JP2001054100A - Monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monitoring device which can detects the abnormal operations of an image pickup means when the image signals of the image pickup means are continuously outputted. SOLUTION: A default image DG, i.e., the image of a monitoring object obtained in a normal operation state of a camera is compared with the sampling images SG1-SG8, i.e., the images of the monitoring object which are obtained at each time among those images sent from the camera which is continuously photographing the monitoring object. When it is detected that the states (SG6-SG8) where the sampling images are not changed last for a prescribed time after non-coincidence is detected between the image DG and the images SG1-SG8, an abnormal operating state of the camera is decided. Thus, it is possible to detect even an abnormal state of the camera where the lens part of the camera is covered with a piece of cloth, etc., and the monitoring function of the camera stops even when the image signals of the camera are continuously outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring apparatus for monitoring an object to be monitored based on an image obtained by an image pickup means.

[0002]

2. Description of the Related Art In a conventional analog type monitoring apparatus, that is, an unmanned monitoring apparatus which records a monitoring image captured by a camera as analog data and automatically detects an abnormality of the camera, an abnormality of the camera itself is considered. As a method of detecting the abnormal state, the abnormality is detected by monitoring the presence or absence of the output of the image signal of the camera, such as disconnection of the video cable of the camera or the power supply of the camera.

[0003]

However, in the above-described monitoring apparatus, the image is interrupted by covering the camera with a cloth or the like. For example, when an image cannot be obtained, since the output of the image signal by the camera is continued, the abnormal operation of the camera is not detected depending on the presence or absence of the image signal, and the image of the monitoring target is not obtained. A situation occurred in which monitoring was no longer necessary.

The present invention is intended to overcome the above-mentioned problems in the prior art, and provides a monitoring device capable of detecting an abnormal operation of the imaging means even when the image signal of the imaging means continues to be output. The purpose is to:

[0005]

In order to achieve the above object, the present invention is directed to an image pickup means for picking up an image of a monitoring target and a reference image recording means for recording a predetermined reference image of the monitoring target. And an image acquisition unit for acquiring a monitoring target image obtained by the imaging unit as a sampling image, and comparing the obtained sampling image with the reference image to detect a state where the sampling image and the reference image are different from each other. After that, when a state where the sampled images are the same continues for a predetermined time or more, an abnormality detection unit that determines the imaging unit to be in an abnormal operation state is provided.

According to a second aspect of the present invention, there is provided the monitoring device according to the first aspect, wherein the monitoring device includes a plurality of image pickup means, and the plurality of image pickup means are changed in position so as to change an image pickup position. A plurality of swinging driving means for swinging driving, and when an abnormal operation state is detected by the abnormality detecting means, the imaging means in a normal operating state other than the imaging means in the abnormal operating state is swung by the swinging driving means. And control means for performing control.

According to a third aspect of the present invention, there is provided the monitoring apparatus according to the first aspect, wherein the monitoring apparatus includes a plurality of image pickup units each having a zoom function, and performs zooming of each of the plurality of image pickup units. A plurality of zoom driving means for driving to change, and when an abnormal operation state is detected by the abnormality detection means, the imaging means in the abnormal operation state is regarded as an abnormal imaging means, and a normal operation state other than the abnormal imaging means is determined. When the imaging means is a normal imaging means, the image processing apparatus further includes control means for controlling the zoom driving means to zoom out the normal imaging means so that the imaging range of the normal imaging means includes the imaging range of the abnormal imaging means.

According to a fourth aspect of the present invention, there is provided the monitoring device according to any one of the first to third aspects, wherein a part of the image of the monitoring target captured by the imaging unit is a partial image. Further comprising a partial image extracting means for extracting, wherein the reference image recording means has no abnormality in the monitoring target,
The partial image extracted by the partial image extracting means is recorded as a reference image, and the image acquiring means also acquires, as a sampling image, the partial image extracted by the partial image extracting means for the monitoring target.

Further, according to a fifth aspect of the present invention, there is provided the monitoring device according to any one of the first to third aspects, wherein the resolution of the image of the monitoring target imaged by the imaging means is reduced to convert the low-resolution image. The reference image recording means records the low-resolution image obtained by the resolution reduction means of the normal image to be monitored as a reference image, and the image acquisition means records the resolution of the image to be monitored. The low-resolution image obtained by the lowering means is obtained as a sampling image.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

<1. First Embodiment> FIG. 1 is a block diagram of a monitoring apparatus according to a first embodiment of the present invention. As shown in FIG. 1, the monitoring apparatus includes a plurality of cameras 11, a decoder 12, an encoding / decoding circuit 13, a recording unit 14, an encoder 15, a memory 16, a recording / reading control unit 17, a CPU 18 and a display 19. Have.

The camera 11 is an image pickup means for picking up an image to be monitored. The camera 11 sends the obtained image signal to the next decoder 12 and also performs a swing drive means (swing operation) for swinging the camera. (Not shown), and the operation is controlled by a command signal from the CPU 18 described later. The decoder 12 digitizes an analog image signal from each camera 11 and outputs a digital image signal that can be handled by a CPU 18 and the like described later. Then, the encoding / decoding circuit 13 compresses (encodes) the obtained image data and records it on the recording unit 14 constituted by recording means such as a fixed disk, or decompresses the compressed image data ( After decoding, a part of the image data is sent to an encoder 15 described later. Further, the encoder 15 converts the entire image of each camera 11 decoded by the encoding / decoding circuit 13 into an analog signal again, and outputs the analog image in a data format that can be displayed on the display 19.

[0013] The digitized image signal from the decoder 12 is also sent to a memory 16. By the way, the first
In the embodiment of the present invention, a partial image extracted from an image obtained by each camera 11 in a state where the camera 11 is in a normal operation state and there is no abnormality in a monitoring target (described in detail later with reference to FIG. 3) is a default image. (Reference image), and a partial image extracted from the monitoring target image obtained by each camera 11 at predetermined time intervals is set as a sampling image. The memory 16 includes a RAM for recording the default image and the sampling image, and a CPU 18 to be described later.
And a ROM in which a control program for the processing in is stored in advance. For this reason, the recording / reading control unit 17 uses the image signal sent from the decoder 12
The memory 16 stores only the partial image in the memory 16.
Control the timing of recording image signals to
It controls reading of a default image or a sampling image from the memory 16 to the CPU 18.

The CPU 18 compares image data between a default image and a sampled image, as will be described in detail later, according to a control program read from the memory 16, and identifies the state of the camera 11 based on the result. Or control the operation of the camera 11. Further, the display 19 includes the encoder 15
And a display device such as a CRT for displaying an image signal from the CRT.
A combination of the decoder 12, the memory 16, and the recording / reading control unit 17 corresponds to an image acquiring unit in the present invention.

Hereinafter, a specific monitoring operation will be described.

FIGS. 2A and 2B are diagrams for explaining the monitoring operation in the first embodiment. FIG. 2A shows a state of monitoring during normal operation of the camera 11, and FIG. Each state of monitoring during abnormal operation is shown. FIG.
As shown in (a), a plurality of cameras 11 are mounted on the floor to be monitored, and an image of almost the entire floor can be captured by imaging with each camera 11. However, FIG. 2 shows an example of a monitoring device provided with only two cameras 11a and 11b as imaging means.

First, the input image from each camera 11 is recorded in the memory 16 as a default image when monitoring is started, that is, when the camera 11 is operating normally and there is no abnormality in the monitoring target. FIG. 3 is a diagram for explaining a state of recording partial images of image data and comparing the partial images according to the first embodiment. FIG. 3A shows the entire image to be monitored when the default image is obtained. FIG. 3B shows an entire image of a monitoring target at the time of acquiring a sampling image. FIG.
As shown in (a), first, each camera 11 at the start of monitoring
Is in a normal operation state, and among the digital image signals representing the entire image of the monitoring target in a state where there is no abnormality in the monitoring target,
Images of a plurality of rectangular areas SA1 and AS2 (shaded portions in FIG. 3) dispersed at predetermined intervals throughout the image;
That is, only the image signal corresponding to the partial image is extracted and recorded as the default image. In the first embodiment, the image signal from the camera 11 is converted into digital data in pixel units by the decoder 12 in advance.
Under the control of the recording / reading control unit 17, the rectangular area S
Only the image signals of the pixels included in A1 and AS2 are recorded /
A partial image is extracted by selectively recording the image in the memory 16 under the control of the reading control unit 17. Then, such a default image is recorded for each camera 11 when a plurality of cameras 11 are provided as shown in FIG.

In addition, when there are no abnormalities in the monitoring target, the monitoring target does not include a moving object such as a person such as a store or a financial institution outside business hours. This includes a case where the moving object is included in the monitoring target such as a financial institution (see FIG. 2A).

Next, the image signal output from each camera 11 is sampled at predetermined time intervals and compared with a default image. In other words, a partial image is extracted from the image signal captured by each camera 11 at predetermined time intervals, and is used as a sampling image. Each time the image signal is obtained, it is compared with the default image. That is, since the default image is a partial image as shown in FIG. 3A, the sampling image also extracts and compares only the image of the same portion as the default image as shown in FIG. 3B. The comparison between the default image and the sampled image is based on the difference between the image signals (luminance signals in the first embodiment) of each pixel of the two images, and the difference between the predetermined level and the predetermined level (the first embodiment). When a pixel having a luminance difference is detected, it is determined that there is a difference between the two images. This comparison method can use any known method.

By comparing the partial images in this way, the comparison process can be performed quickly because the data amount is small, and the capacity of the memory 16 for storing the default image can be small, so that the manufacturing cost can be reduced. it can. In addition, by comparing partial images dispersed over the entire image as shown in FIG. 3, compared with a case where partial images concentrated at one place in the image are compared with each other, the camera's entire area within the angle of view of the camera is compared. An abnormal operation state can be detected.

When the above comparison processing is repeatedly executed and it is detected that the sampled image is different from the default image, the sampled image obtained at each time and the immediately preceding sampled image are added. And compare
If the state in which both sampling images are the same, that is, the state in which the sampling images do not change, continues for a predetermined time or more, the camera 11 is in an abnormal operation state (unusable state).
Judge that it fell into.

FIG. 4 is a diagram for explaining the abnormal operation detection processing of the camera 11. In FIG. 4, comparing the default image DG with the sampling images SG1 to SG8, the default image D
Considered to be identical to G. However, the sampling image SG
6 is determined to be different from the default image DG. When the next sampled image SG7 is obtained, the sampled image SG7 is compared with the immediately preceding sampled image SG6. Then, the sampling image S
If G6 is the same as sampling image SG7,
Each time a sampled image is obtained, it is compared with the immediately preceding sampled image. Then, the sampling image SG6
When it is determined that the state in which the sampled image does not change has continued for a predetermined period of time, as in steps SG8 to SG8, the camera 1
It is determined that the state is the abnormal operation state of No. 1.

The reason for making such a determination is as follows. In other words, when a moving object (human, animal, moving machine, etc.) is included in the monitoring target,
There is a difference between the default image and the sampled image, but this is not an abnormal operation of the camera. Therefore, in order not to regard such movement of the monitoring target as an abnormal operation of the camera, the abnormal operation of the camera is performed only when the default image and the sampling image are determined to be different from each other and the sampling image does not change for a predetermined time or longer. It is judged.

Further, when it is detected that the sampled image is different from the default image, if the state in which the sampled image does not change does not continue for a predetermined period of time, that is, if the sampled image differs from the immediately preceding sampled image before the predetermined time has elapsed. In this case, the next sampled image is compared with the default image again, and the same determination as above is repeated.

It should be noted that as a comparison target of the sampling image after the sampling image and the default image are different,
The sampling image and the default image may always be compared with the first sampling image (the sampling image SG6 in the example of FIG. 4) in which the default image is different.

When it is determined that the camera 11 is in an abnormal operation state, the other cameras 11 are controlled so as to perform a predetermined operation programmed in advance. In particular,
In the first embodiment, the following control is performed. FIG.
In (b), the camera 11a has been determined to be in an abnormal operation (unusable) state. Then, in the first embodiment, the camera 11b in the normal operation state is always swung (rotated around the direction perpendicular to the paper surface), and the entire monitoring target (the entire floor in FIG. 2) is rotated by the camera 11b. Take an image. Thus, it is possible to cover the monitoring range of the camera 11 determined to be in the abnormal operation state and continue to capture an image of the entire monitoring target.

FIG. 2 shows an example in which only two cameras are provided. However, in a monitoring apparatus having three or more cameras,
All the cameras other than the camera determined to be in the abnormal operation state (all the cameras in the normal operation state) may be swung, or only some of the cameras in the normal operation state may be swung. .

As described above, according to the first embodiment, the sampling image is compared with the default image, and after the state where the sampling image and the default image are different from each other is detected, the sampling image is kept for a predetermined time or more. If the camera does not change, the camera 11 is determined to be in an abnormal operation state, so that the image signal output from the camera 11 is interrupted, and the image is cut off by covering the lens portion of the camera 11 with a cloth or the like. For example, when a partial failure occurs in the camera 11, an abnormal operation such that a normal image cannot be obtained although an image signal is output from the camera 11 can be detected.

Further, when a plurality of cameras 11 are provided, and an abnormal operation state is detected by any one of the cameras 11, the camera 11 in a normal operation state other than the camera 11 is swung, so that an abnormal operation state is set. The surveillance range of the camera 11 can be covered by the other normal operation state of the camera 11, and the surveillance function can be prevented from deteriorating.

Since the default image and the sampling image are partial images obtained by extracting a part of the monitoring target image picked up by the camera 11, the data amount of the image to be compared is small, and the comparison process can be performed quickly. In addition to this, the capacity of the memory 16 can be reduced, so that the manufacturing cost can be reduced.

<2. Second Embodiment> A second embodiment of the present invention will be described below. FIG. 5 is a view for explaining the resolution of a default image and a sampling image in the second embodiment. As shown in FIG. 5, in the second embodiment, the resolutions of the default image and the sampling image are reduced (dropped) for comparison, or are recorded in the memory 16.

Specifically, a known technique can be used for the resolution conversion, such as averaging the image data of a predetermined number of adjacent pixels and lowering the resolution by making the gradation of the corresponding pixel. . As described above, by reducing the resolution, the comparison process can be performed quickly because the data amount is small, and the capacity of the memory 16 for storing the default image may be small, so that the manufacturing cost can be suppressed.

In the second embodiment, the camera 11
Has a zoom function (provided with a zoom drive unit (not shown)), and the operation of the camera 11 in a normal operation state after the detection of an abnormal operation is different from that of the first embodiment. FIG. 6 is a diagram for explaining a monitoring operation according to the second embodiment, and particularly shows a state of monitoring at the time of an abnormal operation of the camera 11a. As shown in FIG. 6, in the second embodiment, the camera 11b in the normal operation state is slightly rotated (turned slightly to the left in FIG. 6) to the camera 11a determined to be in the abnormal operation state, and further zoomed out. As a result, the angle of view of imaging by the normally operating camera 11b is widened to cover the monitoring range of the camera 11 in an abnormally operating (unusable) state, to continuously obtain an image of the entire monitoring target, and to perform a monitoring function. Is not reduced.

Here, the determination as to whether the camera is in an abnormal operation state is the same as in the first embodiment, and the control different from that of the first embodiment is a control program executed by the CPU 18 and This is realized by making the control by the recording / reading control unit 17 corresponding to the control. Therefore, the device configuration is almost the same as that of the first embodiment.

It is to be noted that, in a camera in a normal operation state, the monitoring range of the camera in an abnormal operation state may be covered only by sufficiently widening the angle of view by zooming out without performing a slight swing drive. FIG. 6 shows an example in which only two cameras are provided. However, in a case where three or more cameras are provided, all the cameras (all the cameras in the normal operation state) other than the cameras in the abnormal operation state are described above. (Zoom out and slight swing drive), or only some of the normally operating cameras may be so controlled.

As described above, according to the second embodiment, the sampled image and the default image are compared with each other, and after the state where the sampled image and the default image are different from each other is detected, the sampled image is compared with the default image for a predetermined time or more. If the camera does not change, the camera 11 is determined to be in an abnormal operation state, so that the image signal output from the camera 11 is interrupted, and the image is cut off by covering the lens portion of the camera 11 with a cloth or the like. For example, when a partial failure occurs in the camera 11, an abnormal operation such that a normal image cannot be obtained although an image signal is output from the camera 11 can be detected.

Further, when a plurality of cameras 11 each having a zoom function are provided, and an abnormal operation state is detected,
To zoom out the camera 11 in the normal operation state so that the imaging range of the camera 11 in the normal operation state includes the imaging range of the camera 11 in the abnormal operation state, the monitoring range of the camera 11 in the abnormal operation state is changed to the normal operation state. Can be covered by the camera 11 and the monitoring function can be prevented from deteriorating.

In addition, since the resolution of the monitoring target image captured by the camera 11 is reduced to obtain a low-resolution image and the default image and the sampling image are set to the low-resolution image, the data amount of the image to be compared is small. Since the processing can be performed quickly and the capacity of the memory 16 can be small, the manufacturing cost can be reduced.

<3. Modifications> In the first and second embodiments, examples of the monitoring device and monitoring by the monitoring device have been described, but the present invention is not limited to this.

For example, in the first and second embodiments, a partial image or an image with reduced resolution is used as the default image and the sampling image.
It is also possible to compare images as they were taken in step 1, ie, whole images that do not lose resolution,
Also, the image at the stage of starting monitoring is used as the default image. However, during normal operation of the camera before starting monitoring, an image of a monitoring target that has no abnormality is previously stored in the memory as a default image. May be recorded and used.

[0041]

As described above, according to the first to fifth aspects of the present invention, a state where the sampling image and the reference image are different from each other is detected by comparing the sampling image with the reference image. Thereafter, when the sampling image does not change for a predetermined time or more, the imaging unit is determined to be in an abnormal operation state, so that an abnormal operation of the imaging unit can be detected even when the image signal of the imaging unit continues to be output.

According to a second aspect of the present invention, a plurality of image pickup means are provided, and when an abnormal operation state is detected, the image pickup means in a normal operation state is swung. According to the invention, a plurality of imaging units each having a zoom function are provided, and when an abnormal operation state is detected, the normal imaging unit is zoomed so that the imaging range of the normal imaging unit includes the imaging range of the abnormal imaging unit. Therefore, the monitoring range of the imaging unit in the abnormal operation state can be covered by the imaging unit in the normal operation state, and the monitoring function can be prevented from deteriorating.

According to the fourth aspect of the present invention, a part of the monitoring target image picked up by the image pickup means is extracted as a partial image, and the reference image and the sampled image are used as the partial images. In particular, according to the invention of claim 5, in order to obtain a low-resolution image by lowering the resolution of the image of the monitoring target imaged by the imaging means and to make the reference image and the sampling image low-resolution images, Since the data amount is small, the comparison process can be performed quickly, and the capacity of the reference image recording means can be small, so that the manufacturing cost can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a monitoring device according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining a monitoring operation according to the first embodiment.

FIG. 3 is a diagram for explaining a state of recording partial images of image data and comparing partial images in the first embodiment.

FIG. 4 is a diagram for explaining an abnormal operation detection process of the camera.

FIG. 5 is a diagram illustrating a resolution of a default image and a sampling image according to the second embodiment.

FIG. 6 is a diagram for explaining a monitoring operation according to the second embodiment.

[Explanation of symbols]

11, 11a, 11b Camera (imaging means) 12 Decoder 16 Memory (reference image recording means) 17 Recording / reading control unit (partial image extraction means, resolution reduction means) 18 CPU (abnormality detection means, control means) DG Default image ( Reference image) SG1 to SG8 Sampling image

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06F 15/66 355A F-term (Reference) 5B057 AA19 BA02 BA19 BA28 CA12 CA16 CB08 CB12 CD05 CD09 CH18 DA08 DB02 DB09 5C054 AA01 AA05 AA10 CA04 CC02 CF07 CG03 DA06 EA05 EJ00 5C084 AA01 AA06 AA13 BB40 CC19 DD11 GG39 GG43 GG52 GG54 GG65 GG78 HH10 HH12

Claims (5)

[Claims] An imaging unit that captures an image of a monitoring target; a reference image recording unit that records a predetermined reference image of the monitoring target; and an image of the monitoring target obtained by the imaging unit is acquired as a sampling image. An image acquisition unit, comparing the obtained sampled image with the reference image and detecting a state in which the sampled image and the reference image are different from each other, and thereafter, the state in which the sampled image is the same for a predetermined time or more continues A monitoring unit that determines that the imaging unit is in an abnormal operation state in the event of a failure. 2. The monitoring device according to claim 1, further comprising a plurality of said image pickup means, wherein said plurality of image pickup means are respectively driven to swing so as to change an image pickup position. Means for controlling, when the abnormal operation state is detected by the abnormal state detecting means, the image pickup means in a normal operation state other than the image pickup means in the abnormal operation state to be swung by the head swing driving means. And a monitoring device. 3. The monitoring apparatus according to claim 1, further comprising a plurality of said imaging units each having a zoom function, wherein said plurality of imaging units are driven to change respective zooms. Zoom driving means; and when the abnormal operation state is detected by the abnormality detecting means, the abnormal operation state imaging means is regarded as abnormal imaging means, and the normal operation state imaging means other than the abnormal imaging means is regarded as normal imaging means. And controlling means for controlling the zoom driving means to zoom out the normal imaging means so that the imaging range of the normal imaging means includes the imaging range of the abnormal imaging means. Monitoring device. 4. The monitoring device according to claim 1, wherein a partial image is extracted as a partial image from the monitoring target image captured by the imaging unit. Means for recording the partial image extracted by the partial image extracting means as the reference image when the reference image recording means has no abnormality in the monitoring target. A monitoring apparatus for acquiring, as a sampling image, a partial image of a target extracted by the partial image extracting means. 5. The monitoring device according to claim 1, wherein a resolution lowering unit that obtains a low-resolution image by lowering a resolution of the image of the monitoring target captured by the imaging unit is provided. The reference image recording unit records a low-resolution image obtained by the resolution reduction unit of the normal image of the monitoring target as the reference image, and the image acquisition unit records the image of the monitoring target. A monitoring device for acquiring a low-resolution image obtained by the resolution reducing unit as the sampling image.