Control device, control method, and program

Abstract

To easily perform settings for tracking even when a wireless device used for tracking is replaced.SOLUTION: Acquisition means acquires first setting information for tracking processing on a substrate using a first wireless device. Tracking control means controls the tracking processing on the subject on the basis of a radio wave received by a communication unit from the first wireless device and the first setting information. Determination means determines whether to stop the tracking processing using the first wireless device on the basis of the radio wave received from the first wireless device. When the determination means determines to stop the tracking processing using the first wireless device, the communication unit makes a transition to a mode for newly connecting a wireless device. When the communication unit and a new wireless device are connected to each other, the tracking control means uses second setting information based on the first setting information as setting information for tracking processing on the subject using the new wireless device.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a control technique for wireless devices. [Background technology]

[0002] Cameras that can control pan, tilt, and zoom are known. Some of these cameras have a function (automatic tracking) that automatically controls the imaging direction according to the position of the subject so that the subject is kept within the screen.

[0003] When the subject is a person, video analysis such as human body detection is generally used to identify the position, but depending on the imaging environment and the state of the subject in the video, such as color changes due to lighting fluctuations or the person's direction and posture, the subject cannot be detected and tracking becomes unstable.

[0004] Meanwhile, in recent years, technology has emerged that uses wireless communication to identify the position of a subject. Version 5.1 of the wireless communication standard Bluetooth (registered trademark) added specifications for a function (direction detection) that can detect the direction in which radio waves come (radio wave direction). By installing wireless communication modules that comply with this standard in both the camera and the wireless device, and by using the wireless communication module on the camera to identify the direction of the radio waves coming from the wireless device, it becomes possible to identify the position of the wireless device. Then, by having the wireless device held by the subject, the camera can identify the subject's position.

[0005] When implementing automatic tracking using this method, the wireless device carried by the subject is associated with ID information (identifier) ​​that distinguishes it from other wireless devices, and automatic tracking is set up on the camera.

[0006] However, in the method using a wireless device, it is assumed that a battery-powered wireless device will be used, and therefore it is possible that the battery will run out during automatic tracking. Also, it is possible that a malfunction of the wireless device will make it difficult to identify the location of the wireless device.

[0007] In such a case, in order to minimize the time during which automatic tracking is interrupted, it may be possible to resume automatic tracking by replacing the wireless device that was being used with another wireless device. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2005-223487 A [Patent Document 2] International Publication No. 2017 / 163857 Summary of the Invention [Problem to be solved by the invention]

[0009] In Patent Document 1, device data received from a newly connected device is compared with device data received from an existing device to determine whether it is a replacement target, and if it is a replacement target, the device data is sent with the same identifier as the existing device. In this case, it is assumed that the existing device exists in the network, and if the existing device breaks down before the new device is connected, the replacement operation cannot be performed.

[0010] In addition, in Patent Document 2, when a new device is connected, the model information of the device is identified via a server prepared in advance, and the new device is automatically registered. However, it is necessary to prepare the server and whether the device is a model that can be registered in advance, which reduces usability.

[0011] Therefore, an object of the present invention is to enable easy setting of tracking even when a wireless device used for tracking is replaced. [Means for solving the problem]

[0012] In order to solve the above problem, the control device of the present invention has the following configuration: That is, the control device has a communication unit that communicates with a first wireless device carried by a subject, an acquisition unit that acquires first setting information for a tracking process on the subject using the first wireless device, a tracking control unit that controls the tracking process on the subject based on radio waves received from the first wireless device by the communication unit and the first setting information, and a determination unit that determines whether to stop the tracking process using the first wireless device based on the radio waves received from the first wireless device, and when the determination unit determines that the tracking process using the first wireless device is to be stopped, the communication unit transitions to a mode for connecting a new wireless device, and when the communication unit and the new wireless device are connected, the tracking control unit uses second setting information based on the first setting information as setting information for the tracking process on the subject using the new wireless device. Effect of the Invention

[0013] According to the present invention, even when the wireless device used for tracking is replaced, tracking settings can be easily performed. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a diagram illustrating an example of a system configuration in each embodiment. [Diagram 2] FIG. 2 is a block diagram showing a configuration of a network camera in each embodiment. [Diagram 3] 6A to 6C are diagrams illustrating examples of setting information of tracking settings in each embodiment. [Figure 4] 11A and 11B are diagrams illustrating an example of a process for identifying a radio wave direction in each embodiment. [Diagram 5] 5 is a flowchart of a process for exchanging wireless devices in the first embodiment. [Figure 6] 13 is a flowchart for determining whether a connected wireless device is an intended replacement wireless device in the second embodiment. [Figure 7]13A and 13B are diagrams illustrating an example of a subject position identified from an image in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the term "video" does not necessarily mean a moving image, but may also mean a still image. Similarly, the term "image" does not necessarily mean a still image, but may also mean a moving image.

[0016] First Embodiment 1 is a diagram showing an example of a system configuration in this embodiment. The system configuration includes a network camera (an imaging device including a control device) 101, a client device 102, a wireless device 103, and a wireless device 104. These are connected via a network 105 and a wireless network 106.

[0017] In this embodiment, an example in which the network camera 101 functions as a control device will be described, but the part that functions as a control device may be provided outside the network camera 101. For example, the client device 102 may function as a control device.

[0018] The network camera 101 is capable of distributing video and controlling the camera via a wired or wireless network.

[0019] The client device 102 is connected to the network camera 101 via a network 105. A user can control the network camera 101 via an operation screen (browser or the like) displayed by the client device 102. In addition, the client device 102 outputs (displays) various information acquired from the network camera 105.

[0020] The wireless devices 103 and 104 each have a built-in wireless communication module that complies with the direction detection function of the Bluetooth (registered trademark) 5.1 specification, and are connected to the network camera 101 via a wireless network 105. Note that Bluetooth 5.1 is just an example, and wireless communication that complies with other standards may also be used.

[0021] The wireless device 104 is a wireless device that is used as a replacement when the wireless device 103 becomes unusable. In this embodiment, the wireless device 103 or the wireless device 104 is assumed to be carried by the subject 107 in order for the network camera 101 to automatically track the subject 107. Note that more wireless devices may be used. In that case, the wireless devices may be carried by different subjects, respectively, so that a plurality of subjects can be tracked.

[0022] The network 105 is a network for distributing the video captured by the network camera 101 to an external recording server, etc. In this embodiment, the communication form of the network 105 is a wired LAN, but it may be a wireless LAN.

[0023] The wireless network 106 enables mutual communication between the network camera 101 and the wireless devices 103 and 104 in accordance with any one of wireless communication standards such as Bluetooth (registered trademark), Z-Wave (registered trademark), Zigbee (registered trademark), etc.

[0024] Here, the configuration of the network camera 101 in this system will be described with reference to the block diagram of FIG.

[0025] The imaging unit 201 has a zoom lens, a focus lens, an aperture, and an image sensor. The zoom lens and the focus lens are moved along the optical axis by the lens control unit 202, and the aperture is driven and operated by the lens control unit 202. The image sensor photoelectrically converts light that has passed through the zoom lens, the focus lens, and the aperture, and generates an analog image signal. The generated analog image signal is subjected to amplification processing by sampling, and then output to the A / D conversion unit 204.

[0026] The camera platform 203 has a pan drive unit and a tilt drive unit (not shown), and is controlled via an actuator (not shown) to rotate (move) the imaging unit 201 in the horizontal direction (pan direction) and vertical direction (tilt direction).

[0027] The A / D conversion unit 204 converts the analog image signal into a digital image signal and outputs it to the camera signal processing unit 205 .

[0028] The camera signal processor 205 performs various types of image processing on the digital image signal to generate a video signal. The various types of image processing include, for example, offset processing, gamma correction processing, gain processing, RGB interpolation processing, noise reduction processing, and color correction processing.

[0029] The storage unit 206 has a RAM (Random Access Memory), a ROM (Read Only Memory), and a storage device for writing information thereto. The RAM is a volatile memory such as an SRAM or a DRAM, and the ROM is a non-volatile memory such as an EEPROM or a flash memory. The storage device is an HDD (Hard Disk Drive) or an SSD (Solid State Drive). Programs for implementing the functions according to this embodiment and data used when the programs are executed are stored in the ROM. These programs and data are appropriately read into the RAM via the bus 207 under the control of the CPU 212, and are executed by the CPU 212, causing the CPU 212 to function as each unit according to this embodiment.

[0030] The video analysis unit 208 is a processing unit that performs various detection processes by executing video analysis such as human body detection, face detection, and moving object detection. In this embodiment, as an example of video analysis for identifying the position of the subject 107, human body detection for detecting a human body within an image frame is assumed to be used, but is not limited to this. For example, face detection or moving object detection may be used depending on the use scene. The video analysis result is notified to the CPU 212 via the bus 207.

[0031] The compression / decompression unit 209 performs compression processing on the captured image to generate compressed data in accordance with a control instruction from the CPU 212 via the bus 207. If data compression is not required, the compression / decompression unit 209 may be omitted.

[0032] The wired communication unit 210 communicates with the client device 102 via the network 105 .

[0033] The wireless communication unit 211 performs wireless communication between the wireless device 103 and the wireless device 104 via the wireless network 106. In this embodiment, it is assumed that the wireless communication unit 211 uses a wireless communication module that complies with the Bluetooth (registered trademark) 5.1 specification, but is not limited to this. For example, an external wireless communication module may be connected using a general-purpose interface such as USB to function as the wireless communication unit 211.

[0034] The CPU 212 is a central processing unit. The CPU 212 includes a radio wave position identifying unit 213 according to this embodiment, a video analysis position identifying unit 214, a stability determining unit 215, a position identifying execution control unit 216, a PTZ control unit 217, and a tracking control unit 218. Each unit will be described below.

[0035] The radio wave position identification unit 213 detects the direction (coming direction) of radio waves transmitted from the wireless devices 103 and 104, and identifies the relative positions of the wireless devices 103 and 104 as seen from the network camera 101. The method of identifying the positions is based on a direction detection function that complies with the Bluetooth (registered trademark) 5.1 specifications, and details will be described later with reference to FIG.

[0036] The video analysis position identifying unit 214 identifies the position of the subject 107 in the image captured by the imaging unit, based on the human body detection result by the video analysis unit 208. That is, the video analysis unit 208 cooperates with the video analysis unit 208 to function as an identifying means for identifying the position of the subject by performing video analysis on the image data obtained by the imaging unit 201.

[0037] The stability determination unit 215 determines whether the position determination in the radio wave position determination unit 213 described above can be performed stably. That is, in performing automatic tracking, the stability determination unit 215 determines whether the subject's position can be determined stably based on a predetermined rule. Details will be described in the explanation of FIG. 5 and subsequent figures. If the predetermined rule is satisfied, the stability determination unit 215 determines that the position determination is performed stably, and if not, determines that the position determination is unstable.

[0038] The position identification execution control unit 216 controls the subject position identification process by the radio wave position identification unit 213 and the video analysis position identification unit 214. For example, when the position identification by the radio wave position identification unit 213 is unstable, the position identification is controlled so as to be executed using only the position identification by the video analysis position identification unit 214.

[0039] The PTZ control unit 217 controls the pan-tilt-zoom drive (hereinafter, PTZ drive) using the lens control unit 202 and the camera platform 203 based on the position of the subject acquired by the position identification by the radio wave position identification unit 213 or the video analysis position identification unit 214. Here, at least one of pan drive, tilt drive, and zoom drive may be performed to track the subject. Then, by controlling the PTZ drive so that the imaging direction of the camera is directed to the position of the subject 107, automatic tracking of the subject 107 becomes possible. For example, automatic tracking is performed so that the subject is always reflected in the center of the image. Note that it is not necessary to always reflect the subject in the center of the image, and automatic tracking may be performed so that the subject does not go outside the image.

[0040] The tracking control unit 218 performs automatic tracking in cooperation with other components. The tracking control unit 218 performs automatic tracking based on various parameters (setting information for tracking) previously set by the user. For example, by registering the device ID unique to the wireless device to be tracked as a parameter, it is possible to identify and track the position of only a specific device even among multiple wireless devices.

[0041] 3, body parts of the subject 107 can be specified as setting information (parameters) for tracking, such as face area 301, upper body area 302, and whole body area 303. In other words, it is possible to specify which part of the subject 107 should be preferentially included in the image (as the tracking target) during tracking. For example, when information on face area 301 is set as setting information, automatic tracking is performed so that face area 301 is imaged at a predetermined size at the center of the angle of view. When information on whole body area 303 is set as setting information, automatic tracking is performed so that whole body area 303 fits within the angle of view.

[0042] The parameters related to the parts of the subject mentioned in this embodiment are an example of the setting information for tracking, and the setting information may be in any form as long as it is necessary or useful for performing tracking processing. For example, the setting information for tracking may be face detection information. When face detection information cannot be used to detect a face, that is, when the subject is not facing forward, automatic tracking may be performed so that the subject is not included in the angle of view. The setting information for tracking may be at least one of the driving speed and driving torque in pan driving, tilt driving, and zoom driving during tracking. The setting information for tracking may also be information that specifies the area to be tracked.

[0043] The setting information for these tracking operations is stored for each device ID in association with the device ID in the storage unit 206. The setting information may be specified by the user via the client device 102, or may be stored in the network camera 101 in advance.

[0044] 4 is a conceptual diagram showing an example of the principle by which the network camera 101 identifies the direction of radio waves from the wireless device 103. The direction detection function conforming to the Bluetooth (registered trademark) 5.1 specification uses an antenna array with multiple antennas to detect the direction of radio waves by utilizing the phase difference of radio waves caused by the different locations of the antennas.

[0045] There are two main detection methods: The first method is called Angle Of Arrival (AoA), in which the receiving device calculates the reception angle of the radio wave. The second method is called Angle Of Departure (AoD), in which the transmitting device calculates the emission angle and transmits it to the receiving device.

[0046] In this embodiment, it is assumed that the wireless device 103 is positioned as the transmitting device and the network camera 101 is positioned as the receiving device, and that direction detection is performed by AoA. However, almost the same effect can be obtained by using AoD. Below, the principle of identifying the radio wave direction by the network camera 101 will be explained with reference to FIG. 3.

[0047] The wireless communication unit 211 of the network camera 101 includes a receiver 401 and multiple antennas 402, and the wireless device 403 includes a transmitter 403 and a single antenna 404. The transmitter 403 transmits radio waves 405 including a special direction detection signal from the antenna 404, and the radio waves 405 are received by the multiple antennas 402 of the network camera 101. At this time, as shown in FIG. 4, the multiple antennas 402 arranged at equal intervals receive the radio waves 405 at their respective antennas. As a result, a distance difference occurs between the antennas on the transmitting side and the receiving side, such as distance D1 and distance D2, and the radio wave position identification unit 213 and the wireless communication unit 211 cooperate to detect signals with different phases for each antenna. The receiver 401 acquires a modulated signal (IQ modulated signal) having an in-phase component and a quadrature phase component as phase information of the radio wave while switching the active antenna. The receiver 401 can calculate the incident angle θ, which is the relative direction of the signal, based on the IQ modulated signal by the radio wave position identification unit 213 of the network camera 101. The calculation method is performed using the wavelength of the radio waves, the distance between the antennas, and the phase difference, but since it is well known, a description thereof will be omitted. Furthermore, since the network camera 101 can grasp the current orientation of the camera in three-dimensional space by calibration performed at the time of installation, it becomes possible to identify the relative position of the wireless device 103 from the direction of the radio waves received from the wireless device 103.

[0048] The position identification execution control unit 216 converts the relative position of the wireless device 103 identified by the radio wave position identification unit 213 into a position on the image captured by the imaging unit 201. The position identification execution control unit 216 identifies the relative position of the captured image as seen from the network camera 101 based on the current pan direction angle and tilt direction angle. Then, by comparing this with the relative position of the wireless device 103, the relative position of the wireless device 103 is converted into a position on the image captured by the imaging unit 201.

[0049] The processing procedure in the network camera 101 of the present invention is shown in the flowchart of FIG.

[0050] After automatic tracking is started, in S (step) 501, the stability determination unit 215 determines whether the location information from the wireless device 103 can be stably acquired. Here, in order to determine whether the location information can be stably acquired without being lost, the strength of the radio wave received from the wireless device 103 is used as an example. If the strength of the radio wave is equal to or greater than a threshold, the stability determination unit 215 determines that the reception situation is stable, and if it is less than the threshold, determines that the radio wave communication is unstable. If it is determined that the reception situation is stable, the current state (mode) is maintained, and if it is determined that the reception situation is unstable, the process proceeds to S502. Note that the stability determination unit 215 may determine that the identification of the location information using the wireless device 103 is unstable if the frequency at which the strength of the radio wave received from the wireless device 103 becomes greater than a predetermined threshold is less than a predetermined frequency.

[0051] For example, the radio wave strength is measured in units of dBm (decibels per milliwatt), and the value is judged to be higher or lower than a threshold. The output strength of radio waves is determined by wireless communication standards, and for example, in the case of Bluetooth (registered trademark), a standard range of radio wave strength is set for each class. If the radio wave strength is 30% or less of the maximum value of this range, it is judged to be unstable.

[0052] In S502, the position identification execution control unit 216 stops position identification by the radio wave position identification unit 213 using the currently used wireless device 103. Then, the position identification execution control unit 216 switches control to perform position identification and automatic tracking using only position identification by the video analysis position identification unit 214. In other words, automatic tracking using position identification by the radio wave position identification unit 213 is also stopped.

[0053] In S503, after a certain time has elapsed since the location determination and automatic tracking are performed using only the location determination by the video analysis location determination unit 214, the stability determination unit 215 again determines whether the radio communication is stable. If it is determined that the radio communication is stable, the process proceeds to S504, where the location determination execution control unit 216 resumes the location determination by the radio wave location determination unit 213. If it is determined that the radio communication is unstable again, the process proceeds to S505. It is also possible to omit the process of S503 and immediately proceed to S505. In other words, if the strength of the radio wave received from the wireless device 103 is smaller than a predetermined threshold even after a predetermined time has elapsed, it is finally determined that the tracking process using the wireless device 103 is stopped (without resuming).

[0054] In S505, the device ID of wireless device 103 determined to be unstable by stability determination unit 215 is stored in storage unit 206. Tracking control unit 218 has the device ID of wireless device 103 as a setting value as a parameter for tracking control, but stores it in storage unit 206 as a device ID for which radio communication does not operate normally.

[0055] In S506, the location determination execution control unit 216 transitions the wireless communication unit 211 to a ready state (mode) in which a connection with a new wireless device is possible. By being in the ready state, a connection request from an unconnected wireless terminal can be received, and a wireless communication connection is established upon reception of a connection request from a new terminal. The ready state (mode) refers to a state in which a connection with another wireless device is established when a specific connection request signal is received from that wireless device. If the wireless communication unit 211 is not in this state, no connection is made even if a connection request signal is received, and when a wireless communication connection with a new terminal is to be established, it is necessary to explicitly transition to this mode beforehand.

[0056] The wireless connection method in this embodiment is an example, and for example, as in the Bluetooth (registered trademark) specification, wireless devices may perform pairing with a button operation as a trigger. However, it is preferable to control the device to transition to a ready state in which it can be connected to a wireless device without requiring user operations as much as possible.

[0057] In S507, the wireless communication unit 211 detects whether or not it has succeeded in connecting to the new wireless device 104. If it has, the process proceeds to S508, and if not, the process proceeds to S509.

[0058] In S508, upon detection of the connection of a new wireless device 104, the device ID stored in S505 is obtained, and the tracking control unit 218 obtains from the memory unit 206 the setting information associated with the device of the wireless device 103 whose location determination was stopped in S502.

[0059] Then, the acquired setting information is stored in the storage unit 206 in association with the device ID of the newly connected wireless device 104. The position identification execution control unit 216 also sets the acquired setting information in the radio wave position identification unit 213 and the tracking control unit 218. Then, the tracking control unit 218 starts automatic tracking based on the position identification by the new wireless device 104. Note that it is not necessary to carry over all the setting information of the previously used wireless device, and it is sufficient to carry over at least a part of the setting information to the automatic tracking using the new wireless device 104. In other words, it is sufficient to use the setting information based on the setting information of the previously used wireless device 103 in the automatic tracking using the new wireless device 104. Also, the setting information of the previously used wireless device 103 may be used as it is as the setting information for the automatic tracking using the new wireless device 104.

[0060] In S509, the system waits for a certain period of time to see if a new wireless device is connected, and if no new wireless device is detected, the system proceeds to S510, where the ready state of the wireless communication unit is cancelled and the process ends.

[0061] As described above, when it is determined that the tracking process using the existing wireless device 103 is to be stopped, the mode automatically shifts to a mode for connecting a new wireless device. Then, when the new wireless device 104 is connected, setting information based on setting information used in the existing wireless device 103 is used as setting information for the tracking process of the subject using the new wireless device 104. Therefore, even when replacing the wireless device used for tracking, it is possible to easily set the tracking.

[0062] <Second embodiment> Next, a second embodiment will be described with reference to the block diagram of Fig. 1 and the flow chart of Fig. 6. Specifically, the process will be described in the case where a new wireless device is connected and a wireless device other than the expected replacement device (for example, a wireless device carried by a subject other than the expected subject) is connected to the network camera 101. Note that the description of the same parts as in the other embodiments will be omitted as appropriate.

[0063] In S601, the position identification execution control unit 216 acquires the position of the subject identified by the radio wave position identifying unit 213 from radio wave information obtained from a newly connected wireless device.

[0064] In S602, the position identification execution control unit 216 acquires the position of the subject identified by the video analysis position identifying unit 214.

[0065] In S603, position identification execution control unit 216 compares the subject position obtained in S601 with the subject position obtained in S602. At this time, position identification execution control unit 216 converts the subject position obtained from the new wireless device into a position on the video before comparing.

[0066] 7(a), if there is no significant difference between the center position of the subject area 701 acquired by video analysis and the position 702 of the wireless device acquired by radio wave information, it is determined that the position information of the wireless device held by the subject has been correctly acquired and that the wireless device is the wireless device to be replaced. For example, if the difference (distance L) between the center position of the subject area 701 acquired by video analysis and the position 702 of the wireless device acquired by radio wave information is equal to or less than a predetermined threshold, the position identification execution control unit 216 determines that the correct wireless device has been connected. Note that this distance may be calculated as the number of pixels.

[0067] On the other hand, as shown in Fig. 7(b), if the distance L between the center position of the subject area 703 acquired by video analysis and the position 704 of the wireless device acquired by radio waves from the wireless device obtained in S602 is greater than the threshold, the following is done. That is, the position identification execution control unit 216 determines that the newly connected wireless device is broken, or that a wireless device different from the wireless device carried by the subject is connected. If the difference L between the two positions is greater than the threshold, the process proceeds to S604, and if it is equal to or less than the threshold, the process proceeds to S606.

[0068] In S604, the user is notified that the position obtained in S601 is significantly different from the position obtained in S602 and / or that the wireless device has not been replaced correctly. The method of notification may be of any form as long as it is a method that conveys that fact to the user. For example, the notification may be made by a blinking pattern of an LED mounted on the network camera, or a predetermined message may be displayed on the display unit.

[0069] In S605, the use of the location specification by the new wireless device is stopped. The means for stopping the use may be any form as long as it can stop the use of the tracking process associated with the device ID stored in the storage unit 206. For example, a method of disconnecting the wireless connection with the new wireless device may be used.

[0070] In S606, the device ID stored in S505 is acquired, and the setting information associated with the acquired device ID is acquired from the tracking setting information held by the tracking control unit. Then, the tracking control unit 218 associates the acquired setting information with the device ID of the newly connected wireless device, and notifies the location identification execution control unit 216 of the setting update, and the location identification execution control unit 216 starts location identification by the radio wave location identification unit 213. This operation is basically the same as S508. This ends the process.

[0071] As described above, even if a wireless device other than the intended replacement device is mistakenly connected, it is possible to properly notify the user of this fact.

[0072] Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention.

[0073] (Other Examples) As described in Fig. 2, each component of the network camera (imaging device including a control device) 101 other than the imaging element and lens, and the client device 102 in each embodiment can be realized by a hardware configuration. Such a hardware configuration includes a RAM 206 that temporarily stores a computer program executed by the CPU 212. The RAM 206 also temporarily stores data (commands and video data) acquired from the outside via a wired interface (wired communication unit 210) or a wireless communication interface (wireless communication unit 211). The RAM 206 also provides a work area used when the CPU 212 executes various processes. The RAM 206 also functions as, for example, a frame memory or a buffer memory.

[0074] The CPU 212 executes computer programs stored in the RAM 206. In addition to the CPU 212, a processor such as a DSP (Digital Signal Processor) or an ASIC (Application Specific Integrated Circuit) may be used.

[0075] The ROM 206, such as a Hard Disk Drive (HDD), stores the operating system program and video data, and also stores computer programs.

[0076] The computer programs and data stored in the ROM 206 are loaded into the RAM 206 as appropriate under the control of the CPU 212, and are executed by the CPU 212. Other storage media such as flash memory may be used in addition to the HDD. A bus 1005 connects the various pieces of hardware. The various pieces of hardware exchange data via a bus 207. The above is the hardware configuration in each embodiment.

[0077] The present invention can also be realized by a process in which one or more processors read and execute a program that realizes one or more functions of the above-mentioned embodiments. The program may be supplied to a system or device having a processor via a network or a storage medium. The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions of the above-mentioned embodiments.

[0078] Moreover, the control device in each embodiment may be realized by the hardware shown in FIG. 2, or can be realized by software.

[0079] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the scope of the present invention. For example, combinations of the embodiments and modifications are also included in the disclosure of this specification. [Explanation of symbols]

[0080] 211 Radio Communication Department 213 Radio wave location identification section 214 Video analysis position identification unit 215 Stability judgment section 216 Location Identification Execution Control Unit 217 PTZ control unit 218 Tracking control section

Claims

1. a communication unit that communicates with a first wireless device carried by the subject; an acquisition unit that acquires first setting information for a tracking process of the subject using the first wireless device; a tracking control unit that controls a tracking process for the subject based on radio waves received from the first wireless device by the communication unit and the first setting information; a determination means for determining whether to stop a tracking process using the first wireless device based on a radio wave received from the first wireless device; having When the determination means determines that the tracking process using the first wireless device is to be stopped, the communication unit is transitioned to a mode for connecting a new wireless device, When the communication unit and a new wireless device are connected, the tracking control means uses second setting information based on the first setting information as setting information for a tracking process for the subject using the new wireless device. A control device comprising:

2. The tracking control means starts the tracking process based on radio waves received from the new wireless device and the second setting information in response to the connection of the new wireless device. The control device according to claim 1 .

3. The determination means determines to stop the tracking process using the first wireless device when the strength of the radio wave received from the first wireless device is smaller than a predetermined threshold. The control device according to claim 1 .

4. The determination means determines to stop the tracking process using the first wireless device when the frequency at which the intensity of the radio wave received from the first wireless device becomes greater than a predetermined threshold is less than a predetermined frequency. The control device according to claim 1 .

5. The determination means determines to stop the tracking process using the first wireless device when the strength of the radio wave received from the first wireless device is smaller than a predetermined threshold and when the strength of the radio wave received from the first wireless device is still smaller than the predetermined threshold even after a predetermined time has elapsed. The control device according to claim 1 .

6. The setting information for the tracking process includes at least information specifying a part of a subject to be tracked. The control device according to claim 1 .

7. The second setting information includes at least an identifier for identifying the new wireless device and at least a part of the first setting information. The control device according to claim 1 .

8. The imaging device further includes a determining unit for determining a position of the subject by performing image analysis on image data obtained by the imaging unit. The control device according to claim 1 .

9. The tracking control means does not start a tracking process for the subject using the new wireless device when a difference between a position of the subject based on radio waves received from the new wireless device and a position of the subject identified by the identification means is greater than a predetermined magnitude. The control device according to claim 8 .

10. The tracking control means controls the tracking process of the subject using the identification means at least from when the tracking process using the first wireless device is stopped until the tracking process of the subject using the new wireless device is started. The control device according to claim 8 .

11. The first setting information and the second setting information are the same setting information. The control device according to claim 1 .

12. a communication step of communicating with a first wireless device carried by a subject using a communication unit; an acquisition step of acquiring first setting information for a tracking process of the subject using the first wireless device; a tracking control step of controlling a tracking process for the subject based on radio waves received from the first wireless device in the communication step and the first setting information; a determination step of determining whether to stop a tracking process using the first wireless device based on a radio wave received from the first wireless device; having When the determination means determines that the tracking process using the first wireless device is to be stopped, the communication unit is transitioned to a mode for connecting a new wireless device, In the tracking control step, when the communication unit and a new wireless device are connected, second setting information based on the first setting information is used as setting information for a tracking process for the subject using the new wireless device. A control method comprising:

13. A program for causing a computer to execute the control method according to claim 12.

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