JP4423819B2 - Surveillance image recording / reproducing method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a monitoring image recording / reproducing method and apparatus for recording and reproducing a plurality of monitoring images on a single recording medium by switching frames.
[0002]
[Prior art]
FIG. 3 is a diagram showing a schematic configuration of a conventional surveillance system using four surveillance cameras. Reference numerals 21 to 24 denote four surveillance cameras installed at four surveillance locations, and the four surveillance images taken there are sent to the frame switcher 30. The frame switcher 30 performs an operation of sequentially switching the monitoring images of the cameras 21 to 24 in units of frames and capturing them as one video signal. At this time, the frame switcher 30 is in the vertical blanking period of each frame. A unique frame code (camera identification code) is added. Thus, for example, the first frame of the camera 21 → the first frame of the camera 22 → the first frame of the camera 23 → the first frame of the camera 24 → the second frame of the camera 21 →. The obtained monitoring images are sequentially and repeatedly captured in time series with the frame code added. Therefore, in this case, one frame is captured for every four consecutive frames for one camera. The monitoring images of the four cameras captured by the frame switcher 30 are then sent to the monitoring image recording / reproducing device 40, where the image of the frame and the frame code are recorded. Also, playback is performed at the same time as recording, and the playback image is taken into the frame switcher 30 again, and for example, a quadrant screen is created by identification of the frame code and displayed on the monitor device 50. As described above, the monitoring images captured by the four monitoring cameras 21 to 24 are recorded because they may be required later as evidence, and at the same time, displayed on the monitor device 50 in real time.
[0003]
[Problems to be solved by the invention]
However, in the conventional surveillance image recording / reproducing apparatus 40, when a frame code is recorded, it is identified and decoded into a camera number, and encoded into a frame code when reproduced. That is, a decoder / encoder is required, and in addition, a decoder / encoder for a plurality of types of code systems is required in order to support a plurality of types of frame switchers with different frame code systems.
[0004]
An object of the present invention is to provide a monitoring image recording / reproducing method and apparatus that do not require an encoder.
[0005]
[Means for Solving the Problems]
According to a first aspect of the present invention for solving the above-mentioned problem, in the surveillance image recording / reproducing method for recording and reproducing video signals of a plurality of surveillance images on a recording medium, the frame code in the video signal is used as a camera number. The image is converted and recorded on the recording medium together with the monitoring image in the video signal, and the image of the frame code is stored in the storage means in association with the camera number, and the storage is performed by the camera number read from the recording medium. A monitoring image recording / reproducing method is characterized in that the image of the frame code of the means is read and reproduced as one frame together with the monitoring image read from the recording medium.
[0006]
According to a second aspect of the present invention, there is provided a monitoring image recording / reproducing apparatus for recording video signals of a plurality of monitoring images on a recording medium and reproducing the same, decoding a frame code in the video signal into a camera number and storing the video signal on the recording medium. A decoding means for sending, and a storage means for storing the frame code as image data at an address corresponding to the camera number, reading the frame code from the storage means according to the camera number read from the recording medium, and recording the recording The monitoring image recording / reproducing apparatus is characterized in that the monitoring image read from the medium is reproduced as one frame.
[0007]
According to a third aspect of the present invention, there is provided the surveillance image recording / reproducing apparatus according to the second aspect, further comprising address conversion means for converting the camera number read from the recording medium into an address of the storage means. .
[0008]
According to a fourth aspect of the present invention, there is provided the camera according to the second aspect of the present invention, further comprising a compressing unit that compresses the monitoring image data in the video signal, and the image data obtained by the compressing unit and the camera that outputs from the decoding unit A monitoring image recording / reproducing apparatus is characterized in that a set of numbers is recorded on the recording medium.
[0009]
According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the image processing apparatus according to the fourth aspect further includes decompression means for decompressing the image data read from the recording medium, and reads the monitoring image data obtained by the decompression means and the storage means. The monitoring image recording / reproducing apparatus is characterized in that the image data of the frame code is reproduced as one frame.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram of a monitoring image recording / reproducing apparatus 10 according to an embodiment of the present invention. Reference numeral 11 denotes an A / D converter (video decoder) that converts an analog video signal of a monitoring image input from the frame switcher 30 into a digital signal. Reference numeral 12 denotes an image compression unit that compresses image data in the image area of the digital video signal (area data excluding the vertical blanking period). A frame code decoder 13 identifies a frame code (for example, superimposed on 10H to 20H) during the vertical blanking period in the digital video signal and decodes it into a camera number. Reference numeral 14 denotes a memory (storage means) that has become non-volatile by battery backup or the like, and the frame code is stored as it is as image data at an address corresponding to the camera number. Reference numeral 15 denotes a recording medium such as a hard disk in which the image data compressed by the image compression unit 12 and the camera number data decoded by the frame code decoder 13 are recorded. Reference numeral 16 denotes an image expansion unit that expands image data read from the recording medium 15, and reference numeral 17 denotes an address conversion unit that converts camera number data read from the recording medium 15 into address data in the memory 14. Reference numeral 18 denotes a D / A converter (video encoder) which includes image data output from the image expansion unit 16 in the image area unit and frame codes read from the memory 14 in the vertical blanking period, for example, 10H to 20H. Generating an analog video signal of the frame to be recorded. The cameras 21 to 24 and the monitor device 40 are connected to the frame switcher 30 as in FIG.
[0011]
When the video signal of the monitoring image is input from the frame switcher 30, the A / D converter 11 converts the video signal into a digital signal. The video signal per frame is a frame code decoder 13 for the frame code in the vertical blanking period. The image data in the image area is compressed by the image compression unit 12 and recorded together with the camera number data on the same recording medium 15 as the camera number data.
[0012]
At this time, the frame code is stored in the memory 14 as image data, but the memory address at this time is an address corresponding to the camera number decoded by the frame code decoder 13. FIG. 2 is a diagram showing the contents of the memory 14, and addresses are given in advance such as 100, 200, 300, and 400 corresponding to the camera numbers 1 to 4 of the four cameras 21 to 24 described above. ing. Therefore, when the current A / D converted video data is for the camera 21 with the camera number 1, the image data of the frame code is stored in the address 100 with the camera number 1. Thereafter, the image data of the frame codes of the cameras 22, 23, and 24 are similarly stored in the addresses 200, 300, and 400 of the camera numbers 2, 3, and 4 in order. After the frame code image data of all four cameras 21 to 24 is stored in the memory 14, the subsequent writing is not performed and the stored contents are retained. That is, the writing operation to the memory 14 is performed only once when the monitoring system is installed. The frame code input after this is only decoded into camera number data.
[0013]
When the image data is read from the recording medium 15, the image data for the image area and the camera number data are read for each frame. The image data in the image area is expanded by the image expansion unit 16. The camera number data is converted into an address signal in the memory 14 by the address conversion unit 17, whereby the image data of the frame code is read from the memory 14. Then, the image data of the image area is allocated to the image area of the frame, the frame code is allocated to, for example, 10H to 20H in the vertical blanking period, converted into an analog video signal by the D / A converter 18, and the frame Returned to the switcher 30.
[0014]
As described above, in the monitoring image recording / reproducing apparatus of this embodiment, the frame code added by the frame switcher 30 is separated and stored as it is as image data in the memory 14, read from the recording medium 15, and decompressed. Since it is added to the image data, it is not necessary to re-encode the data decoded to the camera number by the frame code decoder 13 into the frame code again. That is, the input frame code is reproduced from the monitoring image recording / reproducing apparatus without any processing.
[0015]
【The invention's effect】
As described above, according to the present invention, it is possible to realize a monitoring image recording / reproducing apparatus that does not require an encoder. The frame code may be stored in the memory only when the monitoring system is installed or when the number of cameras is changed or the frame switcher is changed to another type. Therefore, any frame switcher can be supported.
[Brief description of the drawings]
FIG. 1 is a block diagram of a monitoring image recording / reproducing apparatus according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram of a memory.
FIG. 3 is a block diagram showing a schematic configuration of a conventional monitoring system.
[Explanation of symbols]
10: surveillance image recording / reproducing apparatus, 11: A / D converter (video decoder), 12: image compression unit, 13: frame code decoder, 14: memory, 15: recording medium, 16: image expansion unit, 17: Address conversion unit, 18: D / A converters 21 to 24: surveillance camera 30: frame switcher 40: surveillance image recording / reproduction device 50: monitor device

Claims (5)

In a monitoring image recording / reproducing method for recording video signals of a plurality of monitoring images on a recording medium and reproducing them,
Converting the frame code in the video signal into a camera number and recording it on the recording medium together with the monitoring image in the video signal, and storing the image of the frame code in the storage means in association with the camera number;
A monitoring image recording / reproducing method, wherein an image of a frame code stored in the storage means is read by the camera number read from the recording medium and reproduced as one frame together with the monitoring image read from the recording medium. In a monitoring image recording / reproducing apparatus that records video signals of a plurality of monitoring images on a recording medium and reproduces them,
Decoding means for decoding a frame code in the video signal into a camera number and sending it to the recording medium, and a storage means for storing the frame code as image data at an address corresponding to the camera number,
A monitoring image recording / reproducing apparatus, wherein a frame code is read from the storage unit in accordance with a camera number read from the recording medium, and is reproduced as one frame together with the monitoring image read from the recording medium. In claim 2,
A monitoring image recording / reproducing apparatus comprising: an address conversion unit that converts the camera number read from the recording medium into an address of the storage unit. In claim 2,
The image data obtained by the compression means and the camera number output from the decoding means are recorded as a set on the recording medium. A surveillance image recording / reproducing apparatus. In claim 4,
It has decompression means for decompressing the image data read from the recording medium, and reproduces the monitoring image data obtained by the decompression means and the frame code image data read from the storage means as one frame. A monitoring image recording / reproducing apparatus characterized in that the monitoring image recording / reproducing apparatus is provided.

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