Control device, control method, and system

Abstract

To enable realization of a composition intended by a user.SOLUTION: A control device having control means for executing processing for controlling an imaging direction so as to keep a position of a subject in an imaged image imaged by an imaging device, at a target position, comprises: acquisition means for acquiring a setting related to a second target position different from a first target position set at the target position; and calculation means for calculating a distance between the first target position and the second target position in the imaged image. When the acquisition means acquires change in the target position, the control means changes a dead zone according to the distance between the first target position and the second target position.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a control technique for an imaging device that tracks a subject. [Background technology]

[0002] A technology is known for cameras called PTZ cameras that can control pan, tilt, and zoom, in which a subject is detected from a captured image and tracked by controlling the pan, tilt, and zoom of the PTZ camera. This tracking technology makes it possible to automatically control the pan, tilt, and zoom (hereinafter referred to as PTZ) of the camera so that the subject remains at a preset size and position (hereinafter referred to as the target position) in the captured image.

[0003] Patent Document 1 discloses that when it is determined that the subject to be tracked (hereinafter referred to as the tracked subject) is within the range of the dead zone, the shooting direction of the camera is not moved, and when it is determined that the subject is outside the range of the dead zone, the shooting direction of the camera is moved in the direction to track the subject. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4189534 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in Patent Document 1, even if the target position is changed, if it is determined that the tracked subject is within the dead zone or if the tracked subject enters the dead zone, the change in the shooting direction will be stopped even before the tracked subject reaches the target position.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a captured image that satisfies the user's intention. [Means for solving the problem]

[0007] In order to solve the above problem, the control device in this embodiment is a control device having a control means that executes processing to control the imaging direction so that the position of the subject in the captured image captured by the imaging device remains at the target position, and has an acquisition means that acquires a setting for a second target position that is different from a first target position that is set at the target position, and a calculation means that calculates the distance between the first target position and the second target position in the captured image, and is characterized in that when the acquisition means acquires a change in the target position, the control means changes the dead zone according to the distance between the first target position and the second target position. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a captured image that the user intends. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a system configuration according to a first embodiment; [Figure 2] Functional block diagram of a PTZ camera according to a first embodiment [Figure 3] 1 is a diagram showing the hardware configuration of a PTZ camera and a client device according to a first embodiment; [Figure 4] FIG. 10 is a diagram showing calculation of a distance when a target position is changed according to the first embodiment; [Figure 5] FIG. 10 is a diagram showing the setting of a target position and a dead zone according to the first embodiment; [Figure 6] 1 is a flowchart showing automatic tracking control according to a first embodiment; [Figure 7] Flowchart showing automatic tracking control according to the second embodiment [Figure 8] 10 is a flowchart showing automatic tracking control according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] (First embodiment) 1 is a configuration diagram of an imaging system according to a first embodiment. The imaging system A1000 in this embodiment includes a PTZ camera 100, a client device 200, and a network 300. The PTZ camera 100 and the client device are connected via the network 300, but the method of connection between the devices is not limited to a specific method. For example, the devices may be connected via an SDI (Serial Digital Interface) or an HDMI (High-Definition Multimedia Interface), a registered trademark.

[0012] The client device 200 controls the imaging direction, angle of view, image quality control, or registration and playback of composition settings by sending control commands to the PTZ camera 100. Here, composition settings refer to settings related to the position and size of the subject in the captured image. Each position of the drive unit 107 (described later) can be registered as a preset position by associating it with a predetermined number (preset number). Furthermore, by inputting a preset number, the drive unit 107 and the imaging unit 106 can be driven to each position registered with the preset number, thereby reproducing the preset position. Furthermore, settings related to imaging, such as image quality and white balance, can also be associated with the preset number.

[0013] The PTZ camera 100 transmits a response to the control command received from the client device 200 to the client device 200. Furthermore, the PTZ camera 100 changes the imaging range of the PTZ camera 100 so as to track a subject detected by a detection unit 102 (described later) based on a composition setting received from the client device 200. The position of the subject in the captured image set by the composition setting at this time is hereinafter referred to as a target position. The PTZ camera 100 is controlled to keep the subject at the target position in the captured image. In this control system, the imaging range is changed by the client device 200 transmitting a control command to the PTZ camera 100, which has a driving unit 107 that drives the camera in horizontal and vertical directions. However, this is not limited to this. For example, the imaging direction of the camera may be changed by connecting a camera without a driving unit to an external device such as a camera platform having the driving unit 107, or the imaging range (zoom ratio) may be changed by connecting a control device to a removable interchangeable lens.

[0014] Next, an example of the functional configuration of the control device according to this embodiment will be described with reference to Fig. 2. Fig. 2 is a block diagram showing the functional configuration of the PTZ camera 100 according to this embodiment.

[0015] Note that some of the functional blocks shown in FIG. 2 are realized by causing a CPU or the like serving as a computer (not shown) included in the automatic photography system to execute a computer program stored in a memory serving as a storage medium (not shown).

[0016] However, some or all of these functions may be implemented by hardware, which may be a dedicated circuit (ASIC) or a processor (reconfigurable processor, DSP).

[0017] Furthermore, the functional blocks shown in FIG. 2 do not have to be housed in the same housing, and may be configured as separate devices connected to each other via signal paths.

[0018] The PTZ camera 100 includes a storage unit 101, a detection unit 102, a determination unit 103, a control unit 104, a communication unit 105, an imaging unit 106, a drive unit 107, and an internal bus 106 that enables mutual communication.

[0019] The storage unit 101 outputs the composition setting received from the communication unit 105 to the detection unit 102, the determination unit 103, and the control unit 104. Position information of the subject acquired from the detection unit 102 is output to the determination unit 103 and the control unit 104. Furthermore, in this embodiment, the composition setting includes at least information about the subject to be tracked and composition information, but may also include other information such as loss determination criteria for determining whether the subject to be tracked has been lost.

[0020] The detection unit 102 analyzes the video input from the imaging unit 106 based on the composition setting input from the storage unit 101, detects the tracking target, and stores the detection information in the storage unit 101. The detection unit 102 detects the position (center point) of the tracking target subject in the captured image by processing to detect objects from the captured image using a trained model. This is then stored in the storage unit 101 as position information of the subject. The subject position is information expressed in pixels [PIX], with the resolution of the captured image being the unit. In this embodiment, the detection result is position information of the tracking target within the screen, but other information such as size information and detection accuracy may also be included.

[0021] When the determination unit 103 acquires a new composition setting (target position) from the storage unit 101, it calculates the distance in the captured image between the acquired target position (second target position) and the immediately preceding target position (first target position) and determines whether the distance is equal to or less than a predetermined threshold. Furthermore, the determination result is transmitted to the control unit 104. At this time, the predetermined threshold may be changed depending on the zoom value. In this case, the zoom value (zoom ratio) of the captured image is also acquired from the storage unit 101. For example, when the zoom value of the PTZ camera 100 varies between 0 and 100, the predetermined threshold for a zoom value of 0 is set to be larger than the predetermined threshold for a zoom value of 100. In this way, when the composition setting is set so that the subject appears large in the captured image, the user can make detailed changes to the composition setting.

[0022] The control unit 104 controls the imaging unit 106 and the driving unit 107 based on the result of the determination by the determination unit 103, the composition setting and the position information of the subject acquired from the storage unit 101, and changes the imaging range.

[0023] The communication unit 105 communicates with external devices such as the client device 200 via the network 300. The communication unit 105 outputs information about an image captured by an imaging unit 106 (described later) to the client device 200, and outputs information input from the client device to the storage unit 101.

[0024] The imaging unit 106 changes the imaging range based on a control command obtained from the control unit 104. Furthermore, the imaging unit 106 outputs information such as a zoom value to the storage unit 101.

[0025] The driving unit 107 changes the imaging range based on a control command obtained from the control unit 104. Furthermore, the driving unit 107 outputs the current pan and tilt driving positions to the storage unit 101.

[0026] Next, the hardware configuration of the PTZ camera 100 in this embodiment will be described with reference to Fig. 3. The PTZ camera 100 in this embodiment has a CPU 1001, a ROM 1002, a RAM 1003, a network I / F 1004, and an internal bus 1005 that enables mutual communication.

[0027] The CPU 1001 controls the entire device by controlling each component of the PTZ camera 100. The CPU 1001 corresponds to the control unit 104, the detection unit 101, and the determination unit 103 in FIG.

[0028] The ROM 1002 is used as a permanent storage area for the OS, various programs, and various data, as well as a short-term storage area for various data. In FIG. 2, the ROM 1002 functions as part of the control unit 104.

[0029] The RAM 1003 is a volatile, high-speed storage device, such as a DRAM, into which the OS, various programs, and various data are loaded, and which is also used as a working area for the OS and various programs. The RAM 1003 corresponds to the storage unit 102 in FIG. 2.

[0030] The network I / F 1004 is an interface for connecting to the above-mentioned LAN 400, and is responsible for communication with external devices such as the client 200 and the camera platform 300 via a communication medium such as ETHERNET (registered trademark). The network I / F 1004 corresponds to the communication unit 105 in FIG. 2.

[0031] Next, the hardware configuration of the client device 200 in this embodiment will be described with reference to Fig. 3. The client device 200 in this embodiment has a CPU 2001, a ROM 2002, a RAM 2003, a network I / F 2004, a display unit 2005, an operation unit 2006, and an internal bus 2007 that enables intercommunication.

[0032] The CPU 2001 controls the entire client device 200 by controlling each component of the client device 200. In this embodiment, the CPU 2001 analyzes operation commands related to composition setting of an operation unit 2006 (described later) and outputs the commands as control commands to the PTZ camera 100 via the network I / F 2004.

[0033] The ROM 2002 is used as a permanent storage area for the OS, various programs, and various data, and is also used as a short-term storage area for various data.

[0034] The RAM 2003 is a volatile, high-speed storage device, such as a DRAM, into which the OS, various programs, and various data are loaded, and which is also used as a work area for the OS and various programs. In this embodiment, the RAM 2003 stores operation information input to an operation unit 2006, which will be described later.

[0035] The network I / F 2004 is an interface for connecting to the network 300 described above, and is responsible for communication with external devices such as the PTZ camera 100 via a communication medium such as ETHERNET (registered trademark).

[0036] The display unit 2005 is a display such as an LCD for displaying captured images acquired from the PTZ camera 100, various settings, and the like.

[0037] The operation unit 2006 is a mouse, keyboard, or the like for receiving operations from the user and outputting the received results to the CPU 2001. In this embodiment, composition change settings are received from the user and output to the CPU 2001 and RAM 2003.

[0038] Next, automatic tracking control when this embodiment is applied to automatic tracking photography in which a person is the subject to be tracked will be described with reference to FIGS. 4, 5 and 6. FIG.

[0039] In this embodiment, if a user issues an instruction to change the composition setting (target position) during tracking, and the amount of change in the target position is equal to or less than a threshold, the dead zone setting is changed to a narrower dead zone (second range) than the currently set dead zone (first range). Here, the amount of change in the target position refers to the distance (px) between the first target position and the second target position in the captured image. If the subject is subsequently detected to be located within the second range in the captured image, the dead zone setting is returned to the first range. Here, the dead zone refers to an area set within a predetermined range centered on the subject position. In this embodiment, the subject position is the center of the subject's face, but this is not limited thereto. For example, the subject position may be the center of gravity of the subject. If the subject detected by the detection unit 101 in the captured image is located within the dead zone, the control unit 104 does not change the imaging range. Furthermore, in this embodiment, the dead zone is a predetermined range centered on the subject position, but this is not limited thereto. For example, a predetermined range centered on the target position can achieve the same effect. The determination process in the determination unit 103 will be described with reference to FIG. 4, and the PTZ control determination will be described with reference to FIG.

[0040] In FIG. 4A, P101 and P102 represent the thresholds for the pan and tilt directions, respectively, used by the determination unit 103 when changing the target position. In this embodiment, the thresholds are set to 50% of the screen width of the captured image, and if both the pan and tilt are below the thresholds, it is determined that the change in the target position is below the predetermined threshold. However, this is not limited to this. For example, other information may be used for the determination, such as the PTZ speed at the time of the composition change, the subject speed, or the PTZ speed calculated based on the composition change. In FIGS. 4B and 4C, P111 represents the target position (first target position) and subject position before the target position is changed, and P112 represents the target position (second target position) changed by the user. P113 represents the change in the target position in the pan direction due to the setting change, and P114 represents the change in the target position in the tilt direction due to the setting change. In FIG. 4B, both P113 and P114 are below the set thresholds, so it is determined that the change in the target position is below the predetermined threshold. In FIG. 4C, the amount of change in the target position of P114 is below the threshold, but the amount of change in the target position of P113 is equal to or greater than the threshold, so it is determined that the amount of change in the target position is greater than the predetermined threshold.

[0041] In FIG. 5, P201 represents the target position and subject position before the target position is changed (first target position), and P202 represents the target position changed by the user (second target position). Dead zone F1 represents a preset dead zone (first range), and dead zone F2 represents a dead zone (second range) when it is determined that the change in the target position is equal to or less than a predetermined threshold. In FIG. 5A, both the pan / tilt direction values are below the predetermined threshold, so it is determined that the change in the target position is equal to or less than the predetermined threshold. At this time, the control unit 104 changes the dead zone used for control from the first range F1 to the second range F2. Furthermore, in FIG. 5A, the change in the dead zone causes the second target position P202 to fall outside the dead zone, so the pan / tilt direction and drive speed are calculated so that the target position falls within the dead zone. In this embodiment, the direction and speed of the PTZ are calculated according to the difference between the subject position and the target position, and the control unit 104 changes the imaging range by sending control commands to the imaging unit 106 and the driving unit 107. Furthermore, if the target position falls within the dead zone, the imaging range is not changed (PTZ control is stopped). For example, during PTZ control, if the second target position P202 falls within the second range as shown in FIG. 5(B), it is determined that the target position falls within the dead zone, and PTZ control is stopped. At this time, the set dead zone F2 (second range) is changed to the dead zone F1 (first range) (FIG. 5(C)).

[0042] Here, automatic tracking control when this embodiment is applied to automatic tracking photography in which a person is the target subject to be tracked will be described using the flowchart of Fig. 6. The flowchart of Fig. 6 is realized by loading an OS, various programs, and various data into a RAM (storage device) that temporarily stores a computer program executed by the CPU 1001, and executing the program by the CPU 1001. This flowchart also starts by acquiring a captured image from the PTZ camera 100, and is executed repeatedly until a command to end automatic tracking is received from the user.

[0043] In step S001, the detection unit 102 acquires video information (captured image) from the imaging unit 106. After acquiring the captured image, the process proceeds to step S002.

[0044] In step S002, the detection unit 102 detects the object to be tracked from the captured image. If the object to be tracked is detected, the detection unit 102 outputs its position information to the storage unit 101. After outputting the object's position information, the process proceeds to step S003. If the object to be tracked is not detected, step S002 is repeated until the object to be tracked is detected from the video information (captured image).

[0045] In step S003, the determination unit 103 acquires the composition setting (target position) from the storage unit 101. It then compares it with the currently set composition setting (target position). If the target position has been changed (YES in S003), the process proceeds to step S004. If the target position has not been changed (NO in S003), the process proceeds to step S009. At this time, if there is no currently set target position, initial information stored in advance in the PTZ camera 100 or the center point of the captured image is set as the target position.

[0046] In step S004, the determination unit 103 calculates the amount of change in the target position from the acquired target position (second target position) and the currently set target position (first target position), and determines whether the amount of change is equal to or less than a preset threshold. If true (YES in S004), proceed to step S005. If false (NO in step S004), proceed to S009.

[0047] In step S005, the control unit 104 sets the dead zone F1 (first range) that has been set to a dead zone F2 (second range) that is narrower than the first range. After the dead zone is set, the process proceeds to step S006.

[0048] In step S006, the control unit 104 calculates PTZ control information for the imaging unit 106 and the drive unit 107 based on a dead zone F2 (second range) narrower than the first range. Based on the PTZ control information, the control unit 104 outputs control commands to the imaging unit 106 and the drive unit 107 to perform PTZ control. The imaging unit 106 and the drive unit 107 change the imaging range based on the acquired control commands. After the control unit 104 outputs the control commands to the imaging unit 106 and the drive unit 107, the process proceeds to step S007.

[0049] In step S007, the control unit 103 determines whether the target position (second target position) is located within the dead zone F2 (second range). If the target position is located within the dead zone F2 (second range), the process proceeds to step S008. If the target position is not located within the dead zone F2 (second range), the process proceeds to step S006.

[0050] In step S008, the control unit 104 sets the dead zone to the dead zone F1 (first range). After setting the dead zone to the dead zone F1 (first range), the process proceeds to step S010.

[0051] In step S009, the control unit 104 calculates PTZ control information for the imaging unit 106 and the drive unit 107 based on the setting of the dead zone F1 (first range). Based on the PTZ control information, the control unit 104 outputs control commands to the imaging unit 106 and the drive unit 107 to perform PTZ control. The imaging unit 106 and the drive unit 107 change the imaging range based on the acquired control commands. After the control unit 104 outputs the control commands to the imaging unit 106 and the drive unit 107, the process proceeds to step S010.

[0052] In step S010, the process proceeds to step S001 if a command to stop automatic tracking and shooting has not been received from the client device 200. If a command to stop automatic tracking and shooting has been received, the process ends this flowchart.

[0053] As described above, when the target position is changed, by changing the range of the dead zone, it is possible to provide a captured image with the composition desired by the user, even if the user wishes to fine-tune the composition.

[0054] (Second embodiment) In the first embodiment, when the target position is changed during tracking, if the amount of change in the target position is equal to or less than a threshold, PTZ control is performed based on a dead zone (second range) narrower than a preset dead zone (first range).

[0055] In this embodiment, when the target position is changed during tracking, in addition to the first embodiment, in order to prevent PT disturbances due to narrowing the dead zone, PTZ control is performed so that the PTZ drive speed is slower than the PTZ drive speed (first speed) when the dead zone is set to the first range. Thereafter, when the subject position falls within the dead zone F2 (second range), PTZ control is stopped, the dead zone is returned to the dead zone F1 (first range), and the PTZ drive speed is returned to the first speed. When the subject position falls within the dead zone F2, the dead zone F2 is changed back to the dead zone F1, but this is not limited to this. For example, other conditions may be used, such as changing the dead zone setting back to the dead zone F1 after a certain time has elapsed since the dead zone F2 was set.

[0056] Here, automatic tracking control when this embodiment is applied to automatic tracking photography in which a person is the target subject to be tracked will be described using the flowchart of Fig. 7. The flowchart of Fig. 7 is realized by loading an OS, various programs, and various data into a RAM (storage device) that temporarily stores a computer program executed by the CPU 1001, and executing the program by the CPU 1001. This flowchart also starts by acquiring a captured image from the PTZ camera 100, and is repeatedly executed until a command to end automatic tracking is received from the user. The processing from steps S001 to S010 is the same as in the first embodiment, so description thereof will be omitted.

[0057] In step S201, the control unit 103 determines whether the target position (second target position) is located within the dead zone F1 (first range). If the target position (second target position) is located within the dead zone F1 (first range), the process proceeds to step S202. If the target position (second target position) is not located within the dead zone F1 (first range), the process proceeds to step S204.

[0058] In step S202, the control unit 103 sets the set speed for driving the imaging unit 106 and the drive unit 107 to a second speed that is slower (lower) than the set speed (first speed) when the dead zone setting is dead zone F1. After changing the set speed, the process proceeds to step S203.

[0059] In step S203, the control unit 103 calculates PTZ control information for the imaging unit 106 and the driving unit 107 based on the dead zone F2 and the second speed. After calculating the PTZ control information, the process proceeds to step S007.

[0060] In step S204, the control unit 103 calculates PTZ control information for the imaging unit 106 and the driving unit 107 based on the dead zone F2 and the first speed. After calculating the PTZ control information, the process proceeds to step S007.

[0061] In step S205, the control unit 103 calculates PTZ control information for the imaging unit 106 and the driving unit 107 based on the dead zone F1 and the first speed. After calculating the PTZ control information, the process proceeds to step S010.

[0062] As described above, by changing the range of the dead zone when the target position is changed, it is possible to provide a captured image with the user's desired composition even when the user wishes to fine-tune the composition. Furthermore, by slowing down the PTZ control speed when the dead zone is narrowed, it is possible to provide a captured image in which PT disturbance caused by narrowing the dead zone is suppressed.

[0063] (Third embodiment) In the first embodiment, when the target position is changed during tracking, if the amount of change in the target position is equal to or less than a threshold, PTZ control is performed based on a dead zone (second range) narrower than a preset dead zone (first range).

[0064] In this embodiment, if the target position changes during tracking, the dead zone setting is changed based on the amount of change in the target position and the current PTZ drive speed. This makes it possible to automatically track the subject so that it remains at the target position desired by the user when the drive speed used for PTZ control is variable or when a drive speed set by the user is used. Specifically, if the amount of change in the target position is equal to or less than a threshold and the current PTZ drive speed is equal to or less than a threshold, the dead zone setting is turned off. Furthermore, PTZ control is performed so that the position of the subject detected by the detection unit 104 matches the target position set by the user. This makes it possible to provide a captured image with the composition intended by the user while suppressing PT image distortion caused by eliminating the dead zone setting.

[0065] In this embodiment, if the change in the target position is equal to or less than the threshold and all PTZ speeds are slower than the threshold, the dead band setting is turned OFF, and PTZ control is performed so that the subject position matches the target position. Similarly, if the change in the target position is equal to or less than the threshold and at least one of the PTZ speeds is faster than the threshold, the dead band setting is set to dead band F2, and PTZ control is performed, as in the first embodiment. Thereafter, when the subject position matches the target position or is within dead band F2, the PTZ is stopped, and the dead band setting is changed to dead band F1. In this embodiment, when the subject position matches the target position or is within dead band F2, the dead band setting is changed to dead band F1, but this is not limited to this. For example, other conditions may be used, such as changing the dead band setting to dead band F1 after a certain period of time has elapsed since the dead band setting was turned OFF or set to dead band F2.

[0066] Here, automatic tracking control when this embodiment is applied to automatic tracking photography in which a person is the target subject to be tracked will be described using the flowchart of Fig. 8. The flowchart of Fig. 8 is realized by loading an OS, various programs, and various data into a RAM (storage device) that temporarily stores a computer program executed by the CPU 1001, and executing the program by the CPU 1001. This flowchart also starts by acquiring a captured image from the PTZ camera 100, and is repeatedly executed until a command to end automatic tracking is received from the user. The processing from steps S001 to S010 is the same as in the first embodiment, so description thereof will be omitted.

[0067] In step S301, the control unit 104 acquires the current PTZ speeds from the storage unit 101 and determines whether each is equal to or less than a set threshold. If each PTZ speed is equal to or less than a threshold, the process proceeds to step S302. If at least one of the PTZ speeds is greater than a threshold, the process proceeds to step S305.

[0068] In step S302, the control unit 104 calculates PTZ control information for the imaging unit 106 and the driving unit 107 so that the subject position detected by the detection unit 102 coincides with the target position. After calculating the PTZ control information, the process proceeds to step S303. In this embodiment, the dead zone setting is set to OFF, but this is not limiting. For example, the dead zone may be set to coincide with the subject position.

[0069] In step S303, the control unit 104 performs PTZ control by outputting control commands to the imaging unit 106 and the driving unit 107 based on the PTZ control information calculated in step S302. The imaging unit 106 and the driving unit 107 change the imaging range based on the acquired control commands. After the control unit 104 outputs the control commands to the imaging unit 106 and the driving unit 107, the process proceeds to step S304.

[0070] In step S304, the control unit 104 determines whether the subject position detected by the detection unit 102 matches the target position. If it is determined that they match, the process proceeds to step S008. If it is determined that they do not match, the process proceeds to step S303. Here, it is described that the process proceeds to step S008 when the subject position matches the target position, but this is not limited to this. For example, it may be determined that the target position and the subject position match when the target position and the subject position match for a predetermined number of seconds or a predetermined number of times. It may also be determined that the target position and the subject position match when a predetermined time has passed after PTZ control.

[0071] As described above, in this embodiment, if the amount of change in the target position is equal to or less than a threshold and the PTZ speed is equal to or less than a threshold, PTZ control is performed so that the target position and the subject position coincide. This makes it possible to automatically track the subject so that it remains at the target position desired by the user when the drive speed used for PTZ control is variable or when a drive speed set by the user is used.

[0072] Furthermore, in the first to third embodiments, the PTZ camera 100 and the driving unit 107 have been described as being integrated, but this is not limiting. If the PTZ camera 100 and the driving unit 107 are separate, the client device 200 transmits a control instruction to an external device, such as a camera platform, that has the driving unit 107. Alternatively, the client device 200 can issue a control instruction to an external device, such as a camera platform, that has the driving unit 107 via the PTZ camera 100, thereby driving the driving unit 107 and enabling remote control of the imaging direction of the camera 100.

[0073] Although the preferred 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. [Explanation of symbols]

[0074] 100 PTZ cameras 101 Storage section 102 Detection unit 103 Judgment section 104 Control Unit 106 Imaging unit 107 Drive Unit

Claims

1. A control device having a control means for executing a process for controlling an imaging direction so that a position of a subject in an image captured by an imaging device is kept at a target position, an acquisition means for acquiring a setting for a second target position different from the first target position set in the target position; a calculation means for calculating a distance between the first target position and the second target position in the captured image; and When the acquisition means acquires a change in the target position, the control means changes the dead zone in accordance with the distance between the first target position and the second target position. A control device characterized by:

2. When the distance calculated by the calculation means is greater than a predetermined threshold, the control means changes the imaging direction so that the second target position in the captured image remains within a first dead zone; when the distance calculated by the calculation means is equal to or less than a predetermined threshold, the control means changes the imaging direction so that the second target position remains within a second dead zone; the first dead zone and the second dead zone are ranges centered on the position of the subject, the first dead band is smaller than the second dead band; 2. The control device according to claim 1.

3. the distance between the first target position and the second target position indicates a distance in a pan direction and a distance in a tilt direction in the captured image, The calculation means determining that the distance calculated by the calculation means is greater than a predetermined threshold value when at least one of the distance in the pan direction and the distance in the tilt direction is greater than a predetermined threshold value; a determining unit that determines that the distance calculated by the calculating unit is equal to or less than a predetermined threshold when both the distance in the pan direction and the distance in the tilt direction are equal to or less than the predetermined threshold; 3. The control device according to claim 2.

4. when the control means determines that the second target position is included in the second dead zone, the control means changes the imaging direction so that the second target position remains within the first range.

4. The control device according to claim 3.

5. when it is determined that the distance calculated by the calculation means is greater than a predetermined threshold, the control means controls the imaging direction at a first speed so that the second target position remains within the first dead zone; when it is determined that the distance calculated by the calculation means is equal to or less than a predetermined threshold, the imaging direction is controlled so that the second target position is kept within the second dead zone at a second speed; 5. The control device of claim 4, wherein the second speed is slower than the first speed.

6. When it is determined that the distance calculated by the calculation means is greater than a predetermined threshold, the control means changes the imaging direction at a first speed so as to keep the second target position within the first range; when it is determined that the distance calculated by the calculation means is equal to or less than a predetermined threshold value and when the second target position is not included in the first dead zone, changing the imaging direction so that the second target position remains in the second dead zone at the first speed; when it is determined that the distance calculated by the calculation means is equal to or less than a predetermined threshold value and when the second target position is included in the first dead zone, changing the imaging direction at the second speed so that the second target position remains within the second dead zone; 5. The control device according to claim 4.

7. When the distance calculated by the calculation means is equal to or smaller than a predetermined threshold and the control speed of the imaging direction is equal to or smaller than a predetermined threshold, the imaging direction is controlled so that the position of the subject coincides with the second target position.

4. The control device according to claim 3.

8. The control speed of the imaging direction refers to the control speed of each of the pan and tilt of the imaging device, The control means determining that the control speed is greater than a predetermined threshold when at least one of the pan and tilt control speeds of the imaging device is greater than a predetermined threshold; determining that the control speeds are equal to or less than a predetermined threshold when all of the pan and tilt control speeds of the imaging device are equal to or less than a predetermined threshold; 8. The control device according to claim 7.

9. when the control means determines that the position of the subject coincides with the second target position, the control means changes the imaging direction so that the second target position remains within the first dead zone; 9. The control device according to claim 8.

10. 1. A control method for a control device, comprising a control step of executing a process for controlling an imaging direction so that a position of a subject in an image captured by an imaging device is kept at a target position, an acquisition step of acquiring a setting for a second target position different from a first target position that is set in advance to the target position; a calculation step of calculating a distance between the first target position and the second target position in the captured image; and When a change in the target position is acquired in the acquiring step, in the control step, the control means changes the dead zone in accordance with a distance between the first target position and the second target position. A control device characterized by:

11. A program for causing a computer to execute the control method according to claim 10.

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