JPH08214288A - Image monitoring device - Google Patents

Abstract

PURPOSE: To obtain an image monitoring device capable of reducing the generation of malfunction due to the flashing of a lighting equipment by judging a change in a video signal level due to the flashing of the lighting equipment when the output timing of plural movement detection signals is simultaneously outputted within prescribed time and restricting the output of the movement detection signals to the external. CONSTITUTION: An inputted video signal 17 is converted into a digital video signal 11 by an A/D converter 23 and the signal 11 is inputted to an input data adder 2. Simultaneously with the input of the signal 11, a detection area signal 12a optionally set up by a detection area input device 6 is inputted to the adder 2, which adds only a digital video signal within an area restricted by the inputted detection area signal 12a in each digital sampling data. The adder 2 calculates the sum of signal levels within the detection area and outputs a current addition data 13. A difference between the data 13 and current addition data 14 is detected by a difference detecting means 4. The detected time variation data 22 are compared with a threshold 15, a detection signal is not outputted when the signal is due to a lighting equipment and a detection signal due to a normal object is outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image monitoring apparatus for monitoring an ITV camera or the like for detecting intrusion of a third party into a monitoring area.

[0002]

2. Description of the Related Art In recent years, many construction sites, large plants,
At convenience stores and the like, a monitoring system that centrally monitors each place by a monitoring camera or the like has been introduced in order to ensure safety and security. Among them, the image monitoring device automatically detects a movement, which is caused by, for example, a third party without permission, from an image of the surveillance area captured by the camera, and warns the area where there should be no movement. Since it is emitted, it is possible for the monitoring personnel to minimize the occurrence of accidents and damages without constantly monitoring visually by the monitoring monitor.

Conventionally, an image monitoring device detects a change in the signal level of an input video signal, and further, it has been disclosed in Japanese Patent Laid-Open No. 17508/1992.
As disclosed in Japanese Patent Publication No. 9, the difference in the temporal fluctuations of the input signal generated when an object enters the monitoring area is compared and detected in field units, and the change is a threshold value set in advance. If it exceeded, it was determined that there was movement.

FIG. 12 is a block diagram showing an example of a circuit configuration of a motion signal generating means for detecting a motion generated in a video signal and generating a motion signal. In FIG. 12, reference numeral 100 denotes A / which converts the input video signal 106 into a digital signal.
D converter, 101 is an input digital video signal 107
Is added to each of the digital sampling data within the range of the detection area signal 108 indicating a predetermined range on the monitor screen, and the present addition data 109 is output, and 102 is a video signal on the monitor screen. Area setting means for outputting a detection area signal 108 for setting a range for adding levels, 103 is area setting means 102
The data delay means for delaying the video signal level addition data within the range set in step 1 by the field unit and outputting the delay addition data 110, and 104 is the difference between the input current addition data 109 and the delay addition data 110. The difference detecting means for calculating and outputting the time-varying data 111, 105 is the time-varying data 111 of the video signal detected by the difference detecting means 104.
Comparison threshold value 1 for determining whether the object is a motion
A threshold value input means for generating 12 and a comparison means 113 for comparing the time variation data 111 with the comparison threshold value 112 and outputting a motion detection signal 114 if the time variation data 111 is larger than the comparison threshold value 112. Is.

With the motion detecting means having such a configuration,
If there is a change in the video signal in the detection area set at a predetermined location on the monitor screen, the time-dependent signal fluctuation in the detection area is detected and compared with the threshold value, and the signal change is determined by the threshold. If the value exceeds the value, it is determined that there is motion in the surveillance image, and "1" is output as the motion detection signal 114. If the temporal change does not exceed the threshold value, it is determined that there is no motion in the surveillance image “0” is output as the detection signal 114.

The sensitivity can be adjusted by changing the threshold value. The variable range of the threshold value is determined by the size of the detection area. For example, if the video signal sampling data in the detection area is 1000 points, and the number of gradations of the video signal is 256 gradations with 8-bit sampling,
Since the maximum value of the video signal addition data in the detection area is 1000 × 256 = 256000, the variable range of the addition data is 0 to 256000.
Becomes The threshold value can be varied within this range. For example, if the threshold value is lowered, the motion signal "1" is output even if there is a slight motion in the video signal, so the sensitivity is increased, and conversely the threshold value is set. If it is raised, even if there is a large movement, it is judged as "0", and the movement signal remains low.

[0007]

As described above, the conventional image monitoring apparatus detects the temporal signal level change of the input video signal, determines the movement from the difference, and issues an alarm. As a result, even if a person does not constantly look at the monitor, it is possible to automatically monitor the movement inside the monitor without any person.

However, in this case, there are the following problems.

FIG. 13 shows a monitor screen when the inside of the building is actually photographed by a surveillance camera or the like.

As shown in the figure, when there is no motion of the object within the motion detection area 115 set on the monitor screen, the motion detection signal 114 remains low. However, even when there is no movement of an object such as a person in the screen in this way, the lighting equipment such as a fluorescent lamp installed in the building as shown in the figure photographed by the camera at time t1 is turned on or off. In this case, since the video signal changes, the motion detection signal 114 is output at time t1 as shown in FIG.

As described above, even if there is no movement of the object to be detected in the movement detection area in the related art, there is a problem that the movement detection signal is erroneously output due to the fluctuation of the video signal level due to the lighting fixture such as the fluorescent lamp. there were.

It is an object of the present invention to eliminate a malfunction of detecting a video signal fluctuation caused by blinking of a lighting device such as a fluorescent lamp in a region photographed by a camera while detecting a normal movement of an object well. An object of the present invention is to provide an image monitoring device that performs accurate motion detection.

[0013]

In order to achieve the above object, the present invention detects whether or not the output timing of a plurality of motion detection signals detected by a plurality of motion detection means is within a predetermined time, When it is detected that the time is within a predetermined time, an illumination variation detecting unit that outputs a switch control signal that limits the output of the motion detection signal to the outside is provided.

Further, switch means for limiting the output of the motion detection signal to the outside is provided by the switch control signal from the illumination variation detecting means.

Further, an illumination detection area generating means for setting the above-mentioned motion detecting means is provided at a predetermined position apart from the vertical synchronizing signal and the horizontal synchronizing signal by a predetermined time.

[0016]

The illumination fluctuation detecting means detects whether the output timing of the motion detection signals detected by the plurality of motion detecting means is within a predetermined time, and when it is detected that the output timing is within the predetermined time. , It is possible to output a switch control signal that limits the output of the motion detection signal to the outside.

The switch means can limit the output of the motion detection signal to the outside by the switch control signal from the illumination variation detection means.

Further, the illumination detecting area generating means is provided with the above-mentioned motion detecting means at a predetermined position apart from the vertical synchronizing signal and the horizontal synchronizing signal for a predetermined time and is not easily affected by the normal movement of the object on the screen. Can be set.

With these means, it is possible to prevent an erroneous operation caused by the fluctuation of the video signal level due to the blinking of the lighting equipment such as a fluorescent lamp which occurs in the area where the motion detection is performed, and to perform the image monitoring apparatus capable of highly accurate motion detection. realizable.

[0020]

1 is a block diagram of an image monitoring apparatus showing a first embodiment of the present invention.

In FIG. 1, 17 is an input video signal and 23
Is an A / D converter for converting an analog signal into a digital signal, 1 is a motion detecting means, 2 is an input data adding means for adding the signal level of the input digitally converted digital video signal 11 for each pixel, 3 Is a data delay means for delaying the addition data output from the input data addition means 2 in time, and 4 is the current addition data 13 not delayed and the delayed addition data 1 delayed by the data delay means 3.
The difference detecting means 5 for calculating the difference 4 and outputting the time variation data 22 representing the time variation of the video signal is the time variation of the sum total data of the video signal levels outputted from the difference detecting means 5. It is a comparison means for comparing with a threshold value input from the outside. Further, 6 is an area signal 12 for arbitrarily setting a detection area for detecting the fluctuation of the video signal on the monitor screen.
a and 12b are detection area input means, and 8 is a detection sensitivity setting means for generating a reference threshold value signal 15 which is a reference for motion detection in comparison with the temporal change of the video signal level sum. , 19 are motion detection signals output by the comparison means 5 as a result of comparing a temporal change amount of the video signal with a threshold value input from the outside.

Reference numeral 10 is an illumination fluctuation detecting means for detecting whether or not there is a video signal level fluctuation in the input video signal due to a lighting device or the like due to a temporal difference in the output timing of the motion detection signals 18, 19, and 20 is a lighting fluctuation detection. It is a signal.
Further, a time threshold value signal 1 serving as a reference for detecting a temporal difference between the output timings of the motion detection signals 18 and 19
6 is variably input by the time threshold variable means 7. Reference numeral 24 denotes a switch means, which is switched and controlled according to a switch control signal 21 output from the illumination variation detecting means. 25 and 26 are motion detection alarm signals output to the outside.

Next, the operation of the embodiment shown in FIG. 1 will be described.

The input video signal 17 is input to the A / D converter 2
It is converted into a digital video signal 11 by 3 and input to the input data adding means 2. At the same time, the detection area signals 12a and 12b arbitrarily set by the detection area input means 6 are input to the input data addition means 2, and the input data addition means 2 outputs a digital image in an area limited by the input detection area signal. Only the signals are added in digital sampling data units, the sum of the signal levels in the detection area is calculated, and the current addition data 13 is output.

On the one hand, the current addition data 13 is the difference detecting means 4
And the other is input to the data delay means 3.

The data delay means 3 delays the input data and outputs the delayed addition data 14 delayed in time.

The current addition data 13 and the delayed addition data 14 are input to the difference detecting means 14 and the difference between the addition data is calculated. Since the current addition data 13 and the delay addition data 14 have a time difference, when there is a time change in the input video signal, the time change amount is detected and output as a difference.

Time variation data 2 of the detected video signal
2 is input to the comparison means 5, is compared with the comparison threshold value 15 set by the detection sensitivity setting means 8, and the comparison result is output as motion detection signals 18 and 19. As a result, it is possible to detect the movement that has occurred in the detection area set on the screen.

The output motion detection signals 18 and 19 are
It is input to the illumination variation detecting means 10.

The operation of the illumination variation detecting means 10 will now be described with reference to FIG.
~ It demonstrates using FIG.

FIG. 2 is an explanatory diagram in the case where a predetermined location is photographed by a camera and a video signal output from the camera is subjected to motion detection by an image monitoring apparatus having the configuration as in the first embodiment of FIG. is there. In FIG. 2, 30 is a monitor screen,
The detection areas set by the detection area input means 6 on the monitor screen are 32 and 33. Also, 31
Is a lighting device installed in a place where doors 1 and 2 are provided on the left and right sides of the corridor as shown in the figure.

FIG. 3 shows the states of the motion detection signals 18 and 19 output from the motion detecting means 1 when the lighting fixture 31 is turned on or off at the time t1 in such a state. When the illumination is turned on at the time t1, the brightness of the place as shown in FIG. 2 instantaneously changes and becomes bright at that moment, so that the input video signal level fluctuates greatly. Therefore, even if there is no motion by a person or the like on the monitor screen, the motion detection signal is output at time t1 as shown in FIG. At this time, both the motion detection signals 18 and 19 are simultaneously output at time t1 according to the change in brightness at the moment when the illumination is turned on.

The output motion detection signals 18 and 19 are input to the illumination variation detecting means.

FIG. 4 is a block diagram showing the configuration of the illumination variation detecting means 10. In FIG. 4, reference numeral 34 is a time difference calculating means for obtaining the time difference between the output timings of the input motion detection signals 18, 19 and outputting the time timing difference signal 37. Reference numeral 35 is the time timing difference signal 37 and the time input from the outside. The threshold value signals are compared, and when the time timing difference signal is smaller than the time threshold value, it is considered that a plurality of motion detection signals are simultaneously detected, and the illumination variation detection signal 2
A time difference comparing means for outputting 0, and a switch control signal generating means 36 for generating a switch control signal for switching the switch means 24 for limiting the output of the motion detection signals 18, 19 to the outside according to the illumination variation detection signal 20. .

The operation in FIG. 4 is explained by the timing chart in FIG. When the luminaire is turned on as shown in FIG. 2, the video signal level of the entire surface of the monitor changes instantaneously, so that the motion detection signals 18 and 19 are input almost simultaneously as shown in the figure. In this case, since there is no time difference between the output timings of the two signals, the time timing difference 37 becomes smaller than the time threshold value 16, and it is determined that a plurality of motion detection signals are output at the same time, and the illumination variation detection is performed. The signal 20 is output. At this time, the switch control signal also goes low at the same time, and the switch means 24 is controlled to limit the output of the motion detection signal to the outside, so that the motion detection alarm signals 25 and 26 are not output.

As described above, when the lighting equipment or the like blinks in the place where the motion is detected, the level of the entire video signal fluctuates greatly at the moment of blinking. Therefore, the motion is detected simultaneously from a plurality of set motion detecting means. The signal is output. Judging whether the output timings of the output motion detection signals are the same, it is possible to determine whether the output motion signals are due to normal movement of an object or due to blinking of lighting equipment such as a fluorescent lamp. Can be done. Thus, by limiting the output of the motion detection signal to the outside, it is possible to realize an image monitoring apparatus that does not cause a malfunction even when the light flashes.

Further, the structure shown in FIG. 1 has the following merits. FIG. 6 is an explanatory diagram for explaining this.

When the fluorescent lamp is blinked as shown in FIG. 2, particularly when it is lit, the fluorescent lamp may repeat blinking several times until the lighting is completely completed. There may be a time difference between the detection signals.

In such a case, the time threshold value changing means 7
At, the time threshold value t5 is set as shown in FIG.
First, the motion detection signal 18 is output at time t1,
When the one motion detection signal 19 is output at t2, (t2
If -t1) is smaller than the threshold value t5, it is determined that the motion detection signals 18 and 19 are simultaneously output, and the illumination variation detection signal 20 is output. A timing chart explaining this is shown in FIG.

As shown in FIG. 7, after the motion detection signal 18 is first input at the time t1, the motion detection signal 19 is input until the time t5 set by the time threshold elapses, that is, by the time t4. If so, it is possible to judge that a plurality of motion detection signals are simultaneously input and output the illumination detection. As a result, the output of the motion detection signal to the outside can be limited, so that it is possible to realize an image monitoring device that performs motion detection without causing malfunction due to blinking of the illumination.

Further, when the plurality of motion detecting means set on the monitor detect the motion of a normal object or the like, the operation is as follows. In this case, the entire brightness of the predetermined place where the camera is shooting does not change instantly like when the lighting fixture blinks, so motion detection signals are rarely output at the same time, and It is often output at intervals. In such a case, as shown in the timing chart of FIG. 8, the other motion detection signal is input over the set time threshold value t5, and (t2-t1)> time threshold value t5. In such a case, even if a plurality of motion detection signals are output, it is considered that the motion detection signal is a normal motion of an object, not a momentary change in brightness due to blinking of a lighting fixture, etc. It is determined that the object is a motion detection signal due to the object, and the illumination variation detection signal 20 is not output. Further, at this time, the switch control signal 21 becomes high again as shown in the figure after the time t5 set by the time threshold value changing means elapses, so that the switch means 24 is switched and the motion detection alarm signals 25 and 26 are externally output. Is output to.

Therefore, according to the configuration of the first embodiment,
As described above, it is possible to realize an image monitoring apparatus which detects a motion of a normal object as usual and does not cause a malfunction even when the signal level changes due to blinking of a lighting fixture.

FIG. 9 is an explanatory view of the case where the number of motion detecting means is increased as compared with the case of FIG. Reference numerals 40 to 48 are motion detection areas of each motion detection means set on the monitor screen. Even when the detection areas of the motion detecting means set in the monitor are increased as described above, if the motion detecting signals from the respective motion detecting means are output within the set time threshold t5, the embodiment of FIG. In the same manner as above, it can be determined that the signal level changes due to the lighting equipment. by this,
Since it is possible to limit the output of motion detection signals to the outside,
It is possible to prevent malfunction due to lighting equipment. Further, in the case of normal movement of the object, the motion detection signal is output in order from the detection area in which the object has entered in accordance with the movement of the object, and therefore, at a time interval exceeding the time threshold t5 set from the outside. A motion detection signal is output. As a result, it can be determined that the movement of the object is normal, so that a movement detection alarm signal can be output to the outside to perform good movement detection.

Further, if a large number of motion detecting means are set on the screen as shown in FIG. 9, each motion detecting means outputs a motion detecting signal within a time threshold value t5 in the case of a normal movement of an object. Since the possibility is reduced, it is possible to more accurately distinguish the video signal level fluctuation due to the blinking of the lighting fixture and the video signal level fluctuation due to the normal movement as compared with the case where the number of setting points is small.

FIG. 10 is an explanatory view for explaining the second embodiment of the present invention.

In FIG. 10, reference numeral 50 is a sync separation means for separating the sync signal 51 from the input video signal 17, and 52.
Is an illumination detection area generation means for generating a detection area signal for setting the motion detection means at a predetermined position on the screen from the synchronization signal 51, 53 is an area setting signal output from the area generation means, and other than that is shown in FIG. Is the same.

The operation in FIG. 10 will be described with reference to FIG. In FIG. 11, 54 is a motion detection area arbitrarily set in 6 of FIG. 10, and 55 is an illumination detection area set by the illumination detection area generating means 52 at a predetermined position on the monitor screen. In the case of this embodiment, in addition to the motion detection area arbitrarily set on the monitor screen, the illumination detection area can be set at a predetermined place on the monitor screen based on the synchronizing signal of the input video signal. As shown in FIG. 11, this is automatically set on the upper part of the monitor screen near the lighting fixture installed on the ceiling, for example, based on the vertical synchronizing signal and the horizontal synchronizing signal of the video signal. If the motion detecting means is set at a predetermined location such as the edge of the screen in this way, the following merits are obtained. For example, as shown in FIG. 11, if it is set at a predetermined position near the ceiling, it is possible to detect the fluctuation of the video signal level due to the blinking of the lighting fixture very accurately. Also, since the area is set at the top edge of the monitor screen, it is unlikely that a normal object will enter the area, and even if an object enters the area, the illumination detection area will be set at the top edge of the monitor screen. Therefore, the motion detection signal output from the illumination detection area is less likely to be output at the same time as the motion detection signal output from the motion detection means arbitrarily set by the user near the center of the screen.

As described above, by automatically setting the motion detecting means at a predetermined position corresponding to the end portion of the monitor screen based on the synchronizing signal of the video signal, the fluctuation of the video signal level due to the normal motion of the object and the illumination It is easy to determine the difference from the video signal level fluctuation due to blinking, and malfunctions can be reduced. Further, since the area is automatically set at the end of the monitor screen based on the horizontal synchronizing signal and the vertical synchronizing signal, there is no need for the user to set the area, which is advantageous in terms of usability.

Other than this, the same applies when the illumination detection areas are set at the left end, right end, lower end, etc. of the monitor screen. By setting the illumination detection area at the edge of the screen, it is less likely that a plurality of motion detection signals will be output at the same time in the case of normal object motion, and malfunctions can be reduced. As a result, it is possible to realize an image monitoring apparatus which is easy to use and has less malfunctions due to blinking of lighting equipment.

[0050]

EFFECT OF THE INVENTION The illumination variation detecting means is a variation of the video signal level due to the blinking of the luminaire according to the time interval of the output timing of the motion detection signal generated in a plurality of detection areas set on the monitor screen. It is possible to determine whether the level fluctuation is caused by the movement of the object, and output the illumination fluctuation signal. Further, the time threshold value varying means is such that the output timing of the motion detecting signals inputted from the plurality of motion detecting means is temporally changed. It is possible to set a time threshold value that is a threshold value for determining whether or not they are simultaneous.

Further, the illumination detection area means can automatically set the motion detection area at a predetermined portion of the video signal with reference to the synchronization signal of the video signal.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a first embodiment.

FIG. 2 is an explanatory diagram illustrating a state in which a motion detection area is set on a monitor screen according to the first embodiment.

FIG. 3 is a timing chart showing a motion detection signal output from the motion detection means.

FIG. 4 is a configuration diagram showing a configuration of an illumination variation detection unit.

FIG. 5 is a timing chart for explaining the operation of the illumination variation detecting means when the lighting fixture blinks.

FIG. 6 is a timing chart illustrating the relationship between the output timing of the motion noisy detection signal and the time threshold value.

7 is a timing chart for explaining the operation of the illumination variation detecting means in the case of FIG.

FIG. 8 is a timing chart for explaining the operation of the illumination variation detection means when a motion detection signal is output by a normal object.

FIG. 9 is an explanatory diagram illustrating a state in which a plurality of motion detection means are set on a monitor screen.

FIG. 10 is a configuration diagram showing a configuration of a second embodiment of the present invention.

FIG. 11 is an explanatory diagram illustrating a case where a detection area is set on the monitor screen with the configuration of the second embodiment.

FIG. 12 is a block diagram of a conventional motion detecting means.

FIG. 13 is an explanatory diagram illustrating a case where a detection area is set on a monitor screen in the configuration of the conventional motion detection means.

FIG. 14 is a timing chart showing the state of the motion detection signal when there is a video signal level change due to the lighting equipment at t1 in the configuration of the conventional motion detection means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Motion detection means, 2 ... Input data addition means, 3 ... Data delay means, 4 ... Difference detection means, 5 ... Comparison means, 6 ... Detection area setting means, 7 ... Time threshold variable means, 8 ... Detection sensitivity Setting means, 10 ... Illumination fluctuation detecting means, 11 ... Digital video signal, 12 ... Area signal, 13 ... Current addition data, 14 ... Delayed addition data, 15 ... Reference threshold signal, 16 ... Time threshold signal, 17 Input video signal, 18, 19 ... Motion detection signal, 20 ... Illumination fluctuation signal, 21 ... Switch control signal, 22 ... Time fluctuation data, 23 ... A / D converter, 24 ... Switch means, 25, 26 ... Motion Detection alarm signal, 30 ... Monitor screen, 31 ... Lighting equipment, 32-33 ... Motion detection area, 34 ... Time difference calculating means, 35 ... Time difference comparing means, 36 ... Switch control signal generating means, 0-48 ... motion detection areas, 50 ... synchronization separation means, 52 ... illumination detection area generator, 53 ... illumination detection area setting signal, 55 ... lighting detection area.

Claims (3)

[Claims] 1. An image monitoring apparatus for detecting a motion in a video signal, comprising: first motion detecting means for detecting a temporal fluctuation difference of a video signal level; and detecting a temporal fluctuation difference of a video signal level. The second motion detection means, the first motion detection signal output from the first motion detection means, and the second motion detection signal output from the second motion detection means are input, and An image monitoring apparatus, comprising: an output control unit that controls a motion detection signal output to the outside according to a difference in output timing of the first and second motion detection signals. 2. A time threshold value changing means for changing a time as a threshold value for detecting a difference between output timings of motion detection signals output from the first and second motion detecting means according to claim 1. An image monitoring device comprising: 3. The first motion detection means according to claim 1, wherein the first motion detection means arranged at an arbitrary position of the video signal detects a video signal level fluctuation due to a motion of an object in the video signal, An image monitoring apparatus characterized in that the second motion detecting means set at a place different from the place where the means is set detects a video signal level fluctuation other than the motion of an object in the video signal.