JPH09205640A - Remote monitor system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inexpensive remote monitor system with simple circuit configuration by comparing a compressed image with a reference image so as to detect a fault and employing a storage circuit with a small capacity. SOLUTION: In the processing by an image input side, an image received from a camera 1 is compressed by an image compression section 2 employing the MPEG or the like, a code amount comparator section 3 extracts a code amount, and it is compared with a reference code amount in a reference code amount storage section 4. As the reference code amount, a standard image or an image before a prescribed time may be used. When a difference over a threshold level or over is detected after the comparison of the code amounts, error detection is informed to a data transmission section 5. Upon the receipt of an error detection notice, a data transmission section 5 adds it to compressed image data and sends the resulting data to a transmission line. In the processing of the image output side, data are received from the transmission line and the error notice of the data is discriminated and when an error is detected, expansion processing is conducted and the image is displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote monitoring system used for monitoring intruders.

[0002]

2. Description of the Related Art Image compression technology has been developed, equipment for realizing standardized image compression technology (MPEG, JPEG) has become very inexpensive, and it has been applied to remote monitoring systems.

On the other hand, in a remote monitoring system using a conventional monitoring camera, as shown in FIG. 4, an image comparison unit for detecting an abnormality detects a difference (brightness value, motion vector, etc.) between a reference image and a current image. The method of doing is generally used.
As an example of such an image comparison circuit, an example of a circuit for detecting an abnormality by a brightness value is shown in FIG. It has a complicated circuit configuration including a sampling pulse generation circuit, an A / D conversion circuit, an input image memory, a brightness value extraction circuit, and a brightness value comparison CPU.

[0004]

The conventional remote monitoring system as described above requires a large-capacity storage circuit for storing the reference brightness value. Therefore, when monitoring multiple points, a large number of image comparison units and reference storage units are required, and the configuration is complicated and expensive.

In view of the above problems, it is an object of the present invention to provide a remote monitoring system which has a simple circuit structure and is inexpensive.

[0006]

In order to solve the above problems, a surveillance system according to the present invention comprises a surveillance image input section, an input image compression section, a compressed image comparison section, and storage of reference data for comparison. And a data sending unit.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a remote monitoring system of the present invention will be described below with reference to the drawings. 1 is a block diagram of a remote monitoring system according to an embodiment of the present invention, FIG. 6 is a block diagram of a code amount comparison unit, FIG. 7 is a block diagram of a receiving side system, and FIGS. 2 and 3 are flow charts of processing. .

In FIG. 1, 1 is an image input unit, 2 is an image compression unit, 3 is an image code amount comparison unit, 4 is a reference code amount storage unit,
5 is a data transmission unit. In FIG. 6, 61 is an image input unit, and 6
2 is an image compression unit, 63 is a code amount comparison unit, 64 is a reference code amount storage unit, 65 is a data transmission unit, 66 is a code amount extraction circuit, and 67 is a code amount comparison circuit. In FIG. 7, 71 is a transmission path, 72 is a data receiving section, 73 is a data selecting section, 74 is an image expanding section, and 75 is an image display section.

The operation of the remote monitoring system configured as described above will be described with reference to FIGS. 1, 2, 3, and 7. First, in the processing on the image input side, the image input from the camera 1 is compressed by the image compression unit 2. (21, 22, 23 in FIG. 2) MPEG is used as a compression means.
, JPEG, etc. are conceivable, but other compression means capable of realizing the same thing may be used.

The code amount of the compressed image is extracted in the code amount comparison unit 3 and compared with the reference code amount of the reference data storage unit 4. (24 and 25 in FIG. 2) At this time, the extraction unit of the code amount is a unit that can be compared, for example, a picture or slice in MPEG.

As the reference code amount, there is a method of using a standard image (image in the case of no abnormality) or an image before a fixed time.

Further, when the coding type is different for each image like MPEG, a method of storing the reference code amount for each coding type to be compared is possible. Compared to,
When a difference equal to or larger than a certain threshold is detected, the data transmission unit 5 is notified of the abnormality detection. (25, 26 in FIG. 2) At this time,
Statistical information can be used as the threshold for comparison.

If there is an abnormality detection notification, the data transmission unit 5 adds the abnormality detection notification to the compressed image data and sends it. (27 in FIG. 2) It is also possible to reduce the traffic on the transmission path by transmitting the compressed image data only when the abnormality is detected.

Next, in the processing on the image output side, the data receiving section 72 receives data from the transmission line 71. (31 in FIG. 3) For the received data, the data selection unit 73 determines an abnormality notification (32 in FIG. 3), and if an abnormality is detected, the image decompressor 74 performs decompression processing (33 in FIG. 3). The image is displayed on the image display unit 75 (34 in FIG. 3).

As described above, by comparing the code amount of the compressed image with the reference code amount, the abnormality can be detected and the remote monitoring system can be realized at low cost.

Although the present embodiment has been described on the premise of a dedicated transmission line, it is also possible to use a public network as the transmission line.

Further, as the processing on the receiving side, it is possible to perform a function of automatically receiving an incoming call in the case of automatic calling, and adding an abnormal notice to the accumulated data and accumulating it in the case of always receiving data.

The configuration shown in FIG. 6 is conceivable as the code amount comparison unit, but the code amount may be extracted by another configuration.

As described above, by comparing the code amounts of the compressed images, the abnormality is detected by the difference from the reference image. Generally, in image compression, various domain division methods (spatial domain, frequency domain, etc.) are used. When compression coding is performed for each area (MPEG pictures, slices, macroblocks, etc.), and if there is a difference between an intruding object and the like in the reference image and the comparison image, the difference in the code amount compressed in the area unit Occur. If the difference exceeds the threshold, it is determined to be abnormal. The image comparison section need only have a code amount counting function for compressed images and a numerical value comparison function with a reference code amount, and a simple circuit configuration can be realized. Further, since only the code amount is stored, it can be configured with a storage circuit having a considerably small capacity as compared with the case of recording the reference image. Therefore, it becomes possible to construct a low cost remote monitoring system.

[0020]

According to the remote monitoring system of the present invention, abnormality detection is performed by comparing a compressed image with a reference image, and therefore a storage circuit with a small capacity can be used.

Further, by comparing the code amount of the compressed image with the code amount of the reference image as the image comparing means, it is possible to realize with a simple circuit configuration.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a remote monitoring system according to an embodiment of the present invention.

FIG. 2 is a diagram showing processing on the image input side according to the present invention.

FIG. 3 is a diagram showing processing on the image output side of the present invention.

FIG. 4 is a schematic diagram of a conventional remote monitoring system.

FIG. 5 is a diagram showing a configuration example of an image comparison unit of a conventional remote monitoring system.

FIG. 6 is a diagram showing a configuration example of a code amount comparison unit of the remote monitoring system of the present invention.

FIG. 7 is a configuration diagram of a receiving side system in the embodiment of the remote monitoring system of the present invention.

[Explanation of symbols]

 1 image input unit 2 image compression unit 3 code amount comparison unit 4 reference code amount storage unit 5 data transmission unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshikazu Akama 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Ryota Hata, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A remote monitoring system for detecting abnormality by comparing a monitoring image input from an image input unit with a reference image, the image compression unit compressing the monitoring image, and reference data for comparison. A remote monitoring system, comprising: a reference data storage unit that stores the image data; and an image comparison unit that compares the compressed monitoring image with the reference data. 2. The remote monitoring system according to claim 1, wherein the reference data for comparison is the compression code amount of the reference image, and the image comparison unit is configured to compare the compression code amount of the monitoring image with the reference data. .