JPH06153033A - Monitor camera system and its control method - Google Patents

Abstract

PURPOSE:To speedily take action after an event occurs. CONSTITUTION:CCD 12 takes the still picture of a place to be monitored whenever a photographing timing signal is generated (at every prescribed time, for example). The picture data is data-compressed by a data compression circuit 18 and is stored in a memory 20. When an abnormality detection signal is generated from an abnormality detection circuit 24, latest compression picture data for the appropriate number of frames, which are accumulated in the memory 20, are transmitted from a transmission device 21 to the police and a security service through ISDN and the like and they are reproduced and displayed. The still picture of the monitored place is taken at every prescribed time from time when abnormality occurs, and also the compression picture data is transmitted.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a surveillance camera system mainly installed in a store such as a bank or a convenience store, and a control method thereof.

[0002]

[Background Art] Many conventional surveillance (or security) cameras installed in stores such as banks and convenience stores are video cameras, which continuously capture and record images in the surveillance area of the store. To do.

When any incident occurs, the police or security company is notified of that fact. Only after a police officer or security guard rushes to the scene, verification of the video imaged and recorded by the surveillance camera is started. By this time, the people involved in the incident have already fled.

Therefore, the conventional surveillance camera system, even if the image of the person involved in the case is recorded, is not very useful for quick arrangement or investigation of the person.

Further, since the conventional surveillance camera is a video camera as described above and the video imaged is a moving image, it is not always possible to obtain a video image of sufficient quality.

[0006]

DISCLOSURE OF THE INVENTION It is an object of the present invention to provide a surveillance camera system and a control method therefor capable of taking prompt action for incident processing immediately after the occurrence of an incident.

Another object of the present invention is to make it possible to obtain clear image information.

The surveillance camera system according to the present invention comprises:
Still image photographing means adjusted and arranged to photograph a place to be monitored, photographing timing generating means for generating a photographing timing signal representing a moment to photograph, and a photographing timing signal given from the photographing timing generating means. Then, the still image photographing means is caused to perform a photographing operation,
Shooting control means for controlling to output image data obtained by shooting operation, data compression processing means for compressing image data output from the still image shooting means, and compressed image data obtained from the data compression processing means are stored. Storage means, abnormality detection means for detecting the occurrence of an abnormality that should transmit compressed image data, and the latest predetermined number of frames stored in the storage means in response to the abnormality detection signal output from the abnormality detection means. And a transmission means for transmitting the compressed image data.

A control method for a surveillance camera system according to the present invention compresses data of still image photographing means adjusted and arranged so as to photograph a place to be monitored, and image data output from the still image photographing means. Using the surveillance camera system having a data compression processing means and a storage means for storing the compressed image data obtained from the data compression processing means, in response to a shooting timing signal indicating the moment of shooting, the still image shooting is performed. The image data obtained thereby is compressed by the data compression processing means, the obtained compressed image data is stored in the storage means, and the photographing operation is performed every time a photographing timing signal is given. Data compression and storage processing are repeated, and in response to an abnormality detection signal indicating the occurrence of an abnormality in which compressed image data should be transmitted, Is to transmit compressed image data of the latest number of predetermined frames through a communication line to 憶 means are stored.

When the surveillance camera system according to the present invention is installed in a store such as a bank or a convenience store, the surveillance camera is installed near the bank counter, ATM or CD.
Will be adjusted (focal length, exposure amount, angle) so that it can be photographed at the installation location, near the electronic cash register installation location, especially where the products that require monitoring are displayed.

Shooting by a surveillance camera will most commonly be done at regular intervals (eg, 30 seconds, 1 minute, etc.).
That is, the photographing timing generation means is realized by a timer means that generates a photographing timing signal at predetermined constant time intervals.

It is also possible to take a picture of a specific place only when required by the surveillance camera. For example, when a person comes to a counter in a bank store, when a person comes to a place where particularly expensive goods are displayed in a store such as a convenience store, when an electronic cash register is used. Etc.

For this reason, the photographing timing generation means is realized by a human detector which detects that a human enters a predetermined range within the photographing area of the still image photographing means and outputs a photographing timing signal. , Or a drawer opening detector that detects the opening of the drawer of the electronic cash register and outputs a shooting timing signal.

By doing so, the number of frames to be photographed will probably be reduced as compared with the case where images are photographed at regular intervals.

If the storage means has a large capacity, all the compressed image data obtained by photographing will be stored. When the storage capacity of the storage means is limited, the compressed image data is stored in an alternative storage capacity, the compressed image data is erased in the oldest order, and the latest compressed image data is sequentially stored instead. Will be.

Abnormality detection can be realized in various ways. If a store clerk, a clerk, or a clerk in the store detects an abnormality, the emergency switch will be pressed. That is, the abnormality detecting means is realized by the emergency switch.

It is also possible to automatically detect an abnormality. For example, the abnormality detection signal is generated by detecting that an abnormally high voice (for example, scream) is generated, or some noise is made at night.

In this case, the abnormality detecting means may include a microphone and a processing means for extracting a predetermined feature from the sound signal output from the microphone and outputting the abnormality detecting signal. The predetermined characteristic means that the signal level is higher than the predetermined level, that the signal component in the predetermined frequency band is equal to or higher than the predetermined level, and the like. When detecting an abnormality only at night, the abnormality detecting means is controlled by a switch or an output of a clock so as to operate only at night.

In the store where the electronic cash register is installed, it is preferable to detect an abnormality in association with the operation or operation of the electronic cash register.

For example, the abnormality detection signal can be generated by detecting that the drawer of the electronic cash register is continuously pulled out (opened) for a predetermined period of time which is not possible in normal business. In this case,
The abnormality detecting means determines a drawer opening detector for detecting the opening of the drawer of the electronic cash register, and judges that the drawer opening detector continuously outputs the drawer opening detection signal for a predetermined time or longer. A timer means for generating an abnormality detection signal.

It is also possible to detect that the drawer of the electronic cash register is forcibly opened without going through a formal procedure. In this case, the abnormality detecting means is a drawer opening detector that detects opening of the drawer of the electronic cash register, and opening of the drawer is prohibited (that is, opening of the drawer is not permitted). And an abnormality determining means for determining that the drawer opening detection signal is output from the drawer opening detector and generating an abnormality detection signal. It can be considered that the opening of the drawer is prohibited, the drawer drive signal is not output, or the normal mode such as the registration mode is not set by the mode switch.

In any case, in a mode in which an abnormality is detected in association with the electronic cash register, a crime prevention mode or a monitoring mode is provided in order to prevent the abnormality from being erroneously detected during normal operation of the electronic cash register.
The abnormality detection operation may be performed under the condition that this mode is set.

As described above, according to the present invention, a still image is photographed in a normal state, the image data obtained by this photographing is data-compressed and stored in the memory, and when an abnormality is detected. In addition, since the latest one or more frames of the compressed image data stored in the memory are immediately transmitted to the police or security company through ISDN or public line, the police officer or the security officer must The transmitted image data can be reproduced and displayed for confirmation, and then countermeasures can be swiftly taken or dispatched. Since the compressed image data is transmitted, the time required for the transmission is short (several seconds to tens of seconds).

Further, since the photographing is not performed continuously, but the photographing is performed intermittently, the amount of photographed image data is small, and since the image data is compressed, the image data is stored. It requires less memory capacity and can provide a low-cost system. In this invention, since a still image is obtained instead of a moving image, a clear image (an image with less blurring and high resolution) can be obtained.

In a further preferred embodiment of the present invention, in response to the occurrence of the abnormality detection signal,
In the still image capturing means, every predetermined time (for example, every 1/60 seconds, which is the time to obtain the image data of one field, or from 1/30 seconds that is the time to obtain the image data of one frame, A predetermined number of frames are photographed at every arbitrary time up to several seconds, which is the time required to transmit the compressed image data for the frames, and the image data obtained by this photographing is sequentially subjected to data compression processing. Then, it is stored in the storage means. Then, after the photographing of the predetermined number of frames is completed or in parallel with the photographing, the compressed image data including the compressed image data of the predetermined number of frames is transmitted.

Since the case has occurred when the abnormality detection signal is generated, or immediately after the case has occurred, the captured image at this time may include an image that represents the decisive moment of the case. By storing and transmitting the video of the scene when the anomaly detection signal occurs, it can be expected to be useful for early resolution of the incident.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the electrical construction of a surveillance camera system.

A space to be monitored and an image of a subject such as a person in the space are formed on the CCD 12 by the imaging lens 11. As will be described later, when a shooting operation is performed under the control of the shooting control circuit 22, a video signal for one frame representing a subject image is output from the CCD 12, and a preprocessing circuit 13 that performs amplification processing and other preprocessing is provided. After that, this analog video signal is A /
It is converted into digital image data by the D converter.

Digital image data for one frame (one field or one frame) is temporarily stored in the frame memory 16 under the control of the frame memory controller 15. Thereafter, the digital image data is read from the frame memory 16, separated into luminance data and color data by the luminance / color (Y / C) processing circuit 17, and stored again in the frame memory 16.

The image data separated into the luminance data and the color data is read again from the frame memory 16 and compressed in the image data compression circuit 18. The image data compression circuit 18 uses, for example, discrete cosine conversion,
Image data is compressed by Huffman coding, run-length coding, etc. The data-compressed image data is stored in the compressed data memory 20 under the control of the compressed data memory controller 18.

The compressed data memory 20 is most preferably a semiconductor memory, and can be realized, for example, by a so-called memory card containing a semiconductor memory. Of course, it is needless to say that another storage medium such as a magnetic disk memory can be used. Preferably,
The compressed image data is stored with an identification number in the order in which they were taken. It is more preferable to store the data representing the shooting time in association with the compressed image data.

The shooting timing is defined by a shooting timing signal supplied from the shooting timing generation circuit 23. This shooting timing signal is given to the shooting control circuit 22.

The photographing control circuit 22 preferably includes a microprocessor, a clock signal generating circuit, etc., and the CCD 12,
A clock signal is given to the pre-processing circuit 13, the A / D converter 14, etc., and the CCD 12 is cleared and read out in response to the photographing timing signal. In addition, the shooting control circuit 22
Performs exposure control and focus control including control of shutter speed and aperture as necessary. However, the exposure amount and the focus position may be fixed in advance. Further, the photographing control circuit 22 controls the memory controllers 15 and 19 and controls the compression processing of image data and the storage of compressed image data in the compressed data memory 20.

The Y / C separation of the image data, the data compression, and the storage of the compressed image data in the memory 20 are performed every time one frame of a still image is taken.

When an abnormality detection signal is generated from the abnormality detection circuit 24, the latest compressed image data for one or a predetermined plurality of frames stored in the compressed data memory 20 is read out under the control of the memory controller 19. And transmitted to the transmission device 21. The transmission device 21 is connected through ISDN, a public communication line, etc. to a monitor device, a work station, etc. installed in a police station, a security company's packinghouse, etc. To transmit. The monitor device decompresses the received compressed image data and displays it on the display screen. Needless to say, the telephone number of the monitor device or the like is preset in the transmission device 21, and the line with the monitor device or the like is connected by automatic dialing.

The process of transmitting the compressed image data based on the shooting timing and the abnormality detection will be described in detail later.

This surveillance camera system is installed in a store such as a bank or a convenience store, and a counter or window of a bank, a doorway, an ATM, a CD, etc.
It is arranged so as to photograph the vicinity of the location of the electronic cash register, the place where expensive products are displayed, etc.
Generally, the imaging lens 11, CCD 12, pre-processing circuit 13, A
/ D converter 14, memory controller 15, 19, memory 1
6, 20, the Y / C processing circuit 17, the data compression circuit 18, and the photographing control circuit 22 will be built in the case of the surveillance camera. However, when it is necessary to downsize the case of the surveillance camera, at least the imaging lens 11, the CCD 12, the preprocessing circuit 13, and the photographing control circuit 22 may be built in the case of the surveillance camera. As described above, such a camera is fixed in advance in a state suitable for photographing a person in a space to be monitored (for example, exposure conditions, focus position, photographing angle, etc.) or by automatic control. To be done.

The photographing timing generation circuit 23 has various embodiments. These will be described below.

(A1) Fixed time (for example, 10 seconds, 20
Second, 30 seconds, 1 minute, 2 minutes, 3 minutes, 5 minutes, 10 minutes, etc.) A timer that generates a shooting timing signal.

The timer can be realized by a hardware circuit, or can be realized by a memory of a microcomputer.
It is also possible to set the area as a timekeeping area and measure the time on the program.

(A2) A human detection sensor which detects that a human has entered a predetermined range within the photographing area of the surveillance camera and outputs a photographing timing signal.

This human detection sensor is
Detects people who pass through the entrance, people who arrive at counters or counters in bank stores, people who come to places where expensive products are displayed in general stores, people who come near electronic cash registers, etc. Will be provided.

(A3) A drawer opening detection sensor which detects opening of the drawer of the electronic cash register and outputs a photographing timing signal.

This drawer opening detection sensor can be realized by a limit switch, a proximity switch, a photoelectric switch or the like for detecting that the drawer is actually pulled out, and a drawer opening command (or control) signal can be output at the photographing timing. It can also be a signal.

(A4) A combination of at least two circuits selected from the above (A1) to (A3).

An OR logic signal of the shooting timing signals output from the timer or the sensor will be given to the shooting control circuit 22 as a shooting timing signal.

FIG. 2 shows a flow of processing procedures mainly controlled by the photographing control circuit 22 from photographing using the CCD 12 to recording image data obtained by photographing in the memory 20.

The maximum number of frames that can be stored in the compressed data memory 20 is P _max . Further, the count value of the storage frame number counter for counting the sequence of the frames of the image data stored in the memory 20 is P. This count value P can also specify the address of the location in the memory 20 where the compressed image data should be stored. The count value P can also be used to give an identification number (frame number) to the image data stored in the memory 20.

First, the value of the counter P is initialized to 1 (step 51). As described above, when the photographing timing signal is generated from the photographing timing signal generation circuit 23 realized by the timer or the sensor to the photographing control circuit 22 (step 52), the CCD 12 performs photographing.

That is, the unnecessary charges of the CCD 12 are cleared,
After a certain time (equivalent to the shutter speed), the CCD
The video signal from 12 is read. As described above, this video signal is converted into digital image data, then data is compressed, and the frame number represented by the value P of the counter is given and stored in the memory 20. Preferably, the data representing the date and time at that time is also stored in the memory 20 in association with the compressed image data (step 53).

Subsequently, the value P of the counter is incremented (step 54) and the process returns to step 52 again. When the value P of the counter exceeds the maximum number of stored frames Pmax (step
55), the value P of the counter is reinitialized to 1 (step
56).

The abnormality detection circuit 24 also has various embodiments. Examples of these are as follows.

(B1) A circuit including the emergency push button switch 31 (see FIG. 3).

The emergency push button switch 31 is used for a store clerk, a clerk, or a clerk in the store when an emergency or an incident occurs.
It will be pushed by staff, guards, etc. When this switch 31 is pressed, an abnormality detection signal is generated.

(B2) A level at which the microphone 32 and the output signal of the microphone 32 are discriminated by a predetermined threshold level, and an abnormality detection signal is generated when the level of the output signal of the microphone 32 exceeds the threshold level. A circuit composed of a discrimination circuit 33 (see FIG. 4).

This circuit is particularly useful at night. This is because it is generally quiet at night, and it is considered that some kind of incident occurred when there was a loud noise.

Instead of the level discriminating circuit 33, a circuit for extracting a signal component in a predetermined frequency band from the output signal of the microphone 32 and generating an abnormality detection signal when the extracted signal component is at a predetermined level or higher is provided. Good. This will enable detection of screams and the like.

(B3) A sensor 42 for detecting the opening of the drawer 41 of the electronic cash register 40, and a timer 43 for judging that the detection signal of the sensor 42 is continuously output for a predetermined time or longer. Circuit (see FIG. 5).

The detection of the opening of the drawer 41 is realized by the various switches and the drawer opening command signal as described above. The timer 43 is set with a set time that is longer than the time that is not possible in normal business. The timer 43 can be implemented not only on a hardware circuit but also on a program. Timer 43
Is set by the detection of opening of the drawer 41 (rising of the detection signal), starts the timing operation, and is reset by detection of closing of the drawer 41 (falling of the detection signal). After being set, the timer 43 generates an abnormality detection signal when the above set time has elapsed without being reset.

(B4) The sensor 42 that detects the opening of the drawer 41 of the electronic cash register 40 and the sensor 42 when the opening of the drawer 41 is prohibited (when the opening of the drawer 41 is not permitted). A circuit including an abnormality determination circuit (44, 45) for determining that the open detection signal has been output and generating an abnormality detection signal (see FIG. 6).

The electronic cash register 40 is provided with a mode switch 44 for switching between an off mode, a registration mode, a settlement mode and the like by inserting and turning a key. Since the electronic cash register 40 is not used when the mode switch 44 is in the off mode,
Opening of drawer 41 is prohibited (not allowed). Therefore, the AND circuit 45 can determine that the mode switch 44 is in the off mode and the sensor 42 detects the opening of the drawer 41, and when this determination is made, an abnormality detection signal is generated. . The judgment realized by the AND circuit 45 can of course be realized by a microcomputer.

The state in which opening of the drawer 41 is prohibited is as follows.
Detection can be based on other conditions or signals than the mode switch 44. For example, when the drive signal of the drawer 41 is not output.

The electronic cash register 40 is preferably provided with a crime prevention mode switch 46. AND circuit only when this crime prevention mode switch 46 is on
So that the 45 output signal is output as an abnormality detection signal,
The AND circuit 47 is connected.

Similarly in the embodiment shown in FIG. 5, the output signal of the timer 43 may be output as the abnormality detection signal only when the crime prevention mode is set.

(B5) A circuit constituted by a combination of at least two circuits among the circuits (B1) to (B4) described above.

As described above, when the abnormality detection signal is generated from the abnormality detection circuit 24, the latest compressed image data for one or a plurality of frames stored in the compressed data memory 20 is read out and transmitted from the transmission device 21. Is transmitted.

When the abnormality detection signal is generated, some kind of abnormal situation or incident has occurred. Therefore, it may be useful for early resolution of the incident if the situation at that time is imaged by the surveillance camera.

In another preferred embodiment of the present invention, the photographing control circuit 22 operates so as to photograph an appropriate number of frames when an abnormality detection signal is generated.

The procedure for this preferred embodiment is shown in FIG. The microcomputer of the photographing control circuit 22 performs the photographing control processing and the control of the transmission device 21 in response to the abnormality detection signal given from the abnormality detection circuit 24.

Let L be the number of frames to be photographed after the abnormality detection signal is generated. An abnormal frame number counter is provided for counting the number of frames photographed after the abnormality detection signal is generated, and the counted value is i. Further, it is assumed that an interval of photographing performed after the abnormal signal is generated is m seconds. This interval m seconds is arbitrary, and the shortest time is 1/60 seconds or 1/30 seconds, and as an example of a relatively long time, the time required for transmission,
There is a few seconds. It may be set as appropriate in consideration of these times.

First, the count value i of the abnormal frame number counter is preset to L (step 61), and when m seconds have elapsed (step 62), photographing, image data compression, and storage in the memory 20 are performed (step). 63). The value P of the memory frame number counter is incremented (step 64), and the value i of the abnormal frame shooting frame number counter is decremented (step 64).
67). When the value P of the memory piece number counter exceeds P _max ,
This counter is reinitialized to 1 as described above (steps 65 and 66).

The above operation is repeated every m seconds. When the count value i of the abnormal frame number counter becomes 0 (step 68), the compressed image data of L frames photographed up to that point and the latest compressed image data of an appropriate number of frames photographed before the abnormality occurs. The transmission device 21 is read from the memory 20.
(Step 69). It is more preferable to transmit the latest compressed image data of a proper number of frames photographed before the occurrence of the abnormality while the photographing of L frames is being executed. Further, it is preferable to perform shooting and transmission of compressed image data in parallel even after the occurrence of an abnormality.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall electrical configuration of a surveillance camera system.

FIG. 2 is a flow chart showing a series of processing procedures of photographing, data compression, and storage in a memory.

FIG. 3 is a circuit diagram showing an example of an abnormality detection circuit.

FIG. 4 is a circuit diagram showing an example of an abnormality detection circuit.

FIG. 5 is a circuit diagram showing an example of an abnormality detection circuit.

FIG. 6 is a circuit diagram showing an example of an abnormality detection circuit.

FIG. 7 is a flow chart showing a processing procedure of another embodiment in which shooting is performed even after an abnormality occurs.

[Explanation of symbols]

 11 Imaging lens 12 CCD 14 A / D converter 15 Frame memory controller 16 Frame memory 18 Image data compression circuit 19 Compressed data memory controller 20 Compressed data memory 21 Transmission device 22 Shooting control circuit 23 Shooting timing generation circuit 24 Abnormality detection circuit 31 Abnormal push button switch 32 Microphone 33 Level discrimination circuit 40 Electronic cash register 41 Drawer 42 Drawer opening detection sensor 43 Timer 44 Mode switch 45, 47 AND circuit 46 Crime prevention mode switch

Claims (10)

[Claims] 1. A still image photographing means adjusted and arranged to photograph a place to be monitored, a photographing timing generating means for generating a photographing timing signal representing a moment to be photographed, and the photographing timing generating means. Shooting control means for controlling the still image shooting means to perform a shooting operation in response to a shooting timing signal and outputting image data obtained by the shooting operation; data compression of image data output from the still image shooting means Data compression processing means, storage means for storing compressed image data obtained from the data compression processing means, abnormality detection means for detecting the occurrence of an abnormality in which compressed image data should be transmitted, and abnormality output from the abnormality detection means Transmission for transmitting the latest predetermined number of compressed image data stored in the storage means in response to the detection signal Surveillance camera system equipped with means. 2. The surveillance camera system according to claim 1, wherein the photographing timing generating means is a timer means for generating a photographing timing signal at a predetermined fixed time. 3. The image pickup timing generation means is a human detector which outputs an image pickup timing signal upon detecting that a person has entered a predetermined range within the image pickup area of the still image pickup means. Surveillance camera system described. 4. The drawer opening detector for detecting the opening of the drawer of the electronic cash register, and outputting the shooting timing signal by the shooting timing means. The surveillance camera system according to claim 1. 5. The surveillance camera system according to claim 1, wherein the abnormality detecting means is an emergency switch. 6. The surveillance camera according to claim 1, wherein the abnormality detection means includes a microphone and a processing means for extracting a predetermined feature from a sound signal output from the microphone and outputting the abnormality detection signal. system. 7. The abnormality detecting means is an electronic cash
A drawer opening detector for detecting the opening of the drawer of the register, and a timer means for determining that the drawer opening detector is continuously outputting a drawer opening detection signal for a predetermined time or longer and generating an abnormality detection signal. Consists of,
The surveillance camera system according to claim 1. 8. The abnormality detecting means is an electronic cash
An abnormality that generates an abnormality detection signal by determining the drawer opening detector that detects the opening of the drawer of the register and the drawer opening detection signal output from the drawer opening detector when the drawer opening is prohibited The surveillance camera system according to claim 1, comprising a determination means. 9. The photographing control means, in response to an abnormality detection signal output from the abnormality detection means, causes the still image photographing means to photograph a predetermined number of frames at predetermined time intervals, and the transmission means The still image capturing means transmits compressed image data including compressed image data for the predetermined number of frames after the predetermined number of frames have been captured.
Surveillance camera system described in. 10. A still image photographing means adjusted and arranged to photograph a place to be monitored, a data compression processing means for compressing image data output from the still image photographing means, and the data compression processing. Using the surveillance camera system provided with a storage means for storing the compressed image data obtained from the means, in response to a photographing timing signal representing a moment to be photographed, the still image photographing means is caused to photograph, thereby obtaining The image data to be compressed is compressed by the data compression processing means, the obtained compressed image data is stored in the storage means, and the photographing, data compression and storage processes are repeated every time a photographing timing signal is given to obtain a compressed image. In response to an abnormality detection signal indicating the occurrence of an abnormality in which data should be transmitted, the latest compressed image of a predetermined number of frames stored in the storage means. A control method for a surveillance camera system that transmits image data through a communication line.