KR100233109B1 - Apparatus and method for automatic monitoring - Google Patents

Abstract

A camera and a monitor for displaying an image signal output from the camera is provided to automatically detect and record the movement of the surveillance area. The apparatus includes a video telephone that compares an input video signal with a video signal of a previous display screen, detects a motion vector, encodes a video signal from which motion is detected, transmits the video signal to a counterpart, and outputs the received video signal. And signal selection means for switching in response to an input of a control signal in a surveillance mode to supply an image signal output from the camera to an input terminal of the video telephone, and when the motion vector output from the video telephone is larger than a preset reference vector. In response to recording the video signal output from the camera on a recording medium and generating an alarm at the same time.

Description

Automatic monitoring method and device

1 is a block diagram of a monitoring apparatus using a video telephone according to the present invention.

FIG. 2 is a detailed circuit diagram of the signal selector shown in FIG. 1 and a connection state diagram of peripheral circuits.

3 is a monitoring control flowchart using a video telephone according to the present invention.

* Explanation of symbols for main parts of the drawings

12,16 Camera 14,18 Monitor

20: signal selector 22: videophone

24: video codec 26: network matching unit

28: sound codec 30: control unit

32: comparison unit 34: alarm unit

36: recording unit

The present invention relates to a monitoring apparatus for automatically monitoring the state of the surrounding environment by using a camera, and more particularly, extracts a motion vector from a continuous video signal to automatically detect the movement of a subject in the surveillance region, and automatically records the state. It relates to an automatic monitoring device and method.

In general, the automatic monitoring device is a device for monitoring the surrounding subjects and is already widely used in a wide range of industries. The most common surveillance apparatus is a camera which records an image signal converted into an electrical signal by capturing an interior of a surveillance region on a recording medium using a recording apparatus such as a video cassette player.

However, such a method has a problem of automatically monitoring the surroundings due to the limitation of the recording medium when using for a long time by continuously recording the video signal output from the camera. In order to solve such a problem, a method of capturing and recording a motion of a subject has been developed.

The technical configuration of detecting and recording a subject's movement is disclosed in Korean Patent Publication No. 93-19029 (published on September 22, 1993, a method and apparatus for monitoring using a one-field memory) (hereinafter referred to as "first application"). .

The first application stores a video signal output from the camera in a field memory in response to a user's selection, and compares the stored video signal with a video signal continuously output from the camera to match the stored video signal with the input video signal. If not, it has a configuration to record the output of the current camera and generate an emergency alarm.

However, a monitoring device such as the patent application has a problem in that malfunctions due to noise are frequently generated by simply controlling the recording by detecting a difference between a previous recorded video signal stored in a field memory and a currently input field video signal. For example, if the peripheral illuminance suddenly changes while a video signal for one field is recorded in the field memory, a difference between the pre-stored video signal and the current video signal occurs even though there is substantially no movement of the subject. do.

Therefore, even when there is no movement, a monitoring alarm is generated, and a problem occurs that a video signal from a camera is recorded.

An object of the present invention is to provide an automatic monitoring apparatus and method capable of more accurately monitoring a surveillance region by using a video telephone which estimates a motion vector and transmits an image signal.

Another object of the present invention is to provide an automatic monitoring apparatus and method for automatically monitoring the state of the surveillance region using a video telephone.

Still another object of the present invention is to provide an automatic monitoring device which automatically switches to a call mode in response to an external call during monitoring of a target area.

Hereinafter, an automatic monitoring apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a monitoring apparatus using a video telephone according to the present invention.

In FIG. 1, reference numeral 22 denotes a video telephone which detects a motion vector from an input video signal and transmits a moving video to the counterpart. The video phone 22 is capable of transmitting and receiving voice data and video data to and from the other party using a BRI (Basic Rate Interface) (2B + D) channel of the ISDN. The basic structure of the video telephone 22 which transmits such a video has a video codec which performs video encoding and decoding on the video signal by the encoding (coding) and decoding (decoding) algorithm of CCITT Recommendation H.261. The video is transmitted and received to the video phone of the other party through the network interface that satisfies the requirements of I.430.

The basic structure of the video telephone 22 digitally converts and inputs an input video signal, detects a motion vector S between frames from the encoded video data, and transmits the changed video as encoded data. A video codec 24 for decoding video data and outputting an analog video signal, and video data encoded and output from the video codec 24 and audio data to be described later on a telephone line. A network matching unit 26 which transmits and receives and separates received video data and audio data, and is connected between a microphone and a speaker of a telephone which transmits and receives audio signals and the network matching unit 26 to encode / decode audio signals. It is composed of a control unit 30 which controls the operation of the audio codec 28 and the video phone 22.

The video phone 22 configured as described above detects movement with the input video signal, encodes the changed video signal and the audio signal input from the microphone, and multiplexes the encoded video signal and the audio signal to perform the network matching unit 26. It transmits to the other party through the video, and decodes the encoded video and audio signals transmitted from the other party and outputs them as display production signals.

Reference numerals 12 and 16 denote video cameras for capturing an image of a subject, converting the image into an electrical image signal, and outputting the image signal. Here, the camera 12 and the monitor 14 are fixedly coupled to the video telephone 22 and used when performing video communication. Then, the camera 16 is installed in the surveillance area for monitoring a specific place, and the monitor 18 displays the image from the camera 16.

Reference numeral 20 is operated in a surveillance mode in response to an input of a mode signal to output and display an image signal output from the camera 16 to the monitors 14 and 18, and at the same time, the video telephone 22. A video signal from the camera 12 to the video phone 22 and output from the video codec 24 in the video phone 22 in response to the detection of a call. A signal selector for outputting a video signal to the monitor (14).

32 compares the reference vector Sref with the motion vector S output from the video codec 24 of the video phone 22 to detect the motion of the subject when the motion vector S is larger than the reference vector Sref. The comparator outputs a signal.

34 is an alarm unit which alerts the current situation in response to the motion detection signal output from the comparison unit 32. 36 is a recording unit for recording the video signal output from the camera 16 in response to the motion detection signal output from the comparison unit 32. The recording unit 36 may use a general video cassette player or a digital recording device.

FIG. 2 is a connection diagram of the concrete circuit and peripheral circuits of the signal selector shown in FIG. The configuration thereof is connected between the output terminal of the camera 12, 16 and the input terminal of the video codec 24, and selects one of the two video signals according to the input of the control signal. A switch 42 for supplying the video codec 24, a switch 44 for switching the output terminal of the video codec 24 and the input terminal of the motor 14 according to the input of the control signal, and the camera ( And a switch 46 for connecting the video signal from 16 to the monitor 14.

Looking at the signal selector 20 configured as described above, it can be seen that the video signal output from the camera 16 is always connected to be supplied to the monitor 18.

3 is a flowchart of a surveillance control using a video telephone according to the present invention, which encodes and decodes an image signal input when the surveillance mode is set, and estimates a motion vector using the current image signal and the decoded previous input image. And extracting a motion vector value by accumulating a motion vector for one screen, comparing the extracted motion vector S with a preset reference vector Sref, determining whether the motion is performed, and driving an alarm. And controlling to record the monitored video signal.

Hereinafter, an example of an operation according to the present invention will be described in detail with reference to the above-described drawings.

Now, when the user sets the monitoring mode in step 50 of FIG. 3 to monitor the surrounding environment by using the external camera 16, the control unit 30 selects a monitoring mode signal of logic “high” as a signal selector. Inputs to the control terminals of the switches 42, 44, and 46 in (20), respectively. The switches 42, 44 and 46 are then switched in response to the input of a logic "high" control signal. That is, the common terminal COM of the switches 42, 44, 46 is switched from the normal cloth terminal NC to the normal open terminal NO by a control signal of logic “high”. The video signal output from the external camera 16 by the above operation is input to the monitor 18 and supplied to the hysteresis terminal of the video codec 24 through the switch 42. It is also supplied to the monitor 14 of the video telephone via the switch 46.

Therefore, when the user inputs a monitoring mode signal (Mode), the surveillance video signal output from the camera 16 installed outside is an external monitor 18 (where the external monitor refers to a monitor separate from the video telephone). Is displayed at the same time and is supplied to the video codec 24 and the monitor 14 in the video telephone 22.

In this case, the video codec 24 displays an external video signal input through the switch 42, that is, the video signal output from the external camera 16, in units of a display screen, that is, in units of frames or fields. Encoding and decoding in the process. In addition, the video codec 24 estimates a motion vector Vi for each block by using a previous image and a current image decoded after being hatched in step 54 of FIG. 3.

In this case, the video codec 24 displays an external video signal input through the switch 42, that is, the video signal output from the external camera 16, in units of a display screen, that is, in units of frames or fields. Encoding and decoding in the process. In addition, the video codec 24 estimates a motion vector Vi for each block by using a previous image and a current image decoded after being hatched in step 54 of FIG. 3.

As described above, a technique for calculating a motion vector value for each block by using a current input image and a previously inputted image signal is disclosed in US Patent No. 5,173,772 filed and filed by the applicant of the US Patent and Trademark Office. ) (Hereinafter referred to as prior patent) can be used.

The foregoing patent describes a method of calculating a motion amount of a video signal for each block by dividing a previous video into a predetermined size by a block matching algorihtm (BMA), and dividing the current video into a predetermined size.

The video codec 24 which estimates the motion vector Vi for each block (where I is a natural number rather than “0”) using the previous image and the current image in step 54 of FIG. 3. In step 56, the sum Vi of the motion vector estimated for each block is accumulated to obtain a sum S of the motion vector of the currently input video signal, that is, the video vector of the frame or field.

In step 58, the video codec 24 performs a search for whether the estimation of the motion vector corresponding to the number of blocks of one frame or field is completed. If the detection of the motion vector corresponding to the number of blocks of one screen is not completed in step 58, the process after step 52 is repeated. If the detection of the motion vector corresponding to the number of blocks of one screen is completed, the video codec 24 outputs the cumulative motion vector value “S” of the current screen to the comparator 32 in step 60.

The comparison unit 32 compares the preset reference vector value Sref with the cumulatively added motion detection vector value S. FIG. The reference vector value Sref is a value obtained by averaging motion vectors of various screens output in units of frames from an external camera photographing a background with no motion. The reason for obtaining the reference vector Sref is to prevent malfunctions caused by external noise caused by external noise despite the fact that there is no movement.

When the motion vector value S currently detected in the comparison state does not exceed the preset reference vector value Sref, the comparator 32 transmits a logic "low" phase state signal to the alarm unit 34. Output to the recording unit 46. The alarm unit 34 and the recording unit 36 which input the steady state signal do not operate.

If the motion vector value S currently detected in the above-described comparison state exceeds the preset reference vector value Sref, the comparison unit 32 transmits a logic “high” motion detection signal to the alarm unit 34. Output to the recording unit 46. The alarm unit 34 generates an alarm sound in step 64 of FIG. 3 in response to the input of the motion detection signal, and the recording unit 36 processes an image signal output from an external camera 16 in step 64 of FIG. Record on the internal recording medium.

As described above, the automatic monitoring device of the present invention combined with a video phone extracts a motion vector using a previous image and a current image in a surveillance mode, and automatically generates an alarm when the movement degree is greater than a preset reference vector. At the same time, the recording is performed only when there is a moving object in the surveillance area. Therefore, it is possible to monitor a specific area for a long time with a small amount of recording medium.

On the other hand, when the call mode is switched during the operation in the monitoring mode as described above, the control signal of the logic "low" is input to the control terminal of the signal selector 20. Switching of call mode is divided into switching by user selection and switching by external call.

When the user switches to the call mode, the controller 30 outputs a call mode control signal of logic “low” to the control terminal of the signal selector 20. If there is a call from the outside, the network matching unit 26 detects this and inputs a call detection signal of logic “low” into the control terminal of the signal selector 20.

Therefore, when the call mode is switched by the above operation, a control signal of logic “low” is input to the control terminal of the signal selector 20. At this time, a control signal of logic “low” input to the control terminal of the signal selector 20 is input to the control terminal of the switches 42, 44, and 46.

The switches 42, 44 and 46 are switched in response to the input of a logic "low" control signal. In other words, the common terminal COM of the switches 42, 44, 46 is switched from the normal open terminal NO to the close terminal NC by a logic "low" control signal.

The video signal output from the external camera 16 is input only to the monitor 18 by the switching operation as described above, and the video signal output from the camera 12 of the video telephone is input to the input terminal of the video codec 24. The received video signal output from the output terminal of the video codec 24 is input to the monitor 14 of the video telephone.

At this time, the video codec 24 codes the video signal of the video camera 12 of the video telephone via the switch 42 according to the CCITT recommendation described above and outputs it to the network splicing unit 26. The voice codec 28 encodes a voice signal input from the telephone and outputs the voice signal to the network junction unit 26. The network junction unit 26 multiplexes the video signal and the audio signal input from the video codec 24 and the audio codec 28 and transmits the multiplexed video signal to the counterpart.

Meanwhile, the network matching unit 26 demultiplexes the video signal and the audio signal which are multiplexed and transmitted from the other party, and outputs the video signal to the video codec 24, and supplies the audio signal to the voice codec 28. The video codec 24 decodes an input video signal and outputs the same to the monitor 14 through the switch 44. Then, the voice codec 28 decodes the input coded and input voice signal and inputs it to the voice call circuit of the telephone.

Therefore, when the call mode is switched, the automatic monitoring device according to the present invention automatically transitions to the call mode with the other party. This call mode is the same as that of the general video telephone.

As described above, the present invention records the monitored video only when there is a movement of the surveillance area by using the motion detection of the video phone, and generates an alarm corresponding thereto, thereby more accurately performing unmanned surveillance, and making a call using the video phone. And the monitoring system can be simply configured as one system.

Claims (6)

An automatic monitoring device having a camera and a monitor for displaying a video signal output from the camera, the automatic monitoring device comprising: comparing a video signal input with a video signal on a previous display screen to detect a motion vector and simultaneously detecting a motion vector; A video telephone that encodes a signal and transmits it to the other party, and outputs a received video signal, and selects a signal for switching a video signal output from the camera to an input terminal of the video telephone by switching in response to an input of a control signal in a surveillance mode. Means and a surveillance image recording means for recording an image signal output from the camera on a recording medium and generating an alarm at a time when the motion vector output from the video telephone is larger than a preset reference vector. Auto Surveillance Using Video Phone Value. The video telephone camera of claim 1, further comprising a video telephone camera for capturing an image of a subject and outputting a video signal in response to an input of a call mode signal, and a video telephone monitor for displaying a video signal output from the video telephone. Automatic surveillance device using video phone. 3. The apparatus of claim 2, wherein the signal selecting means supplies a video signal output from the video telephone camera to an input terminal of the video telephone in response to the input of a call mode signal and simultaneously outputs a video signal output from the video telephone. It is provided as a video telephone monitor, switching in response to the input of the monitoring mode signal, the automatic monitoring device using a video telephone, characterized in that to select the video signal output from the camera and to supply to the input terminal of the video telephone. A camera, a monitor displaying a video signal output from the camera, and an input video signal are compared with a video signal of a previous display screen to detect a motion vector and simultaneously encode a video signal from which a motion is detected and transmit the encoded video signal to a counterpart. In the automatic monitoring method comprising a video telephone for outputting the received video signal, a motion vector for extracting a motion vector for the video signal by comparing the input video signal with a previous video signal in response to the monitoring mode signal; And a surveillance image recording process of comparing the extracted motion vector with a preset reference motion vector and recording the input video signal on a recording medium in response to the extracted motion vector exceeding the reference motion vector. Surveillance method using video phone characterized by the baggage. The method of claim 4, wherein the moving vector extraction process comprises: a screen block division process of dividing the input video signal into blocks having a predetermined pixel size, and a block of dividing the current video signal and the previously input image by the block. An automatic monitoring method using a video telephone comprising a process of extracting a motion vector for each block of a display video signal by comparison and extracting the motion vectors for each block. 6. The method according to claim 4 or 5, further comprising an alarm generating step of generating an alarm in response to the motion vector exceeding the reference motion vector.