Imaging system

Abstract

To appropriately indicate a photographing direction of an imaging apparatus.SOLUTION: An imaging system has a first imaging apparatus and a second imaging apparatus. The first imaging apparatus has control means that, when a subject is present in a video photographed by a first imaging unit, controls a photographing direction of the first imaging apparatus to track the subject, and when a subject is not present in the video photographed by the first imaging unit, controls the photographing direction of the first imaging apparatus according an indication from the second imaging apparatus. The second imaging apparatus has inclination acquisition means that acquires the amount of inclination of the first imaging apparatus relative to the second imaging apparatus on the basis of a radio wave received from the first imaging apparatus, and indication means that indicates the photographing direction of the first imaging apparatus to the first imaging apparatus so that the first imaging apparatus can capture the subject in its angle of view on the basis of the inclination amount.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] In recent years, remote cameras that can control pan, tilt, and zoom have become known. Some of these remote cameras have a function (automatic tracking) that automatically controls the imaging direction so that the subject is kept within the screen. Hereinafter, pan, tilt, and zoom will be abbreviated as PTZ.

[0003] Here, if a subject is displayed large on the screen and moves quickly, the camera's PTZ control may not be able to track it in time, resulting in the subject being lost. In such cases, one method is to resume tracking of the subject by using a camera that keeps the subject captured on the screen with a wider imaging range, separate from the camera that tracks the subject. Hereinafter, the camera that tracks the subject will be referred to as a PTZ camera, and the camera that keeps the subject captured on the screen with a wide imaging range will be referred to as a bird's-eye view camera.

[0004] With this method, the relative position between the PTZ camera and the overhead camera is measured in advance. When the PTZ camera loses track of the subject, a PTZ command is generated that enables the PTZ camera to recapture the subject based on the position information of the subject that the overhead camera continues to capture and the relative position information that was measured in advance. The PTZ camera then performs PTZ drive based on this PTZ command, allowing it to resume tracking of the subject.

[0005] If the relative position between the PTZ camera and the overhead camera is measured manually, the measurement information may be inaccurate, and a PTZ command may be generated for a misaligned position.

[0006] Patent Document 1 discloses a method for acquiring the relative positions of an imaging device and another imaging device using a wireless positioning technique using Bluetooth (registered trademark) or Wi-Fi (registered trademark) as a method for measuring the relative positions.

[0007] Patent Document 2 discloses a method in which, when movement occurs between two imaging devices whose relative positions are calculated using a common marker, the amount of positional shift is calculated from the difference in feature points between a background image captured in advance and a background image captured after the movement, and the shift is reflected in a relative position conversion formula. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2023-25897 [Patent Document 2] Japanese Patent Publication No. 2022-101959 Summary of the Invention [Problem to be solved by the invention]

[0009] However, in Patent Document 1, the wireless positioning method cannot detect the tilt between the imaging devices, so if the front position of the PTZ camera's platform is not parallel to the front position of the overhead camera, a PTZ command for a shifted position will be generated. As a result, when a PTZ command for a shifted position is used, it becomes difficult to fit the subject within the angle of view.

[0010] In Patent Document 2, the calculation of the amount of deviation requires that the background be one in which there is an object that does not move semi-permanently, and there are restrictions on the locations where it can be used, such as the fact that calculation is not possible if there is no common object as a result of the deviation.

[0011] An object of the present disclosure is to enable appropriate instruction of the shooting direction of an imaging device. [Means for solving the problem]

[0012] The imaging system includes a first imaging device and a second imaging device, and the first imaging device has a control means for controlling the imaging direction of the first imaging device so as to track the subject when a subject is present in the image captured by the first imaging unit, and for controlling the imaging direction of the first imaging device in accordance with instructions from the second imaging device when a subject is not present in the image captured by the first imaging unit, and the second imaging device has a tilt acquisition means for acquiring the amount of tilt of the first imaging device relative to the second imaging device based on radio waves received from the first imaging device, and an instruction means for instructing the first imaging device on the imaging direction of the first imaging device based on the amount of tilt so that the first imaging device can capture the subject within its angle of view. [Effects of the Invention]

[0013] According to the present disclosure, it is possible to appropriately instruct the shooting direction of an imaging device. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of an imaging system. [Figure 2] FIG. 1 illustrates an example of the configuration of an imaging device. [Figure 3] 10 is a flowchart of a PTZ command generation process. [Figure 4] 10A and 10B are diagrams illustrating an example of a method for acquiring the tilt amount of an imaging device. [Figure 5] 10 is a flowchart of a position identification process. [Figure 6] 10 is a flowchart of a process using one wireless transmission device. DETAILED DESCRIPTION OF THE INVENTION

[0015] Preferred embodiments will be described in detail below with reference to the drawings. Note that the following embodiments do not limit the scope of the claims, and not all of the combinations of features described in the embodiments are necessarily essential to the solution. Note that the same components will be described with the same reference numerals.

[0016] (First embodiment) 1 is a diagram showing an example of the configuration of an imaging system 100 according to the first embodiment. The imaging system 100 includes an imaging device 101, an imaging device 102, an information terminal 103, a wireless network 104, and a network 105, and captures an image of a subject 106.

[0017] The imaging devices 101 and 102 continuously capture a subject 106 in an image, and are capable of video distribution and camera control via a wired or wireless network 105. The imaging devices 101 and 102 each incorporate a wireless communication module that complies with the direction detection function of the Bluetooth (registered trademark) 5.1 specification, and are connected to each other via a wireless network 104. Note that while FIG. 1 illustrates a configuration with two imaging devices, the imaging device 101 and the imaging device 102, the configuration is not limited to this, and three or more devices may be used.

[0018] The information terminal 103 is connected to the image capturing apparatus 101 and the image capturing apparatus 102 via a network 105, and controls the image capturing apparatus 101 and the image capturing apparatus 102 and outputs information via a browser.

[0019] The wireless network 104 enables mutual communication between the image capturing apparatus 101 and the image capturing apparatus 102 in accordance with wireless communication standards such as Bluetooth (registered trademark) and UWB (Ultra Wide Band).

[0020] The network 105 is a network for distributing the images captured by the image capturing devices 101 and 102 to an external recording server, etc. In this embodiment, the communication format of the network 105 is a wired LAN, but it may also be a wireless LAN.

[0021] Fig. 2 is a diagram showing an example of the configuration of the imaging device 101 and the imaging device 102 in Fig. 1. The imaging device 101 has an imaging unit 201, a lens control unit 202, a driving unit 203, a camera signal processing unit 204, a video analysis unit 205, a wired communication processing unit 206, a wireless communication processing unit 207, a storage unit 208, and a CPU 209. Each unit will be described below.

[0022] 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 on the optical axis by the lens control unit 202. The aperture is operated by the lens control unit 202. The image sensor converts light that has passed through the zoom lens, the focus lens, and the aperture into an electrical signal by photoelectric effect, and converts it into a digital signal by A / D conversion.

[0023] The driving unit 203 has a pan driving unit and a tilt driving unit, and can rotate the imaging unit 201 in the horizontal and vertical directions by controlling it via an actuator (not shown).

[0024] The camera signal processing unit 204 generates a video signal by performing various image processing on the digital signal from the imaging unit 201. Here, the various image processing includes scratch correction, chromatic aberration correction, gamma processing, noise reduction processing, and the like.

[0025] The video analysis unit 205 is a processing unit that analyzes video and performs various detection processes such as human body detection and face detection. In this embodiment, the video analysis unit 205 uses human body detection and face detection as video analysis processes for identifying the position of the subject 106.

[0026] The wired communication processing unit 206 processes network communications with the information terminal 103 via the network 105 .

[0027] The wireless communication processing unit 207 processes wireless communication with the wireless communication processing unit 214 via the wireless network 104. In this embodiment, the wireless communication processing unit 207 is included in a wireless communication module that complies with the specifications of Bluetooth (registered trademark) or UWB (Ultra Wide Band). These wireless communication modules are attached at a position in front of the camera platform of the imaging device 101 and at a position rotated 180 degrees from the position in front of the camera platform around the center of the camera platform.

[0028] The "front" refers to a direction parallel to the direction in which the lens faces when the imaging device 101 is started and the initial drive is completed. In this embodiment, the wireless communication module is attached to a camera platform, but it may also be attached to a position linked to the PTZ mechanism.

[0029] The storage unit 208 includes RAM, ROM, and a storage device (not shown). The RAM is a volatile memory such as an SRAM or DRAM. The ROM is a non-volatile memory such as an EEPROM or flash memory. The storage device is an HDD, SSD, or the like.

[0030] The programs for realizing the functions of this embodiment and the data used when the programs are executed are stored in a ROM or a storage device. These programs and data are loaded into a RAM as appropriate under the control of a CPU 209, and are executed by the CPU 209 to function as each unit in this embodiment.

[0031] The CPU 209 is a central processing unit. The CPU 209 includes a video analysis position specifying unit 209-1, a tracking system control unit 209-2, a lost determination unit 209-3, and a PTZ control unit 209-4 according to this embodiment. Each unit will be described below.

[0032] Video analysis position specifying unit 209-1 specifies the position of subject 106 in the image based on the human body or face detection result by video analysis unit 205.

[0033] The tracking system control unit 209-2 controls the tracking of the subject 106 based on various parameters set in advance by the user.

[0034] The lost determination unit 209-3 determines whether or not it is possible to continue tracking the subject 106. For example, when the lost determination unit 209-3 determines that the subject 106 has been lost, it notifies the imaging device 102 that the subject 106 has been lost.

[0035] The PTZ control unit 209-4 controls the pan-tilt-zoom drive using the lens control unit 202 and the drive unit 203, based on the position of the subject 106 acquired by the position identification of the video analysis position identification unit 209-1 or the PTZ command generation unit 217-4. The PTZ control unit 209-4 controls the pan-tilt-zoom drive so that the shooting direction of the imaging device 101 is directed toward the position of the subject 106, thereby enabling automatic tracking of the subject 106.

[0036] The imaging device 102 includes an imaging unit 210, a lens control unit 211, a camera signal processing unit 212, a video analysis unit 213, a wireless communication processing unit 214, a wired communication processing unit 215, a storage unit 216, and a CPU 217. Each unit will be described below.

[0037] The imaging unit 210 has a zoom lens, a focus lens, an aperture, and an image sensor. The zoom lens and the focus lens are moved on the optical axis by a lens control unit 211. The aperture is operated by the lens control unit 211. The image sensor converts light that has passed through the zoom lens, the focus lens, and the aperture into an electrical signal by photoelectric effect, and converts it into a digital signal by A / D conversion.

[0038] The camera signal processing unit 212 generates a video signal by performing various image processing on the digital signal from the imaging unit 210. Here, the various image processing includes scratch correction, chromatic aberration correction, gamma processing, noise reduction processing, and the like.

[0039] The video analysis unit 213 is a processing unit that analyzes video and performs various detection processes such as human body detection and face detection. In this embodiment, the video analysis unit 213 uses human body detection and face detection as video analysis processes for identifying the position of the subject 106.

[0040] The wireless communication processing unit 214 processes wireless communication with the wireless communication processing unit 207 via the wireless network 104. In this embodiment, the wireless communication processing unit 214 is included in a wireless communication module that complies with the specifications of Bluetooth (registered trademark) or UWB (Ultra Wide Band), and this wireless module is attached to a position in front of the image capture device 102.

[0041] The front is defined as a direction parallel to the direction in which the lens faces when the imaging device 102 is started and the initial drive is completed.

[0042] The wired communication processing unit 215 processes network communications with the information terminal 103 via the network 105 .

[0043] The storage unit 216 includes RAM, ROM, and a storage device (not shown). The RAM is a volatile memory such as an SRAM or DRAM. The ROM is a non-volatile memory such as an EEPROM or flash memory. The storage device is an HDD, SSD, or the like.

[0044] The programs for realizing the functions of this embodiment and the data used when the programs are executed are stored in a ROM or a storage device. These programs and data are loaded into a RAM as appropriate under the control of a CPU 217, and are executed by the CPU 217 to function as the various components of this embodiment.

[0045] The CPU 217 is a central processing unit. The CPU 217 includes a video analysis position specifying unit 217-1, a wireless position specifying unit 217-2, a tilt specifying unit 217-3, and a PTZ command generating unit 217-4 according to this embodiment. Each unit will be described below.

[0046] Video analysis position specifying unit 217-1 specifies the position of subject 106 in the image based on the human body or face detection result by video analysis unit 213.

[0047] The wireless position determination unit 217-2 calculates the direction of arrival of radio waves transmitted from the two wireless modules attached to the image capture device 101, and determines the relative position of each wireless module with respect to the front of the image capture device 102. For example, a direction detection function conforming to the Bluetooth (registered trademark) 5.1 specification can be used to determine the relative position. Alternatively, a determination method such as Angle of Departure (AoD) can also be used to determine the relative position.

[0048] The tilt specification unit 217-3 calculates the tilt of the front position of the camera platform of the image capturing device 101 relative to the front position of the image capturing device 102. Details of this will be described later with reference to FIG.

[0049] The PTZ command generation unit 217-4 calculates the pan / tilt / zoom drive amount to orient the imaging direction of the imaging device 101 toward the position of the subject 106, based on the position of the subject 106 acquired by the video analysis position identification unit 217-1, the position of the imaging device 101 relative to the imaging device 102 acquired by the wireless position identification unit 217-2, and the tilt amount acquired by the tilt identification unit 217-3.

[0050] 3 is a flowchart showing a method for controlling the image capturing apparatus 101 and the image capturing apparatus 102. An example of a PTZ command generation process is shown in the flowchart of FIG. 3. Steps S301 to S304 and S313 to S314 are processes performed by the image capturing apparatus 101. Steps S305 to S312 are processes performed by the image capturing apparatus 102.

[0051] In step S301, the imaging unit 201 converts light that has passed through the zoom lens, focus lens, and diaphragm into an electrical signal by photoelectric effect, and then converts it into a digital signal by A / D conversion. The camera signal processing unit 204 performs various image processing on the digital signal from the imaging unit 201 to generate a video signal. The video analysis unit 205 performs video analysis on the video signal generated by the camera signal processing unit 204 to detect the human body or face of the subject 106.

[0052] Here, there are cases where the video analysis results in failure to detect the subject 106. For example, when the subject 106 moves from within the angle of view to outside the angle of view, or when the subject 106 is behind an obstacle, it becomes difficult to detect a human body and face through video analysis, and the video analysis unit 205 fails to detect the subject 106.

[0053] Video analysis position identification unit 209-1 acquires position information of subject 106 in the video captured by imaging unit 201 based on the result of human body or face detection by video analysis unit 205.

[0054] In step S302, video analysis position identification unit 209-1 determines, based on step S301, whether or not subject 106 is present in the video captured by imaging unit 201. If subject 106 is present in the video, the process proceeds to step S303. If subject 106 is not present in the video, the process proceeds to step S304.

[0055] In step S303, the PTZ control unit 209-4 performs pan-tilt-zoom driving based on the position of the subject 106 identified in step S302 so that the center of the body or face of the subject 106 is located at the center of the screen. The PTZ control unit 209-4 controls the shooting direction of the imaging device 101 by this pan-tilt-zoom driving so as to track the subject 106. The shooting direction of the imaging device 101 includes information on the pan, tilt, and zoom of the imaging device 101. Then, the process returns to step S301.

[0056] Here, pan driving is horizontal movement of the imaging unit 201 by the pan driving unit of the driving unit 203. Tilt driving is vertical movement of the imaging unit 201 by the pan driving unit of the driving unit 203. Zoom driving is movement of the zoom lens of the imaging unit 201 by the lens control unit 202.

[0057] In step S304, the CPU 209 transmits to the image capture device 102 a lost notification of the subject 106 indicating that the subject 106 does not exist in the video captured by the image capture unit 201 as a result of the video analysis in step S302.

[0058] In step S305, the imaging unit 210 converts light that has passed through the zoom lens, focus lens, and diaphragm into an electrical signal by photoelectric effect, and then converts it into a digital signal by A / D conversion. The camera signal processing unit 212 performs various image processing on the digital signal from the imaging unit 210 to generate a video signal. The video analysis unit 213 performs video analysis on the video signal generated by the camera signal processing unit 212 to detect the human body or face of the subject 106.

[0059] Here, as a result of the video analysis, there are cases where it is not possible to detect the subject 106. For example, when the subject 106 moves from within the angle of view to outside the angle of view, or when the subject 106 is behind an obstacle, it becomes difficult to detect a human body and face through video analysis, and the detection by the video analysis unit 213 fails.

[0060] Video analysis position identification section 217-1 acquires position information of subject 106 in the video captured by imaging section 210 based on the result of human body or face detection by video analysis section 213.

[0061] In step S306, video analysis position identification unit 217-1 determines, based on step S305, whether or not subject 106 is present in the video captured by imaging unit 210. If subject 106 is present in the video, the process proceeds to step S307. If subject 106 is not present in the video, the process returns to step S305.

[0062] In step S307, the wireless position determining unit 217-2 receives radio waves transmitted from the two wireless transmission devices 401 and 402 attached to the imaging device 101 in Fig. 4 via the wireless receiving device 403 attached to the imaging device 102 in Fig. 4. Then, the wireless position determining unit 217-2 acquires the azimuth angle, elevation angle, and distance, which are position information of the wireless transmission devices 401 and 402 relative to the wireless receiving device 403, based on the radio waves received from the wireless transmission devices 401 and 402. The wireless position determining unit 217-2 acquires the position information (azimuth angle, elevation angle, and distance) of the wireless transmission device 401 relative to the wireless receiving device 403, and the position information (azimuth angle, elevation angle, and distance) of the wireless transmission device 402 relative to the wireless receiving device 403. The wireless position determining unit 217-2 can determine the positions of the two wireless transmission devices 401 and 402 relative to the wireless receiving device 403 using this acquired position information.

[0063] In step S308, the wireless location identification unit 217-2 determines whether the location information acquired in step S307 has changed from the previously acquired location information. If there has been a change, the process proceeds to step S309. If there has not been a change, the process proceeds to step S310.

[0064] In step S309, the tilt identification unit 217-3 calculates (acquires) the amount of tilt of the image capture device 101 with respect to the image capture device 102, based on the position information of the two wireless transmission devices 401 and 402 acquired in step S307. Details of this will be described later with reference to FIG.

[0065] In step S310, the PTZ command generation unit 217-4 generates a PTZ command based on the position information of the subject 106 acquired in step S305, the position information of the two wireless transmission devices 401 and 402 acquired in step S307, and the tilt amount of the imaging device 101 relative to the imaging device 102 calculated in step S309, so that the imaging device 101 can capture the subject 106 within its angle of view.

[0066] In step S311, the PTZ command generation unit 217-4 determines whether or not a lost notification of the subject 106 has been received from the imaging device 101. If a lost notification has been received, the process proceeds to step S312. If a lost notification has not been received, the process returns to step S305.

[0067] In step S312, the PTZ command generation unit 217-4 transmits the PTZ command generated in step S310 to the image capturing device 101. By transmitting the PTZ command, the PTZ command generation unit 217-4 instructs the image capturing direction of the image capturing device 101 so that the image capturing device 101 can capture the subject 106 within the angle of view.

[0068] In step S313, the PTZ control unit 209-4 of the image capturing device 101 receives the PTZ command transmitted from the image capturing device 102 in step S312.

[0069] In this embodiment, after the subject 106 is lost, the imaging device 101 receives a PTZ command from the imaging device 102, but this is not limiting. For example, the imaging device 101 may receive a PTZ command from the imaging device 102 at regular intervals, record the command in the storage unit 208, and read out the PTZ command recorded in the storage unit 208 when the subject 106 is lost.

[0070] In step S314, the PTZ control unit 209-4 performs pan-tilt-zoom driving based on the PTZ command received in step S313 so that the lost subject 106 can be captured within the angle of view. The PTZ control unit 209-4 controls the shooting direction of the imaging device 101 by this pan-tilt-zoom driving so that the imaging device 101 can capture the subject 106 within the angle of view.

[0071] Next, an example of the detailed processing of step S309 will be described with reference to Fig. 4. Fig. 4 is a diagram showing an example in which the imaging directions of the imaging devices 101 and 102 are different. The wireless receiving device 403 attached to the imaging device 102 receives radio waves transmitted from the wireless transmitting devices 401 and 402 attached to the imaging device 101.

[0072] In this embodiment, wireless transmission device 401 is attached to a position in front of the camera platform. Wireless transmission device 402 is attached to a position rotated 180 degrees from the front of the camera platform around the center of the camera platform. The attachment positions of wireless transmission devices 401 and 402 are not limited to this.

[0073] For example, wireless transmitting device 401 may be mounted in a position in front of the camera and linked to the PTZ mechanism, and wireless transmitting device 402 may be mounted in a position rotated 180 degrees from the front of the camera around the center of the PTZ mechanism as an axis and linked to the PTZ mechanism.

[0074] Wireless transmitting device 401 transmits radio waves from the position of wireless transmitting device 401. Wireless transmitting device 402 transmits radio waves from a position of wireless transmitting device 402 that is different from the position of wireless transmitting device 401. Wireless receiving device 403 receives radio waves from wireless transmitting device 401 and radio waves from wireless transmitting device 402.

[0075] The wireless position specifying unit 217-2 calculates the direction of arrival of the radio waves received by the wireless receiving device 403 from the wireless transmitting devices 401 and 402. Based on the direction of arrival of the radio waves, the wireless position specifying unit 217-2 calculates the distance d1 of the wireless transmitting device 401 to the wireless receiving device 403 and the azimuth angle φ x , elevation angle φ y , and the distance d2 of the wireless transmitting device 402 to the wireless receiving device 403, and the azimuth angle ω x , elevation angle ω y Then, the wireless position specifying unit 217-2 obtains the obtained distances d1 and d2 and the azimuth angle φ x and ω x , and the elevation angle φ y and ω yThe tilt specifying unit 217-3 obtains the tilt amount θ of the image capturing device 101 with respect to the image capturing device 102 based on the output of the tilt specifying unit 217-3.

[0076] As described above, according to this embodiment, the wireless receiving device 403 of the imaging device 102 can obtain the amount of tilt between the two imaging devices 101 and 102 by using information on radio waves received from the wireless transmitting devices 401 and 402 of the imaging device 101. This allows the imaging device 102 to generate a PTZ command that takes into account the tilt of the imaging device 101, without any burden on the user.

[0077] For example, the imaging device 101 is an example of a PTZ camera, and the imaging device 102 is an example of an overhead camera. Even when the positional relationship between the imaging devices 101 and 102 is complex, the imaging device 102 can generate a PTZ command for the imaging device 101 to move to the correct position. Using the wireless transmitting devices 401 and 402 and the wireless receiving device 403, the imaging device 102 can generate a PTZ command that takes into account the amount of tilt between the two imaging devices 101 and 102, without burdening the user.

[0078] (Second embodiment) In the first embodiment, a method was shown in which radio waves transmitted from two wireless transmitting devices 401 and 402 were acquired by one wireless receiving device 403, and the amount of tilt between the two imaging devices 101 and 102 was calculated based on the acquired information.

[0079] However, with this method, if one of the two wireless transmission devices 401 and 402 becomes unusable, it may become impossible to obtain the tilt amount of the image capture device 101. For example, if the battery of either the wireless transmission device 401 or 402 runs out, radio wave transmission becomes impossible, making it difficult to obtain the tilt amount.

[0080] 5 and 6, a second embodiment will be described that can calculate the tilt amount of the image capture device 101 even when radio waves are received from one wireless transmission device. Note that the same components of the second embodiment as those of the first embodiment will be designated by the same reference numerals as those used in the first embodiment, and detailed descriptions thereof will be omitted.

[0081] In the second embodiment, wireless transmission devices 401 and 402 are attached to the imaging device 101. The wireless transmission device 401 is attached to a position in front of the imaging device 101 where it is interlocked with the PTZ mechanism. The wireless transmission device 402 is attached to a position rotated 180 degrees from the front of the imaging device 101 around the center of the PTZ mechanism as an axis and where it is interlocked with the PTZ mechanism.

[0082] Figure 5 adds steps S501 and S502 to Figure 3. The differences between Figure 5 and Figure 3 will be explained below. If a lost notification is received in step S311, the process proceeds to step S501. If a lost notification is not received, the process returns to step S305.

[0083] In step S501, the wireless location determination unit 217-2 determines whether or not radio waves were received in step S307 from each of the two wireless transmission devices 401 and 402 via the wireless communication processing unit 214. If radio waves were received from each of the wireless transmission devices 401 and 402, the process proceeds to processing step S312. If radio waves were not received from each of the wireless transmission devices 401 and 402, the process proceeds to step S502.

[0084] In step S502, the tilt identification unit 217-3 executes a process of calculating the tilt amount of the image capture device 101 with respect to the image capture device 102, using one of the wireless transmission devices 401 or 402 that has been able to receive radio waves. The details of this operation will be described with reference to FIG. 6.

[0085] Next, an example of the detailed processing of step S502 will be described with reference to the flowchart of FIG.

[0086] In step S611, the wireless location specifying unit 217-2 specifies one of the wireless transmitting devices 401 or 402 that is the source of the radio waves received by the wireless receiving device 403 in step S307.

[0087] In step S612, the wireless position determination unit 217-2 receives radio waves from the wireless transmission device 401 or 402 capable of wireless communication identified in step S611 via the wireless reception device 403. Then, the wireless position determination unit 217-2 acquires the azimuth angle, elevation angle, and distance from the identified wireless transmission device 401 or 402 to the wireless reception device 403 based on the received radio waves.

[0088] For example, if radio waves from wireless transmitting device 401 can be received but radio waves from wireless transmitting device 402 cannot be received, wireless transmitting device 401 transmits radio waves from a position in front of the camera platform. Wireless position specifying unit 217-2 receives radio waves from wireless transmitting device 401 and acquires the azimuth angle, elevation angle, and distance of wireless transmitting device 401 relative to wireless receiving device 403.

[0089] In step S613, the PTZ command generation unit 217-4 issues an instruction from the imaging device 102 to the imaging device 101 to perform 180-degree panning. For example, the PTZ command generation unit 217-4 instructs the imaging device 101 on the shooting direction (pan angle) of the imaging device 101 so that the wireless transmission device 401 is positioned 180 degrees rotated from the position in front of the camera platform. This causes the positions of the wireless transmission devices 401 and 402 to be swapped in the imaging device 101. In response to the instruction in step S613, the wireless transmission device 401 transmits radio waves from a position rotated 180 degrees from the position in front of the camera platform.

[0090] In step S614, the wireless position specifying unit 217-2 receives radio waves from the wireless transmission device 401 or 402 specified in step S611 via the wireless reception device 403 after having performed 180-degree panning in step S613. Then, the wireless position specifying unit 217-2 acquires the azimuth angle, elevation angle, and distance from the specified wireless transmission device 401 or 402 to the wireless reception device 403 based on the received radio waves.

[0091] For example, if radio waves from wireless transmitting device 401 can be received but radio waves from wireless transmitting device 402 cannot be received, wireless transmitting device 401 will transmit radio waves from a position rotated 180 degrees from the position in front of the camera platform. Wireless position specifying unit 217-2 receives radio waves from wireless transmitting device 401 and acquires the azimuth angle, elevation angle, and distance of wireless transmitting device 401 relative to wireless receiving device 403.

[0092] In step S615, the tilt identification unit 217-3 calculates (acquires) the amount of tilt of the image capturing device 101 relative to the image capturing device 102 using the azimuth angle, elevation angle, and distance acquired in step S612 and the azimuth angle, elevation angle, and distance acquired in step S614.

[0093] Here, if the pan position of the imaging device 101 is different from the front position of the camera platform in step S612, the tilt amount is the sum of the pan drive amount from the front position of the camera platform of the imaging device 101 and the tilt amount of the front position of the camera platform of the imaging device 101 relative to the front position of the imaging device 102. Therefore, the tilt identification unit 217-3 can calculate the tilt amount of the front position of the camera platform of the imaging device 101 relative to the front position of the imaging device 102 by subtracting the pan drive amount from the calculated tilt amount.

[0094] In step S310, the PTZ command generation unit 217-4 generates a PTZ command based on the position information of the subject 106 acquired in step S305, the position information of the two wireless transmission devices acquired in steps S612 and S614, and the tilt amount of the imaging device 101 relative to the imaging device 102 calculated in step S615, so that the imaging device 101 can capture the subject 106 within its angle of view.

[0095] After that, in step S312 of FIG. 5, the PTZ command generation unit 217-4 transmits the PTZ command generated in step S310 to the image capturing device 101.

[0096] As described above, according to this embodiment, even when radio waves cannot be received from one of the two wireless transmission devices 401 and 402 attached to the imaging device 101, the tilt amount can be obtained using one of the wireless transmission devices 401 or 402.

[0097] (Other embodiments) The present disclosure can also be realized by a process in which a program that realizes one or more functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in the computer of the system or device read and execute the program. The present disclosure can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0098] Although the above-described embodiments have been described, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist thereof.

[0099] The disclosure of this embodiment includes the following configuration, method, and program. (Configuration 1) a first imaging device; a second imaging device; the first imaging device, a control means for controlling the imaging direction of the first imaging device so as to track an object when an object is present in the image captured by the first imaging unit, and for controlling the imaging direction of the first imaging device in response to an instruction from the second imaging device when an object is not present in the image captured by the first imaging unit; the second imaging device, tilt acquisition means for acquiring an amount of tilt of the first imaging device with respect to the second imaging device based on radio waves received from the first imaging device; and an instruction means for instructing the first imaging device on a shooting direction of the first imaging device based on the tilt amount so that the first imaging device can capture a subject within an angle of view. (Configuration 2) the second imaging device further includes a first position acquisition means for acquiring position information of a subject in an image captured by the second imaging unit; The imaging system according to configuration 1, wherein the instruction means instructs the first imaging device on a shooting direction of the first imaging device based on the tilt amount and position information of the subject so that the first imaging device can capture the subject within an angle of view. (Configuration 3) the first imaging device further includes a wireless transmission device that transmits a first radio wave from the first position and transmits a second radio wave from a second position different from the first position; the second imaging device further includes a wireless receiving device that receives the first radio wave and the second radio wave; The imaging system according to configuration 2, wherein the tilt acquisition means acquires the amount of tilt of the first imaging device relative to the second imaging device based on the first radio wave and the second radio wave received by the wireless receiving device. (Configuration 4) The wireless transmission device a first wireless transmitting device that transmits the first radio wave from the first position; 4. The imaging system according to configuration 3, further comprising a second wireless transmitting device that transmits the second radio wave from the second position. (Configuration 5) 4. The imaging system according to configuration 3, wherein the wireless transmission device transmits the first radio wave from the first position and then transmits the second radio wave from the second position. (Configuration 6) the tilt acquisition means, when the wireless receiving device can receive the first radio wave of the first wireless transmitting device and the second radio wave of the second wireless transmitting device, acquires an amount of tilt of the first imaging device with respect to the second imaging device based on the first radio wave of the first wireless transmitting device and the second radio wave of the second wireless transmitting device; the instruction means instructs the first imaging device to change the imaging direction of the first imaging device so that the first wireless transmission device is at the second position when the wireless reception device can receive the first radio wave of the first wireless transmission device but cannot receive the second radio wave of the second wireless transmission device; the first wireless transmission device transmits a second radio wave from the second position in response to an instruction from the instruction means; The imaging system according to configuration 4, wherein the tilt acquisition means acquires the amount of tilt of the first imaging device relative to the second imaging device based on the first radio wave of the first wireless transmission device and the second radio wave of the first wireless transmission device when the wireless receiving device can receive the first radio wave of the first wireless transmission device but cannot receive the second radio wave of the second wireless transmission device. (Configuration 7) the second imaging device further includes a second position acquisition means for acquiring position information of the first position and position information of the second position based on the first radio wave and the second radio wave received by the wireless receiving device; The imaging system according to any one of configurations 3 to 6, wherein the tilt acquisition means acquires the amount of tilt of the first imaging device relative to the second imaging device based on position information of the first position and position information of the second position. (Configuration 8) The imaging system according to configuration 7, wherein the instruction means instructs the first imaging device on a shooting direction of the first imaging device based on the tilt amount, position information of the subject, position information of the first position, and position information of the second position so that the first imaging device can capture the subject within its angle of view. (Configuration 9) The imaging system according to configuration 7 or 8, wherein the second position acquisition means calculates the direction of arrival of the first radio wave and the direction of arrival of the second radio wave, and acquires position information of the first position and position information of the second position based on the direction of arrival of the first radio wave and the direction of arrival of the second radio wave. (Configuration 10) the location information of the first location includes a distance, an azimuth angle, and an elevation angle of the first location relative to the wireless receiving device; 10. The imaging system according to any one of configurations 7 to 9, wherein the position information of the second position includes a distance, an azimuth angle, and an elevation angle of the second position relative to the wireless receiving device. (Configuration 11) the first imaging device further comprises a transmission means for, when a subject does not exist in the video captured by the first imaging unit, transmitting to the second imaging device a message that the subject does not exist in the video; The imaging system according to any one of configurations 1 to 10, wherein the instruction means, when receiving information that a subject does not exist in the video, instructs the first imaging device on the shooting direction of the first imaging device so that the first imaging device can capture the subject within its angle of view. (Configuration 12) 11. The imaging system according to any one of configurations 1 to 10, wherein the control means receives an instruction from the second imaging device at regular intervals. (Configuration 13) 13. The imaging system according to any one of configurations 1 to 12, wherein the imaging direction of the first imaging device includes information on pan, tilt, and zoom of the first imaging device. (Configuration 14) the first wireless transmission device is provided in front of a camera platform of the first imaging device, 5. The imaging system according to configuration 4, wherein the second wireless transmission device is provided at a position rotated 180 degrees from a position in front of the camera platform of the second imaging device. (Configuration 15) An imaging device, tilt acquisition means for acquiring an amount of tilt of another imaging device relative to the imaging device based on radio waves received from the other imaging device; an instruction means for instructing the other imaging device on a shooting direction of the other imaging device based on the tilt amount so that the other imaging device can capture a subject within an angle of view; An imaging device comprising: (Configuration 16) An imaging device, An imaging device characterized by having a control means for controlling the imaging direction of the imaging device so as to track a subject when the subject is present in the video captured by the imaging unit, and for controlling the imaging direction of the imaging device in response to an instruction from another imaging device when the subject is not present in the video captured by the imaging unit. (Method 1) a first imaging device; a first imaging device and a second imaging device, a control step of controlling an imaging direction of the first imaging device so as to track an object when an object is present in the image captured by the first imaging unit, and controlling an imaging direction of the first imaging device in accordance with an instruction from the second imaging device when an object is not present in the image captured by the first imaging unit; a tilt acquisition step in which the second imaging device acquires an amount of tilt of the first imaging device with respect to the second imaging device based on radio waves received from the first imaging device; an instruction step in which the second imaging device instructs the first imaging device on a shooting direction of the first imaging device based on the tilt amount so that the first imaging device can capture a subject within an angle of view; 1. A method for controlling an imaging system, comprising: (Method 2) A control method for an imaging device, comprising: a tilt acquisition step of acquiring a tilt amount of the other imaging device relative to the imaging device based on radio waves received from the other imaging device; an instruction step of instructing the other imaging device on a shooting direction of the other imaging device based on the tilt amount so that the other imaging device can capture a subject within an angle of view; 10. A method for controlling an imaging device, comprising: (Method 3) A control method for an imaging device, comprising: A control method for an imaging device, comprising a control step of controlling the imaging direction of the imaging device so as to track a subject when the subject is present in the video captured by the imaging unit, and controlling the imaging direction of the imaging device in accordance with an instruction from another imaging device when the subject is not present in the video captured by the imaging unit. (Program 1) A program for causing a computer to function as the imaging system or imaging device according to any one of the first to sixteenth aspects. [Explanation of symbols]

[0100] 101 imaging device, 102 imaging device, 103 information terminal, 104 wireless network, 105 network, 106 subject, 201 imaging unit, 202 lens control unit, 203 driving unit, 204 camera signal processing unit, 205 video analysis unit, 206 wired communication processing unit, 207 wireless communication processing unit, 208 storage unit, 209 CPU, 209-1 video analysis position identification unit, 209-2 tracking system control unit, 209-3 lost determination unit, 209-4 PTZ control unit, 210 imaging unit, 211 lens control unit, 212 camera signal processing unit, 213 video analysis unit, 214 wireless communication processing unit, 215 wired communication processing unit, 216 storage unit, 217 CPU, 217-1 video analysis position identification unit, 217-2 wireless position identification unit, 217-3 tilt identification unit, 217-4 PTZ instruction generator

Claims

1. a first imaging device; a second imaging device; the first imaging device, a control means for controlling the imaging direction of the first imaging device so as to track an object when an object is present in the image captured by the first imaging unit, and for controlling the imaging direction of the first imaging device in response to an instruction from the second imaging device when an object is not present in the image captured by the first imaging unit; the second imaging device, a tilt acquisition unit that acquires a tilt amount of the first imaging device with respect to the second imaging device based on radio waves received from the first imaging device; and an instruction means for instructing the first imaging device on a shooting direction of the first imaging device based on the amount of tilt so that the first imaging device can capture a subject within an angle of view.

2. the second imaging device further includes a first position acquisition means for acquiring position information of a subject in an image captured by the second imaging unit; 2. The imaging system according to claim 1, wherein the instruction means instructs the first imaging device on a shooting direction of the first imaging device based on the tilt amount and position information of the subject so that the first imaging device can capture the subject within its angle of view.

3. the first imaging device further includes a wireless transmission device that transmits a first radio wave from the first position and transmits a second radio wave from a second position different from the first position; the second imaging device further includes a wireless receiving device that receives the first radio wave and the second radio wave; 3. The imaging system according to claim 2, wherein the tilt acquisition means acquires the amount of tilt of the first imaging device relative to the second imaging device based on the first radio wave and the second radio wave received by the wireless receiving device.

4. The wireless transmission device a first wireless transmitting device that transmits the first radio wave from the first position; 4. The imaging system according to claim 3, further comprising a second radio transmission device that transmits the second radio wave from the second position.

5. 4. The imaging system according to claim 3, wherein the wireless transmission device transmits the first radio wave from the first position, and then transmits the second radio wave from the second position.

6. the tilt acquisition means, when the wireless receiving device can receive the first radio wave of the first wireless transmitting device and the second radio wave of the second wireless transmitting device, acquires an amount of tilt of the first imaging device with respect to the second imaging device based on the first radio wave of the first wireless transmitting device and the second radio wave of the second wireless transmitting device; the instruction means instructs the first imaging device to change the imaging direction of the first imaging device so that the first wireless transmission device is at the second position when the wireless reception device can receive the first radio wave from the first wireless transmission device but cannot receive the second radio wave from the second wireless transmission device; the first wireless transmission device transmits a second radio wave from the second position in response to an instruction from the instruction means; 5. The imaging system according to claim 4, wherein the tilt acquisition means acquires the amount of tilt of the first imaging device relative to the second imaging device based on the first radio wave of the first wireless transmission device and the second radio wave of the first wireless transmission device when the wireless reception device can receive the first radio wave of the first wireless transmission device but cannot receive the second radio wave of the second wireless transmission device.

7. the second imaging device further includes a second position acquisition means for acquiring position information of the first position and position information of the second position based on the first radio wave and the second radio wave received by the wireless receiving device; 4. The imaging system according to claim 3, wherein the tilt acquisition means acquires the amount of tilt of the first imaging device relative to the second imaging device based on position information of the first position and position information of the second position.

8. 8. The imaging system according to claim 7, wherein the instruction means instructs the first imaging device on a shooting direction of the first imaging device based on the tilt amount, position information of the subject, position information of the first position, and position information of the second position so that the first imaging device can capture the subject within its angle of view.

9. The imaging system of claim 7, characterized in that the second position acquisition means calculates the direction of arrival of the first radio wave and the direction of arrival of the second radio wave, and acquires position information of the first position and position information of the second position based on the direction of arrival of the first radio wave and the direction of arrival of the second radio wave.

10. the location information of the first location includes a distance, an azimuth angle, and an elevation angle of the first location relative to the wireless receiving device; 8. The imaging system according to claim 7, wherein the position information of the second position includes a distance, an azimuth angle, and an elevation angle of the second position relative to the wireless receiving device.

11. the first imaging device further includes a transmission means for, when a subject does not exist in the video captured by the first imaging unit, transmitting to the second imaging device a message that the subject does not exist in the video; 2. The imaging system according to claim 1, wherein, when receiving a notification that a subject does not exist in the video, the instruction means instructs the first imaging device on a shooting direction of the first imaging device so that the first imaging device can capture the subject within its angle of view.

12. 2. The imaging system according to claim 1, wherein said control means receives instructions from said second imaging device at regular intervals.

13. 2. The imaging system according to claim 1, wherein the imaging direction of the first imaging device includes information on pan, tilt, and zoom of the first imaging device.

14. the first wireless transmission device is provided in front of a camera platform of the first imaging device, 5. The imaging system according to claim 4, wherein the second wireless transmission device is provided at a position rotated 180 degrees from a position in front of the camera platform of the second imaging device.

15. An imaging device, tilt acquisition means for acquiring an amount of tilt of another imaging device relative to the imaging device based on radio waves received from the other imaging device; an instruction means for instructing the other imaging device on a shooting direction of the other imaging device based on the tilt amount so that the other imaging device can capture a subject within an angle of view; An imaging device comprising:

16. An imaging device, An imaging device characterized by having a control means for controlling the imaging direction of the imaging device so as to track a subject when the subject is present in the video captured by the imaging unit, and for controlling the imaging direction of the imaging device in response to an instruction from another imaging device when the subject is not present in the video captured by the imaging unit.

17. a first imaging device; a first imaging device; and a second imaging device, a control step in which, when a subject is present in the video captured by the first imaging unit, the first imaging device controls the imaging direction of the first imaging device so as to track the subject, and, when a subject is not present in the video captured by the first imaging unit, controls the imaging direction of the first imaging device in accordance with an instruction from the second imaging device; a tilt acquisition step in which the second imaging device acquires a tilt amount of the first imaging device with respect to the second imaging device based on radio waves received from the first imaging device; an instruction step in which the second imaging device instructs the first imaging device on a shooting direction of the first imaging device based on the tilt amount so that the first imaging device can capture a subject within an angle of view; 1. A method for controlling an imaging system, comprising:

18. A control method for an imaging device, comprising: a tilt acquisition step of acquiring a tilt amount of the other imaging device relative to the imaging device based on radio waves received from the other imaging device; an instruction step of instructing the other imaging device on a shooting direction of the other imaging device based on the tilt amount so that the other imaging device can capture a subject within an angle of view; 10. A method for controlling an imaging device, comprising:

19. A control method for an imaging device, comprising: A control method for an imaging device, comprising a control step of controlling the imaging direction of the imaging device so as to track a subject when the subject is present in the video captured by the imaging unit, and controlling the imaging direction of the imaging device in accordance with an instruction from another imaging device when the subject is not present in the video captured by the imaging unit.

20. A program for causing a computer to function as the imaging system or imaging device according to any one of claims 1 to 16.

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