switched to a power saving mode.

2. The imaging system according to claim 1, wherein:

4. When the holding and communication unit moves at a certain distance or at a certain speed along with the movement of the subject, the power saving mode of the plurality of imaging devices is cancelled.

4. The imaging system according to claim 3.

5. The holding communication unit, the first communication unit, and the second communication unit are configured as UWB devices.

2. The imaging system according to claim 1, wherein:

6. an imaging device for imaging a movable subject, the imaging device including a first communication unit for communicating with a communication unit held by the subject; a second imaging device that captures an image of the subject, the second imaging device being disposed at a position different from that of the first imaging device and including a second communication unit that communicates with the holding communication unit; A control method for an imaging system having a plurality of imaging devices, When the first communication unit in the first imaging device communicates with the holding communication unit to track the subject, if the distance between the first communication unit and the holding communication unit becomes equal to or greater than a predetermined distance and the distance between the second communication unit and the holding communication unit becomes less than the predetermined distance, the imaging device that tracks the subject is changed from the first imaging device to the second imaging device.

10. A control method for an imaging system comprising:

7. A program for causing a computer to function as the imaging system according to any one of claims 1 to 5.

Images