JP4097541B2 - Surveillance camera device and surveillance camera system - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a surveillance camera device and a surveillance camera system.
[0002]
[Prior art]
In recent years, crime prevention has been increasing by installing surveillance camera devices in banks and stores. On the other hand, people who are trying to invade the store, etc. are continually following, for example, when the intruder sprays paint spray on the surveillance camera device, the paint adheres to the lens and makes imaging difficult. It has been made difficult to take an image by covering the surveillance camera device with a cloth or the like. In this way, to prevent intruders from recognizing their face and appearance is called a plan. From the viewpoint of the recording side, it is said to be an image plan because it seems that the image is intentionally manipulated.
[0003]
Various measures have been proposed as countermeasures for the above-mentioned schemes (see Patent Document 1). As such a countermeasure, for example, it is conceivable to perform image processing in a monitoring camera or a device connected to the monitoring camera. For example, as shown in FIGS. 7A and 7B, the luminance value integration processing of the captured video for each area obtained by dividing the captured video into a plurality (M × N) (this processing is used for iris and retrograde correction). This integrated value is monitored using Specifically, for example, when the paint is applied to the lens by spraying, as shown in FIG. 8, the integrated value in field units changes little by little (depending on how the spray is sprayed). A threshold is set for such a change, and it is determined whether or not it is a plan with this threshold as a boundary. Further, when the lens is covered with a cloth or the like, as shown in FIG. 8, the integrated value changes more rapidly than in the case of using the spray. Also in this case, it is possible to determine the plan by setting a threshold value for the integral value and a threshold value for the change amount. When it is determined that it is a plan, an alarm is output and a security guard goes to the site.
[0004]
Note that the following can be considered as other determination methods based on image processing. For example, a histogram is created from the luminance information of each pixel, a threshold value is automatically or manually determined, the image is binarized, and a method for judging whether the plan is normal or not from a rough luminance change, and the luminance for each pixel is preset. A method is conceivable in which all the portions exceeding (or falling below) the threshold are integrated and the luminance distribution of each field is used as a judgment material.
[0005]
[Patent Document 1]
JP-A-8-293073 [0006]
[Problems to be solved by the invention]
However, in the above-described determination process, the image determination is performed by simply comparing the luminance integrated value of the captured image with the threshold value. It is difficult to distinguish from the video state, and misjudgment is likely to occur. If a security guard goes out for every misjudgment, a large dispatch cost will occur.
[0007]
In view of the above circumstances, an object of the present invention is to provide a monitoring camera device and a monitoring camera system capable of accurately distinguishing between extinguishing and an image plan.
[0008]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided means for converting a video signal from an image sensor into a digital captured video, a means for performing luminance related value generation processing of the captured video for each area obtained by dividing the captured video, A monitoring camera system using a brightness-related value and a means for determining whether it is a light extinction or an image plan , wherein a lighting switch is turned on / off within an imaging range of the monitoring camera device ON / OFF in conjunction with OFF, but there is a light emitter that forms a state that the image sensor senses for a while after OFF, and the area of the captured image corresponding to the light emitter position is set as a specific area It is a surveillance camera system .
[0009]
According to a second aspect of the present invention, in the surveillance camera system of the first aspect, the surveillance camera device is configured to determine whether it is extinguished or a measure by comparing a brightness-related value of a specific area with a threshold value. It is characterized by.
[0010]
According to a third aspect of the present invention, in the surveillance camera system of the first aspect, the surveillance camera device is configured to determine whether it is extinguished or a measure by comparing a change amount of a luminance related value in a specific area with a threshold value. It is characterized by that.
[0011]
According to a fourth aspect of the invention, there is provided means for converting a video signal from the image sensor into a digital captured video, a means for performing luminance related value generation processing of the captured video for each area obtained by dividing the captured video, A monitoring camera system using a brightness-related value and a means for determining whether it is a light extinction or an image plan, wherein a lighting switch is turned on / off within an imaging range of the monitoring camera device It is turned ON / OFF in conjunction with OFF, but a heating element that forms a state that the image sensor senses is present for a while after the OFF, and the area of the captured image corresponding to the heating element position is set as a specific area It is a surveillance camera system.
[0012]
According to a fifth aspect of the present invention, in the surveillance camera system according to the fourth aspect of the invention, the surveillance camera device is configured to determine whether the surveillance camera device is extinguished or a scheme by comparing a brightness-related value of a specific area with a threshold value. It is characterized by .
[0013]
According to a sixth aspect of the present invention, in the surveillance camera system of the fourth aspect, the surveillance camera device is configured to determine whether the monitoring camera device is turned off or a measure by comparing a change amount of a luminance related value in a specific area with a threshold value. It is characterized by that .
[0015]
Here, when the light is turned off, the captured image becomes dark in the entire imaging range of the surveillance camera device (conventionally), and the brightness-related value for each area obtained by dividing the captured image into a plurality of areas changes abruptly. However, in the surveillance camera system of the present invention, the luminance-related values in the areas corresponding to the existing lighting fixtures, light emitters, heating elements, phosphorescent bodies, or thermal radiators described above are other areas. There will be no sudden changes like those On the other hand, when measures such as spraying the paint on the lens or covering the lens with a cloth are taken, the brightness-related values will show abrupt changes even in specific areas, making it easy to distinguish from the case of turning off the light. , False determination can be reduced as much as possible.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
A monitoring camera device according to an embodiment of the present invention will be described below with reference to FIGS.
[0017]
FIG. 1 is an explanatory view showing the surveillance camera device 1. The surveillance camera device 1 includes a camera body 1a, an imaging direction control device (pan / tilt mechanism) 1b, an I / O interface 1c, and the like. Each of these elements is controlled by, for example, the microcomputer 14 (see FIG. 2) of the camera body 1a. The imaging direction control device 1b is a device that performs pan / tilt control in the camera body 1a, and includes an actuator such as a motor (not shown). A drive control signal to the actuator of the imaging direction control device 1b is given from the microcomputer 14, for example.
[0018]
When installing the monitoring camera device 1, a control unit (not shown) in the monitoring camera device 1 or an external controller (not shown) connected to the I / O interface unit 1 c is used. Teaching For example, if the installation location of the door is to be monitored, the imaging direction control device 1b is controlled by the control unit or the external controller, and the pan / tilt operation is executed to direct the camera body 1a to the installation location of the door. Then, zoom adjustment is performed so that a desired enlarged image can be obtained, further focus setting is performed, and information for reproducing these states (pan / tilt position, zoom setting, focus setting) is stored in the memory 18 (see FIG. 2). ). After the installation, the monitoring camera device 1 reads the stored information from the memory 18 and automatically executes the pan / tilt operation, and performs the zoom operation and the focus operation in a state where the pre-designated monitoring location is imaged. Run automatically. If a plurality of locations are to be monitored, the above operations are automatically executed sequentially at each monitoring location, or the above operations are automatically executed at the monitoring location designated by the operator.
[0019]
Further, in the setting for monitoring the installation location of the door as described above, in addition to the above-described pan / tilt position, zoom setting, focus setting setting and information writing processing for reproducing the same, for example, FIG. ), A phosphorescent (fluorescent) tape 20 is affixed to the wall, and an area for imaging the phosphorescent tape 20 is specified among a plurality of areas (details will be described later) on the captured image according to the imaging setting. The area is set and this specific area setting information is written in the memory 18. The specific area setting process is performed at each imaging location. When the threshold value (which will be described later in detail) is different in each specific area, the threshold value is set in each specific area. In the case of a fixedly installed surveillance camera, the setting process for a specific area is only required in one place, and only one threshold is required.
[0020]
FIG. 2 is a block diagram showing the camera body 1a. The lens mechanism 11 includes a lens group 11a, a focus control device (not shown) that adjusts the position of the lens group 11a to form a focused state, and a diaphragm unit 11b that performs diaphragm adjustment (incident light amount adjustment). The CCD 12 receives the image light of the subject that has passed through the lens mechanism 11, converts it into an electrical signal, and outputs it.
[0021]
A CDS (correlated double sampling) / AGC (auto gain controller) circuit 15 removes noise contained in the output signal of the CCD 12 and outputs the CCD 12 in accordance with a control signal from the microcomputer 14. Controls the signal amplification. The signal processing circuit 13 performs various signal processing (digital video generation processing, luminance processing, color processing, etc.) on the signal (analog signal) output from the CDS / AGC circuit 15 and then performs D / A conversion. For example, the video signal is converted into an NTSC video signal and output, or is output as a digital video (or encoded data or the like). Also, as shown in FIGS. 3A and 3B, the digitized captured video is divided into a plurality of areas (M × N), and digital integration of the captured video (luminance information) is performed for each divided area. Perform processing. The integral value is conventionally used as a reference value for AGC, iris, retrograde correction, and the like.
[0022]
The microcomputer 14 inputs the integration value of the specific area from the signal processing circuit 13 through the interface (I / F), for example, in one field cycle, and determines whether the light is extinguished or a plan using the integration value of the specific area. Do. For example, as shown in FIG. 3A, when the range near the door is monitored as the imaging range, the phosphorescent tape 20 is allowed to exist in the imaging range, and the location where the phosphorescent tape 20 is imaged. By setting the area as a specific area, as shown in FIGS. 3B and 6, when the area is turned off, the integral value of the specific area (this integral value is A) is more than the threshold value (this threshold is TH). High state can be maintained. On the other hand, as shown in FIG. 4, when an intruder takes the camera field of view of the monitoring camera device 1 with paint spray, the CCD 12 cannot sense the light from the phosphorescent tape 20, and as shown in FIG. The value A is in a state below a predetermined threshold value TH. Note that the threshold TH is not limited to a preset value, and may be automatically set or changed by image processing of a captured video.
[0023]
FIG. 5 is a flowchart simply showing work contents and process contents in the monitoring camera system described above. When the monitoring camera device 1 is installed, a monitoring imaging range is set, a phosphorescent tape 20 is affixed within the imaging range (step S1), and the area of the location where the phosphorescent tape 20 is imaged is determined by the monitoring camera device 1 for plan determination The operation for setting the specific area and the threshold value TH in the specific area for determining the plan are performed (step S2). The monitoring camera device 1 performs a normal operation and acquires an integral value A of a specific area (step S3), and performs a plan determination by comparing the integral value A with a threshold value TH (step S4). When it is determined that it is not a plan, the process proceeds to step S3, and when it is determined that it is a plan, an abnormality detection is notified by an alarm or the like (step S5).
[0024]
Further, the phosphorescent tape 20 continues to emit light for a relatively long time after the light is extinguished, but the amount of radiation gradually decreases. Instead of the phosphorescent tape 20, an existing lighting device (for example, a fluorescent lamp) is used, or is turned on / off in conjunction with turning on / off of the lighting switch, but forms a state where the CCD 12 senses for a while after turning off. Heating elements (incandescent bulbs, resistors, etc.) that use light emitters (incandescent bulbs, etc.), or that turn on / off in conjunction with the lighting switch on / off, but that are sensed by the CCD 12 for some time after turning off. It is conceivable to use thermal radiators that absorb infrared energy and emit infrared rays (for example, infrared ceramics). For example, although the time until the integral value of the specific area reaches the threshold value is long, it eventually falls below the threshold value. In a simple comparison process between the integration value of the specific area and the threshold value TH, it is determined that any of them is a plan. Therefore, when the integrated value of the specific area exceeds the threshold value after the integrated value of the other area falls below the threshold value, even if the integrated value of the specific area falls below the threshold value, It is good also as performing determination processing that it does not exist. Alternatively, setting a threshold value for the change amount of the integral value instead of the threshold value for the integral value can also be a countermeasure against such inconvenience.
[0025]
On the other hand, the above time needs to be taken into account when the illuminant is made to emit light or the heating element is caused to generate heat even after being extinguished within the surveillance imaging range (or when the phosphorescent tape etc. continues to emit light for about 8 hours, for example). Disappear.
[0026]
【The invention's effect】
As described above, according to the present invention, it is possible to accurately distinguish between extinguishing and planning. Further, since existing (existing) techniques such as integral value calculation can be used and no special change is required for the camera system, the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a surveillance camera device of the present invention.
2 is a block diagram showing a camera body of the surveillance camera device of FIG. 1. FIG.
FIG. 3A is an explanatory diagram of divided areas of the monitoring imaging range, and FIG. 3B is an explanatory diagram showing the luminance (integrated value) of each area after being turned off.
FIG. 4 is an explanatory diagram showing a state of an image plan.
FIG. 5 is a flowchart showing work contents and process contents.
FIG. 6 is an explanatory diagram showing a change in an integral value in a specific area.
7A is an explanatory diagram showing a captured image, and FIG. 7B is an explanatory diagram showing a luminance integrated image (integrated value).
FIG. 8 is an explanatory diagram showing an integration value change (luminance value) when the light is extinguished.
[Explanation of symbols]
1 Surveillance Camera Device 1a Camera Body 2 VCR
3 Monitor 11 Lens mechanism 11b Aperture unit 12 CCD
13 Signal Processing Circuit 14 Microcomputer 18 Memory

Claims (6)

A means for converting a video signal from the image sensor into a digital captured video, a means for performing luminance related value generation processing of the captured video for each area obtained by dividing the captured video, and a luminance related value of a specific area. It means for judging whether it is a scheme unlit Te, a surveillance camera system using a surveillance camera apparatus Ru provided with,
Within the imaging range of the surveillance camera device, the lighting device is turned on / off in conjunction with the ON / OFF of the illumination switch, but after the turning off, there is a light emitter that forms a state that the image sensor senses, and corresponds to the light emitter position. A surveillance camera system characterized in that an area of a captured video to be used is the specific area . The surveillance camera system according to claim 1, wherein the surveillance camera device is configured to determine whether it is extinguished or a scheme by comparing a brightness-related value of a specific area with a threshold value. Surveillance camera system . The monitoring camera system according to claim 1, wherein the monitoring camera device is configured to determine whether the monitoring camera device is turned off or a measure by comparing a change amount of a luminance-related value in a specific area with a threshold value. Characteristic surveillance camera system . A means for converting a video signal from the image sensor into a digital captured video, a means for performing luminance related value generation processing of the captured video for each area obtained by dividing the captured video, and a luminance related value of a specific area. A monitoring camera system that uses a monitoring camera device comprising:
  Within the imaging range of the surveillance camera device, the heating element is turned ON / OFF in conjunction with the ON / OFF of the illumination switch, but there is a heating element that forms a state that the imaging device senses for a while after it is turned OFF, and corresponds to the heating element position. A surveillance camera system characterized in that an area of a captured video to be used is the specific area. 5. The surveillance camera system according to claim 4, wherein the surveillance camera device is configured to determine whether it is extinguished or a scheme by comparing a brightness-related value of a specific area with a threshold value. Surveillance camera system . 5. The monitoring camera system according to claim 4, wherein the monitoring camera device is configured to determine whether the monitoring camera device is extinguished or a measure by comparing a change amount of a luminance-related value in a specific area with a threshold value. Characteristic surveillance camera system .

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