JPH08307758A - Object monitoring device - Google Patents

Abstract

PURPOSE: To accurately monitor an abnormal state by ensuring an autofocus operation in an object monitoring device using a TV camera. CONSTITUTION: An image pickup means 2 such as a CCD camera picks up an image within a prescribed monitoring range through an image pickup optical means 1 and outputs a video signal to an image processing means 3. The image processing means 3 has a video signal fetching means 3a, an image memory 3b, a control part 3c, an image quality adjusting means 3d and an autofocus device 3e, etc. The autofocus device 3e is controlled by the control part 3c, drives a lens moving means 5 according to the peak value of the high frequency component of the video signal and detects a focusing location. The image quality adjusting means 3d is controlled by the control part 3c, detects whether the level of the video signal is within a proper level or not before an autofocus operation and adjusts image quality by changing the AGC level of the CCD camera or electronic shutter speed according to the detection result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an object monitoring system or an object monitoring device used for extinguishing a fire.

[0002]

2. Description of the Related Art Currently, monitoring for monitoring fires and objects,
In the fire extinguishing system, a surveillance TV camera (CCD camera) having an autofocus means is used to monitor flames and intruders within a predetermined surveillance range. In order to focus the camera in the above system, for example, as shown in FIG. 5, the optical system is scanned from a near point to a far point, and a high frequency component is extracted from the image signal from the CCD camera obtained thereby. The contrast detection method is used to detect the in-focus position from the peak position of this high frequency component.

In the case of monitoring a television camera by the contrast detection method, the high frequency component of the video signal and the depth of focus have a relationship as shown in FIG. 6, and in order to detect the focus position more accurately, the depth of focus of the optical system is set. It is preferably shallow. As a method of making the depth of focus shallow, it is conceivable to make the F value small (brighten the lens) and make the focal length long (increase the imaging magnification).

Next, in order to construct a fire and security system using the surveillance TV camera, the camera 71 is controlled by the image processing means 72 as shown in FIG. 8 as shown in FIG. First, the optical system of the camera is set to a wide state, the monitoring area is expanded as shown in FIG. 7 to monitor a wide area, and the image processing of the video signal at that time is processed in the image processing means 72 to detect the presence or absence of abnormality. To do. If an abnormal condition is detected due to a suspicious change in the image signal and it is judged that a fire has occurred, the camera surveillance area is moved in the direction in which the suspicious motion is detected as shown in FIG. Monitor the anomaly detection area that is detected as suspicious. In this state, the depth of focus becomes sufficiently shallow, so the autofocus operation is performed, the distance to the fire is measured, and an alarm is issued.

[0005]

In the above-described conventional fire prevention and crime prevention system, the surveillance TV camera functions well in a normal environment, but when an external illumination device receives light, an abnormality is detected. There is a risk that it will not be possible to detect a fire or intruder by correctly detecting it.

For example, when external light enters from a window as shown in FIG. 9 (a), depending on the condition of the external light, the area around the window may be bright and the thief may be dark, and the intrusion of the thief may not be detected. Further, even if a fire has occurred as shown in FIG. 6B, if the fire is still small, the resident may be better reflected and the flame may not be recognized correctly because it is small. In addition, the image of the fire is very bright and can even be saturated to white levels. To judge whether there is a fire, the color temperature is judged based on the RGB ratio and it is judged that there is a fire. Therefore, if the image is saturated to the white level, the color temperature cannot be judged and it is judged that there is a fire. become unable.

When an autofocus operation is performed to detect whether or not there is an abnormality, an image that is saturated at a white level causes erroneous focusing. That is, in an image saturated with a white level, a high frequency component around a blurred flame is largely detected, which causes erroneous focusing. This is because the blur reduces the contrast, but the area of the blurred image increases, so that the detected high frequency component increases and the value of the high frequency component becomes larger than the original focus point.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide an object monitoring apparatus capable of reliably performing an autofocus operation.

[0009]

In order to achieve the above object, an object monitoring apparatus according to a first aspect of the present invention comprises an image pickup optical means including a focusing optical system, an image pickup optical means including the focusing optical system, and the image pickup. Imaging means for imaging a predetermined monitoring range through the optical means and outputting a video signal, focusing optical system driving means for driving the focusing optical system, and a focus position detected from the video signal from the imaging means. Focus adjusting means for controlling the focusing optical system driving means, image quality detecting means for receiving a video signal from the imaging means and detecting whether the video signal is within an appropriate level, and the image quality detecting means A level changing means for changing the level changing parameter of the image pickup means in response to a detection result is provided.

An object monitoring apparatus according to a second aspect of the present invention is, in the apparatus of the first aspect, characterized in that the level changing parameter of the image pickup means is an automatic gain control level or an electronic shutter speed.

An object monitoring apparatus according to a third aspect of the present invention is an image pickup optical means including a focusing optical system, an image pickup means for picking up a predetermined monitoring range through the image pickup optical means and outputting a video signal, and the video signal. Image processing means for receiving and performing predetermined image processing; focusing optical system driving means for driving the focusing optical system;
Focus adjusting means for controlling the focusing optical system driving means by detecting a focus position from the image signal from the image pickup means, auto iris means for mechanically controlling the amount of light incident on the image pickup means, and the image pickup means The electronic iris means for electronically controlling the amount of light incident on the electronic iris means is provided, and the aperture is adjusted by the auto iris means in the normal monitoring state, while the aperture value by the auto iris means is operated when the focusing optical system driving means is operated. The gist is that the electronic iris means adjusts the aperture while fixing the aperture.

An object monitoring apparatus according to a fourth aspect of the present invention is the apparatus according to the first or second aspect of the present invention, wherein an auto iris means for mechanically controlling the amount of light incident on the image pickup means and an electronic amount of light incident on the image pickup means are electronically controlled. And an electronic iris means for controlling the aperture, and the aperture is adjusted by the auto iris means in the normal monitoring state, while the aperture is adjusted by the electronic iris means when the focusing optical system driving means is operated. That is the summary.

An object monitoring apparatus according to a fifth aspect of the present invention is the apparatus according to the first or second aspect of the present invention, which includes change detection means for receiving a video signal from the image pickup means and detecting a change in the video signal.
And a detection area setting means for receiving the output of the change detection means and setting a detection area for focus adjustment.

[0014]

In the apparatus of the first aspect of the invention, the image quality is detected depending on whether or not the video signal is within an appropriate level, and the level changing parameter of the image pickup means, for example, of the second aspect of the invention is detected according to the detection result. Change the auto gain control level or electronic shutter speed as follows.

In the device of the third invention, during normal monitoring,
The aperture is adjusted by the auto iris means, while the aperture value is fixed by the auto iris means and the aperture is adjusted by the electronic iris means during the autofocus operation.

According to a fourth aspect of the present invention, in addition to the first or second aspect of the invention, the aperture is adjusted by the auto iris means during normal monitoring, while the aperture value is fixed by the auto iris means during auto focus operation. Then, the diaphragm is adjusted by the electronic iris means.

In the device of the fifth invention, in the device of the first or second invention, a change of the video signal is further detected, and a change region for focus adjustment is set according to the output, and the change region is set. On the other hand, the image quality is detected.

[0018]

Embodiments of the present invention shown in the drawings will be described below.
FIG. 1 shows an embodiment of the present invention, in which 1 is an image pickup optical means including a focusing optical lens system, and 2 is a CCD camera for picking up an image of a predetermined monitoring range through the image pickup optical means 1 and outputting a video signal. Image pickup means for receiving a video signal from the image pickup means 2 and performing a predetermined image processing, 3 is an image processing means, 4 is a camera rotating mechanism for changing an area to be picked up by a camera, and 5 is an optical system which is a near point. And a lens moving means (focusing optical system driving means) for performing an operation for moving between a point and a far point.

The image processing means 3 includes a video signal capturing means 3a for receiving a video signal from a CCD camera, and an image memory 3 for storing the video signal from the image signal capturing means 3a.
b, a control unit (CPU) 3 for controlling the entire image processing means
c, image quality adjusting means 3d for detecting / adjusting whether the image quality of the captured video signal is appropriate, and an autofocus device 3e for autofocusing a predetermined object.

The basic operation of the object monitoring apparatus according to the present invention shown in FIG. 1 is as follows. That is, in the normal operation state, the lens system of the image pickup optical means 1 is set to the wide state, and first, the wide area is monitored. The video signal being monitored is output from the CCD camera 2 at a predetermined interval,
It is captured via the video signal capturing means 3a and stored in the image memory 3b.

During wide area monitoring, a change in an image is detected in a wide range of captured images, and in order to detect in more detail, a place where a change is recognized is set as a detection area. This function is achieved by the change detecting means 3f and the detection area setting means 3g.

The operation of the change detecting means 3f is as shown in the flow chart of FIG. That is, in the change detecting means 3f, the video signal relating to the new screen and the video signal relating to the screen two screens before are fetched from the image memory 3b,
Compare both. If no change is detected in the video signal by comparing the two, it is determined that there is no abnormality, and the above operation is continued. If a change in the video signal is detected by comparing the two, the place of the change is detected. In the detection area setting means 3g, the place where the change has occurred is set as the detection area based on the output of the change detection means 3f, and more detailed detection, that is, the change in the video signal is detected by a thief or a fire. Detect if there is no.

In the control section 3c, the detection area setting means 3g is provided.
The camera rotation mechanism 4 is operated on the basis of the output of 1 to direct the camera 2 and the optical system 1 to a position to be detected. And
Image quality adjusting means 3d based on the image signal which is picked up and stored in the memory.
To adjust the image quality of the captured video signal.

The operation of the image quality adjusting means 3d is as shown in the flow chart of FIG. 3, and the latest image signal is fetched from the image memory 3b, and the image quality judging section 3d1 determines whether or not the image signal is within the proper range. Detect. The video signal to be detected is a video signal in a predetermined area, and for example, a video signal corresponding to a window set outside the monitoring area is excluded. If the image quality determination unit 3d1 determines that the signal level of the video signal is within the proper range, it is determined that the image quality is proper, and more detailed monitoring is performed on the detection area set by the detection area setting unit 3g. , In order to perform detection, the operation shifts to auto focus operation. In this case, since the image quality is appropriate, the imaging parameter changing unit 3d2 does not give an instruction to change the imaging parameter.

Next, when the image quality determination unit 3d1 determines that the signal level of the video signal, that is, the signal level in the monitoring area is not within the proper range, it is determined that the image quality needs to be adjusted, and the imaging parameter is set. The processing in the changing unit 3d2 is executed. The imaging parameter changing unit 3d2 first determines whether the signal level of the video signal is too low. If the signal level is too low, the imaging parameter changing unit 3d2 outputs a command to increase the electronic shutter speed of the CCD camera 2 by a predetermined time interval, and the electronic shutter speed of the CCD camera 2 is changed. After that, the image quality adjusting means 3d determines again whether the signal level of the video signal is too low. For this determination, the image quality determination unit 3d1 again captures the video signal and detects whether the signal level is within the proper range. However, in the flowchart of FIG. 3, the detailed steps described above are not shown. Omitted.

Next, when the signal level does not rise within the proper range only by the electronic shutter speed, the image pickup parameter changing section 3d2 outputs an output to raise the AGC level of the CCD camera 2 by a predetermined width. Then, the same processing as that of changing the electronic shutter speed is performed, and by this processing, the signal level of the video signal falls within an appropriate range.

On the other hand, if the signal level of the video signal is not low, that is, if it is too high, a command to reduce the electronic shutter speed of the CCD camera 2 by a predetermined time interval is output from the image pickup parameter changing unit 3d2, and the CCD camera 2 is output.
The electronic shutter speed is changed, and thereafter, the image quality adjusting means 3d determines again whether the signal level of the video signal is too high. Then, when the signal level does not fall within the proper range only by the electronic shutter speed, the image pickup parameter changing unit 3d2 outputs to lower the AGC level of the CCD camera 2 by a predetermined width. Then, the same processing as that described above is performed so that the signal level of the video signal falls within an appropriate range.

When the signal level of the video signal is set within the proper range as described above, the operation shifts to the autofocus operation next, and the autofocus operation is performed aiming at the place set by the detection area setting means 3g. More detailed detection is performed, that is, whether the change in the video signal is a thief, a fire, or the like is performed.

In the autofocus operation, as described above, the optical system 1 is scanned from a near point to a far point, a high frequency component is extracted by using a video signal obtained from the CCD camera 2, and the high frequency component is extracted. This is an operation according to a known contrast detection method for detecting the in-focus position from the peak position of the component.

FIG. 4 shows another embodiment of the present invention, in which the same reference numerals as those in FIG. 1 denote the same means. In addition to the configuration shown in FIG. 1, the image processing means 3 mechanically opens and closes a diaphragm. The iris switching means 3h for controlling the automatic iris means 6b is provided, and the camera section 6 including the image pickup optical means 1 and the image pickup means 2 controls the aperture by controlling the charge accumulation time in the CCD camera 2. Iris means 6
a, a level detection circuit 6 for detecting the level of the video signal from the CCD camera 2 and detecting the amount of light incident on the optical system 1.
b, the camera unit 6 is provided to mechanically open and close the diaphragm C
An auto iris means 6c for mechanically controlling the amount of light incident on the CD camera 2 is provided.

As described above, in the abnormality detection during the normal operation, it is preferable to focus on as wide a range as possible from the far point to the near point because it is possible to monitor many areas. Therefore, during this normal operation, it is necessary to set the depth of focus deep with the diaphragm closed (large diaphragm value) for wide area monitoring, and to detect the amount of light incident on the optical system 1 by the level detection circuit 6b. The sensitivity is adjusted by the auto iris means 6c.

On the other hand, during the autofocus operation, it is preferable that the depth of focus be shallow and that the amount of light incident on the optical system 1 be constant. Therefore, in the case of the auto-focus operation, the auto iris means 6c is fixed by the control section 3c via the iris switching means 3h so that its diaphragm is open or fixed to a set diaphragm value, while the electronic iris means 6a is The sensitivity is adjusted by receiving an operation command via the iris switching means 3h. The other operations of the monitoring device having the above configuration are the same as the operations of FIG. 1 already described.

[0033]

As described above, according to the first and second aspects of the present invention, the level changing parameter of the image pickup means, for example, the automatic gain control level or the electronic shutter speed is adjusted so that the level of the video signal becomes appropriate. Since the change is made to adjust the image quality to ensure the autofocus operation, it is possible to accurately monitor the abnormality such as a fire or an intruder. Further, according to the invention of claim 3, in a normal monitoring state, the focal depth is set deep to perform wide area monitoring,
During the autofocus operation, the aperture can be set to a constant value so that the depth of focus becomes shallow, and the sensitivity can be adjusted by the electronic iris means. According to the invention of claim 4, claim 1
Alternatively, in the second aspect, the depth of focus described above can be set in addition to the image quality adjustment. Further, according to the invention of claim 5, in the invention of claim 1 or 2, more detailed abnormality monitoring can be performed by setting a portion where a change in the video signal is recognized as a detection area.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of an embodiment of the present invention.

FIG. 2 is a flow chart showing an operation example of a change detecting means of the above embodiment.

FIG. 3 is a flowchart showing an operation example of image quality adjusting means of the above-described embodiment.

FIG. 4 is a block diagram showing a basic configuration of another embodiment of the present invention.

FIG. 5 is an operation explanatory diagram of a conventional device.

FIG. 6 is a characteristic diagram showing a relationship between a high frequency component of a video signal and a depth of focus.

FIG. 7 is a block diagram showing a configuration example of a conventional crime prevention system.

FIG. 8 is a flowchart showing the operation of the security system.

FIG. 9 is an operation explanatory diagram of the crime prevention system.

[Explanation of symbols]

 1 Imaging Optical Means 2 Imaging Means 3 Image Processing Means 3a Video Signal Acquisition Means 3b Image Memory 3c Control Section 3e Auto Focus Device 4 Camera Rotation Mechanism 5 Lens Moving Means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H04N 7/18 G02B 7/11 K G03B 3/00 A

Claims (5)

[Claims] 1. An imaging optical means including a focusing optical system, an imaging means for imaging a predetermined monitoring range through the imaging optical means and outputting a video signal, and a focusing optical system for driving the focusing optical system. Drive means, focus adjusting means for detecting the in-focus position from the image signal from the image pickup means to control the focus optical system drive means, and receiving the image signal from the image pickup means to make the image signal appropriate. An object monitoring apparatus comprising: an image quality detection unit that detects whether the image quality is within a level; and a level change unit that receives a detection result of the image quality detection unit and changes a level change parameter of the image pickup unit. 2. The object monitoring apparatus according to claim 1, wherein the level changing parameter of the image pickup means is an automatic gain control level or an electronic shutter speed. 3. An image pickup optical means including a focusing optical system, an image pickup means for picking up a predetermined monitoring range through the image pickup optical means and outputting a video signal, and a predetermined image processing for receiving the video signal. Image processing means, focusing optical system driving means for driving the focusing optical system, and focus adjusting means for detecting the focusing position from the image signal from the image pickup means and controlling the focusing optical system driving means. An automatic iris means for mechanically controlling the amount of light incident on the image pickup means and an electronic iris means for electronically controlling the amount of light incident on the image pickup means are provided, and the aperture adjustment is performed by the automatic iris means in a normal monitoring state. On the other hand, when operating the focusing optical system driving means, the aperture value by the auto iris means is fixed while the aperture is adjusted by the electronic iris means. Object monitoring device. 4. An auto iris means for mechanically controlling the amount of light incident on the image pickup means, and an electronic iris means for electronically controlling the amount of light incident on the image pickup means,
The object according to claim 1 or 2, wherein the diaphragm is adjusted by the auto iris means in a normal monitoring state, while the diaphragm is adjusted by the electronic iris means when the focusing optical system driving means is operated. Monitoring equipment. 5. A change detection means for receiving a video signal from the image pickup means to detect a change in the video signal, and a detection area setting means for receiving an output of the change detection means and setting a detection area for focus adjustment. 3. The object monitoring apparatus according to claim 1, further comprising: and configured to perform the image quality detection on the detection area.