KR19990024398A - How to control the recording interval of Time Lapse VR - Google Patents

Abstract

According to the present invention, in a time-lapse VCR in which inputs from one or more video cameras can be sequentially switched to record for a long time, more effective image information can be obtained by shortening the recording interval in proportion to the number of detected video signals. It relates to a recording interval control method of a time-lapse VCR. The recording interval control method of the time-lapse VCR of the present invention includes a motion detection unit, the recording interval control method of the time-lapse VCR of the CCTV system for sequentially recording the video signal provided from at least one or more video cameras while recording and stopping A method comprising: (a) determining whether motion is detected in a video signal input from the video camera; If the motion is detected in the step (a), checking the number of video signals from which the motion is detected; (c) shortening the recording time interval to a preset value in proportion to the number of video signals identified in step (b) to perform recording; And (d) when the motion is not detected in step (a), recording the video at a preset time interval.

Description

How to control the recording interval of Time Lapse VR

The present invention relates to a method of controlling the recording interval of a time-lapse VCR. In particular, when motion is detected on a subject captured by a time-lapse VCR applied to a closed-circuit television system, the monitoring efficiency can be increased by automatically shortening the recording interval. It relates to a recording interval control method of a VCR.

As is well known, Closed Circuit Tele-Vision (hereinafter referred to as CCTV) systems include one or more video cameras that capture surveillance objects, monitors that output video from video cameras, and video cameras. It is composed of a VCR for recording the image captured by the video to be reproduced later. These CCTV systems are currently used for surveillance in banks and factories, and are installed in major intersections to identify traffic conditions.

On the other hand, CCTV systems record the subject to be monitored by one or more cameras, and then record it on a VCR. In order to reduce the amount of tape required for recording, a so-called time-lapse VCR is adopted. Time Lapse VCR does not record multiple video signals from one or more video cameras continuously for the purpose of surveillance recording. Instead, it records and stops at regular intervals. do. For example, a signal input from one video camera can be recorded continuously for 3840 hours by recording one field every four seconds with the VHS 60T tape doubled recording mode, and for 480 hours for eight cameras. It becomes possible.

On the other hand, in a CCTV system employing such a time-lapse VCR, even if motion is detected by any one video camera, the recording efficiency is reduced when recording is performed in the manner described above. Therefore, in this case, weights are conventionally assigned by interposing a video signal from a video camera with motion between video signals without motion. In other words, in the above example, when motion is detected in a video signal input from one video camera, the video signal is recorded every 8 seconds, whereas in the case of a video signal where motion is not detected, every 56 seconds. Recording is performed in units. As a result, the control method of the time-lapse VCR according to the conventional motion detection has no change in the overall recording interval, so video signals from video cameras that have no movement or no motion is detected in the repetitive period of the motion detection circuit are recorded at a gradual period. As a result, there was a drawback in not being able to record a valid screen.

In addition, when only one camera signal is recorded by the time-lapse VCR, since the recording is performed at the same time interval regardless of the presence or absence of motion, there is a problem in that valid image information may be missed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and in a time-lapse VCR in which an input from one or more video cameras can be sequentially switched to record for a long time, the motion is recorded in proportion to the number of video signals detected. It is an object of the present invention to provide a method for controlling the recording interval of a time-lapse VCR in which more effective image information can be obtained by shortening the interval.

Automatic recording interval control method of the time-lapse VCR of the present invention for achieving the above object is a CCTV system having a movement detection unit, and sequentially recording the video signal provided from at least one video camera while repeating the recording and stop A method of controlling a recording interval of a time-lapse VCR of claim 1, comprising: (a) determining whether a motion is detected in a video signal input from the video camera; If the motion is detected in the step (a), checking the number of video signals from which the motion is detected; (c) shortening the recording time interval to a preset value in proportion to the number of video signals identified in step (b) to perform recording; And (d) if the motion is not detected in step (a), recording is performed at a predetermined time interval.

1 is a schematic block diagram of a CCTV system that can be applied to the recording interval control method of the time-lapse VCR of the present invention.

2 is a flowchart for explaining a recording interval control method of a time-lapse VCR according to the present invention.

Explanation of symbols for main parts of drawings

10,10a, 10b, ..., 10n: video camera,

20: matrix switch 30: image processing unit

40: time-lapse VCR 50: motion detection unit

60: control unit

Hereinafter, a recording interval control method of a time-lapse VCR according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic block diagram of a CCTV system to which the recording interval control method of a time-lapse VCR of the present invention can be applied. As shown in FIG. 1, a CCTV system to which the present invention can be applied can receive a video signal input in parallel on a field or frame basis from a video camera (10: 10a, 10b, ..., 10n) connected to a plurality of channels. A matrix switch 20 for multiplexing in series, a time-lapse VCR 40 for storing a plurality of video signals at predetermined time intervals, and a video signal in an analog form switched in units of fields or frames through the matrix switch 20 The image processing unit 30 converts the time-lapse VCR 40 into a signal suitable for recording, and a motion detection unit detecting the motion by comparing the previous and current video signals input at a predetermined time interval from the matrix switch 20. The controller 50 determines whether the motion is detected based on the data provided by the motion detection unit 50 and the motion detection unit 50. 30) and a controller 60 for controlling the time-lapse VCR 40 to shorten the recording time interval.

2 is a flowchart for explaining a recording interval control method of a time-lapse VCR according to the present invention. As shown in Fig. 2, in step S10, initialization is performed, and in this step, the time interval during which the entire recording time and the motion are detected is set to an initial value in case it is not set by the user. . In step S20, it is determined whether there is a video signal in which a motion is detected based on the data provided by the motion detector 50. If no motion is detected in step S20, recording is performed while sequentially switching video signals input from each of the video cameras 10: 10a, 10b, ..., 10n at intervals corresponding to a preset recording time. Let's do it. Here, the preset total recording time may be given as an initial value according to the use environment and use as described above, and may be changed by the user arbitrarily. Next, in step S60, the recording time is calculated by dividing the set recording time by the number of connected video cameras 10: 10a, 10b, ..., 10n, and then recording is performed.

On the other hand, in step S20, if motion is detected, the program proceeds to step S30 to determine the number of video signals for which motion is detected. Next, in step S40, the recording interval corresponding to the set total recording time is changed in proportion to the number of video signals from which motion is detected, and in step S50, recording is performed at the changed time interval.

Hereinafter, the above-described process will be described with a specific example, where 8 cameras are connected, the recording time is set to 480 hours, and the recording interval is shortened by 1/2 in proportion to the number of motions detected. Suppose it is. In the case where the number of video signals for which motion is detected in step S30 is one, the time is changed to 240 hours while the motion is detected, that is, the recording interval is changed from 4 seconds / unit to 2 seconds / unit and the entire recording repetition period is 4 * 8 =. It will be shortened from 32 seconds to 2 * 8 = 16 seconds. When motion is detected on three video signals in this manner, the recording time is changed to 60 hours, so that the recording interval is 0.5 seconds / unit, and the total recording repetition period is 0.5 * 8 = 4 seconds.

On the other hand, even when only one video camera is connected and used, if the originally set recording time is 3840 hours, the recording interval can be adjusted so that the total recording time is 24 hours, which is greatly reduced when there is motion.

As described above, if the movement is not detected in step S20 while repeatedly recording the above-described steps, the process proceeds to step S50 to record at the originally set recording time, that is, the recording interval.

The recording interval control method of the time-lapse VCR of the present invention is not limited to the above-described embodiment, and can be modified in various ways within the scope of the technical idea of the present invention.

According to the method of controlling the recording interval of the time-lapse VCR of the present invention as described above, if there is motion in the video signal provided from the video camera, it is possible to reduce the total recording interval in proportion to the number of motions, thereby causing the other video signal. There is an effect that eliminates irrationality that may miss a valid screen that may be unknown. On the contrary, when the motion is not detected, the tape amount is reduced by increasing the recording interval to the original time interval.

Claims (2)

In the recording interval control method of the time-lapse VCR of the CCTV system having a motion detection unit, to sequentially record the video signal provided from at least one video camera while repeating the recording and stop, (a) determining whether motion is detected in a video signal input from the video camera; If the motion is detected in the step (a), checking the number of video signals from which the motion is detected; (c) shortening the recording time interval to a preset value in proportion to the number of video signals identified in step (b) to perform recording; And and (d) recording the data at a predetermined time interval when the motion is not detected in the step (a). The method of claim 1, wherein the preset interval of recording time is changeable by a user.