KR101223528B1 - Method for operating surveillance camera system in cooperative ways, system and camera for the same - Google Patents

Abstract

A method and system for operating a cooperative surveillance camera system and a camera therefor are provided.
A method of driving a surveillance camera system according to the present invention is a surveillance camera driving method having a threshold of a light quantity change amount for detecting an event, the method comprising: a step of detecting, by N cameras having two or more thresholds, Detecting an event; Changing the threshold value of the camera to a second threshold value lower than the first threshold value if the event is detected by only one or more than N-1 cameras; And detecting an event of the same area with N cameras having the changed second threshold value. According to the present invention, resources for operating the unmanned monitoring system can be reduced. That is, the power and storage capacity can be reduced and the image of a longer time can be stored by the same storage medium as compared with the normal recording system. In addition, through the cooperation of multiple cameras and the dynamic threshold change, it is possible to effectively reduce the non-detection probability and the false alarm probability.

Description

TECHNICAL FIELD [0001] The present invention relates to a cooperative surveillance camera system,

The present invention relates to a method and system for driving a surveillance camera system in a collaborative manner, and more particularly, to a surveillance camera system driving method and system for a cooperative surveillance camera system. More specifically, The present invention relates to a surveillance camera system driving method, system, and camera for collaborative surveillance camera systems capable of effectively reducing undetected probability and false alarm probability through cooperation of multiple cameras and dynamic threshold change.

Conventional unmanned surveillance systems detect and record accidents that may occur between vehicle versus vehicle, vehicle versus human or human versus human. To this end, the conventional unmanned monitoring system includes a sensor node (Sense Node) for monitoring a limited range and a master sensor node (Master Sense Node) for managing a cluster having a plurality of sensor nodes. Each sensor node includes various sensors for sensing the situation, for example, an acoustic sensor, a thermal sensor, a vibration sensor, and the like, and is equipped with a high-resolution camera for image processing. Among them, there are a method using infrared rays and an image filtering method as a motion detection method using a camera.

In the infrared system, after the infrared ray is irradiated at all times, the change amount of the reflected infrared ray is recognized and the operation is recognized. Such an infrared ray method has a drawback in that it can recognize accurate motion recognition, that is, presence or absence of an object in a photographing area, but should be used only in a relatively open space.

The image filtering method removes the infrared filter used in the daytime and allows the infrared light to be received directly from the CCD. The method measures the amount of light that is changed through the image histogram analysis, and the operation performance is determined according to the change amount threshold value designated by the user. However, there is a problem that a misdetection of the camera and a false alarm that is the opposite occurs excessively depending on the threshold value. Furthermore, when the threshold value for the amount of light change is lowered in order to lower the non-detection probability. There is a problem that not only the probability of false alarm increases, but also the amount of storage for video information increases greatly.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a surveillance camera driving method based on an image filtering method, which can reduce a required storage amount of image information and increase a detection probability And a method of driving the camera.

According to an aspect of the present invention, there is provided a method of driving a surveillance camera having a threshold of a light quantity change amount for detecting an event, the method comprising: detecting N events in two or more cameras having a first threshold, ; Changing the threshold value of the camera to a second threshold value lower than the first threshold value if the event is detected by only one or more than N-1 cameras; And detecting an event for the same area with N cameras having the changed second threshold value.

In one embodiment of the present invention, when all of the N cameras having the second threshold detect the event, the method includes storing image information for the event.

In one embodiment of the present invention, when only N-1 or less of N cameras among the N cameras having the second threshold value detect the event, The image information about the event is not stored.

In one embodiment of the present invention, when the number of cameras detecting the event among the cameras having the second threshold is equal to or greater than the number of cameras at the first threshold at which the event is detected, the second threshold is set at a third threshold A step of changing; And detecting an event for the same area with N cameras having the third threshold value.

In one embodiment of the present invention, after the image information of the event detected by the N-1 or less cameras is temporarily stored, only N-1 or fewer cameras among the N cameras having the second threshold value, It is deleted.

According to another aspect of the present invention, there is provided a method of driving a surveillance camera having a threshold value of a light quantity change amount for detecting an event, the method comprising: detecting, by N cameras having two or more thresholds, ; Changing an event to a second threshold value lower than the first threshold value if the event is detected by only one or more than N-x cameras; And detecting an event for the same area with N cameras having the changed second threshold value, wherein x is an integer of 2 or more.

In one embodiment of the present invention, the method further includes the step of storing image information about the event when N-x or more cameras among the N cameras having the second threshold detect the event.

In an embodiment of the present invention, when only Nx or less cameras among the N cameras having the second threshold value detect the event, the image information about the event photographed by the Nx or less cameras is not stored Do not.

In one embodiment of the present invention, when the number of cameras detecting the event among the cameras having the second threshold is less than N-x or more than N-x, the second threshold is changed to a third threshold lower than the second threshold; And detecting an event for the same area with N cameras having the third threshold, wherein the image information of the event detected by the Nx cameras or less is temporarily stored, and then the second threshold value 1 < / RTI > cameras out of the N cameras having the above-mentioned event are detected.

According to another aspect of the present invention, there is provided a surveillance camera driving system having a threshold of a light quantity change amount for detecting an event, the system comprising: a plurality of cameras for monitoring the same area, A camera 210; A storage unit 220 for storing image information on events photographed by the camera; And a control unit (230) for lowering a threshold value of a light amount change amount for detecting an event of the camera (210) when the number of cameras detecting the specific event is smaller than the plurality of cameras do.

In one embodiment of the present invention, when all of the cameras or a predetermined number or more of cameras detect a specific event in response to a lowering of the threshold, the control unit 230 stores the video information of the detected specific event (220).

In an exemplary embodiment of the present invention, when a predetermined number or less of cameras among a plurality of cameras detect a specific event in response to a lowering of the threshold, the control unit 230 may store image information on the detected specific event (220).

The present invention is also a camera used in the above-described surveillance camera system, and the camera provides an image filtering based camera in which a threshold value for a light quantity change amount, which is a criterion for determining an event detection, can be changed in real time.

According to the present invention, resources for operating the unmanned monitoring system can be reduced. That is, the power and storage capacity can be reduced and the image of a longer time can be stored by the same storage medium as compared with the normal recording system. In addition, through the cooperation of multiple cameras and the dynamic threshold change, it is possible to effectively reduce the non-detection probability and the false alarm probability.

1 is a block diagram of a surveillance camera driving method according to an embodiment of the present invention.
2 is a block diagram of a surveillance camera driving method according to another embodiment of the present invention.
3 to 7 are views for explaining a surveillance camera driving method according to an embodiment of the present invention.
8 is a block diagram of a cooperative surveillance camera drive system according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. Even if the terms are the same, it is to be noted that when the portions to be displayed differ, the reference signs do not coincide.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

A surveillance camera driving method according to the present invention uses a plurality of cameras that photograph a predetermined area. In this case, the camera is an image filtering method for detecting an event (i.e., an operation of appearing, moving, or disappearing) of an object in accordance with a change in light amount. The conventional image filtering method is a method in which a user sets a threshold ). However, when the threshold value is excessively high, a problem of so-called misdetection occurs in which an event can not be detected even though an actual event has occurred. On the other hand, when the threshold value is excessively low, a problem of false alarm that is recognized as an event occurs even though the event does not occur. Also, in the false alarm situation, meaningless image information photographed by the camera is stored in a separate recording medium, wasting the entire storage capacity.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above problems, and it is therefore an object of the present invention to provide a surveillance camera driving method and a surveillance camera driving method of a multi-camera collaborative system which can solve the problem of undetecting and false alarming by changing the threshold value by a plurality of cameras, ≪ / RTI >

1 is a block diagram of a surveillance camera driving method according to an embodiment of the present invention.

Referring to FIG. 1, an event in the same area is detected by N cameras of a first threshold value (S100). Here, N is an integer equal to or greater than 2, and when an event is detected in all of N, image information storage according to event detection proceeds without a process such as correction of the first threshold value. On the other hand, when no event is detected in all of N, no separate image information storage is proceeded.

If the event is detected by only one or more than N-1 cameras, the threshold of the camera is changed to a second threshold value lower than the first threshold according to the multi-camera collaboration method according to the present invention. That is, a camera having a low threshold has a low possibility of non-detection when compared with a case having a high threshold value. As a result, as the threshold value is lowered, the probability of undetected by a camera which can not detect an event due to various errors among a plurality of cameras is lowered. Also, even if a specific event is not simultaneously detected by the entire camera, the image information captured by the N-1 or less cameras is stored in the buffer storage unit.

Thereafter, an event in the same area is detected with N cameras of a second threshold (S300). If all the N cameras detect an event as the threshold value is lowered, the surveillance camera driving system and method according to the present invention judges the event as a correctly detected event and stores it in the storage unit (S400).

On the other hand, when only N-1 or less cameras among the N cameras monitoring the same area still detect the event, it is determined that a specific event is not detected, The image information is not stored (S500).

According to another embodiment of the present invention, when the camera detects an event that is equal to or greater than the number of cameras of the first threshold that detects the first event despite the lowering of the threshold value, The threshold value is changed to three thresholds, and event detection by N cameras is performed again (S600). That is, the process of changing the threshold is repeated until all N cameras can detect the event, so that the threshold value can be continuously lowered.

In still another embodiment of the present invention, the number of cameras for which the threshold value is changed is different from the above-described method.

2 is a block diagram of a surveillance camera driving method according to another embodiment of the present invention.

Referring to FIG. 2, the number of cameras whose threshold value is changed first by the user is set to N-x (S110), where x is an integer of 2 or more. That is, in the embodiment of the present invention, when a camera of a predetermined level or higher among all the cameras detects a specific event, it is judged as an event and the corresponding image information is stored.

However, when one or more than N-x cameras detect a specific event, the threshold value of the camera is changed to a second threshold value lower than the first threshold value (S210). That is, the camera having a low threshold has a low probability of non-detection when compared with a case having a high threshold, and thus the probability of undetected events of the camera is lowered as described above.

Thereafter, when the number of cameras exceeding Nx detects a specific event as the threshold value is lowered, the surveillance camera driving system according to the present invention determines the event as a correctly detected event and stores it in the storage unit (S310).

On the other hand, when only Nx cameras among the N cameras monitoring the same area still detect the event, it is determined that the specific event is not detected, so that the image information captured by the camera is not stored (S410).

3 to 7 are views for explaining a surveillance camera driving method according to an embodiment of the present invention.

Referring to FIG. 3, four cameras 110a, 110b, 110c, and 110d for photographing the same area are disclosed, and the first threshold value of the four cameras is 80%.

Referring to FIG. 4, only the first camera 110a among the four cameras detects an event that a person is intruding (emerging), and accordingly, the first threshold 80 of the four cameras 110a, 110b, 110c, % Is lowered to the second threshold of 64%. However, the image information about the event detected by the first camera is temporarily stored in the storage unit.

Referring to FIG. 5, the four cameras changed to the second threshold again detect an event in the same area. When all four cameras detect the same event, the event is determined as an actual event, The image information captured by the four cameras is stored in the storage unit.

On the other hand, if only one camera detects a specific event even though the threshold value has been changed to the second threshold value, it is determined that the event is not actually occurred, and the image information temporarily stored in the storage unit is deleted (Fig. 6).

Alternatively, if two or three cameras detect a particular event, but not all four, depending on the threshold change to the second threshold, the second threshold is again changed to a third threshold (e.g., 48%) , And event detection is again performed (Fig. 7).

8 is a block diagram of a cooperative surveillance camera drive system according to an embodiment of the present invention.

Referring to FIG. 8, a surveillance camera driving system 200 according to the present invention includes a plurality of cameras 210 for monitoring the same area and detecting an event in the area. A storage unit 220 for storing image information on events photographed by the camera; And a controller 230 for lowering a threshold value of the amount of light change for detecting an event of the camera 210 when the number of cameras that detect the specific event is less than the number of cameras.

If all of the cameras or a camera of a predetermined level or higher detects a specific event in response to the threshold change (i.e., lowering), the controller 230 stores the image information of the detected event in the storage unit 220 . In addition, when a specific event is detected only by a predetermined number of cameras or less, the controller 230 does not store the image information on the event in the storage unit 220, Are the same as those described with reference to Figs. 1 to 7, and will not be described below.

The present invention can effectively reduce resources (resources) for operation of the unmanned monitoring system by the above-described method. That is, the power and storage capacity can be reduced and the image of a longer time can be stored by the same storage medium as compared with the normal recording system. In addition, there is an advantage that the non-detection probability and the false alarm probability can be effectively lowered through collaboration of multiple cameras and dynamic threshold change.

Further, the present invention provides an image filtering-based camera in which a threshold value for a light amount variation, which is a criterion for determining an event detection, can be changed in real time, and the change of the threshold value is automatically performed by a control unit connected to the network.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art.

Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (14)

A method of driving a surveillance camera having a threshold of a light quantity change amount for detecting an event,
Detecting an event in the same area by N cameras having 2 or more first thresholds;
Changing the threshold value of the camera to a second threshold value lower than the first threshold value if the event is detected by only one or more than N-1 cameras;
Detecting an event for the same area with N cameras having the changed second threshold value; And
And when the N cameras having the second threshold value detect the event, storing the image information for the event. delete The method of claim 1,
When no more than N-1 cameras among the N cameras having the second threshold value detect the event, the image information on the event photographed by the N-1 or less cameras is not stored The method comprising: The method of claim 1,
Changing the second threshold value to a third threshold value lower than the first threshold value when the number of cameras detecting the event among the cameras having the second threshold value is equal to or larger than the number of cameras of the first threshold value detecting the event; And
And detecting an event for the same area with N cameras having the third threshold value. The method according to claim 1,
The image information of the event detected by the N-1 or less cameras is temporarily stored, and when only N-1 or less cameras among the N cameras having the second threshold value detect the event, Wherein the monitoring camera system comprises: A method of driving a surveillance camera having a threshold of a light quantity change amount for detecting an event,
Detecting an event in the same area by N cameras having 2 or more first thresholds;
Changing an event to a second threshold value lower than the first threshold value if the event is detected by only one or more than Nx cameras; And
And detecting an event of the same area with N cameras having the changed second threshold value, wherein x is an integer of 2 or more. 7. The method of claim 6,
And when the Nx cameras among the N cameras having the second threshold value detect the event, the image information about the event is stored. 7. The method of claim 6,
Wherein when no more than Nx cameras among the N cameras having the second threshold value detect the event, the image information about the event photographed by the Nx cameras or less is not stored. Method of operating the system. 7. The method of claim 6,
Changing the second threshold value to a third threshold value that is lower than Nx when the number of cameras that detect the event among the cameras having the second threshold value is less than N; And
And detecting an event for the same area with N cameras having the third threshold value. The method according to claim 6,
The image information of the event detected by the Nx or less cameras is temporarily stored, and when only N-1 or less cameras among the N cameras having the second threshold value detect the event, The method comprising: 1. A drive system for a surveillance camera having a threshold of a light quantity change amount for detecting an event,
A plurality of cameras (210) for monitoring the same area and detecting an event in the area; A storage unit 220 for storing image information on events photographed by the camera; And a control unit (230) for lowering a threshold value of a light amount change amount for detecting an event of the camera (210) when the number of cameras that have photographed the event is less than the plurality of cameras. The controller (230) Wherein the control unit (230) stores image information on the detected specific event in the storage unit (220) when all or a plurality of cameras of the plurality of cameras detect a specific event. delete 12. The method of claim 11,
When a predetermined number or less of cameras among a plurality of cameras detect a specific event in response to the lowering of the threshold, the controller 230 stores the image information of the detected specific event in the storage unit 220 Wherein the monitoring camera driving system comprises: A camera used in a surveillance camera driving system according to claim 11 or claim 13, characterized in that the camera is an image filtering-based camera in which a threshold value for a light quantity change amount, which is a criterion for determining an event detection, The camera.

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