KR100460959B1 - CCTV system having function motion detection and method for motion detection thereof - Google Patents

Abstract

Disclosed are a surveillance system capable of searching for a motion and a search method thereof. An ADC for converting an analog video signal for a surveillance area captured by a camera into a digital video signal, a compression unit for compressing the converted digital video signal into a predetermined compression format, a recording unit for recording the compressed digital video signal, and recording A decompression unit for decompressing the digital video signal, and a search area when a search area setting signal is received from the area setting key and the area setting key for setting at least one motion search area among the surveillance areas displayed on the display device. And determining a plurality of macroblocks, and controlling the recording unit to output digital image signals for the determined plurality of macroblocks to the decompression unit, wherein the decompression unit includes motion vectors for each of the plurality of macroblocks output from the recording unit. To detect whether the motion. Therefore, when searching the motion of the compressed video signal, a predetermined search area is set, and then a motion search is performed by extracting a motion vector for a macroblock including the set search area, thereby performing a fast motion search without additional equipment. It is possible.

Description

Surveillance system capable of motion search and search method thereof {CCTV system having function motion detection and method for motion detection}

The present invention relates to a surveillance system capable of searching for a motion and a search method thereof. More particularly, the present invention relates to a macroblock including a search area set after setting a predetermined search area when searching for motion of a compressed video signal. The present invention relates to a surveillance system for performing a motion search by extracting a motion vector and a search method thereof.

Next-generation closed-circuit TV (CCTV) surveillance system records the video signal for the surveillance area from at least one CCD (Charge Coupled Devices) camera in the recorder and then plays back the recorded video signal. It is a monitoring system that displays through a display device, and is installed at a predetermined place so that the user can grasp the abnormality of the monitoring place by recording and reproducing the surrounding situation.

An example of such a CCTV surveillance system is a VCR (Video Cassette Recorder) surveillance system and a DVR (Digital Video Recording) surveillance system.

The VCR surveillance system uses an analog video signal input from the camera to record on a magnetic tape. In the VCR surveillance system, it is difficult to record a video signal for a long time due to the narrow recording capacity of the magnetic tape, and the video signal recorded on the magnetic tape easily causes deterioration of image quality due to repeated recording / reproducing.

On the other hand, the DVR surveillance system converts the video signal input from the camera into a digital signal and uses a method of locking the hard disk drive (hereinafter referred to as "HDD") or DVR-RAM. The DVR surveillance system records a video signal in real time using a large-capacity recording unit such as an HDD, and also compresses the video signal into a digital signal so that a large amount of video signal can be recorded for a long time without deterioration in quality compared to a VCR surveillance system. It is possible to play / play.

The DVR surveillance system is capable of high-speed search compared to the method of rewinding the magnetic tape in the VCR surveillance system to search the recorded video signal.

However, in the conventional DVR surveillance system, if a video signal recorded in real time on a recording medium such as an HDD is to be searched, it requires a lot of time since all the recorded video signals must be sequentially searched from the beginning by one frame unit. have. For example, when searching for 24 hours of video recorded in the HDD, since the recorded video signal must be reproduced from the beginning until the desired video is displayed on the display device, a lot of time is required when searching for the video signal.

In addition, in order to solve this problem, the conventional DVR surveillance system has a high speed search function such as 2x / 4x speed. For example, when searching for 24 hours of recorded video on the HDD, it takes up to 12 hours of search time using the 2x speed search function, and up to 6 hours of search time using the 4x speed search function. Thus, the total search time is shortened. However, the high speed search function has a problem that it is difficult to accurately identify a specific motion or a specific event for searching as the search speed increases.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a surveillance system capable of retrieving a motion that can shorten a motion retrieval time of a video signal required to retrieve a recorded video signal, and a retrieval method thereof.

1 is a block diagram schematically showing a surveillance system capable of searching for a motion according to a preferred embodiment of the present invention;

FIG. 2 is a diagram illustrating an embodiment of a search region set among images displayed on a display device connected to the surveillance system of FIG. 1;

3 is a block diagram illustrating a decompression unit provided in FIG. 2;

4A and 4B are diagrams illustrating absolute values of a motion vector and a displacement of a plurality of macroblocks including a search region set in FIG. 2, and

FIG. 5 is a flowchart illustrating a motion searching method of the surveillance system shown in FIG. 1.

Description of the main parts of the drawing

100: monitoring system 110a: area setting key

150: recording unit 160: decompression unit

162: motion vector detector 164: calculator

166: motion determination unit 168: image restoration unit

180: control unit 200: search area

250: multiple macroblocks

In order to solve the above technical problem, a surveillance system according to the present invention, the analog / digital conversion unit for converting an analog video signal for the surveillance region captured by at least one camera into a digital video signal, and the converted digital A compression unit for compressing the video signal into a predetermined compression format, a recording unit for recording the compressed digital video signal, a decompression unit for decompressing the recorded digital video signal, and the surveillance area displayed on the display device. An area setting key for setting at least one motion search area, and a plurality of macro blocks including the search area are determined after receiving the search area setting signal from the area setting key, and then the plurality of macro blocks for the determined plurality of macro blocks are determined. And a control unit controlling the recording unit to output a digital video signal to the decompression unit. It said, the decompression unit to detect a motion vector for each of the plurality of macroblocks outputted from the recording unit determines whether the motion.

In more detail, the decompression unit may include a motion vector detector for detecting a motion vector for each macroblock from the digital video signal for each macroblock output from the recording unit, and the detected motion vector for each macroblock. And a calculation unit for calculating an absolute value of the movement displacement with respect to a macroblock in which the absolute value of the movement displacement is greater than the threshold value by comparing the calculated absolute value of each movement displacement with a preset threshold value. And a video restoring unit for restoring a digital video signal for the plurality of macroblocks including the motion determining unit for determining that there is a motion and the macroblock for determining that there is a motion, and wherein the control unit restores the restored video from the video restoring unit. A digital video signal is output to the display device.

Further, the calculating section calculates the absolute value of the movement displacement by the following.

Here, A is the horizontal movement amount of the motion vector, B is the vertical movement amount of the motion vector.

The apparatus may further include a digital / analog converter for converting the decompressed digital video signal into the analog video signal.

On the other hand, in order to solve the technical problem as described above, to convert the analog video signal for the surveillance region captured by the at least one camera according to the present invention into a digital video signal and to compress it into a predetermined format to record in the recording unit of the A motion search method, comprising: setting at least one motion search area of the surveillance areas displayed on a display device; and when the search area is set, determining the plurality of macroblocks including the search area and determining the plurality of motion search areas. And outputting a digital video signal for a macroblock of a from the recording unit, and determining whether to move by detecting a motion vector from the digital video signal for each of the plurality of output macroblocks.

In more detail, the motion determination step may include detecting the motion vector from the digital video signal for each of the macroblocks output, and calculating an absolute value of the movement displacement for each detected motion vector. And comparing the calculated absolute value of each of the movement displacements with a predetermined threshold value and determining that there is motion for a macroblock in which the absolute value of the movement displacement is larger than the threshold value. Restoring the digital image signals for the plurality of macroblocks including the macroblocks determined to be present, and outputting the digital image signals for the plurality of restored macroblocks to the display device.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

1 is a block diagram schematically illustrating a surveillance system capable of searching for a motion in accordance with a preferred embodiment of the present invention.

Referring to FIG. 1, the monitoring system 100 capable of searching for motion according to the present invention includes a key manipulation unit 110, a search region storage unit 120, an image signal input unit 125, and an analog / digital conversion unit. Converter (hereinafter referred to as " ADC ") 130, compression section 140, recording section 150, decompression section 160, and digital / analog converter (hereinafter referred to as " DAC ") 170, an image signal output unit 175, a controller 180, and a backup unit 190.

Key operation unit 110 is an operation key (not shown) consisting of a plurality of numeric keys, direction keys, function keys, etc. to output a signal for setting or operating a function supported by the monitoring system 100 to the controller 180 to be described later Is provided, and is provided in the main body of the monitoring system 100.

In the present invention, the key operation unit 110 is provided with an area setting key 110a for transmitting the search area setting mode selection signal to the control unit 180. The retrieval area setting mode selects a motion retrieval area (indicated by a dotted line) among the surveillance areas captured by the camera and displayed on the display device by the user to reselect or manipulate the area setting key 110a (not shown). Mode) can be set using at least one.

As shown in FIG. 2, when the surveillance area, that is, the image is displayed, when the region setting key 110a is selected, a keypoint image (not shown) such as an arrow is overlapped and displayed at a predetermined position of the image. The user selects at least one predetermined search area (shown by a dotted line) by moving and / or dragging a keypoint image (not shown) by using a reselection or manipulation key (not shown) of the area setting key 110a. Can be set.

When at least one search area 200 is set, a plurality of macroblocks (macroblocks in a thick solid line) 250 including the set search area 200 are determined by the controller 180 to be described later to store the search area. It is stored in the unit 120.

In addition, when a keypad (not shown) or a joystick (not shown) is applied to the key manipulation unit 110, a user for receiving a signal output from the keypad (not shown) or the joystick (not shown) is applied to the monitoring system 100. It is preferable that an interface unit (not shown) is provided.

The video signal input unit 125 receives an analog video signal for the surveillance region captured by the at least one camera in a wired or wireless manner and outputs the analog video signal to the ADC 130. When the cable is connected to the camera, the image signal input unit 125 preferably has at least one input terminal in order to receive the image signal photographed from the at least one camera.

The ADC 130 converts an analog video signal output from the video signal input unit 125 into a digital video signal and outputs the digital video signal.

The compression unit 140 controls the digital image signal output from the ADC 130 by a control of the control unit 180 connected by the bus BUS to a predetermined format such as MPEG-2 (MPEG2: Motion Pictures Experts Group-2). To compress.

The recording unit 150 uses a medium capable of high-capacity recording, and in the present invention, it is preferable to use an HDD. In the recording unit 150, the digital image signal output from the image compression unit 140 is divided into predetermined standards such as camera, date, and time, and recorded as a file.

The decompression unit 160 decompresses and outputs the digital video signal recorded in the recording unit 150 under the control of the controller 180 connected by the bus BUS.

In addition, in the present invention, after the search area setting mode is selected from the area setting key 110a of the key operation unit 110, at least one search area 200 is controlled by an operation key (not shown) of the key operation unit 110. When this is set, the decompressor 160 may decode the search region (eg, the digital image signal) of the plurality of macroblocks 250 including the search region 200 as shown in FIG. 2 from the recorder 150. Search for movement.

In order to check the movement of the set search area, the decompressor 160 may include a motion vector detector 162, a calculator 164, a motion determiner 166, and an image restorer as illustrated in FIG. 3. 168).

The motion vector detector 162 detects a motion vector for each macroblock from the digital image signal for each of the macroblocks 250 output from the recorder 150.

The calculator 164 calculates the absolute value of the movement displacement for each detected motion vector by using Equation 1 or Equation 2 below.

In Equations 1 and 2, A represents the horizontal movement amount of the motion vector, B represents the vertical movement amount of the motion vector, and Equation 1 compares the absolute values of A and B to obtain a larger value. The absolute value is calculated as the absolute value of the displacement.

If the motion vectors for the plurality of macroblocks 250 shown in FIG. 2 are the same as, for example, FIG. 4A, the movement displacement calculated by Equation 1 is the same as FIG. 4B.

Referring to FIG. 4A, (1, -2) means that the horizontal direction is moved by 1 and the vertical direction by -2. Substituting this in Equation 1, the absolute value of the displacement is calculated as follows.

In other words, it can be seen that the absolute value of the motion displacement of the motion vector for (1, -2) is 2, and the absolute value of the motion displacement for the other motion vectors is also calculated by the above-described method.

The motion determining unit 166 compares the absolute value of each movement displacement calculated by Equation 1 with a preset threshold to determine whether the motion is performed for each macroblock. In detail, the motion determining unit 166 determines that there is motion with respect to a macroblock in which the absolute value of the calculated movement displacement is equal to or larger than a predetermined threshold value. On the other hand, if the absolute value of the calculated displacement is less than the predetermined threshold, it is determined that there is no motion or insignificant motion.

Referring to FIG. 3B, when the threshold value is set to '2', the motion determination unit 166 determines that there is motion with respect to a macroblock (shown by diagonal lines) that is greater than or equal to the threshold value '2'.

The image restorer 168 restores the digital image signals for the plurality of macroblocks 250 including the macroblocks (shown in diagonal lines) that are determined to be in motion.

The DAC 170 converts the decompressed digital video signal by the decompressor 160 into an analog video signal. In particular, when the plurality of macroblocks 250 having motion are determined by the motion determining unit 166 and the digital image signals for the plurality of macroblocks 250 are restored from the image restoring unit 168, the DAC 170 may be restored. ) Converts the output digital video signal into an analog video signal.

The video signal output unit 175 provides an analog video signal output from the DAC 170 to a display device connected to the surveillance system 100. Here, when the display device connected to the monitoring system 100 is a digital display device, the monitoring system 100 provides a digital video signal to the digital display device without analog conversion of the decompressed video signal.

Thus, the user monitors the image output through the display device to determine whether there is an abnormality in the place where the camera is installed. In particular, when searching for an image recorded in the recording unit 150, it is possible to search at high speed by setting the search area 200 by the area setting key 110a to display only the area where the motion is detected on the display device.

The controller 180 controls the overall operation of the monitoring system 100 according to a control program previously stored in a storage unit (not shown). In particular, the controller 180 controls the recording unit 150 to classify the compressed digital image signal for each camera and record the recorded digital image signal in the recording unit 150.

In addition, the controller 180 stores the digital video signal recorded in the recording unit 150 as backup data in the backup unit 190. The backup unit 190 is a backup device that backs up data such as a digital audio tape, a compact disk, or the like.

In addition, when at least one search area 200 is set after the search area setting mode selection signal is received from the area setting key 110a, the controller 180 includes a plurality of macroblocks 250 including the search area 200. Is determined. In addition, the controller 180 allows the determined plurality of macroblocks 250 to be stored in the search region storage unit 120 and controls the decompressor 160 to search for movement of the plurality of macroblocks 250. Do it.

FIG. 5 is a flowchart illustrating a motion searching method of the surveillance system shown in FIG. 1.

1 to 5, when an image of the surveillance area 200 recorded in the recording unit 150 is displayed on the display device, the search area setting mode is selected by the area setting key 110a (S500). ), When at least one search area is set as shown in FIG. 2 by reselection of the area setting key 110a or an operation key (not shown) (S510), the controller 180 includes the set search area 200. A plurality of macroblocks 250 are determined and processed to be stored in the search region storage 120 (S520).

After operation S520, the controller 180 outputs the digital image signals for the plurality of macroblocks 250 stored in the search region storage 120 to the motion vector detector 162 of the decompressor 160. ).

In detail, the motion vector detector 162 detects a motion vector for each macroblock from the digital image signal for each of the macroblocks 250 output from the recording unit 150 (S530).

When the step S530 is performed, the calculation unit 164 calculates the absolute value of the movement displacement for each detected motion vector using Equation 1 or Equation 2 above (S540) and determines the motion. The unit 166 compares the absolute value of the movement displacement calculated in operation S550 with a preset threshold value and determines whether the macroblock moves for each macroblock (S550).

When the motion is detected for the predetermined macroblock in step S550, the image restorer 168 restores and outputs the plurality of macroblocks 250 including the macroblock determined to be in motion (S560).

When the monitoring system 100 and the analog display device are connected, the digital video signal restored in step S560 is converted into an analog video signal by the DAC 170 and provided to the analog display device through the video signal output unit 175 (S570). ).

On the other hand, if the search area setting mode is not selected in step S500, the controller 180 executes a search routine in the general search mode to sequentially search for a file for searching recorded in the recording unit 150 from the beginning (S580).

In addition, when a motion is detected for a predetermined macroblock in step S550, the controller 180 processes the digital video signal restored in step S560 to be temporarily stored in a backup or a buffer (not shown). This is useful for displaying on the display without re-executing steps S530 to S570 when a plurality of areas where motion is detected is to be repeatedly displayed on the display device.

Although the present invention has been described in detail with reference to the exemplary embodiments above, those skilled in the art will understand that various modifications are possible within the scope of the present invention without departing from the scope of the present invention. will be. Therefore, the scope of the present invention should not be limited to the embodiments described, but should be defined by the claims below and equivalents thereof.

As described so far, according to the surveillance system capable of searching for motion and its search method, after setting at least one predetermined search area out of all surveillance areas captured by the camera when searching for motion of the compressed video signal, In the process of decompressing the macroblock including the set search region, the motion vector for each of the macroblocks is detected and the motion is searched to search for the motion at high speed without providing a separate device. That is, the motion search time can be shortened by performing the motion search only on the search area requiring the motion search, not the entire monitoring area.

Claims (7)

An analog / digital converter for converting an analog video signal for a surveillance region captured by at least one camera into a digital video signal; A compression unit which compresses the converted digital video signal into a predetermined compression format; A recording unit to record the compressed digital video signal; A decompression unit for decompressing the recorded digital video signal; An area setting key for setting at least one motion search area among the surveillance areas displayed on the display device; And When the search area setting signal is received from the area setting key, a plurality of macro blocks including the search area are determined, and then the recording unit is controlled to output digital image signals for the determined plurality of macro blocks to the decompressor. A control unit; And the decompression unit detects a motion vector for each of the plurality of macroblocks output from the recording unit, and determines whether to move. The method of claim 1, The decompression unit, A motion vector detector for detecting a motion vector for each macroblock from the digital video signal for each macroblock output from the recording unit; A calculation unit for calculating an absolute value of the movement displacement for each detected motion vector; A motion determination unit for comparing the calculated absolute value of each of the movement displacements with a preset threshold value and determining that there is motion for a macroblock in which the absolute value of the movement displacement is larger than the threshold value; And And an image restoring unit for restoring digital video signals for the plurality of macro blocks including the macro blocks determined to have the movement. And the controller processes the digital video signal restored from the video restorer to be output to the display device. The method of claim 2, And the calculating unit calculates an absolute value of the movement displacement by: Here, A is the horizontal movement amount of the motion vector, B is the vertical movement amount of the motion vector. The method of claim 1, And a digital / analog converter for converting the digital video signal decompressed from the compression unit into the analog video signal. A motion retrieval method of a surveillance system, which converts an analog video signal for a surveillance area captured by at least one camera into a digital video signal, and then compresses the analog video signal into a predetermined format and records it in a recording unit. Setting at least one motion search region among the surveillance regions displayed on the display device; If the search area is set, determining a plurality of macroblocks including the search area and outputting digital image signals for the plurality of macroblocks determined from the recording unit; And And detecting a motion vector from the digital video signal for each of the plurality of macroblocks to be output. The method of claim 5, The determining whether the motion is, Detecting the motion vector from the digital video signal for each of the macroblocks being output; Calculating an absolute value of the movement displacement for each detected motion vector; Comparing the calculated absolute value of each of the movement displacements with a predetermined threshold value and determining that there is motion for a macroblock in which the absolute value of the movement displacement is larger than the threshold value; Restoring digital image signals for the plurality of macroblocks including the macroblocks determined to have movement; And And outputting the digital image signals for the plurality of restored macroblocks to the display device. The method of claim 6, Wherein said calculating step calculates an absolute value of said movement displacement by: Here, A is the horizontal movement amount of the motion vector, B is the vertical movement amount of the motion vector.