JPH10174088A - Monitor system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the monitor system with a simple system configuration in which recording of a prescribed state is recorded from a point of time in a prescribed time before occurrence of the state. SOLUTION: An image picked up by a camera 11 is A/D-converted and compressed by an image compression section 13. A delay processing section 14 stores compressed data to a memory 141 and provides an output at a prescribed time of delay set by a timer setting section 15. Then the compressed image is expanded by an expansion section 16, D/A-converted and displayed on a monitor 18. When a sensor 21 detects a prescribed state, a time lapse recorder 22 starts recording of the image delayed by a prescribed time supplied from the D/A converter section. The delay processing section 14 gives the compression image data with a prescribed time of delay and a prescribed event detection time to a recording section 23 and a transmission section 24. Thus, the image having been picked up earlier than the prescribed event detection time of the sensor 21 by a prescribed time is video-recorded and a situation before and after detection of the prescribed event is later analyzed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring system, and more particularly, to a monitoring system having a function of recording a predetermined situation such as an abnormal state that has occurred.

[0002]

2. Description of the Related Art As part of security in banks, supermarkets, buildings, and the like, a monitoring system is often adopted in which a camera is installed at a predetermined position and the inside of the store is monitored by a monitor in a separate room or a central monitoring room. . In this monitoring system, in general, not only a monitor is used to monitor a predetermined situation that may occur suddenly, such as an abnormal situation such as a robbery or a fire, but also the content of an image captured by a camera is continuously transmitted to a VTR in order to verify the cause of the occurrence. It is recorded and saved. As a method of recording this imaged content using a time lapse recorder (VTR) or the like, (1) a method of constantly recording for 24 hours, (2) one or more sensors are installed at a predetermined position such as around a camera or an entrance. A method in which the VTR is activated to start recording when the sensor detects a predetermined situation; (3) a method in which recording is performed for 24 hours, and a recording density is changed before and after the sensor detects the predetermined situation; That is, before the sensor detection, for example, the situation every 30 seconds is recorded,
There is a method of always recording after detection.

[0003]

The system for constantly recording (1) described above is perfect as a record for confirming the occurrence of a predetermined situation at a later date. In this case, there is a problem that a lot of useless recording is required and the cost is high. In particular, performing recording for 24 hours for all cases where a plurality of monitoring locations exist has a problem in terms of cost.
In the method (2), recording is not performed until the occurrence of a predetermined situation is detected. Therefore, compared to the method of recording for 24 hours, useless recording is less, and efficient recording is performed. However, since the VTR is activated and the recording is started after the occurrence of the predetermined situation is detected by the sensor, the necessary imaging timing may be missed in consideration of the reaction speed of the sensor and the response time to the occurrence of the predetermined situation. was there. Further, when a predetermined situation occurs, since there is no information before the response of the sensor, there is a problem that the amount of information may be insufficient to determine the cause or the like. Furthermore,
The method (3) of changing the recording density before and after the sensor detection is that the recording density before the sensor detection is low, so that there is not much wasteful recording, and it is possible to confirm the previous recording when a predetermined situation occurs. It is possible. However, there is a problem that the information is not sufficient because the recording interval before the occurrence of the predetermined situation is too coarse. If the recording interval before the detection of the sensor is narrowed in order to obtain a sufficient information amount, there is a problem that a useless recording time increases when a predetermined situation does not occur.

Accordingly, the present invention has been made to solve the above-described conventional problems, and has a simple system configuration, and is capable of recording a record of a predetermined state before it occurs. Is to provide.

[0005]

According to the first aspect of the present invention, there is provided an image pickup apparatus for sequentially picking up images, an image compressing means for sequentially compressing images picked up by the image pickup apparatus, and a compressing means for compressing the images. Delay processing means for sequentially outputting the selected images after a predetermined time has elapsed, detection means for detecting the occurrence of a predetermined situation, and output from the delay processing means when the occurrence of the predetermined situation is detected by the detection means The object is achieved by providing a monitoring system with image recording means for recording a compressed image. In the invention according to claim 2,
2. The monitoring system according to claim 1, further comprising a transmission unit that transmits an image output from the delay processing unit when a predetermined situation is detected by the detection unit. According to a third aspect of the present invention, in the monitoring system according to the first or second aspect, a predetermined situation is detected by the image expansion unit that expands the compressed image output from the delay processing unit, and the detection unit. If
Recording means for recording the image expanded by the expansion means.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a monitoring system according to the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a configuration of the monitoring system. As shown in FIG. 1, the surveillance system includes a camera (imaging device) 11 for taking an image for monitoring, and a monitor 18 for monitoring the image taken by the camera 11. The monitoring system includes an A / D conversion unit 12, an image compression unit 13, a delay processing unit 14, a timer setting unit 15, an image expansion unit as components for displaying an image captured by the camera 11 on a monitor 18 for monitoring. 16, D / A
A conversion unit 17 is provided. The monitoring system further includes a sensor 2 for responding to occurrence of a predetermined situation.
1. Time lapse recorder (VTR) 22, recording unit 2
3 and a transmission unit 24.

[0007] The camera 11 supplies a video signal such as an NTSC signal of a captured image to the A / D converter 12. The A / D converter 12 converts an image supplied from the camera 11 into a digital video signal and supplies the digital video signal to the image compressor 13. Image compression unit 13
After performing a compression process by a predetermined method on an image converted into a digital signal, the image is supplied to the delay processing unit 14.

For the image compression in the image compression section 13, various existing compression methods for compressing moving images can be adopted. For example, compression is performed by the FST compression method described in JP-A-5-227547. F
ST compression encodes an A / D-converted video signal into a matrix block consisting of a plurality of pixels and a bitmap representing one of two types of reference values, and finds non-redundancy information in the coded block. Identified and coded,
Comparing each block with the corresponding block in the previous frame removes inter-block and inter-frame redundancy, and also encodes the current color value in the form of a difference to the previous color value This compresses the amount of information. Also, as other image compression methods, well-known compression by MPEG or JP-A-8-15442
Various methods such as TIM compression described in JP-A-61-61 may be used.

[0009] TIM compression is an image compression method capable of easily expanding a compressed image.
In TIM compression, (a) human eyes are sensitive to luminance changes but insensitive to color changes in image compression. (B) When the pixels constituting an image are appropriately blocked, The image compression is performed based on the assumption that there are usually only two colors in one block which is generally established in the natural image. That is, each pixel data is divided into an image composed of a luminance signal Y and color difference signals U and V, and block data composed of n × m (normally 4 × 4) is generated. Then, a first color component (y1, u1, v1) having a luminance signal and a color difference signal representing the generated block.
The data is compressed by generating a block component including two colors, i.e., two colors of a second color component (y2, u2, v2), and an nxm bitmap indicating the distribution of the first color component and the second color component. . Then, the generated block component is coded from the block component, a similar block having the same or most similar block component, and the code data indicating the similar block and the difference data with respect to the block component of the similar block. This is a compression technique that further compresses the data and transmits the data to the image receiving device.

The image compression employed in the present embodiment is processed by a board (printing board) dedicated to image compression arranged in the image compression section 13, and is implemented by a soft FST, a soft TIM, a soft MPEG or the like. The image may be compressed by software processing.

The delay processing unit 14 has a memory 141 composed of a RAM or the like, and sequentially stores the compressed image data supplied from the image compression unit 13 in this memory 141, and outputs the compressed image data after a predetermined time elapses in the input order. Due to the FIFO operation, the compressed image data is supplied to the image decompression unit 16 with a delay of a predetermined time. Memory 141
Controls the address by updating the write pointer and the read pointer. That is, the write pointer and the read pointer have the same update direction, and the FIFO operation is performed by the former always following the latter. The difference between the write pointer and the read pointer indicates the amount of data stored in the memory 141, that is, the time from when the data is stored to when it is output, and corresponds to a predetermined time set by the timer setting unit 15. Thus, the difference between the two pointers is changed.

The predetermined time for delaying the output of the compressed image data supplied from the image compression section 13 is determined by the setting of the timer setting section 15. The setting of the predetermined time by the timer setting unit 15 can be set to an arbitrary time in seconds, but the maximum setting time is determined by the capacity of the memory 141. The capacity of the memory 141 in the present embodiment is a capacity that can be set up to a delay of up to one minute.
Minutes, 30 minutes, 1 hour, 2 hours or more.

When the detection signal is supplied from the sensor 21, the delay processing unit 14 activates the recording unit 23 and the transmission unit 24, sequentially reads out from the memory 141 and supplies the image data to the image decompression unit 16 with a predetermined time delay. The compressed image data is also supplied to the recording unit 23 and the transmission unit 24 and the delay processing unit 14
Is provided with a clock (not shown), and a time obtained by subtracting a predetermined time set by the timer setting unit 15 from a time at which the detection signal is supplied from the sensor 21 is set as a predetermined event detection time, and the recording unit 23 together with the compressed image. To the transmission unit 24.

The image expansion section 16 expands the compressed image data supplied from the delay processing section 14 after a predetermined time delay by a method corresponding to the compression method in the image compression section 13 and converts it into a digital video signal. Is supplied to the D / A converter 17. The image decompression unit 16 of this embodiment is processed by a board (printed board) dedicated to image decompression. However, the image decompression unit 16 may decompress an image by software processing such as software FST, software TIM, and software MPEG. Good. The D / A converter 17 converts the supplied digital video signal into an analog video signal and supplies the analog video signal to the monitor 18 and the time lapse recorder 22.

The monitor 18 displays an image based on the video signal supplied from the D / A converter 17 on a display screen. The monitor 18 includes a delay processing unit 1
4, the output of the compressed image data is delayed by a predetermined time, so that an image that is past the actual time by a predetermined time is displayed. That is, images captured by the camera 11 are sequentially displayed on the monitor 18 with a delay of a predetermined time.

The sensor 21 is a sensor for detecting the occurrence of a predetermined state, and includes one or a plurality of sensors for detecting various states. The predetermined state to be detected varies depending on the application location of the monitoring system of the present embodiment and the like. However, there are various states such as opening and closing a door, entering (invading) a person, generating a fire, generating smoke, and the like. Sensor 21
When these predetermined states are detected, the delay processing unit 1
4, and a detection signal is supplied to the time lapse recorder 22.

The time lapse recorder 22 includes a sensor 21
Is activated when a detection signal is supplied from the D / A converter 17.
Record the image supplied from. That is, the time lapse recorder 22 starts recording when the sensor 21 detects a predetermined state, and the recorded content is such that an image is recorded for a predetermined time before the detection of the sensor 21. .

The recording unit 23 is activated after the sensor 21 detects a predetermined situation, and receives the compressed image data supplied from the delay processing unit 14 for a predetermined time before the detection, and
The time of occurrence of the predetermined situation is recorded. The recording unit 23 includes a recording medium for recording the compressed image data and the recording start time (character data), and a driving device for the recording medium. A hard disk is used as a recording medium in the present embodiment. In addition, a magnetic storage medium such as a RAM, a floppy disk, a magnetic tape, a semiconductor storage medium such as a memory chip or an IC card, a CD-R or a PD (phase change) is used. A storage medium for reading information optically, such as a rewritable optical disk, or a storage medium for recording compressed image data by various methods may be used.

The transmission section 24 has a modem, and secures a communication line with a security department or a security company by various communication means such as a wireless communication by a portable telephone or a wired communication. The compressed image data of a predetermined time before stored in the compressed image data is sequentially transmitted.

Next, the operation of the monitoring system thus configured will be described. A camera 11 installed for monitoring a bank or the like constantly captures an image in a predetermined range. The image picked up by the camera 11 is converted into a digital signal by an A / D converter 12 and then converted into a digital signal.
In 3, the data is compressed by a method such as FST and supplied to the delay processing unit 14. In the delay processing unit 14, a difference between the write pointer and the read pointer of the memory 141 is set corresponding to the predetermined time set by the timer setting unit 15. Then, each time the compressed image data is supplied from the image compression unit 13, the write pointer is updated, and after the compressed image data located at the current read pointer is supplied to the image decompression unit 16, the read pointer is updated.
As a result, the compressed image data before (past) by a predetermined time is delayed from the delay processing unit 14 by the image decompression unit 16.
Will be supplied.

The compressed image data output from the delay processing unit 14 with a delay of a predetermined time is expanded by an image expansion unit 16 and converted into a video signal by a D / A conversion unit 17.
It is displayed on the monitor 18. Therefore, the image displayed on the monitor 18 is an image after a predetermined time has elapsed since the image was captured by the camera 11, that is, an image captured a predetermined time in the past from the display time.

On the other hand, when a predetermined state is detected by the sensor 21, a detection signal is supplied to the delay processing unit 14 and the time lapse recorder 22. When the detection signal is supplied,
The time lapse recorder 22 starts and continues recording an image supplied from the D / A converter thereafter, that is, the same image as the image displayed on the monitor 18. Also,
The delay processing unit 14 activates the recording unit 23 and the transmission unit 24 as soon as the detection signal is supplied,
The compressed image data that is sequentially read from the read pointer position 1 and supplied to the image decompression unit 16 is also supplied to the recording unit 23 and the transmission unit 24. Further, the delay processing unit 14
The time when the detection signal was supplied from the sensor 21 is checked by a clock (not shown), and a time obtained by subtracting a predetermined time set by the timer setting unit 15 from this time is set as a predetermined event detection time, and the recording unit 23 and the transmitting unit 24.

The recording unit 23 sequentially records the supplied compressed image data and the predetermined event detection time on a recording medium. Further, the transmitting unit 24 connects a communication line with a receiving device installed at a pre-designated location such as a centralized monitoring center or a security company, so that the supplied compressed image and the predetermined event occurrence time can be determined. Send sequentially.

As described above, according to this embodiment, since the image (past image) delayed by a predetermined time is output by the delay processing section 14, the occurrence of a predetermined situation is detected by the sensor 21. In the case of being recorded from the image taken only a predetermined time before the detection time,
Recording can be performed. Therefore, after the detection of the predetermined situation, the state before and after the detection is transmitted to the other apparatus on the receiving side from the image recorded on the time lapse recorder 22, the compressed image data recorded on the recording medium of the recording section 23, and the transmitting section 24. The analysis can be performed based on the compressed image data to be performed.

In this embodiment, the compressed image data obtained by performing the compression processing on the image captured by the camera 11 by the image compression unit 13 is supplied to the delay processing unit 14. Compared to delay processing unit 1
4 in the memory 141 and the recording amount of the recording unit 23 in the recording medium can be increased. Therefore, in the delay processing unit 14, the longest predetermined time that can be set by the timer setting unit 15 can be set to a longer time than when no compression is performed.

In the embodiment described above, since the monitor 18 displays the image supplied from the D / A converter 17, the image after a predetermined time has elapsed since the image was taken by the camera 11, that is, the fixed time Only images captured in the past are displayed. For this reason, the occurrence of the predetermined situation detected by the sensor 21 is delayed by a predetermined time from checking the monitor 18. Therefore, when a predetermined situation is detected by the sensor 21, a caution display may be displayed on the monitor 18 to that effect. For example, a display such as “a predetermined situation has been detected. The predetermined situation is displayed after ★★ seconds (predetermined time) from the current display screen” is displayed on the monitor 18. Thereby, the person who monitors the monitor 18 can recognize that the predetermined situation has occurred without delay, and can check the state before and after the occurrence of the predetermined situation in detail while paying attention.

Further, another monitor may be provided, and the image taken by the camera 11 may be directly displayed on the monitor without delay. In this case, a past image is displayed on the monitor 18 for a predetermined time, and a current image is displayed on the other monitor. Further, an image output from the camera 11 and an image output from the D / A conversion unit 17 are supplied to an output switching unit, and by switching the output, a current image and a past image are switched and displayed on a monitor. Is also good. Further, the image output from the camera 11 and the D /
The image output from the A conversion unit 17 may be supplied to the image synthesis unit, and both images may be displayed side by side on a monitor.

[0028]

According to the monitoring system of the present invention, a record of a predetermined situation can be recorded with a simple system configuration from that before the occurrence.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a monitoring system according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 11 camera 12 A / D conversion unit 13 image compression unit 14 delay processing unit 15 timer setting unit 16 image expansion unit 17 D / A conversion unit 18 monitor 21 sensor 22 time lapse recorder 23 recording unit 24 transmission unit

Continued on the front page (72) Inventor Hiroki Ishikawa 2--19-12 Sotokanda, Chiyoda-ku, Tokyo Inside Equos Research Co., Ltd. (72) Inventor Hiroshi Uehara 2-3-20 Tamagawadai, Setagaya-ku, Tokyo 5Y N Building 408 (72) Inventor Kiyoshi Fujinawa 2-1-1-1101 Tachibanadai, Aoba-ku, Yokohama-shi, Kanagawa

Claims (3)

[Claims] An image pickup device for sequentially picking up images, an image compression means for sequentially compressing images picked up by the image pickup device, and a delay processing for sequentially outputting the images compressed by the image compression means after a predetermined time has elapsed. Means, detecting means for detecting occurrence of a predetermined situation, and image recording means for recording a compressed image output from the delay processing means when occurrence of the predetermined situation is detected by the detecting means. A monitoring system characterized by the following. 2. The monitoring system according to claim 1, further comprising a transmitting unit that transmits an image output from the delay processing unit when a predetermined situation is detected by the detecting unit. 3. An image expanding means for expanding a compressed image output from the delay processing means, and a recording means for recording an image expanded by the expanding means when a predetermined situation is detected by the detecting means. The monitoring system according to claim 1 or 2, further comprising: