JP2006109507A - Monitoring camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitoring camera capable of protecting privacy from the image of the camera, without impairing the monitoring functions. <P>SOLUTION: The monitoring camera is capable of executing panning rotation at an angle of 360 degrees and tilt rotation at an angle larger than 90 degrees. The monitoring camera holds masking data for masking 50 a privacy zone displayed on an image, and according to this data, a part of the image is masked. Since only a part of the image is concealed, monitoring function is not impaired, and privacy can be protected. In addition, a quick response is possible, since the masking data are stored to the monitoring camera. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a surveillance camera having a 360-degree surveillance area and an image display method thereof, and in particular, allows a part of an image to be masked and displayed for privacy protection.

  Conventionally, a surveillance camera in which a camera and a camera turntable are housed in a dome-shaped housing is commercially available. This surveillance camera is called a composite camera because it can perform both horizontal camera rotation (pan) and vertical camera rotation (tilt) by the operation of a turntable. An endless rotation of 360 degrees is possible in the pan direction, and a rotation from 0 degrees to 90 degrees, that is, a horizontal to vertical direction is possible in the tilt direction. This composite camera is installed on the ceiling of a public facility or the like, and can capture a desired direction by operating a controller. Further, even when the subject being tracked passes directly below, as shown in FIG. 15, at the moment when the camera 10 is directed downward, it is possible to rotate 180 degrees around the lens and continue tracking as it is. Images can be projected from end to end of the surveillance area.

  FIG. 13 shows a state in which the controller 12 that controls the composite camera 11 and the monitor 13 that displays the video of the composite camera 11 are connected to the composite camera 11 via the coaxial cable 16. The controller 12 includes a joystick 14 and a numeric keypad 15 as operation units.

  In the composite camera 11, for example, a plurality of camera positions such as an entrance direction, an exit direction, and a window direction can be preset in the controller 12 with IDs. After presetting, the camera can be turned in the preset direction by simply inputting the camera position ID from the numeric keypad 15 of the controller 12.

  The joystick 14 of the controller 12 is operated to control the moving speed of the camera. When the joystick 14 is tilted, the camera rotates in the tilt direction at a speed proportional to the vertical axis component of the joystick 14 and pans at a speed proportional to the horizontal axis component, as shown in FIG. Rotate in the direction. While viewing the monitor 13, the operator returns the joystick 14 to the neutral position and stops the rotation in the tilt direction and the pan direction when the rotating camera projects the desired direction.

  Also, when installing these cameras for public place surveillance, when the camera rotation angle is limited or the direction of the house is photographed so that nearby private houses are not displayed on the screen. A function for image processing is added so that the entire image becomes black, thereby protecting privacy.

  However, the conventional method for protecting privacy in a surveillance camera has a problem in that an image other than the area to be protected cannot be seen due to the limitation of the photographing direction or the darkness of the entire image, and the monitoring function is inevitably lowered.

  The group of inventors of the present invention has developed a new composite camera that can rotate 360 degrees in the pan direction and rotate 180 degrees in the tilt direction. In this composite camera, a wide range can be functionally monitored due to an increase in the degree of freedom in the moving direction. However, there is a need for a method for protecting privacy without diminishing these functions.

  The present invention has been made to solve these problems, and it is an object of the present invention to provide a surveillance camera device capable of protecting privacy from an image of a camera without impairing the surveillance function, and a method for displaying the image.

  Therefore, in the present invention, panning and tilting rotation is possible, mask data for masking a privacy zone appearing in an image is held inside, and the mask is masked in a surveillance camera that masks the privacy zone of an image according to the mask data. The data is configured to be fixed at the same ratio as the aspect ratio of the screen.

  Therefore, it is possible to reduce the amount of data to be managed, and it is possible to respond quickly when the camera is rotated.

  As is apparent from the above description, in the surveillance camera device and display method of the present invention, only the screen area that needs privacy protection is masked, so that the privacy can be protected without impairing the surveillance function. .

(First embodiment)
As shown in the side sectional view of FIG. 9 and the plan view of FIG. 10, the composite camera according to the embodiment of the present invention has a surveillance camera in a housing formed of a cylindrical camera base 107 and a hemispherical camera cover. 102, a tilt turntable 105 that directly holds the camera 102, a pan turntable 103 capable of 360-degree endless rotation, a pair of columns 113 standing on the pan turntable 103, and a tilt rotation about the columns 113 A tilt rotation shaft 106 that supports the base 105 and a slip ring 112 that acts as a contact for supplying power to the housing and inputting / outputting electric signals are provided, and the other illustration is omitted. Rotation mechanism of pan turntable 103 and tilt turntable 104, motor as a rotation drive source, motor drive control unit, amplification circuit for amplifying video signal, control unit for controlling operation of composite camera, etc. . Further, in order to determine the rotation base point in the pan direction, a magnet 117 is fixed at the base point position of the housing, and an origin Hall element 32 that detects the magnetic field of the magnet 117 is installed on the pan rotation table 103.

  The tilt turntable 105 that holds the camera 102 can be rotated 180 degrees around the tilt rotation axis 106. As a result, the camera 102 moves from the direction of point A (108) in FIG. The direction can be reversibly changed through the point B (109) to the direction of the point C (110).

  Further, the pan turntable 103 can rotate the rotation locus 206 in the horizontal direction over 360 degrees as shown in FIG.

  In addition, the slip ring 112 realizes power supply from the fixed portion to the movable portion and electrical signal conduction between the fixed portion and the movable portion.

  Therefore, by attaching this composite camera to the ceiling, adjusting the rotation angle of the tilt turntable 105 by remote control, and rotating the pan turntable 103 in a predetermined direction, the camera 102 captures all directions in the monitoring area. be able to.

FIG. 11 shows the internal configuration of this composite camera in function blocks. As the rotation control mechanism of the pan turntable 103 and the tilt turntable 105, the motors 24 and 28 that rotate, the encoders 25 and 29 that detect the rotation speed of the motors 24 and 28, and the motors based on the detection results of the encoders 25 and 29 Motor drivers 23 and 27 for driving 24 and 28; speed reduction mechanisms 26 and 30 for decelerating the rotation of the motors 24 and 28 and transmitting them to the pan turntable 103 and the tilt turntable 105; and a magnet 117 arranged at the base point of the pan An origin hall element 32 located on the pan turntable 103 that is sensitive to the magnetic field of the head and an end point hall located 180 degrees apart from the tilt turntable 105 that is sensitive to the magnetic field of the magnet located at the end position of the tilt. The element 33, the Hall element detection unit 31 that detects the origin of the pan and the end point of the tilt from the detection signals of the Hall elements 32 and 33, and the motor that controls the motor drivers 23 and 27 based on the detection result of the Hall element detection unit 31 And a control unit 22.

  Further, as a control mechanism of the camera lens unit, stepper motors 36 and 40 for zoom and focus adjustment, motor drivers 35 and 39 for outputting drive pulses to the stepper motors 36 and 40, and stepper motors 36 and 40 Controls deceleration mechanisms 37 and 41 that transmit rotation speed to the lens mechanism, limit switch or photo interrupter 38 that detects the limit of zoom adjustment, photo interrupter 42 that detects the limit of focus adjustment, and motor drivers 35 and 39 A lens control unit 34 for adjusting the iris and a driver 43 for adjusting the iris.

  In addition, the camera unit that outputs the video signal includes a CCD 44 that performs imaging, a DSP 45 that encodes the video signal, and an image memory 46 that writes and reads image data.

  Furthermore, a camera control unit 21 for controlling the operation of the composite camera based on a control signal input from the controller, and a memory (E2PROM) 47 for storing data are provided.

  Further, the composite camera is controlled by being connected to the controller 12 and the monitor 13 through the coaxial cable 16 as in the conventional apparatus (FIG. 13), or by RS485 serial communication (18) as shown in FIG. It is also possible to connect the personal computer 19 and the composite camera 11 and control the composite camera 11 from the personal computer 19 while displaying the video of the composite camera 11 on the screen of the personal computer 19.

  In this example, a single composite camera 11 is connected to the controller 12 or the personal computer 19; however, a plurality of composite cameras are connected to the controller 12 or the personal computer 19, and these composite cameras are connected to the controller 12. It is also possible to control with 12 or PC 19.

First, the general operation of this composite camera will be described. In this composite camera, the output pulse of the encoder 25 that detects the rotation of the motor 24 in the pan direction is transmitted to the motor control unit 22, and the time point at which the origin hall element 32 detects the pan base point is transmitted through the hall detection unit 31. This is transmitted to the control unit 22. When the number of pulses output from the encoder 25 during the one rotation of the pan turntable is p, the motor control unit 22 outputs m the number of output pulses from the encoder 25 after the origin Hall element 32 detects the pan base point. Count
Pi = m × 360 / p
To calculate the current pan angle Pi. The calculated current pan angle Pi is held in the memory 47.

Similarly, the output pulse of the encoder 29 that detects the rotation of the motor 28 in the tilt direction is transmitted to the motor control unit 22, and the detection time of the tilt end point by the end point hall element 33 is controlled by the motor through the hall detection unit 31. Reported to Part 22. When the number of pulses output from the encoder 29 during the half rotation of the tilt turntable is q, the motor control unit 22 outputs the number n of pulses output from the encoder 29 after the end point Hall element 33 detects the end point of the tilt. Count
Ti = 90− (n × 180 / q)
Thus, the current tilt angle Ti is calculated. That is, the tilt angle is calculated with the direction immediately below as 0 degrees. The range in which the tilt angle can be taken is from +90 degrees to -90 degrees. The calculated current tilt angle Ti is held in the memory 47.

  The pan angle Pi and the tilt angle Ti indicate the direction of the center of the current camera screen.

  In addition, the angle of view of the captured image is determined by the rotation amount of the stepper motor 36 that defines the zoom amount at the lens unit and the electronic zoom magnification, and this rotation amount is determined by the number of pulses output to the stepper motor 36. The lens control unit 34 counts pulses output to rotate the stepper motor 36 in the positive direction to + and pulses output to rotate in the negative direction to-, and outputs them from the motor driver 35. Accumulate the number of pulses. The camera control unit 21 records the vertical angle of view (Zt) of the angle of view obtained from the cumulative number of pulses and the electronic zoom magnification in tilt coordinates, and the horizontal angle of view (Zp) in pan coordinates and records it in the memory 47. To do.

  Thus, Pi, Ti, Zt and Zp are stored in the memory 47 as data representing the current state quantity of the composite camera.

  The operation of the composite camera is controlled by the controller 12 or the personal computer 19. A command is transmitted from the controller 12 or the personal computer 19, and the camera control unit 21 of the composite camera 11 interprets the received command and controls the operation of each unit.

  When the operator tilts the joystick 14 of the controller 12 in order to change the direction of the camera, in response to this operation, the controller 12 sends the tilted joystick 14 as shown in FIG. The data Vpan representing the x-axis component and the data Vtilt representing the y-axis component are transmitted to the composite camera 11. The camera control unit 21 of the composite camera 11 interprets the received command, sends the data Vpan and data Vtilt to the motor control unit 22, and the motor control unit 22 performs the pan rotation at the speed of Vpan. And the motor driver 27 is controlled to perform tilt rotation at the speed of Vtilt.

  When the operator returns the joystick to the neutral position, similarly, data of Vpan = 0 and Vtilt = 0 are sent to the composite camera together with the command, and the rotation in the tilt direction and the pan direction is stopped.

  When the camera changes its direction, as described above, Pi, Ti, Zt, and Zp data representing the current state of the camera are updated and held.

  The CCD 44 images the direction in which the camera is directed and outputs the video signal to the DSP 45. The DSP 45 encodes an image, and the encoded image data is once written in the image memory 46, then read out from the image memory 46 and output to the monitor 13.

  This composite camera can be realized by turning the pan angle 180 degrees without moving the tilt angle when turning the camera in the opposite direction, and the tilt angle can be changed from positive to negative while the pan angle is fixed. It can be realized even if it rotates. However, the CCD 44 is not inverted when passing through the former route, but the CCD 44 is turned upside down when passing through the latter route. Therefore, in the latter case, the image appears upside down unless the data is read upside down. Therefore, the image data of the CCD 44 is recorded in the image memory 46 in the same manner as before, then read out from the image memory 46 in the reverse direction and sent to the monitor. Such a state, that is, a state where Ti is negative will be referred to as “upside down”.

Similarly, when the camera is rotated 90 degrees horizontally, the tilt angle is not moved and the pan angle can be turned 90 degrees, and the tilt angle is temporarily set to 0 while the pan angle is fixed. It can also be realized by a method of pulling up in a different direction after 90 degrees. In the latter case, it is necessary to read the image data of the CCD 44 through the image memory 46 with the left and right reversed. This state will be referred to as “inverted horizontally”.

  In this composite camera, as shown in FIG. 1, the privacy zone reflected in the image can be covered with a mask 50. When an image is captured while the direction is gradually changed by auto tracing, the mask position changes on the screen according to the movement of the camera, and the privacy zone is continuously hidden. However, in the composite camera of this embodiment, when the camera speed is higher than a certain value, the privacy zone cannot be identified from the image even without the mask, so that the masking is not performed. . Further, no mask area is provided when the tilt angle is between −45 and 45 degrees. As will be described later, if the tilt angle is small, the subject may rotate relatively large due to pan rotation, and the mask may not work effectively, and in a place where there is a privacy zone at such a position. This is because surveillance cameras are not normally installed.

  This mask setting is performed using the personal computer 19 as follows.

  When the operator selects a mask setting procedure from the personal computer 19, a mask setting command is sent to the composite camera. The camera control unit 21 interprets this command and instructs the lens control unit 34 to maximize the zoom. The camera image and Pi, Ti, Zp and Zt data representing the state quantity are sent to the personal computer 19 and the image is displayed on the screen.

  When the operator designates the center position of the privacy zone of the image using the mouse, pan coordinates and positive tilt coordinates corresponding to the position are calculated by a personal computer and sent to the composite camera. The motor control unit 22 is instructed to direct the center of the screen to the pan coordinate and tilt coordinate. As a result, the image is displayed so that the center position of the mask setting is at the center of the screen of the personal computer.

  Next, when the operator moves the cursor on the screen, as shown in FIG. 3, a rectangular zone frame having the center position at the center and the cursor position as one corner is displayed. The vertical / horizontal ratio of the zone frame is fixed at 3: 4, which is the same as the vertical / horizontal direction of the screen. The operator performs the mask zone setting operation after expanding the zone frame so that the privacy zone is hidden. At this time, a number or name representing the mask zone is also set.

  The central coordinates defining the set mask zone and the coordinates of one vertex are managed by a personal computer together with a number. Also, pan coordinates and tilt coordinates representing the mask zone are sent together with the number from the personal computer to the composite camera and stored in the memory 47. Up to four mask zones can be set for one screen.

  At this time, the personal computer calculates the coordinate data of the three corners of the mask zone from the center coordinates and the coordinates of one vertex which are the management data of the mask zone, and sends this coordinate data to the composite camera. Alternatively, the central coordinates and the coordinates of one vertex which are management data of the mask zone are sent to the composite camera, the composite camera stores this management data, and calculates the coordinate data of the four corners of the mask zone when necessary. Also good.

  FIG. 4 shows data stored in the memory 47 of the composite camera corresponding to one mask zone. Data of three points (HLy, LLy, HRy, HLx, LLx, HRx) shown in FIG. 4A is stored for one mask zone, which is shown in FIG. The data of the lower right LR is calculated by LRx = HRx and LRy = LLy.

  The reason for setting the mask zone at the center of the screen is to prevent distortion of the image at the time of setting.

  The reason why the aspect ratio of the zone frame is fixed is to reduce the amount of data to be managed.

  The privacy zone display process in the composite camera after the mask zone is set in this way will be described.

  FIG. 2 is a flowchart showing the operation of the composite camera.

  Step 1: The camera control unit 21 checks whether the pan movement speed or the tilt movement speed is equal to or higher than a predetermined speed. If so, the privacy zone display process is not performed.

  Step 2: Further, it is checked whether the tilt angle Ti is between −45 and 45 degrees. If so, the privacy zone display process is not performed.

Step 3: When the tilt angle Ti is negative,
Step 4: The pan angle Pi is converted to an angle opposite to 180 degrees. That is, when Pi <180 °, (Pi + 180 °) is the pan angle, and when Pi ≧ 180 °, (Pi−180 °) is the pan angle. Also,
Step 5: Convert the tilt angle to (90 ° -Ti).

  By the processing of step 4 and step 5, conversion to pan absolute coordinates (0 to 360 °) and tilt absolute coordinates (0 to 180 °) is performed.

  Step 6: The camera control unit 21 reads the mask data from the memory 47.

Step 7: Check if it is currently upside down. If it is upside down,
Step 8: The mask data HL and LL are exchanged, and the HR and LR are exchanged.

  FIG. 5A shows data (tHL, tLL, tHR, tLR) after the replacement process, and FIG. 5B shows data when the replacement process is unnecessary.

Step 9: Check if it is currently flipping horizontally. If it is flipping horizontally,
Step 10: Swap LL and LR, and swap HL and HR.

  FIG. 6A shows data (tHL, tLL, tHR, tLR) after the replacement process, and FIG. 6B shows data when the replacement process is unnecessary.

  Step 11: Next, the camera control unit 21 converts the mask data expressed in absolute coordinates into screen coordinates. This is because, as shown in FIG. 7, the mask zone (tHL, tLL, tHR, tLR) is displayed on the current screen with the center (Pi, Ti), the horizontal length Zp, and the vertical length Zt. ), And when the mask zone is out of the current screen as shown in FIG. 7A, both tHL and tHR and tLL and tLR are on the boundary of the current screen. (THL = tHR, tLL = tLR) and the mask zone is not displayed.

In addition, as shown in FIG. 7B, when a part of the mask zone is out of the current screen, the mask zone data (tHL, tHR, tLL) out of the screen is converted to the boundary line of the screen. A zone defined by these converted points and tLR is displayed as a mask zone. Further, as shown in FIG. 7C, when all of the mask zone data is located in the current screen, an area defined by (tHL, tLL, tHR, tLR) is displayed as a mask zone. .

Step 12: The mask zone converted into the screen coordinates is converted into data corresponding to the pixels of the CCD 45 and output to the DSP 45.
Step 13: Display processing is performed.

  This mask zone is displayed in a color such as black on the screen, or a mask number or a symbol (private house mark, toilet mark) or the like is displayed.

  When correcting the mask zone, the operator inputs the mask number and executes the mask setting procedure. The camera control unit 21 of the composite camera reads out the mask data of the corresponding number stored in the memory 47, and controls the motor control unit 22 so that the mask zone comes to the center of the screen. When the operator performs an operation such as pan / tilt or zoom while the mask zone is displayed at the center of the screen, the zone is deleted and a new zone can be set.

  As shown in FIG. 8, even if the subject is fixed, the subject image rotates in the screen as the pan rotates. This change becomes more significant as the tilt angle becomes closer to the bottom. For this reason, when the pan angle changes from the angle at the time of mask setting, the privacy zone rotates in the screen and a portion leaking from the mask occurs. This problem is that the mask zone required to cover the current privacy zone (= mask position at the time of setting) is calculated based on the pan angle at the time of setting the mask zone and the current pan angle, and the mask is updated. Can be avoided.

  In addition, when the angle of view is large, there is no risk of losing privacy even if the small mask is turned off. Therefore, masking on / off may be controlled by the angle of view. Further, a mask that has become smaller than a certain value on the monitor screen may be controlled so as not to be further reduced. By such treatment, the arithmetic processing for changing the mask area following the angle of view is reduced. Also, a mask that is too small can be mistaken for an image defect.

  Further, the process of stopping masking when the rotation speed of the camera is high has been described above, but this is also a measure for preventing the coordinate calculation of the mask zone from catching up with the fast rotation of the camera. Conversely, control may be performed to suppress the rotational speed of the camera to the extent that the masking calculation can follow.

  In addition, the personal computer has a function of counting the number of masking and disabling the mask zone setting when the specified number is exceeded. This is because if the number of masking is too large, the processing by the composite camera cannot catch up. In this case, this can be dealt with by covering a plurality of privacy zones with one mask and reducing the number of masks. Further, even when a plurality of masks are included in one screen, the processing time can be shortened by converting the mask into one enlarged mask including all of them and performing the masking process.

  In addition, the masking can be canceled and set only by a specific person having a password, thereby preventing an ordinary person from performing arbitrary operations.

In addition, in order to facilitate the data management of the mask zone, the case where the mask zone is set with the center coordinate and one vertex of the rectangle has been described. It is also possible to use the shape size parameter.

  Further, in the embodiment, the surveillance camera capable of 360-degree pan rotation and 180-degree tilt rotation has been described, but the present invention is similarly applied to other surveillance cameras that perform pan rotation and tilt rotation. Can be applied.

  Since the surveillance camera device according to the present invention masks only the screen area that needs privacy protection, it can protect privacy without impairing the surveillance function, and is useful as an outdoor surveillance camera or the like.

The figure which shows the display screen masked by the composite camera of embodiment Flow chart showing operation of composite camera of embodiment The figure which shows the mask zone setting screen in the display method of the compound camera of embodiment. Explanatory drawing explaining the coordinate of a mask zone in the display method of the composite camera of embodiment The figure which shows the coordinate conversion at the time of upside down in the display method of the compound camera of embodiment The figure which shows the coordinate transformation at the time of right-left inversion in the display method of the compound camera of embodiment The figure which shows the conversion to a screen coordinate in the display method of the compound camera of embodiment. Explanatory drawing explaining correction | amendment of the mask accompanying pan rotation in the display method of the compound camera of embodiment Side sectional view showing the structure of the composite camera of the embodiment Plan sectional view showing the structure of the composite camera of the embodiment 1 is a block diagram showing the configuration of a composite camera of an embodiment The figure which shows the other control system of the compound camera of 1st Embodiment. The figure which shows the control system of the conventional compound camera apparatus Explanatory drawing explaining the camera speed control currently performed with the conventional composite camera apparatus The figure explaining operation of the conventional compound camera

Explanation of symbols

10 Camera
11 Combined camera
12 Controller
13 Monitor
14 Joyce Tech
15 Numeric keypad
18 RS485 serial communication section
19 PC
21 Camera control unit
22 Motor controller
23, 27 Motor driver
24, 28 motor
25, 29 Encoder
26, 30 Deceleration mechanism
31 Hall element detector
32 Origin Hall element
33 End Hall element
34 Lens control unit
35, 39 Motor driver
36, 40 Stepper motor
37, 41 Deceleration mechanism
38 Limit switch / Photo interrupter
42 Photointerrupter
43 Drivers
44 CCD
45 DSP
46 Image memory
47 Memory (E2PROM)
50 mask
102 Camera
103 Pan turntable
105 tilt turntable
106 Tilt rotation axis
107 camera base
112 slip ring
113 support
117 magnet

Claims (1)

Panning and tilting rotation is possible, in the surveillance camera that holds the mask data for masking the privacy zone reflected in the image and masks the privacy zone of the image according to the mask data,
The surveillance camera characterized in that the mask data is fixed at the same ratio as the aspect ratio of the screen.