KR970008283B1 - Method and scene recording system for closed circuit television - Google Patents

Abstract

A CCTV and method using the monitoring camera where record the necessary part because to detecting the moving of the image signal. The said CCTV consists of a memory for storing the image source by the frame during the frame period, and a moving detecting means for detecting the moving vector according to the data of the frame and controlling the recording situation according to the comparing the detected moving vector with the reference value.

Description

Recording device (CCTV) and method using surveillance camera

1 is a recording device (CCTV; Camera Cable Television) using a conventional surveillance camera.

2 is a recording device using a surveillance camera according to the present invention.

* Explanation of symbols for main parts of the drawings

10: camera 20: recorder

30: timer 40: memory

50: threshold input unit 60: motion detection unit

The present invention relates to a recording apparatus and method using a surveillance camera, and more particularly to a recording apparatus and method using a surveillance camera for efficiently recording only the necessary portion.

The recording device using the surveillance camera is generally called CCTV (Closed Circuit Television). Until now, the recording device has handled a large amount of recording by intermittently recording by using a timer.

Referring to Figure 1 in more detail, by measuring the time in the timer 30, the video signal applied through the camera 10 by repeatedly turning on the recorder 20 for a predetermined time and off again for a predetermined time It was controlled to record.

However, in this case, since the video signal is simply recorded every predetermined time, there may be a problem in which a part that may not be actually recorded or a part that is not necessary may be recorded.

Accordingly, an object of the present invention is to provide a recording apparatus and method using a surveillance camera for controlling the recording state by detecting the movement of the video signal applied through the camera in order to solve the above problems.

In order to achieve the above object, the present invention provides a recording apparatus comprising an input source source for converting and outputting a video signal applied from the outside into an electrical signal, and a recorder for recording a video signal provided from the input source source; A memory unit for storing a video signal output from an input source source frame by frame for a predetermined frame period; And a motion detection unit for detecting a motion amount through the frame unit data output from the memory unit, comparing the detected motion amount with a predetermined reference value, and detecting a motion degree to control the recording state of the recorder.

In order to achieve the above object, the present invention provides a video recording method comprising the steps of recording, when the video signal applied from the outside is converted into an electrical signal; A storage step of storing the video signal converted into an electric signal in units of frames for a predetermined frame period; A motion amount detecting step of detecting a motion amount by using the image signal stored in units of frames when the storing is completed by the storing process; A motion degree detecting process of detecting a motion degree by comparing with a predetermined reference value when the motion amount is detected; It characterized in that it comprises a recording control process for controlling the process of recording in accordance with the detected degree of motion.

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

2 is a diagram of a recording apparatus using a surveillance camera according to the present invention, in which a camera 10 converts an external video signal into an electrical signal and provides the same, and data output from the camera 10 is framed for a predetermined frame period. A memory unit 40 for storing data, a recorder 20 for recording data output from the memory 40, a threshold providing unit 50 for providing a predetermined threshold as a reference value for determining the degree of movement, and a memory. Motion detection unit for detecting the degree of motion by using a plurality of video signals in the frame unit output from the unit 40 and the threshold provided by the threshold providing unit 50 and controlling the recording state of the recorder 2 based on the detection result It consists of 60.

In particular, the memory unit 40 includes N frame units of memory (first to N frame memories 41 to 43) corresponding to a predetermined frame period.

The operation of FIG. 2 will now be described in detail.

When a predetermined video signal is applied through the camera 10 as an input source, the memory unit 40 stores the memory using a separate memory in units of one frame. That is, it is stored in the frame memory of the corresponding order among the first to N frame memories 41 to 43 in the order of the applied frames. When data is stored in all of the first to N frame memories 41 to 43, the data is applied to the motion detection unit 60.

In the motion detection unit 60, there are various methods for detecting motion as a part for detecting motion. Two examples are, first, a method of using a frame difference, and another method of using a motion vector.

A method of using the frame difference is as follows. The N frame data applied from the memory unit 40 is subtracted by the unit of 2 frames as shown in the following formula (1).

Where x is the x coordinate of the screen, y is the y coordinate of the screen, F1 (x, y) is the pixel value stored in the first frame memory 41, and F2 (x, y) is the second frame memory. Using the pixel values stored in 42, the respective differences are obtained, and the obtained values are taken as absolute values. The same applies to the pixel values stored in the next frame memory. That is, the difference between the pixel value stored in the second frame memory 42 and the pixel value stored in the third frame memory 42 (not shown) is obtained as shown in Equation (1), and the first to N frame memories (not shown). The difference value is obtained by using the same method for the pixel value stored in the N-th memory and the pixel value stored in the N-th frame memory.

Then, the average value of the obtained difference value is compared with a predetermined threshold value stored in the threshold providing unit 50 in advance. In this case, the threshold value is t, and when the detected average value is D, the degree of movement is determined as shown in Table 1 below.

TABLE 1

When the motion degree is detected by the motion detection unit 60 by the above-described method, the recording state of the video recorder 20 is controlled on / off by the determination as shown in [Table 1].

The motion detector 60 may detect the motion degree by the frame difference as described above, but may also detect the motion degree by using the motion vector.

This is because a motion vector represents a distance and a direction in which an object moves. Detection of the motion vector value is also detected by comparing the frame memories output from the first to N frame memories 41 to 43 in the memory unit 40, respectively. The motion vector value is detected based on the correlation between the previous frame data and the current frame memory, as in the method of motion estimation detection in a moving picture encoding apparatus. The motion vector value detected using two frames takes an absolute value like a frame difference value, detects an average value, and determines the degree of motion as shown in [Table 2] at a predetermined threshold t provided from the threshold value providing unit 50. do.

TABLE 2

The motion detection unit 60 continuously performs the motion detection operation in units of one frame except when the first N frame memory is applied, thereby controlling the on / off period of the recorder 20.

As described above, the present invention stores the video signal applied in the recording apparatus and method using the surveillance camera in units of frames, and detects the difference in motion by detecting the frame difference or the motion vector by using the stored frame memory to detect the degree of motion recording. By controlling the state, recording is performed in a large amount of motion, so that the recording can be adaptively performed for the surrounding environment.

Claims (11)

A recording apparatus comprising: an input source source for converting and outputting an image signal applied from the outside into an electrical signal; and a recorder for recording a video signal provided from the input source source; A memory unit for storing the video signal output from the input source source in units of frames for a predetermined frame period; And a motion detector for detecting a motion amount through the frame unit data output from the memory unit, and detecting a motion degree by comparing the detected motion amount with a predetermined reference value to control the recording state of the recorder. Recording device using a surveillance camera. The apparatus of claim 1, wherein the motion detector detects a frame difference with respect to data output from the memory unit in units of frames to detect the movement amount. The recording using a surveillance camera according to claim 2, wherein the motion detection unit detects the motion degree by comparing the average value detected for the predetermined frame period with the predetermined reference value using the frame differences. Device. The apparatus of claim 1, wherein the motion detector detects a motion vector with respect to data output from the memory unit in units of frames, and detects the motion amount. The surveillance camera of claim 4, wherein the motion detection unit detects the motion degree by comparing an average value detected for the predetermined frame period with the predetermined reference value using absolute values of the motion vector. Recording device using. The motion detection unit of claim 3 or 5, wherein the motion detection unit controls the recording state so that the recorder performs a recording mode when the motion degree is greater than the predetermined reference value, and the motion degree is equal to the predetermined reference value. Or the control unit controls the recording state so that the recorder does not perform the recording mode. The recording apparatus according to claim 1, wherein the memory unit has a memory corresponding to the predetermined frame period in order to store image signals provided from the input source source in units of frames. The apparatus of claim 1, wherein the recording apparatus further comprises a threshold providing unit for providing the predetermined reference value used in the motion detection unit. In the recording method comprising the step of recording when the video signal applied from the outside is converted into an electrical signal; A storage step of storing the video signal converted into the electric signal in units of frames for a predetermined frame period; A motion amount detecting step of detecting a motion amount by using the image signal stored in the frame unit when the storing is completed by the storing process; A motion degree detection process of detecting a motion degree by comparing with a predetermined reference value when the motion amount is detected; And a recording control process for controlling the recording process according to the detected degree of movement. 10. The method of claim 9, wherein the detecting of the motion amount detects the motion amount by using a frame difference with respect to the video signal stored in the frame unit. The method of claim 9, wherein the detecting of the motion amount detects the motion amount by using a motion vector of an image signal stored in the frame unit.