JP2008252331A - Digital monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve operability of camera control without being affected by transmission delay through a network in a monitoring system using a network camera with pan, tilt and zoom functions. <P>SOLUTION: Network cameras 1-4 transmit pan, tilt and zoom information in imaging together with an image through the network 34 to a monitoring controller, and the monitoring controller corrects a position by the received pan, tilt and zoom information, reduces the received image and displays it within the maximum imaging range of the network camera. A user indicates an area on a display screen, the pan, tilt and zoom of the network camera are controlled according to the coordinates and size of the area. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a digital surveillance system comprising a surveillance camera and a surveillance controller connected via a network.

  Conventionally, analog video surveillance systems using coaxial cables and other transmission lines have been used in systems where various surveillance areas are photographed with surveillance cameras and video from each camera is centrally monitored and recorded in a security room. It has been used. In recent years, digital video surveillance systems that handle digital video instead have become widespread. The digital video surveillance system transmits video captured by a camera via a network such as Ethernet (registered trademark).

  FIG. 12 shows a configuration diagram of a conventional digital video monitoring system. In FIG. 12, each device is connected to the network by a hub 21, and the network cameras 5 to 8 transmit the captured image to the monitoring controller 11 after JPEG compression. The monitoring controller 11 receives the image data and displays it on the display. In addition, the monitoring controller 11 selects the network cameras 5 to 8 to be controlled by a pointing device (not shown) such as a mouse, performs button operations such as pan, tilt, zoom, and the like, and performs network buttons 5 to 8 via the network 34. Control by sending commands such as pan, tilt and zoom.

In a normal monitoring system, when a camera is controlled, a user performs an operation while viewing an image of the camera. However, when operating a camera at a remote location via a network, there is a time lag from when the operation is performed until the image after the operation is actually reflected on the camera is displayed. For example, even if you stop panning when some target is in the middle of the screen while panning the camera, the target appears in the image that is sent after that when the target is too far from the center. Will be. Therefore, as described in Patent Document 1 below, a method for performing pan / tilt control of a camera by designating a range on a display screen on which an image of a pan / tilt camera is displayed has been proposed.
JP 2001-36810 A (abstract)

  According to this method, it is possible to control pan and tilt so that the angle of view is accurately centered on the target by specifying the range including the target on the image. However, there is a problem that zoom cannot be supported.

  Therefore, an object of the present invention is to provide a monitoring system that can easily perform a desired camera operation without being affected by a delay caused by network transmission.

  In order to achieve the above object, according to the present invention, the monitoring controller displays a first mode in which an image received from the network camera is displayed in accordance with the size of the display area, the maximum imaging range of the network camera, pan, tilt, and zoom information. Corresponding to the image display means for displaying the image in the second display mode for reducing and displaying the received image, and on the image displayed on the display means by the image display control means instructed by the user An area instructing unit for receiving a signal indicating an area and a camera control unit for controlling the network camera in accordance with the area instructed by the area instructing unit are provided.

That is, according to the present invention, a network camera having pan, tilt, and zoom functions and transmitting a captured image of a monitoring point, an image received from the network camera, displayed on the display means, and control of the network camera A digital monitoring system comprising a monitoring controller for performing
The network camera has means for transmitting pan, tilt, and zoom information at the time of imaging together with an image,
A first display mode in which the monitoring controller displays an image received from the network camera according to a size of a display area; and the received image is reduced as necessary, and panning, tilting, and Image display control means for controlling the display means to display an image in a second display mode for displaying at a position corresponding to the pan, tilt, and zoom information within a maximum imaging range by a zoom operation;
Area instruction means for receiving a signal indicating an area on an image displayed on the display means by the image display control means instructed by a user;
Camera control means for controlling the network camera in response to a signal indicating the area received by the area instruction means;
A digital surveillance system is provided.

  The image display control means has an image buffer for the second display mode, and newly receives an image received in the past from the network camera and after the network camera is panned and / or tilted. According to a first preferred aspect of the present invention, the received image is configured to be displayed in the second display mode by combining the received image on the two-dimensional plane using the image buffer.

  Further, the image display control means is arranged at the edge of the newly received image in order to distinguish it from surrounding images that are past images when displaying the newly received image in the second display mode. It is the 2nd desirable mode of the present invention that it is constituted so that a frame part may be provided and displayed.

  In addition, when the region designated by the region designating unit is an arbitrary point in the image displayed in the second display mode, the camera control unit sets the zoom magnification around the point. The third preferred embodiment of the present invention is configured to control the network camera without changing it.

  Further, the camera control means controls the network camera if the assumed minimum area having the same center as the designated area is designated when the area designated by the area designation means is smaller than the assumed minimum area. Performing is a fourth preferred embodiment of the present invention.

  Further, the camera control means controls the network camera if the assumed maximum area having the same center as the designated area is designated when the area designated by the area designation means is larger than the assumed maximum area. Performing is a fifth preferred embodiment of the present invention.

  In addition, according to a sixth preferred aspect of the present invention, the image display control means can switch and display the first display mode and the second display mode on one display screen.

  According to the present invention, the monitoring controller receives the image data and the pan, tilt and zoom information from the network camera, and the image display means has the corresponding position and size of the image received in the display area indicating the maximum imaging range. Display an image. Thereby, it is possible to immediately confirm in which direction in the maximum imaging range the camera is imaging. When it is desired to change the imaging position of the network camera, when an area in the display area is instructed by the area instructing means, the pan, tilt and zoom information corresponding to the position and size of the instructed area by the camera control means To control the network camera. This makes it possible to accurately obtain an image with a desired angle of view. In addition, the operability of the camera can be improved without being affected by delay due to transmission via the network.

  According to the first preferred aspect of the present invention, all the images received by the image display control means are overwritten and combined in the image buffer, and not only the latest image but also before the pan and / or tilt operations are displayed in the display area. The images taken in the past are also displayed. Therefore, when it is desired to monitor an image in the direction monitored in the past again, the area can be specified while viewing the past image, and a desired direction and angle of view can be easily specified.

  According to a second preferred aspect of the present invention, the image display control means receives the newly received image when displaying it in the second display mode in order to distinguish the newly received image from other images. A frame portion is provided at the edge of the image for display. As a result, the past image and the latest received image can be clearly distinguished, and the area can be easily specified.

  According to the third preferred embodiment of the present invention, when the region designated by the region designating means is not a certain range having an area but a point, the camera control means designates the region centered on that point. The camera is controlled on the assumption that the size of the area is the same as the latest received image at that time. As a result, when it is not necessary to change the zoom magnification, it is only necessary to indicate a point instead of an area having an area, so that a desired direction of the camera can be easily indicated.

  Hereinafter, preferred embodiments of the present invention will be described. FIG. 2 is a schematic diagram showing the overall configuration of the first embodiment of the digital monitoring system of the present invention. This digital monitoring system includes network cameras 1 to 4 with pan, tilt, and zoom functions that capture images and transmit video data, a monitoring controller 10 that controls the network cameras 1 to 4, and network cameras 1 to 4. And a hub 20 that connects the monitoring controller 10. The network cameras 1 to 4 and the monitoring controller 10 are connected via a hub 20 via a network 34 such as Ethernet (registered trademark).

  In FIG. 2, the network cameras 1 to 4 capture an image of the monitoring target area and convert it to a JPEG compressed image, and the pan, tilt, and zoom information (hereinafter referred to as PTZ information) at the time of capturing is stored in the JPEG comment header portion. It is embedded and transmitted to the monitoring controller 10. The monitoring controller 10 receives the JPEG data and displays it on the display screen of the image display unit. In the following description, it is assumed that the camera 1 is selected from the cameras 1 to 4 except that a plurality of cameras are sequentially selected and a plurality of images are displayed simultaneously.

FIG. 3 shows a display screen 30A in the first embodiment of FIG. In FIG. 3, the image received from the selected network camera 1 is displayed as it is in the upper left window 30A-1. This display is referred to as a first display mode. In the lower window 30A-2, the maximum imaging range of the network camera 1 is shown, and the received image is displayed therein (portion 40). This display is referred to as a second display mode. The network cameras 1 to 4 are provided with a pan function, a tilt function, and a zoom function, and each network camera 1 to 4 transmits PTZ (pan, tilt, zoom) information at the time of imaging together with the captured image. Note that the operation range of each of the pan, tilt, and zoom operations is limited. Hereinafter, “network camera” is also simply referred to as “camera”. Assume that the cameras 1 to 4 that are currently receiving the following restrictions.
Pan: minus 150 degrees to plus 150 degrees Tilt: 0 degrees to minus 90 degrees Zoom: horizontal angle of view 3 degrees to 50 degrees

In the horizontal direction, panning is up to 150 degrees, and the maximum angle of view is 50 degrees, so the limit of the maximum imaging range is 150 + 50/2, plus direction is 175 degrees, and minus direction is also 175 degrees .
If the image taken by the camera 1 is VGA size (640 × 480 pixels), the ratio of the horizontal angle of view and the vertical angle of view is 4: 3. Therefore, the vertical field angle of zoom is about 2.3 degrees to 38 degrees. Since the tilt operation range is 0 degree to minus 90 degrees, the plus direction is 0 + 38, 38 degrees, and the minus direction is -90-38, minus 128 degrees. Therefore, the maximum imaging range is plus or minus 175 degrees in the horizontal direction and minus 128 to 38 degrees in the vertical direction.

PTZ information is recorded in the JPEG comment header of the received image,
Pan: -100 °
Tilt: -10 °
Zoom (horizontal direction): 40 °
When this image is displayed in the lower window, as shown in Fig. 3, the horizontal direction is -100 degrees, the vertical direction is -10 degrees, and the horizontal direction is 40 degrees long. Zoom out and display the image.

FIG. 4 shows a display screen when the camera 1 is controlled.
In FIG. 4, when it is desired to see the lower right part in a wider range than the current image, a desired region 30R is indicated in the window 30A-2 in which the maximum imaging range is shown. Here, a mouse 32 is connected to the area instruction unit 22 of the monitoring controller 10, and the user designates the area 30R with the mouse 32 as shown in FIG. The area 30R at that time is center: horizontal minus 60 degrees, vertical minus 30 degrees, length: horizontal 48 degrees, and vertical 30 degrees. First, the lengths in the horizontal and vertical directions are compared.

Since the ratio of the horizontal and vertical angle of view of the actual image sent from the camera 1 is 4: 3, the length in the horizontal and vertical directions is 4: 3 including the designated area 30R without a shortage. Consider the smallest region that becomes. In this case, since the region of 48 degrees in the horizontal direction and 36 degrees in the vertical direction corresponds, the angle of view in the horizontal direction is 48 degrees. Therefore bread: -60 °
Tilt: -30 °
Zoom (horizontal): 48 °
Thus, the camera 1 may be controlled so that By doing so, even if there is a time lag between the operation of the camera 1 and the actually displayed image, the control of the camera 1 can be easily performed. Here, the PTZ information of the camera 1 is recorded in units of angles, but the number of steps in the operation range may be used as units. In that case, the calculation is performed after converting the angle.

If the indicated area 30R is center: horizontal minus 160 degrees, vertical minus 30 degrees, length: horizontal 20 degrees, and vertical 10 degrees, the center of area 30R is the pan limit. Since it exceeds 150, a region having a center of the horizontal direction minus 150 degrees and the vertical direction minus 30 degrees and including the designated area 30R is considered. In this case, it is understood that the horizontal length should be 40 degrees.

Therefore bread: -150 °
Tilt: -30 °
Zoom (horizontal direction): 40 °
The camera 1 may be controlled so that

  FIG. 1 is a block diagram showing the configuration of the monitoring controller 10 of FIG. 2, and an example using the monitoring controller 10 having the configuration of FIG. 1 will be described below as a first embodiment of the present invention. In FIG. 1, the image receiving unit 12 receives a JPEG image from the camera 1 via the network 34 and passes it to the image signal processing unit 14. The image signal processing unit 14 sends the received JPEG image to the first window display control unit 16 that generates an image signal to be displayed as it is in the first display mode, and obtains PTZ information of the image from the header of the JPEG image. To do. The image signal processing unit 14 acquires and receives information on the PTZ operating range of the camera 1, that is, the maximum movable range of each PTZ, from the camera information recording unit 28 in which the spec information of the cameras 1 to 4 is recorded in advance. The image is sent to the second window display control unit 18 together with the JPEG image. The second window display control unit 18 obtains the maximum imaging range of the camera 1 using information related to the operation range of the PTZ of the camera 1, and the image in which area within the maximum imaging range is determined from the PTZ information of the acquired image. To display a frame indicating the maximum imaging range in the second display mode, that is, a signal for displaying an image of the maximum imaging range in the second window 30A-2. At this time, the received image is reduced as necessary.

  The image signals generated by the first window display control unit 16 and the second window display control unit 18 are respectively sent to the image synthesis unit 19 and synthesized into an image signal constituting one raster. It is sent to the image display unit 30. As a result, the synthesized raster is displayed on the display screen 30A of the image display unit 30 as shown in FIG. In the example of FIG. 3, the latest image generated by the first window display control unit 16 is displayed in the upper left window 30A-1 of the display screen 30A, and the second window is displayed in the window 30A-2 below the display screen 30A. An image of the maximum imaging range generated by the display control unit 18 is displayed. The camera information recording unit 28 acquires information such as the specifications and IP addresses of the cameras 1 to 4 from the camera data file, and the camera data file records information about the cameras 1 to 4 as text data. It was created using etc. In the above configuration, the image signal processing unit 14, the first window display control unit 16, the second window display control unit 18, and the image composition unit 19 constitute an image display control unit 13. The unit 13 can be configured by a CPU (Central Processing Unit), memories such as RAM, ROM, and V-RAM, an interface, and the like.

  When controlling the camera 1, the area instruction unit 22 obtains information on the coordinates of the designated area from a pointing device such as a mouse 32 and passes it to the camera control section 24. The camera control unit 24 converts the received coordinate information into coordinates within the maximum imaging range to obtain PTZ information and obtains the IP address of the camera 1 from the camera information recording unit 28. Then, the obtained PTZ information and IP address are passed to the command transmission unit 26, and the command transmission unit 26 creates a command understood by the camera 1 from the PTZ information, and transmits it to the camera 1 via the network 34 using HTTP.

For example, the command is as follows.
http://192.168.0.10/PTZ.cgi?pan=-60.0&tilt=-30.0&zoom=48.0
This is a case where the IP address of the camera 1 is 192.168.0.10, pan: -60 °, tilt: -30 °, zoom 48 °.
Note that the command transmission unit 26 transmits a command by HTTP, but other protocols such as UDP can be used if the camera side supports it.

  FIG. 5 is a block diagram showing the configuration of the monitoring controller 10A in the second embodiment of the digital monitoring system of the present invention. 5, elements that are the same as or correspond to those in FIG. 1 are denoted by the same reference numerals. The image signal processing unit 14 obtains information related to the operation range of the PTZ of the camera 1 from the camera information recording unit 28 in advance, and sends it to the second window display control unit 18 together with the image received by the image signal receiving unit and the PTZ information. send. The second window display control unit 18 obtains the maximum imaging range of the camera 1, determines which area within the maximum imaging range to display the received current image from the acquired PTZ information, and stores it in the image buffer 17. A frame indicating the maximum imaging range is drawn and image data for drawing an image is stored. The image is drawn by overwriting any previously drawn image. When the imaging direction of the camera 1 is changed by panning or tilting operation, the previously drawn part remains as it is. After drawing in the image buffer 17, the second window display control unit 18 transfers the data in the image buffer 17 to the image composition unit 19 and composes it with the current image from the first window display control unit 16. The image is sent to the unit 30 and a composite image is displayed. Immediately after the display, the second window display control unit 18 draws the frame portion 40 indicating the boundary of the region where the latest image is drawn, as shown in FIG. In the above configuration, the image signal processing unit 14, the first window display control unit 16, the second window display control unit 18, the image buffer 17, and the image composition unit 19 constitute an image display control unit 13A. The image display control unit 13A can be configured by a CPU (Central Processing Unit), memories such as RAM, ROM, and V-RAM, an interface, and the like.

  FIG. 6 is a diagram of a display screen showing a state in which the frame portion 40 is drawn with a predetermined line 42. In FIG. 6, the latest image is displayed on the upper left, and an image in the maximum imaging range of the camera 1 is displayed in the lower window 30A-2. The past images received so far are also displayed, but the portions that have never been imaged remain a white background. By doing so, it is possible to instruct a region to be imaged next while confirming a past image, so that the control of the camera 1 can be operated more accurately. The latest image portion is surrounded by a black frame 40 or the like so that it can be easily distinguished from surrounding images, which are past images, and the positional relationship is very easy to understand. Although the black frame portion 40 is displayed here, in the case of a dark image, a frame portion of another color such as a red line frame portion may be used.

  Next, the operation of the monitoring controller 10A in the second embodiment will be described using the display screen of FIG. In FIG. 7, it is assumed that a certain point 44 in the lower window 30A-2 is designated by the mouse 32. As described above, when a region having a predetermined area is designated by the mouse 32, PTZ information is derived from the position and size of the center of the region, but when a point 44 having no area is designated, The camera 1 is controlled so that the point 44 is the center of the region and the zoom magnification is not changed.

The command in that case is as follows.
http://192.168.0.10/PTZ.cgi?pan=-60.0&tilt=-30.0
This is a case where the IP address of the camera 1 is 192.168.0.10, pan: -60 °, and tilt: -30 °.
By doing so, the operation can be performed very easily when there is no need to change the zoom.

Next, the operation of the monitoring controller 10A according to a preferred aspect of the second embodiment will be described on the display screen of FIG. In FIG. 8, it is assumed that a small area 46 in the lower window 30A-2 is designated by the mouse 32. At that time, the area 46 is centered: minus 60 degrees in the horizontal direction, minus 30 degrees in the vertical direction, length: 2 degrees in the horizontal direction, and 1 degree in the vertical direction. Since the ratio of the angle of view in the horizontal direction and the vertical direction is 4: 3, a minimum area including the designated area 46 and having a length in the horizontal direction and the vertical direction of 4: 3 is considered. In this case, since the region of 2 degrees in the horizontal direction and 1.5 degrees in the vertical direction corresponds, the angle of view in the horizontal direction is 2 degrees. However, when the operation zoom range of the camera 1 is 3 to 50 degrees in the horizontal angle of view, the assumed minimum area is 3 degrees in the horizontal direction and cannot be controlled to 2 degrees. Therefore, the camera 1 is controlled assuming that the assumed minimum area is 3 degrees.

The command in that case is as follows.
http://192.168.0.10/PTZ.cgi?pan=-60.0&tilt=-30.0&zoom=3.0
This is a case where the IP address of the camera 1 is 192.168.0.10, pan: -60 °, tilt: -30 °, zoom 3 °.
By doing so, even when an instruction exceeding the performance of the camera 1 is received, it is possible to perform control according to the instruction to the maximum extent.

Next, the operation of the monitoring controller 10A in a preferred mode in the second embodiment will be described using the display screen of FIG. In FIG. 9, it is assumed that a large area 48 in the lower window 30A-2 is designated by the mouse 32. At that time, the area 48 is center: minus 15 degrees in the horizontal direction, minus 70 degrees in the vertical direction, length: 70 degrees in the horizontal direction, and 55 degrees in the vertical direction. Since the ratio of the angle of view in the horizontal direction and the vertical direction is 4: 3, a minimum area including the designated area 48 and having a length in the horizontal direction and the vertical direction of 4: 3 is considered. In this case, since the area of 73.3 degrees in the horizontal direction and 55 degrees in the vertical direction is applicable, the angle of view in the horizontal direction is 73.3 degrees. However, since the operation zoom range of the camera 1 is 3 to 50 degrees in the horizontal angle of view, the assumed maximum area is 50 degrees in the horizontal direction and cannot be controlled to 73.3 degrees. Therefore, the camera 1 is controlled on the assumption that the assumed maximum area is 50 degrees.

The command in that case is as follows.
http://192.168.0.10/PTZ.cgi?pan=-15.0&tilt=-70.0&zoom=50.0
This is a case where the IP address of the camera 1 is 192.168.0.10, pan: -15 °, tilt: -70 °, zoom 50 °.
By doing so, even when an instruction exceeding the performance of the camera 1 is received, it is possible to perform control according to the instruction to the maximum extent.

  Next, the operation of the monitoring controller 10A in another preferred aspect in the second embodiment will be described using the display screens of FIGS. In FIG. 10, images from four cameras 1 to 4 are simultaneously displayed. When the upper left window 30A-1 is selected with the mouse 32 and right-clicked, a pop-up menu is displayed. When the item 50 called "full display" is selected, the normal display shown in FIG. 10 is displayed as shown in FIG. The display mode is switched to the entire image display format in which the maximum imaging range is displayed only in the upper left window. After the entire image is displayed and the cameras 1 to 4 are controlled, a pop-up menu is displayed in the same way as when right-clicking, and when the item of normal display (not shown) is selected, the normal display as shown in FIG. 10 is switched. It is like that. By doing this, even when images from a plurality of cameras 1 to 4 are monitored at the same time and there is no space to display a new whole image on the display screen, image monitoring from other cameras is not interrupted. The cameras 1 to 4 can be controlled. Here, the display is switched by a pop-up menu by right-clicking the mouse 32, but it may be performed by selection on a tool bar or a normal menu operation.

  According to the fourth preferred embodiment of the present invention, when the area indicated by the area indicating means is smaller than the assumed minimum area determined by the zoom range of the network camera, the camera control means is the same as the indicated area. Camera control is performed assuming that the center is the same as the assumed minimum area. As a result, even in the case of an instruction exceeding the performance of the network camera, control according to the maximum instruction is possible.

  According to the fifth preferred embodiment of the present invention, when the area indicated by the area indicating means is larger than the assumed maximum area determined by the zoom range of the network camera, the camera control means is the same as the indicated area. Camera control is performed assuming that the center is the same as the assumed maximum area. As a result, even in the case of an instruction exceeding the performance of the network camera, control according to the maximum instruction is possible.

  According to the sixth preferred aspect of the present invention, the first display mode and the second display mode are switched and displayed on one display screen. As a result, the image display screen of the specific network camera displayed in the first display mode even when there is no room in the display area because the images of the plurality of network cameras are displayed and monitored simultaneously. By switching to the second display mode and performing camera control, and switching to the first display mode after the control is completed, it becomes possible to perform camera control without interrupting image display of other cameras.

  Since the digital monitoring system of the present invention has the above-described configuration, the imaging device and the display device such as an outdoor or indoor monitoring system, a video conference system using a network camera having pan, tilt, and zoom functions are included. The present invention can be widely applied to image pickup display systems connected via a network. Accordingly, the digital monitoring system described in the claims of the present application includes not only the purpose of monitoring itself for crime prevention purposes but also the entire imaging / display network system that captures and transmits an image of a desired range. is there.

It is a block diagram which shows the structure of the monitoring controller in 1st Embodiment of the digital monitoring system of this invention. It is a schematic diagram which shows the whole structure of 1st Embodiment of the digital monitoring system of this invention. It is a figure which shows the display screen of the monitoring controller in 1st Embodiment of the digital monitoring system of this invention. It is a figure which shows the display screen of the monitoring controller in 1st Embodiment of the digital monitoring system of this invention. It is a block diagram which shows the structure of the monitoring controller in 2nd Embodiment of the digital monitoring system of this invention. It is a figure which shows the display screen of the monitoring controller in 2nd Embodiment of the digital monitoring system of this invention. It is a figure which shows the other example of the display screen of the monitoring controller in 2nd Embodiment of the digital monitoring system of this invention. It is a figure which shows the other example of the display screen of the monitoring controller in 2nd Embodiment of the digital monitoring system of this invention. It is a figure which shows the other example of the display screen of the monitoring controller in 2nd Embodiment of the digital monitoring system of this invention. It is a figure which shows the other example of the display screen of the monitoring controller in 2nd Embodiment of the digital monitoring system of this invention. It is a figure which shows the other example of the display screen of the monitoring controller in 2nd Embodiment of the digital monitoring system of this invention. It is a block diagram of the conventional digital video surveillance system.

Explanation of symbols

1-8 network camera 10, 10A, 11 monitoring controller 12 image receiving unit 13 image display control unit (consisting of image signal processing unit 14, first window display control unit 16, second window display control unit, image composition unit 19, Configure image display control means)
13A Image display control unit (consisting of an image signal processing unit 14, a first window display control unit 16, a second window display control unit, an image buffer 17, and an image composition unit 19 constitutes an image display control means)
DESCRIPTION OF SYMBOLS 14 Image signal processing part 16 1st window display control part 17 Image buffer 18 2nd window display control part 19 Image synthetic | combination part 20, 21 Hub 22 Area | region instruction | indication part (The area | region instruction means is comprised with the mouse | mouth 32)
24 Camera control unit (camera control means)
26 Command transmission unit 28 Camera information recording unit 30 Image display unit 30A Display screen 30A-1, 30A-2 Window 30R, 46, 48 Area 32 Mouse 34 Network 40 Frame unit 42 Line 44 Point 50 Item

Claims (4)

A network camera having a pan, tilt, and zoom function and transmitting a captured image of a monitoring point, and a monitoring controller that receives the image from the network camera, displays the image on a display unit, and controls the network camera. A digital surveillance system,
The network camera has means for transmitting pan, tilt, and zoom information at the time of imaging together with an image,
A first display mode in which the monitoring controller displays an image received from the network camera according to a size of a display area; and the received image is reduced as necessary, and panning, tilting, and Image display control means for controlling the display means to display an image in a second display mode for displaying at a position corresponding to the pan, tilt, and zoom information within a maximum imaging range by a zoom operation;
Area instruction means for receiving a signal indicating an area on an image displayed on the display means by the image display control means instructed by a user;
Camera control means for controlling the network camera in response to a signal indicating the area received by the area instruction means;
Having digital monitoring system.   The image display control means has an image buffer for the second display mode, and has received a new image after the image received in the past from the network camera and the network camera has been panned and / or tilted. The digital monitoring system according to claim 1, wherein an image obtained by synthesizing an image on a two-dimensional plane using the image buffer is displayed in the second display mode.   The image display control means is configured to display a frame at the edge of the newly received image in order to distinguish it from surrounding images that are past images when displaying the newly received image in the second display mode. The digital monitoring system according to claim 2, wherein the digital monitoring system is configured to display.   The camera control means does not change the zoom magnification around the point when the area designated by the area designation means is an arbitrary point in the image displayed in the second display mode. The digital monitoring system according to claim 1, wherein the network camera is configured to control the network camera.

Images