JP2009100454A - Moving object tracking control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control a photographing device so that the photographing device tracks a moving object with a small computational amount and high precision. <P>SOLUTION: The moving object tracking control device includes: a motion detection unit 44 for detecting movement from an image frame entered in time series; a centroid calculation unit 452 for calculating the detected centroid position of movement as a centroid position of the moving object; a centroid position analysis unit 455 for determines whether the calculated centroid position of the moving object is in a rotation reaction region, which is a region within a predetermined distance from a frame edge in each direction of the image frame or not; a movement speed calculation unit 456 for calculating the movement speed of the moving object; and a motor control unit 457 for generating a control signal for moving the photographing direction, by adding the amount of movement of the moving object, which is calculated from the movement speed of the moving object, to the distance between the centroid position of the moving object and the central position of the image frame when the movement object enters the rotation reaction region in the direction of movement destination through a center nearby region of the image frame, which is out of the rotation reaction region, and transmitting the signal to a monitor camera 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a moving object tracking control apparatus that controls an imaging apparatus to track a moving object in an image frame based on a motion detection result obtained from an image frame input in time series.

  2. Description of the Related Art Conventionally, in surveillance cameras and the like, a function of automatically tracking and shooting a moving object without using a panning and tilting control mechanism so that a supervisor can look at the screen and make control is known. Yes.

  In such a function, a background difference method for obtaining a luminance difference between a background image acquired in advance and an input image, a frame difference method for obtaining a luminance difference between previous and subsequent frames, and the like are used, and a moving object in the image is used. Is detected, the moving object is tracked.

Patent Document 1 describes means for detecting the movement of only the subject while the camera is rotating. In the motion detection device described in Patent Document 1, the center of the region where the motion is detected is calculated, and the pan and tilt drive motors are controlled at a speed corresponding to the distance from the center of the screen, thereby moving the moving object. Automatic tracking can be performed so that the center is smoothly centered on the screen.
JP 2006-229628 A

  However, if the motion detection device described in Patent Document 1 tries to detect the movement of a moving object while the camera is rotating, the amount of calculation for control increases compared to the background difference method and the frame difference method. Such motion detection and automatic tracking functions are often built into surveillance cameras, and when the amount of calculation increases as in Patent Document 1, a new surveillance camera is added to realize these functions. In addition, expensive hardware such as a microcomputer and DSP (Digital Signal Processor) must be mounted, leading to an increase in cost.

  Therefore, if it is attempted to detect the motion of a moving object with a small amount of calculation without using the technique described in Patent Document 1, the motion detection result must be acquired after the camera is temporarily stopped.

  The graph of FIG. 23 shows the relationship between the moving time and the moving distance of the camera having the pan and tilt control mechanism when the camera is pan-rotated at the maximum speed setting from the stationary state. As can be seen from the graph in the figure, the initial speed is very slow with respect to the maximum speed of the pan rotation that is the set value.

  For this reason, in order to perform automatic tracking using a method of detecting motion by temporarily stopping the camera, (1) obtaining a motion detection result, and (2) controlling the camera with a pan and tilt function toward the motion detection position. , (3) The camera must be stopped, and the three actions must be repeated, and the moving object may leave the screen while the camera is rotating with the slow initial motion during the camera control in (2). As a result, there is a problem that the function cannot be exhibited without tracking the moving object.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a moving object tracking control device that controls an imaging device so as to track a moving object with a small amount of calculation and high accuracy.

  In order to achieve the above object, the moving object tracking device (40A) of the present invention is configured to cause the imaging device (1) having a function of changing a shooting direction by rotation to track and photograph a moving object. The rotation of the shooting direction in (1) is controlled, and the latest image frame of the image frame shot and generated by the imaging device (1) input in time series is input before a predetermined period. A motion detection unit (44) that detects motion by comparing with an image frame, and a centroid calculation unit (452) that calculates the centroid position of the motion detected by the motion detection unit (44) as the centroid position of the moving object And whether the center of gravity position of the moving object calculated by the center-of-gravity calculation unit (452) is within a predetermined rotational reaction region that is within a predetermined distance from the frame end in each direction of the image frame. The center-of-gravity position analysis unit (455) for determining whether or not the center-of-gravity position of the moving object is determined to be in the region near the center of the image frame, which is a region outside the rotation reaction region. Sometimes, the gravity center position of the moving object calculated by the gravity center calculation unit (452) and the gravity center of the moving object calculated by the gravity center calculation unit (452) when an image frame is input before the predetermined period. A moving speed calculation unit (456) that calculates a moving speed of the moving object based on a difference between the position and a frame rate at which the image frame is input; and a center of gravity position of the moving object is outside the rotation reaction region. The gravity center position of the moving object calculated by the gravity center calculation unit (452) when entering the rotation reaction area in the movement destination direction via a region near the center of the image frame. By adding the moving amount of the moving object calculated based on the moving speed of the moving object calculated by the moving speed calculating unit (456) to the distance between the image frame and the center position of the image frame A motor control unit (457) that calculates the rotation distance of (1), generates a control signal for rotating the shooting direction of the imaging device (1) based on the rotation distance, and transmits the control signal to the imaging device (1). ).

  Further, the moving object tracking control device (40B) according to another embodiment of the present invention allows the imaging device (2) having a function of changing the imaging direction by rotation to track and image a moving object. 2) Controls the rotation of the photographing direction in 2), and the latest image frame and the image inputted before a predetermined period of the image frame photographed and generated by the imaging device (1) inputted in time series. A motion detection unit (44) that detects motion by comparing with a frame, and a centroid calculation unit (452) that calculates the centroid position of the motion detected by the motion detection unit (44) as the centroid position of the moving object; The gravity center position of the moving object calculated by the gravity center calculation unit (452) and the gravity center of the moving object calculated by the gravity center calculation unit (452) when an image frame is input before the predetermined period. A moving speed calculating unit (456) that calculates a moving speed of the moving object based on a difference between the moving image and a frame rate at which the image frame is input, and the movement calculated by the gravity center calculating unit (452). The moving distance of the moving object per unit time based on the gravity center position of the object and the gravity center position of the moving object calculated by the gravity center calculation unit (452) when the image frame is input before the predetermined period. A unit movement distance calculation unit (458) for calculating a unit movement distance, and a unit movement distance calculated by the unit movement distance calculation unit (458) calculated by the gravity center calculation unit (452). The final position where the center of gravity of the moving object is within the image frame when the center of gravity of the moving object is larger than the distance from the image frame end on the extension line in the moving direction of the moving object. A final position determination unit (459) that determines that the center of gravity of the moving object is determined to be a final position within an image frame by the final position determination unit (459). The moving object calculated on the basis of the moving speed of the moving object calculated by the moving speed calculating unit (456) is calculated based on the distance between the center of gravity of the moving object calculated in (4) and the center position of the image frame. The rotational distance of the imaging device (2) is calculated by adding the movement amount of the imaging device, and a control signal for rotating the imaging direction of the imaging device (2) is generated based on the rotational distance to generate the control signal. And (2) a motor control unit (457) for transmission.

  In addition, the moving object tracking control device (40C) according to another embodiment of the present invention is configured so that the imaging device (3) having a function of changing the shooting direction by rotation can track the moving object and capture the image. 3) Control of rotation in the shooting direction, and the latest image frame and the image input before a predetermined period of the image frame shot and generated by the imaging device (1) input in time series. A motion detection unit (44) that detects motion by comparing with a frame, and a centroid calculation unit (452) that calculates the centroid position of the motion detected by the motion detection unit (44) as the centroid position of the moving object; Whether or not the center of gravity position of the moving object calculated by the center-of-gravity calculation unit (452) is within a preset rotation reaction region that is a region within a predetermined distance from the frame end in each direction of the image frame. The A center-of-gravity position analyzing unit (455) to be determined, and when the center-of-gravity position of the moving object enters the rotation reaction area in the movement destination direction via a region near the center of the image frame that is outside the rotation reaction area. The rotational distance of the imaging device (3) is calculated based on the preset moving speed of the moving object and the tilt angle of the imaging direction of the imaging device (3), and the imaging device is calculated based on the rotational distance. And (3) a motor control unit (457) that generates a control signal for rotating the photographing direction and transmits the control signal to the imaging device (3).

  In addition, the moving object tracking control device (40D) according to another aspect of the present invention is configured to change the shooting direction of the imaging device in order to cause the imaging device having a function of changing the shooting direction by rotation to track and photograph the moving object. In the moving object tracking control device that controls rotation, the latest image frame and the image frame input before the predetermined period of the image frames captured and generated by the imaging device are compared in time series. A motion detection unit for detecting motion, a centroid calculation unit for calculating a centroid position of the motion detected by the motion detection unit as a centroid position of the moving object, and a centroid position of the moving object calculated by the centroid calculation unit And the position of the center of gravity of the moving object calculated by the center of gravity calculation unit when the image frame is input before the predetermined period and the frame in which the image frame is input. A moving speed calculating unit that calculates a moving speed of the moving object based on a moving rate; a center of gravity position of the moving object calculated by the center of gravity calculating unit; and a moving speed of the moving object calculated by the moving speed calculating unit The predicted centroid position, which is the centroid position of the moving object in the next input frame, is calculated, and is set in advance for each rotation time that is an elapsed time since the imaging device started changing the imaging direction. When the shooting direction of the imaging device rotates at a high speed, the moving object moving at the moving speed calculated by the moving speed calculating unit from the predicted gravity center position is captured at a predetermined position of the image frame. A rotation time calculation unit that calculates the rotation time of the imaging device, and the movement speed calculation unit within the rotation time of the imaging device calculated by the rotation time calculation unit. A moving distance in the image frame of the moving object that moves at the moving speed that is taken out, a moving distance of a field of view to be taken in which the imaging device moves by rotating a shooting direction at the preset speed; Whether or not there is a point in time when the center of gravity of the moving object protrudes from the image frame frame by becoming larger than the sum of the predicted center of gravity position and the distance from the image frame end on the extension line in the moving direction of the moving object. A frame-in-frame determining unit that determines the center-of-frame position of the moving object calculated by the center-of-gravity calculating unit when the frame-in-frame determining unit determines that the center of gravity position of the moving object protrudes from the image frame frame. And the center position of the image frame, the shift calculated based on the moving speed of the moving object calculated by the moving speed calculator. A motor that calculates the rotational distance of the imaging device by adding the moving amount of the moving object, generates a control signal for rotating the imaging direction of the imaging device based on the rotational distance, and transmits the control signal to the imaging device And a control unit.

  According to the moving object tracking control device of the present invention, it is possible to control the imaging device so as to track a moving object with a small amount of calculation and high accuracy.

<< First Embodiment >>
<Configuration of Surveillance Camera According to First Embodiment>
A configuration of a surveillance camera incorporating a moving object tracking control apparatus according to a first embodiment of the present invention will be described with reference to FIG. As shown in the figure, the surveillance camera 1 to which the present embodiment is applied includes an imaging device 10, an image input unit 20, an image output unit 30, a moving object tracking control device 40A, and a motor unit 50. Yes.

  The image sensor 10 is a CMOS image sensor (Complementary Metal Oxide Semiconductor Image Sensor), a CCD image sensor (Charge Coupled Device Image Sensor), or the like, and forms an image of incident light incident at the time of photographing by an optical system such as a lens. The light and darkness of the image is photoelectrically converted into an amount of electric charge, and the amount of electric charge is sequentially read and converted into an electric signal. The image input unit 20 converts the electrical signal converted by the image sensor 10 into digital data, and sequentially generates image frames. The image output unit 30 converts the image frame generated by the image input unit 20 into an image display signal and outputs the image display signal to an external display device such as a CRT (Cathode Ray Tube) display or a liquid crystal display. Further, when outputting to a DVD drive or the like for storage on a storage medium such as a DVD (Digital Versatile Disc), the image output unit 30 code-compresses a plurality of image frames and outputs them as MPEG (Moving Picture Experts Group) data. .

  The moving object tracking control device 40A includes an operation input unit 41, a set value recording unit 42, a memory 43, a motion detection unit 44, and a pan / tilt control unit 45A.

  The operation input unit 41 includes a frame interval, which is an interval at which the motion detection process is performed in the motion detection unit 44, a threshold used when motion detection is performed in the motion detection unit 44, and a pan / tilt control unit 45A described later. The position of the rotation reaction region R used for determining whether to perform tilt control is input as a set value by a user operation.

  An example of the rotation reaction region R set by the operation input unit 41 is shown in FIG. The rotation reaction region R is a region within a predetermined distance from the upper, lower, left, and right frames of the image frame. As shown by the hatched lines in FIG. 2, the rotation reaction region R is from the upper, lower, left, and right frames in the image frame divided into a predetermined number of blocks. A region corresponding to two blocks is set as the rotation reaction region R.

  The set value recording unit 42 records the set value input from the operation input unit 41. The memory 43 records an image frame before a predetermined period acquired from the image input unit 20 by the motion detection unit 44. The motion detection unit 44 acquires the image frame generated by the image input unit 20, and the acquired image frame at the frame interval recorded in the setting value recording unit 42 and the image frame before a predetermined period recorded in the memory 43. And a motion due to a moving object is detected in the image frame.

  The pan / tilt control unit 45A includes a rotation determination setting unit 451, a centroid calculation unit 452, a non-detection time measurement timer 453, a timer control unit 454, a centroid position analysis unit 455, a movement speed calculation unit 456, a motor And a control unit 457.

  The rotation determination setting unit 451 sets the rotation determination on state, which is a state in which control is performed, or the rotation determination off state, which is a state in which control is not performed, of whether to perform pan / tilt control. When a motion is detected by the motion detection unit 44, the center of gravity calculation unit 452 calculates the center of gravity position of this motion as the center of gravity position of the moving object. The non-detection time measurement timer 453 measures the time during which no motion is detected in the motion detection unit 44. The timer control unit 454 resets the non-detection time measurement timer 453. The center-of-gravity position analysis unit 455 determines whether or not the center-of-gravity position of the moving object calculated by the center-of-gravity calculation unit 452 is within the rotation reaction region R that is set in advance and recorded in the setting value recording unit 42. The moving speed calculation unit 456 calculates and stores the moving speed of the center of gravity position of the moving object calculated by the center of gravity calculation unit 452.

  The motor control unit 457 determines that the center of gravity position of the moving object is within the rotation reaction region R by the center of gravity position analysis unit 455 and the rotation determination setting unit 451 sets the rotation determination to on, that is, the moving object is The movement calculated by the center-of-gravity calculation unit 452 enters from the rotation reaction area in the movement source direction and enters the rotation reaction area R in the movement destination direction via the area near the center of the image frame outside the rotation reaction area R. To perform pan / tilt control by adding the moving amount of the moving object calculated based on the moving speed calculated by the moving speed calculating unit 456 to the distance between the center of gravity position of the object and the center position of the image frame. Is sent to the motor unit 50.

  The motor unit 50 acquires the command issued by the motor control unit 457, and operates the direction of the lens of the monitoring camera 1 according to this command.

<Operation of Surveillance Camera According to First Embodiment>
Next, in the present embodiment, processing when the surveillance camera 1 tracks and captures a moving object will be described.

  FIG. 3 is a flowchart showing the operation of the moving object tracking control device 40A when the surveillance camera 1 tracks and photographs a moving object. In this embodiment, the frame interval at which the motion detection process is executed in advance by the motion detection unit 44, the threshold value used in the motion detection unit 44, and the rotation reaction used for determining whether to perform pan / tilt control. The position of the region R is input as a set value from the operation input unit 41 by a user operation and recorded in the set value recording unit 42.

  When the monitoring camera 1 is powered on, as an initial setting, the rotation determination setting unit 451 of the pan / tilt control unit 45A in the moving object tracking control device 40A determines whether to perform pan / tilt control. The rotation determination OFF state, which is a state that is not broken, is set, and the movement speed stored in the movement speed calculation unit 456 is initialized to “0” as described later (S1).

  By setting the rotation determination off state in step S1, for example, as shown in FIG. 4, since the person P, which is a moving object, crosses the shooting area A in the direction of the arrow, the outside of the shooting area A moves to the right end of the shooting area A. When approaching, the lens of the surveillance camera is prohibited from moving in the right end direction of the screen opposite to the moving direction of the person P, moves only in the same direction as the movement of the person P, and the person P is tracked with smooth control.

  When photographing is started by the monitoring camera 1 in this initial setting state and incident light is incident, light and darkness due to the incident light is photoelectrically converted into an amount of electric charge in the image sensor 10, and the amount of electric charge is sequentially read out. And converted into an electrical signal. The electrical signal converted by the image sensor 10 is converted into digital data by the image input unit 20, and image frames are sequentially generated.

  The image frame generated by the image input unit 20 is converted into an image display signal by the image output unit 30 and displayed on an external display device, or a plurality of image frames are code-compressed and output as MPEG data. Recorded on the device.

  On the other hand, the image frame generated by the image input unit 20 is also acquired by the motion detection unit 44, sent from the motion detection unit 44 to the memory 43, and recorded (S2).

  The motion detection unit 44 compares the acquired current image frame with the image frame before a predetermined period already recorded in the memory 43 by the process of step S2, and determines whether or not there is motion in the image frame. Determination is made and motion is detected (S3).

  Detailed processing in the motion detection unit 44 when this motion is detected will be described with reference to the flowchart of FIG.

  First, in the motion detection unit 44, a plurality of (m × n) positions so that the number of image frames X acquired from the image input unit 20 is m in the horizontal direction and n in the vertical direction as shown in FIG. Are divided into blocks X (0,0) to X (n-1, m-1) (S21).

  When the image frame X is divided into a plurality of blocks X (0,0) to X (n-1, m-1), x (i, j) which is the average luminance value of all the pixels in each block X [i = 0,1,... m−1, j = 0,1,... n−1] are calculated (S22) and recorded in the memory 43 as reference image frames (S23).

  The calculation and recording of the luminance average value is repeated until the processing for all the blocks in the image frame X is completed (S24).

  Next, the motion detection unit 44 waits until the frame interval recorded in the set value recording unit 42 elapses (S25). The frame interval is the number of frames indicating the interval at which the motion detection process is executed, and the minimum value is “1”. The smaller the frame interval value, the faster the moving object can be detected without missing it, but the load on the motion detector 44 increases.

  When it is determined in step S25 that the predetermined frame interval has passed (“YES” in S25), a plurality of motion detection target image frames Y newly acquired at this time are the same as the image frame X described above. Block Y (0,0) to block Y (n-1, m-1), and y (i, j) [i = 0,1, which is the average luminance value of all the pixels in each block Y. ... M-1, j = 0, 1,... N-1] are calculated (S26).

  When the average luminance value y (i, j) of each block Y is calculated, the average luminance value x (i, j) of the block X of the image frame X corresponding to each block Y is read from the memory 43. Then, the difference between the average brightness value x (i, j) and the average brightness value y (i, j) is calculated, and this difference is stored in the set value recording unit 42 as a preset value. It is determined whether or not it exceeds (S27). That is, it is determined whether or not the following formula (1) is satisfied.

[Equation 1]
| Y (i, j) −x (i, j) |> Th (1)
As a result of the determination, when the above equation (1) is satisfied (“YES” in S27), it is determined that there is movement from the block X (i, j) to the block Y (i, j) (S28). .

  On the other hand, as a result of the determination, if the above expression (1) is not satisfied (“NO” in S27), it is determined that there is no movement from the block X (i, j) to the block Y (i, j) ( S29).

  The luminance average value y (i, j) of the block Y (i, j) used for determining the presence or absence of motion is the luminance average value of the past block X (i, j) referred to in the next motion detection processing. It is recorded in the memory 43 as x (i, j) (S30).

  The calculation and recording of the luminance average value is repeated until the processing for all the blocks in the image frame Y is completed (S31).

  When the processing for all the blocks in the image frame Y is completed (“YES” in S31), the presence / absence of motion for each block is output as a motion detection result (S32).

  When the motion detection result is output, the process returns to step S25, and the processes of steps S26 to S32 are repeated at predetermined frame intervals.

  This is the end of the description of the processing when motion in the image frame is detected, and the description returns to the flowchart of FIG.

  It is determined whether or not motion is detected in at least one block in the image frame to be detected by the motion detection process described above (S4).

  When motion is detected in at least one block (“YES” in S4), the center of gravity calculation unit 452 of the pan / tilt control unit 45A calculates the center of gravity of the motion as the center of gravity of the moving object (S5).

  In this embodiment, the center of gravity position of the moving object is the sum of the coordinate values of the block Y (i, j) where the motion is detected, as shown in the following equation (2), and the number of blocks Y where the motion is detected. Calculated by dividing by.

[Equation 2]
Horizontal center of gravity = (Σi) / number of blocks where motion was detected Vertical center of gravity = (Σj) / number of blocks where motion was detected (2)
When the center of gravity position of the moving object is calculated, the non-detection time measurement timer 453 for measuring the non-detection time without movement is reset to “0” by the timer control unit 454 (S6), and the center of gravity position of the moving object is calculated. Is analyzed and determined by the center-of-gravity position analysis unit 455 to determine whether or not is in the rotational reaction region R set as shown in FIG. 2 (S7).

  When the center-of-gravity position analysis unit 455 determines that the center-of-gravity position of the moving object is outside the rotation reaction region R and in the region near the center of the image frame (“NO” in S7), pan / tilt control is not performed. The rotation determination setting unit 451 sets the rotation determination on state so that pan / tilt control is performed when the center of gravity of the moving object enters the rotation reaction region R later.

  In other words, pan / tilt control is not performed when the center of gravity of the moving object is near the center of the image frame, but only when the center of gravity of the moving object is once captured near the center of the image frame in this way. The rotation determination on state, which is a state in which tilt control is performed, is set. Then, the moving speed calculation unit 456 calculates the moving speed with respect to each of the horizontal direction and the vertical direction of the detected gravity center position of the moving object (S8).

[Equation 3]
Movement speed = (Previous center of gravity position−Current center of gravity position) / Motion detection interval (3)
Here, the motion detection interval is calculated by the following equation (4).

[Equation 4]
Motion detection interval = frame interval of motion detection × in the image sensor 10 and the image input unit 20
Time required to process one frame (4)
When the rotation determination is set to on and the moving speed is calculated in step S8, the process returns to step S3 and the motion detection process is continued.

  On the other hand, when it is determined in step S4 that there is no block in which motion is detected (“NO” in S4), measurement is started in the non-detection time measurement timer 453 that measures the non-detection time without motion (S9). .

  Next, it is determined whether or not the measurement time of the non-detection time in the non-detection time measurement timer 453 has reached a predetermined time set in advance (S10), and if it has reached the predetermined time (“YES” in S10) The rotation determination setting unit 451 returns the rotation determination to the off state (S11), and is repeated from the motion detection process from step S3.

  The predetermined time is a time for determining that the state has moved to a state where there is no moving object or that the detected motion is a false detection, and is, for example, about 5 seconds or 10 seconds.

  If it is determined in step S10 that the measurement time of the non-detection time has not reached the predetermined time set in advance ("NO" in S10), the process returns to step S3 and is repeated from the motion detection process.

  If the center of gravity position analysis unit 455 determines in step S7 that the center of gravity position of the moving object is within the rotation reaction region R (“YES” in S7), whether or not pan / tilt control is performed by the motor control unit 457 is determined. It is determined whether the rotation determination indicating the state is OFF or ON (S12).

  When it is determined by the motor control unit 457 that the rotation determination is off (“YES” in S12), since the moving object has entered from outside the image frame, the pan / tilt control is not performed, and the process returns to step S3. When the motion detection process is repeated and it is determined that the rotation determination is on (“NO” in S12), the moving object enters from the rotation reaction region R in the movement source direction and passes through the region near the center of the image frame. A command issuance process is performed to perform tracking by causing the motor unit 50 to perform pan / tilt control so that the moving object is not taken out of the image frame. (S13).

  Here, as described above, since the initial speed when the camera is rotated by the motor is slow, when performing the command issuance processing for performing the pan / tilt control, the motor capacity is increased by moving the distance as much as possible. The tracking performance for moving objects is higher.

  Specifically, a command for performing pan / tilt control is issued so that the camera unit is rotated by the motor unit 50 at a rotation distance calculated as in the following equation (5).

[Equation 5]
Camera rotation distance = distance between the center of gravity of the moving object and the center position of the image frame + the moving object
Moving distance
= Distance between center of gravity of moving object and center position of image frame + of moving object
Movement speed x movement time (5)
In this way, a command is sent from the motor control unit 457 so that the monitoring camera 1 is rotated by the rotation distance of the camera calculated according to the moving speed in addition to the distance between the center of gravity position of the moving object and the center position of the image frame. By being issued, tracking performance is improved and tracking is performed appropriately.

  When a command is issued by the motor control unit 457, this command is sent to the motor unit 50, and a moving object is tracked by performing pan / tilt control in the motor unit 50 (S14). As the rotation direction in the command issued at this time, the pan angle and the tilt angle are set so as to rotate in the moving direction of the moving object.

  When the pan / tilt control by the motor unit 50 is completed, monitoring is continued until the rotation of the monitoring camera 1 is stopped (“NO” in S15), and when the rotation of the monitoring camera 1 is stopped (“YES” in S15), step S3. The process is repeated from the motion detection process.

  Whether or not the rotation of the monitoring camera 1 has been stopped is determined by calculating the time until the rotation of the monitoring camera 1 stops in the pan / tilt control in step S14 and counting until this time has elapsed. Alternatively, the determination may be made by monitoring until the pan angle and the tilt angle become angles set by the motor control unit 457 to the motor unit 50 by a command.

  According to the first embodiment described above, since pan / tilt control is performed based on the position and moving speed of the moving object, it is possible to perform shooting while tracking the moving object with high accuracy.

  In addition, according to the first embodiment, since the pan / tilt control is not performed on the moving object that has entered from outside the imaging area until it reaches the vicinity of the center of the image frame, the camera is opposite to the moving direction of the moving object. It is possible to avoid useless tracking that would cause the to rotate.

<< Second Embodiment >>
As described in the first embodiment, when tracking a moving object, the tracking performance is improved by rotating the surveillance camera at a distance as large as possible according to the moving speed of the moving object.

  In order to further improve the tracking performance, the distance between the center of gravity of the moving object and the center position of the image frame is used when calculating the rotation distance of the camera in Equation (5). It is desirable to start pan / tilt control of the surveillance camera when a moving object is detected at a close position.

  For example, when the moving object moves in the direction of the arrow in the image frame divided into a plurality of blocks as shown in FIG. It is desirable that the pan / tilt control is started when there is a moving object at the position b which is the final position to be accommodated.

  In the case of FIG. 7, if the rotation reaction region R is three blocks from the frame of the image frame, pan / tilt control is started when the moving object reaches the position c. Further, if the rotation reaction region R is one block from the image frame frame, the moving object is missed out of the shooting screen and cannot be tracked.

  In the case of FIG. 7, it is appropriate if the rotation reaction region R is two blocks from the image frame frame, but the rotation reaction region R has an appropriate size depending on the moving speed and moving direction of the moving object.

  Therefore, in the second embodiment, the final position immediately before the moving object goes out of the image frame is detected according to the speed of the moving object, and pan / tilt control is performed at this position.

<Configuration of Surveillance Camera According to Second Embodiment>
A configuration of a surveillance camera incorporating a moving object tracking control device according to a second embodiment of the present invention will be described with reference to FIG. As shown in the figure, the surveillance camera 2 to which this embodiment is applied has the same configuration as that of the first embodiment except that it has a pan / tilt control unit 45B instead of the pan / tilt control unit 45A in the first embodiment. Since it is the same, detailed description is abbreviate | omitted.

  The pan / tilt control unit 45B includes a center of gravity calculation unit 452, a movement speed calculation unit 456, a motor control unit 457, a unit movement distance calculation unit 458, and a final position determination unit 459.

  When a motion is detected by the motion detection unit 44, the center of gravity calculation unit 452 detects the center of gravity position of the movement as the center of gravity position of the moving object. The moving speed calculation unit 456 calculates and stores the moving speed of the center of gravity position of the moving object calculated by the center of gravity calculation unit 452. When the final position determination unit 459 described later determines that the center of gravity position of the moving object is the final position within the image frame, the motor control unit 457 determines the position of the center of gravity of the moving object calculated by the center of gravity calculation unit 452 and the image. A command for performing pan / tilt control is issued by adding the moving amount of the moving object calculated based on the moving speed calculated by the moving speed calculating unit 456 to the distance from the center position of the frame. Sent to the unit 50.

  The unit movement distance calculation unit 458 calculates and stores a unit movement distance that is a movement distance per unit time of the centroid position of the moving object calculated by the centroid calculation unit 452. The final position determination unit 459 compares the unit movement distance calculated by the unit movement distance calculation unit 458 with the distance from the center of gravity position of the moving object to the end of the image frame on the extension line in the moving direction of the moving object. When the distance is larger, the center of gravity position of the moving object is determined to be the final position that fits within the image frame, and when the unit moving distance is smaller, the center of gravity position of the moving object is determined not to be the final position that fits within the image frame. To do.

<Operation of Surveillance Camera According to Second Embodiment>
Next, in the present embodiment, processing when the surveillance camera 2 tracks and captures a moving object will be described.

  FIG. 9 is a flowchart showing the operation of the moving object tracking control device 40B when the surveillance camera 2 tracks and photographs a moving object. In the present embodiment, the frame interval at which the motion detection process is executed in the motion detection unit 44 and the threshold value used in the motion detection unit 44 are input from the operation input unit 41 as a set value by the user operation in advance. It is recorded in the recording unit 42.

  When the monitoring camera 2 is powered on, the initial setting is stored in the moving speed and unit moving distance calculating unit 458 stored in the moving speed calculating unit 456 of the pan / tilt control unit 45B in the moving object tracking control device 40B. The unit movement distance is initialized to “0” (S41).

  When shooting is started by the monitoring camera 2 and incident light is incident in the initially set state as described above, an image frame of an image shot by the same processing as in the first embodiment is output to a display device or the like. The motion detector 44 acquires the data and sends it to the memory 43 for recording (S42).

  Further, the motion detection unit 44 compares the acquired current image frame with the image frame before a predetermined period already recorded in the memory 43 by the process of step S42, and determines whether or not there is motion in the image frame. Is determined and a motion is detected (S43).

  Detailed processing in the motion detection unit 44 when this motion is detected is similar to the processing described using the flowchart of FIG. 5 in the first embodiment, and thus detailed description thereof is omitted.

  When motion detection processing is performed by the motion detection unit 44, it is determined whether or not motion is detected in at least one block in the image frame to be detected (S44).

  If motion is detected in at least one block (“YES” in S44), the center of gravity calculation unit 452 of the pan / tilt control unit 45B calculates the center of gravity of the motion as the center of gravity of the moving object (S45).

  Since the calculation process of the center of gravity position of the moving object is the same as the calculation process of the center of gravity position described using the expression (2) in the first embodiment, detailed description thereof is omitted.

  When the center-of-gravity position of the moving object is calculated, if the current motion detection is the first motion detection (when no motion is detected in the previous motion detection process) (“YES” in S46), the process proceeds to step S43. Returning, the motion detection process is performed again.

  When the current motion detection is not the first motion detection (“NO” in S46), the moving speed of the center of gravity position of the detected moving object is calculated by the moving speed calculation unit 456 and the center of gravity position of the moving object is calculated. The unit movement distance calculation unit 458 calculates a unit movement distance that is a movement distance per motion detection time interval (S47).

  Since the calculation process of the moving speed of the center of gravity position of the moving object is the same as the calculation process of the moving speed described using the equations (3) and (4) in the first embodiment, detailed description thereof is omitted.

  The unit movement distance (movement distance per movement detection interval) is calculated by the following equation (6).

[Equation 6]
Unit movement distance = | Previous center of gravity position−Current center of gravity position | (6)
Next, the final position determination unit 459 compares the unit movement distance calculated by the unit movement distance calculation unit 458 with the distance from the center of gravity position of the moving object to the image frame end on the extension line in the moving direction of the moving object. Thus, it is determined whether or not the center of gravity position of the moving object is the final position within the image frame (S48).

  Whether or not the center of gravity of the moving object is the final position within the image frame is determined based on whether or not the following equation (7) is satisfied.

[Equation 7]
Unit moving distance> From the center of gravity of the moving object to the edge of the image frame on the extension line in the moving direction
Distance + α (7)
Here, α is a constant value that can be arbitrarily set, and is for absorbing a measurement error of a unit moving distance and a speed change caused by a moving object.

  As a result of the determination, when the unit moving distance is larger and satisfies the above equation (7), it is determined that the center of gravity position of the moving object is the final position within the image frame (“YES” in S48).

  When it is determined that the center of gravity position of the moving object is the final position within the image frame, a command for tracking by causing the motor unit 50 to perform pan / tilt control so that the moving object does not go out of the image frame. An issuing process is performed (S49).

  Since this command issuance process is the same as the command issuance process described using the expression (5) in the first embodiment, a detailed description thereof will be omitted.

  Since the processing in steps S50 and S51 after the command issuance processing is the same as the processing in steps S14 and S15 of FIG. 3 in the first embodiment, detailed description thereof is omitted.

  In step S48, when the unit moving distance is smaller and the above equation (7) is not satisfied, it is considered that the moving object can be captured even in the next motion detection. It is determined that the final position does not fall within the range ("NO" in S48), the process returns to step S43, and the motion detection process is repeated.

  When it is determined in step S44 that there is no block in which motion is detected (“NO” in S44), the previous motion is taken into account when the final position where the center of gravity of the moving object falls within the image frame is missed. It is determined whether or not motion has been detected in the detection process (S52).

  When a motion has been detected in the previous motion detection process (“YES” in S52), the process proceeds to step S49, and a command issue process is performed based on the previous motion detection result. When no motion is detected in the previous motion detection process (“NO” in S52), the process returns to step S43 and is repeated from the motion detection process.

  According to the second embodiment described above, the pan / tilt control is performed based on the position and moving speed of the moving object immediately before the moving object goes out of the frame of the image frame. You can take a picture.

  Further, according to the second embodiment, even when the final position where the center of gravity of the moving object falls within the image frame is missed due to a change in the speed of the moving object, etc., tracking is continued based on the previous motion detection. Shooting can be performed.

  In the surveillance camera 2 of the present embodiment, the case where the unit movement distance is calculated every time motion is detected has been described. However, the average value of the values calculated by several motion detections is employed to determine the center of gravity of the moving object. It may be determined whether or not the position is the final position within the image frame.

<< Third Embodiment >>
In the first embodiment and the second embodiment described above, it was possible to target a plurality of types of moving objects having different speeds. However, in the third embodiment, a single type of person such as a human, a car, or a ship is used. A monitoring camera with a simpler configuration that is applied when a moving object or a moving object having the same moving speed is set as a monitoring target will be described.

<Configuration of Surveillance Camera According to Third Embodiment>
The configuration of the surveillance camera according to the third embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 10, the surveillance camera 3 according to the present embodiment is the same as the configuration of the first embodiment except that the pan / tilt control unit 45C of the moving object tracking control device 40C does not include a moving speed calculation unit. Therefore, detailed description of the processing units having the same function is omitted.

  In this embodiment, the motor control unit 457 determines that the center of gravity position of the moving object is within the rotation reaction region R by the center of gravity position analysis unit 455 and determines that the rotation determination is on in the rotation determination setting unit 451. In other words, when the moving object enters from the rotation reaction area R in the movement source direction and enters the rotation reaction area R in the movement destination direction via the area near the center of the image frame outside the rotation reaction area R, A command for pan / tilt control is issued based on the position of the center of gravity of the moving object calculated by the center of gravity calculating unit 452, the tilt angle of the monitoring camera 3, and the moving speed of the moving object stored in advance. It is sent to the motor unit 50.

  In addition, as shown in FIG. 11, the surveillance camera 3 according to the present embodiment is installed on the ceiling of a room and can rotate within a tilt angle range of 0 degrees to 90 degrees.

<Operation of Surveillance Camera According to Third Embodiment>
Next, the operation of the monitoring camera 3 according to the present embodiment will be described with reference to the flowchart of FIG.

  In the present embodiment, the operations in steps S1 to S12 are the same as those in the first embodiment, and thus detailed description thereof is omitted.

  A process when a command issuance process for performing pan / tilt control is performed by the motor unit 50 in step S13 will be described.

  Here, in the present embodiment, the surveillance camera 3 is installed on the ceiling of the room in a state where it can rotate within a tilt angle range of 0 to 90 degrees.

  When the monitoring camera 3 installed in this way captures and displays a person at a certain angle within the above tilt angle range, as shown in FIG. The person S who is far away is displayed smaller on the screen.

  Therefore, when the person Q and the person S move to the left and right, even if they actually move at the same speed, the apparent movement speed on the display screen increases as they are closer to the monitoring camera 3. This moving speed further varies depending on the tilt angle, and becomes faster as the tilt angle is larger (closer to 90 degrees).

  Based on this feature, in this embodiment, the rotation distance of the monitoring camera 3 is determined based on the position of the center of gravity of the moving object, the tilt angle of the monitoring camera 3, and the moving speed of the moving object stored in advance. A command for performing tilt control is issued and sent to the motor unit 50.

  Specifically, the rotational distance of the monitoring camera 3 is calculated as in the following formula (8).

[Equation 8]
Camera rotation distance = maximum rotation distance-(maximum rotation distance x area coefficient x tilt angle coefficient)
(8)
Here, the maximum rotation distance is the movement speed of the moving object stored in advance when the monitoring camera 3 and the moving object are closest, that is, the monitoring camera 3 per unit time when tracking at the maximum speed. Is the rotation distance.

  The area coefficient is a coefficient calculated based on the vertical position of the moving object in the image frame based on a preset graph as shown in FIG. 13, and the coefficient becomes smaller as the position becomes lower in the image frame. Become.

  Furthermore, the tilt angle coefficient is a coefficient calculated from the tilt angle of the surveillance camera 3 based on a preset graph as shown in FIG. 14, and the coefficient increases as the tilt angle increases (closer to 90 degrees). Becomes smaller. The smaller the coefficient, the greater the rotational distance of the camera according to the above equation (8).

  Tracking is appropriately performed by issuing a command by the motor control unit 457 so that the monitoring camera 3 is rotated by the calculated rotation distance of the camera.

  Moreover, since the process of step S14, S15 is the same as that of 1st Embodiment, detailed description is abbreviate | omitted.

  According to the third embodiment described above, it is possible to perform shooting while tracking a moving object with high accuracy with a simple apparatus configuration without actually measuring the moving speed.

<< 4th Embodiment >>
As described in the second embodiment, the panning / tilting control of the surveillance camera is started when a moving object is detected as close as possible to the image frame so that the surveillance camera is rotated by a distance as large as possible. However, the tracking performance is improved. However, as described above, since the initial speed when the camera is rotated by the motor is slow, the person P is detected as a moving object at a position close to the image frame as shown in FIG. In such a case, the person P may once disappear from the image frame as shown in FIG.

  Thereafter, the rotation speed of the surveillance camera gradually increases, and as shown in (c), the camera first catches up with the moving object and starts to catch it in the image frame. Then, as shown in (d), the person P is tracked and shooting is continued. However, once the moving object disappears from the image frame as shown in (b), the monitoring person who monitors the moving object with the image on the screen cannot see it psychologically.

  Therefore, in the fourth embodiment, pan / tilt control is performed so that a moving object is always captured in an image frame while the surveillance camera is rotating.

<Configuration of Surveillance Camera According to Fourth Embodiment>
A configuration of a surveillance camera incorporating a moving object tracking control device according to a fourth embodiment of the present invention will be described with reference to FIG. As shown in the figure, the surveillance camera 4 to which this embodiment is applied has the same configuration as that of the second embodiment except that it has a pan / tilt control unit 45D instead of the pan / tilt control unit 45B in the second embodiment. Since it is the same, detailed description is abbreviate | omitted.

  The pan / tilt control unit 45D includes a center-of-gravity calculation unit 452, a moving speed calculation unit 456, a motor control unit 457, a rotation time calculation unit 460, and an in-frame determination unit 461.

  When a motion is detected by the motion detection unit 44, the center of gravity calculation unit 452 detects the center of gravity position of the movement as the center of gravity position of the moving object. The moving speed calculation unit 456 calculates and stores the moving speed of the center of gravity position of the moving object calculated by the center of gravity calculation unit 452. The motor control unit 457 calculates the gravity center calculation unit 452 when the frame frame determination unit 461 described later determines that the position of the center of gravity of the moving object protrudes from the image frame frame while the surveillance camera 4 is rotating. Pan / tilt control is performed by adding the moving amount of the moving object calculated based on the moving speed calculated by the moving speed calculating unit 456 to the distance between the center of gravity position of the moving object and the center position of the image frame. A command for performing is issued and sent to the motor unit 50.

  The rotation time calculation unit 460 calculates a predicted gravity center position that is the gravity center position of the moving object in the next frame, and is set in advance for each rotation time that is an elapsed time since the monitoring camera 4 started changing the shooting direction. When the shooting direction of the monitoring camera 4 is rotated at a speed, the moving object moving at the moving speed calculated by the moving speed calculating unit 456 from the predicted gravity center position is captured at the center position of the image frame and stopped. A certain rotation time of the monitoring camera 4 is calculated. The in-frame determination unit 461 includes the “moving distance of the moving object”, the “moving distance of the visual field of the monitoring camera 4”, and “in the next frame within the rotation time of the monitoring camera 4 calculated by the rotation time calculation unit 460. Compared with the sum of the “distance from the predicted center of gravity of the moving object to the end of the image frame on the extension line in the moving direction”, and when the “movement distance of the moving object” is always smaller, the center of gravity of the moving object during the rotation of the monitoring camera 4 It is determined that the position does not protrude from the image frame frame, and when it is determined that there is a point in time when the “movement distance of the moving object” is larger, it is determined that the gravity center position of the moving object may protrude from the image frame frame.

<Operation of Surveillance Camera According to Fourth Embodiment>
Next, in this embodiment, a process when the surveillance camera 4 tracks and moves a moving object will be described.

  FIG. 17 is a flowchart showing the operation of the moving object tracking control device 40D when the surveillance camera 4 tracks and photographs a moving object. In the present embodiment, the frame interval at which the motion detection process is executed in the motion detection unit 44 and the threshold value used in the motion detection unit 44 are input from the operation input unit 41 as a set value by the user operation in advance. It is recorded in the recording unit 42.

  When the monitoring camera 4 is turned on, the initial setting is stored in the moving speed and rotation time calculating unit 460 stored in the moving speed calculating unit 456 of the pan / tilt control unit 45D in the moving object tracking control device 40D. The rotation time of the monitoring camera 4 is initialized to “0” (S61).

  When shooting is started by the monitoring camera 42 and incident light is incident in the initial setting state as described above, an image frame of an image shot by the same processing as in the first embodiment is output to a display device or the like. The motion detector 44 acquires the data and sends it to the memory 43 for recording (S62).

  Further, the motion detection unit 44 compares the acquired current image frame with the image frame before a predetermined period already recorded in the memory 43 by the process of step S42, and determines whether or not there is motion in the image frame. Is determined and a motion is detected (S63).

  Detailed processing in the motion detection unit 44 when this motion is detected is similar to the processing described using the flowchart of FIG. 5 in the first embodiment, and thus detailed description thereof is omitted.

  When motion detection processing is performed by the motion detection unit 44, it is determined whether or not motion is detected in at least one block in the image frame to be detected (S64).

  When the motion is detected in at least one block (“YES” in S64), the center of gravity calculation unit 452 of the pan / tilt control unit 45D calculates the center of gravity of the motion as the center of gravity of the moving object (S65).

  Since the calculation process of the center of gravity position of the moving object is the same as the calculation process of the center of gravity position described using the expression (2) in the first embodiment, detailed description thereof is omitted.

  When the center-of-gravity position of the moving object is calculated, if the current motion detection is the first motion detection (if no motion is detected in the previous motion detection process) (“YES” in S66), the process proceeds to step S63. Returning, the motion detection process is performed again.

  When the current motion detection is not the first motion detection (“NO” in S66), the moving speed of the center of gravity position of the detected moving object is calculated by the moving speed calculating unit 456 and at the rotation time calculating unit 460. A predicted centroid position, which is a centroid position of the moving object in the next frame, is calculated, and tracking processing of the moving object is started from the predicted centroid position (that is, the monitoring camera 4 starts rotating), and then the moving object is set to the center of the image frame. A time (rotation time of the monitoring camera 4) until the rotation of the monitoring camera 4 is stopped by capturing the position is calculated (S67). Here, in this embodiment, it is assumed that the moving object is moving at a constant speed.

  Since the calculation process of the moving speed of the center of gravity position of the moving object is the same as the calculation process of the moving speed described using the equations (3) and (4) in the first embodiment, detailed description thereof is omitted.

  Further, the rotation time of the monitoring camera 4 is calculated based on the following formula (9).

[Equation 9]
Field of view movement distance of surveillance camera 4 (A)
= Distance between predicted center of gravity position of moving object and center position of image frame (B)
+ Moving distance of moving object (C)
= Distance between predicted center of gravity position of moving object and center position of image frame (B)
+ Moving speed of center of gravity of moving object x rotation time of surveillance camera 4 (9)
Here, the movement distance (A) of the field of view of the monitoring camera 4 is the movement distance from before the rotation of the monitoring camera 4 to after the rotation, expressed by the number of pixels in the image frame. Calculated based on the same stationary object shown. For example, in FIG. 18, when the image showing the field of view before rotation of the surveillance camera 4 is (a) and the image showing the field of view after rotation is (b), the distance from the left frame of the image frame to the same stationary object Z Since the number of pixels is X pixels in the image (a) before rotation and Y pixels in the image (b) after rotation, the movement distance of the field of view of the surveillance camera 4 is indicated by (XY) pixels. . Further, the movement distance of the field of view of the monitoring camera 4 for each rotation time (seconds) after the rotation of the monitoring camera 4 is started is acquired in advance as shown in FIG. 19 and stored in the rotation time calculation unit 460. As can be seen from FIG. 19, the monitoring camera 4 rotates at a low initial speed, so that the moving distance of the visual field of the monitoring camera 4 is shortened when the rotation time is short.

  Further, the distance (B) between the predicted gravity center position of the moving object and the center position of the image frame is a distance indicated by an arrow (B) in FIG. 20 which is the predicted image of the next frame.

  Further, the moving speed of the center of gravity position of the moving object is a value calculated by the moving speed calculating unit 456, and as described above, in this embodiment, the moving object is moving at a constant speed. The moving distance of the moving object every rotation time (seconds) from the start is expressed in a directly proportional relationship as shown in FIG.

  In this embodiment, the monitoring camera 4 that rotates at a speed as shown in FIG. 19 rotates the monitoring camera 4 when the tracking of a moving object that moves at a speed as shown in FIG. 21 is started from the next frame. The relationship between the speed and the moving speed of the moving object is shown in FIG.

  As shown in FIG. 22, the moving distance (A) of the field of view of the monitoring camera 4, the distance (B) between the predicted gravity center position of the moving object and the center position of the image frame, and the moving distance (C) of the moving object The rotation time of the monitoring camera 4 at the time of the point (D) at which they become equal is calculated as the time from when the monitoring camera 4 starts to rotate until the moving object is captured at the center of the image frame and the rotation of the monitoring camera 4 stops. The

  Next, it is determined whether or not the following expression (10) is always satisfied during the calculated rotation time of the monitoring camera 4 to determine whether or not the position of the center of gravity of the moving object may protrude from the image frame. Is determined by the in-frame determination unit 461 (S48).

[Equation 10]
Moving distance of moving object (C)
<Moving distance of view of surveillance camera 4 (A) + Distance from predicted center of gravity position to end of image frame on extension line in moving direction (E) (10)
Here, the distance (E) from the predicted center-of-gravity position to the end of the image frame on the extension line in the moving direction is a distance indicated by an arrow (E) in FIG. 20 which is the predicted image of the next frame.

  As a result of the determination, when it is determined that the above expression (10) is always satisfied during the rotation time of the monitoring camera 4 and the center of gravity of the moving object does not protrude from the image frame during the rotation (“NO” in S68). ), It is determined that the moving object can always be captured even when the tracking process of the moving object is started from the time of the next motion detection (that is, when the monitoring camera 4 starts to rotate), and the process returns to step S63 to start the motion detection process. Repeated.

  If it is determined in step S68 that there is a time that does not satisfy the above formula (10) during the rotation time of the monitoring camera 4 and the center of gravity of the moving object may protrude from the image frame during the rotation. (S68 “YES”), at this time, command issue processing for tracking by causing the motor unit 50 to perform pan / tilt control is performed (S69).

  Since this command issuance process is the same as the command issuance process described using the expression (5) in the first embodiment, a detailed description thereof will be omitted.

  Since the processing in steps S70 and S71 after the command issuance processing is the same as the processing in steps S14 and S15 in FIG. 3 in the first embodiment, detailed description thereof is omitted.

  If it is determined in step S64 that there is no block in which motion has been detected (“NO” in S64), the previous motion is taken into consideration when the position where the center of gravity of the moving object always falls within the image frame is missed. It is determined whether or not motion has been detected in the detection process (S72).

  When a motion is detected in the previous motion detection process (“YES” in S72), the process proceeds to step S69, and a command issue process is performed based on the previous motion detection result. When no motion is detected in the previous motion detection process (“NO” in S72), the process returns to step S63 and is repeated from the motion detection process.

  According to the above fourth embodiment, even when the initial speed of the surveillance camera is slow, pan / tilt control is performed so that a moving object does not temporarily protrude from the image frame during rotation and is always captured in the image frame. Therefore, it is possible to perform shooting while tracking a moving object with higher accuracy.

  The number of motion detection blocks used in any of the first to fourth embodiments described above, the frame interval of motion detection, the threshold value (sensitivity: Th) used when performing motion detection, and the rotation reaction region R These positions and the like can be changed by operating the operation input unit 41 by the user.

  Moreover, it is also possible to make the computer function as a moving object tracking control device by programming the functional configuration of the moving object tracking control device according to any of the first to fourth embodiments described above into a computer. is there.

It is a block diagram which shows the structure of the surveillance camera 1 incorporating the moving object tracking control apparatus 40A which is 1st Embodiment of this invention. It is explanatory drawing which shows an example of the rotation reaction area | region R preset in an image frame with the moving object tracking control apparatuses 40A and 40C by 1st Embodiment and 3rd Embodiment of this invention. It is a flowchart which shows operation | movement of the surveillance cameras 1 and 3 incorporating the moving object tracking control apparatuses 40A and 40C by 1st Embodiment and 3rd Embodiment of this invention. It is explanatory drawing which shows a state when the person P moves in the imaging | photography area which image | photographs with the monitoring cameras 1 and 3 incorporating the moving object tracking control apparatuses 40A and 40C by 1st Embodiment-3rd Embodiment of this invention. is there. It is a flowchart which shows operation | movement when performing motion detection with the surveillance cameras 1-3 which incorporate the moving object tracking control apparatus 40A, 40B, 40C by 1st Embodiment-3rd Embodiment of this invention. Explanatory drawing which shows the image frame divided | segmented into predetermined number when detecting the motion with the surveillance cameras 1-3 which incorporate the moving object tracking control apparatus 40A, 40B, 40C by 1st Embodiment-3rd Embodiment of this invention. It is. It is explanatory drawing which shows the log | history of the gravity center of the moving object in the image frame detected by the moving object tracking control apparatus 40B by 2nd Embodiment of this invention. It is a block diagram which shows the structure of the surveillance camera 2 incorporating the moving object tracking control apparatus 40B by 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the surveillance camera 2 incorporating the moving object tracking control apparatus 40B by 2nd Embodiment of this invention. It is a block diagram which shows the structure of the surveillance camera 3 incorporating the moving object tracking control apparatus 40C by 3rd Embodiment of this invention. It is explanatory drawing which shows the state by which the surveillance camera 3 incorporating the moving object tracking control apparatus 40C by 3rd Embodiment of this invention was installed in the ceiling of the room. It is a screen block diagram which shows an example when the person who is a moving object is image | photographed and displayed with the monitoring camera 3 incorporating the moving object tracking control apparatus 40C by 3rd Embodiment of this invention. It is a graph which shows the area | region coefficient with respect to the gravity center position of the moving object in an image frame utilized when calculating the rotational distance of the monitoring camera 3 in the moving object tracking control apparatus 40C by 3rd Embodiment of this invention. It is a graph which shows the tilt angle coefficient with respect to the tilt angle of the surveillance camera 3 utilized when calculating the rotational distance of the surveillance camera 3 in the moving object tracking control apparatus 40C by 3rd Embodiment of this invention. It is a screen block diagram which shows an example when the person who is a moving object is image | photographed and displayed with the monitoring camera 2 incorporating the moving object tracking control apparatus 40B by 2nd Embodiment of this invention. It is a block diagram which shows the structure of the surveillance camera 4 incorporating the moving object tracking control apparatus 40D by 4th Embodiment of this invention. It is a flowchart which shows operation | movement of the surveillance camera 4 incorporating the moving object tracking control apparatus 40D by 4th Embodiment of this invention. The screen block diagram which shows an example when (a) the visual field before rotation image | photographed with the surveillance camera 4 incorporating the moving object tracking control apparatus 40D by 4th Embodiment of this invention, and (b) the visual field after rotation are displayed. It is. It is a graph which shows the movement distance of the visual field of the monitoring camera 4 for every rotation time of the monitoring camera 4 which incorporates the moving object tracking control apparatus 40D by 4th Embodiment of this invention. It is a screen block diagram which shows the estimated image of the next frame of the image image | photographed with the monitoring camera 4 incorporating the moving object tracking control apparatus 40D by 4th Embodiment of this invention. It is a graph which shows the moving distance of the moving object for every rotation time of the surveillance camera 4 incorporating the moving object tracking control apparatus 40D by 4th Embodiment of this invention. It is a graph which shows the relationship between the moving distance of the visual field of the monitoring camera 4 for every rotation time, and the moving distance of a moving object of the monitoring camera 4 incorporating the moving object tracking control apparatus 40D by 4th Embodiment of this invention. It is a graph which shows the relationship between the moving time and moving distance of a camera when panning is rotated at a maximum speed setting from a stationary state in a conventional surveillance camera.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2, 3 ... Surveillance camera 10 ... Image sensor 20 ... Image input part 30 ... Image output part 40A, 40B, 40C, 40D ... Moving object tracking control apparatus 41 ... Operation input part 42 ... Setting value recording part 43 ... Memory 44 ... motion detection units 45A, 45B, 45C, 45D ... pan / tilt control unit 50 ... motor unit 451 ... rotation determination setting unit 452 ... center of gravity calculation unit 453 ... non-detection time measurement timer 454 ... timer control unit 455 ... center of gravity position analysis unit 456 ... Movement speed calculation unit 457 ... Motor control unit 458 ... Unit movement distance calculation unit 459 ... Final position determination unit 460 ... Rotation time calculation unit 461 ... In-frame determination unit

Claims (4)

In the moving object tracking control device that controls the rotation of the imaging direction of the imaging device in order to cause the imaging device having a function of changing the imaging direction by rotation to track and image the moving object,
A motion detection unit that detects motion by comparing a latest image frame and an image frame input before a predetermined period of the image frames captured and generated by the imaging device in time series;
A centroid calculating unit that calculates a centroid position of the motion detected by the motion detecting unit as a centroid position of the moving object;
The center of gravity for determining whether or not the center of gravity position of the moving object calculated by the center of gravity calculating unit is within a rotation reaction region that is a predetermined distance from a frame end in each direction of the image frame. A position analysis unit;
The centroid position of the moving object calculated by the centroid calculation unit when the centroid position analysis unit determines that the centroid position of the moving object is in a region near the center of the image frame that is an area outside the rotation reaction region. The moving object based on the difference between the position and the gravity center position of the moving object calculated by the gravity center calculating unit when the image frame is input before the predetermined period and the frame rate at which the image frame is input A moving speed calculation unit for calculating the moving speed of
The movement calculated by the barycentric calculation unit when the barycentric position of the moving object enters the rotation reaction area in the destination direction via the area near the center of the image frame that is outside the rotation reaction area. The imaging is performed by adding the moving amount of the moving object calculated based on the moving speed of the moving object calculated by the moving speed calculating unit to the distance between the gravity center position of the object and the center position of the image frame. A motor control unit that calculates a rotation distance of the apparatus, generates a control signal for rotating a shooting direction of the imaging apparatus based on the rotation distance, and transmits the control signal to the imaging apparatus;
A moving object tracking control device comprising: In the moving object tracking control device that controls the rotation of the imaging direction of the imaging device in order to cause the imaging device having a function of changing the imaging direction by rotation to track and image the moving object,
A motion detection unit that detects motion by comparing a latest image frame and an image frame input before a predetermined period of the image frames captured and generated by the imaging device in time series;
A centroid calculating unit that calculates a centroid position of the motion detected by the motion detecting unit as a centroid position of the moving object;
The difference between the centroid position of the moving object calculated by the centroid calculation unit and the centroid position of the moving object calculated by the centroid calculation unit when the image frame is input before the predetermined period, and the image frame A moving speed calculation unit that calculates a moving speed of the moving object based on a frame rate to which
Based on the centroid position of the moving object calculated by the centroid calculation unit and the centroid position of the moving object calculated by the centroid calculation unit when an image frame is input before the predetermined period, A unit moving distance calculating unit that calculates a unit moving distance that is a moving distance of the moving object;
The unit moving distance of the moving object calculated by the unit moving distance calculation unit is larger than the distance from the center of gravity position of the moving object calculated by the center of gravity calculation unit to the end of the image frame on the extension line in the moving direction of the moving object. A final position determination unit that determines that the position of the center of gravity of the moving object is sometimes the final position within an image frame;
When the final position determining unit determines that the center of gravity of the moving object is the final position within the image frame, the center of gravity of the moving object calculated by the center of gravity calculating unit and the center position of the image frame The rotational distance of the imaging device is calculated by adding the moving amount of the moving object calculated based on the moving speed of the moving object calculated by the moving speed calculation unit to the distance, and based on this rotational distance A motor control unit that generates a control signal for rotating the shooting direction of the imaging device and transmits the control signal to the imaging device;
A moving object tracking control device comprising: In the moving object tracking control device that controls the rotation of the imaging direction of the imaging device in order to cause the imaging device having a function of changing the imaging direction by rotation to track and image the moving object,
A motion detection unit that detects motion by comparing a latest image frame and an image frame input before a predetermined period of the image frames captured and generated by the imaging device in time series;
A centroid calculating unit that calculates a centroid position of the motion detected by the motion detecting unit as a centroid position of the moving object;
The center of gravity for determining whether or not the center of gravity position of the moving object calculated by the center of gravity calculating unit is within a rotation reaction region that is a predetermined distance from a frame end in each direction of the image frame. A position analysis unit;
The moving speed of the moving object set in advance when the center of gravity of the moving object enters the rotation reaction area in the movement destination direction via the area near the center of the image frame that is outside the rotation reaction area. And a tilt angle in the shooting direction of the imaging device to calculate a rotation distance of the imaging device, and generate a control signal for rotating the shooting direction of the imaging device based on the rotation distance to generate the control signal. A motor controller to transmit to
A moving object tracking control device comprising: In the moving object tracking control device that controls the rotation of the imaging direction of the imaging device in order to cause the imaging device having a function of changing the imaging direction by rotation to track and image the moving object,
A motion detection unit that detects motion by comparing a latest image frame and an image frame input before a predetermined period of the image frames captured and generated by the imaging device in time series;
A centroid calculating unit that calculates a centroid position of the motion detected by the motion detecting unit as a centroid position of the moving object;
The difference between the centroid position of the moving object calculated by the centroid calculation unit and the centroid position of the moving object calculated by the centroid calculation unit when the image frame is input before the predetermined period, and the image frame A moving speed calculation unit that calculates a moving speed of the moving object based on a frame rate to which
A predicted centroid that is a centroid position of the moving object in the next input frame from the centroid position of the moving object calculated by the centroid calculating unit and the moving speed of the moving object calculated by the moving speed calculating unit. By calculating the position and rotating the imaging direction of the imaging device at a preset speed for each rotation time that is an elapsed time since the imaging device started changing the imaging direction, A rotation time calculation unit that calculates a rotation time of the imaging device until the moving object that moves at the movement speed calculated by the movement speed calculation unit is captured at a predetermined position of the image frame;
The moving distance within the image frame of the moving object that moves at the moving speed calculated by the moving speed calculating unit within the rotation time of the imaging apparatus calculated by the rotating time calculating unit is determined by the imaging device. More than the sum of the moving distance of the field of view to be taken that moves when the shooting direction rotates at a preset speed and the distance from the predicted center of gravity position to the edge of the image frame on the extension line of the moving direction of the moving object An in-frame frame determination unit that determines whether or not there is a point in time when the center of gravity of the moving object protrudes from the image frame frame by becoming larger;
When it is determined by the intra-frame frame determination unit that there is a time when the center of gravity position of the moving object protrudes from the image frame frame, the center of gravity position of the moving object calculated by the center of gravity calculation unit and the center position of the image frame The rotational distance of the imaging device is calculated by adding the moving amount of the moving object calculated based on the moving speed of the moving object calculated by the moving speed calculation unit to the distance, and based on this rotational distance A motor control unit that generates a control signal for rotating the shooting direction of the imaging device and transmits the control signal to the imaging device;
A moving object tracking control device comprising:

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