JP3240777B2 - Remote monitoring device and monitoring device control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote monitoring device and a monitoring device.
More specifically, the present invention relates to a remote monitoring apparatus for transmitting an image input from an image input unit such as a TV camera to a remote place via a network, and a control method of the monitoring apparatus. .

[0002]

2. Description of the Related Art A conventional remote monitoring apparatus for transmitting a captured image of a monitoring target area via a network has a configuration as shown in FIG. In FIG. 1, a video input device 10
The monitoring target area is photographed, and the video encoding circuit 12 compression-encodes the image captured by the video input device 10. As the encoding method in the video encoding circuit 12, intra-frame encoding / inter-frame encoding, motion compensation, and discrete cosine transform are used together. Further, the sound in the monitoring target area is detected by the microphone 14, and the sound encoding circuit 16 encodes the sound signal output from the microphone 14. Under the control of the system control circuit 18, the terminal control signal generation circuit 20 generates a communication control signal required for image / audio transmission, and the network control signal generation circuit 22
A network control signal for connecting to the SDN network is generated. The transmission encoding circuit 24 multiplexes the encoded image data, the encoded audio data, and the communication control signal from the video encoding circuit 12, the audio encoding circuit 16, and the terminal control signal generation circuit 18 to form a predetermined transmission frame. And outputs it to the network.

The line network used is, for example, an ISDN line, and usually compresses and transmits an image signal corresponding to several tens of Mbit / sec. The video encoding circuit 12 reduces the temporal redundancy of the image signal by, for example, inter-frame prediction and motion compensation prediction, and reduces the redundancy in the spatial frequency domain of the image by orthogonal transform.

[0004]

In the conventional example, since a photographed image is always transmitted as a moving image, there is a disadvantage that the line must be constantly maintained in a connected state, which is costly.

[0005] It is an object of the present invention to provide a remote monitoring apparatus and a control method of the monitoring apparatus which solve such a problem.

Further, in the conventional example, since the image is always transmitted with the same information amount regardless of the state of the monitoring target, the information amount of the normally unimportant normal image becomes unnecessarily large. When recorded on a tape or the like, there is a problem that the amount of recorded information becomes enormous.

Another object of the present invention is to provide a remote monitoring apparatus and a control method of the monitoring apparatus that solve such a problem.

[0008]

According to the present invention, there is provided a remote monitoring apparatus comprising: image input means for photographing an area to be monitored; abnormality detecting means for detecting occurrence of a predetermined abnormality in the area to be monitored; In accordance with the output of the means, usually, the image captured by the image input means is image-compressed as a still image using intra-frame coding, and when an abnormality is detected by the abnormality detection means, the image is input by the image input means. a photographed image, frame
It is characterized by comprising an image compression unit for compressing an image as a moving image using inter-frame coding, and a transmission unit for transmitting compressed data by the image compression unit.

The remote monitoring device according to the present invention is also a remote monitoring device comprising one main device and at least one image transmitting device connected to the main device via a line, wherein each image transmitting device is usually At the time, the captured image is intermittently transmitted to the main device as a still image, and when a predetermined abnormality occurs in the monitoring target area in charge, the captured image is transmitted as a moving image to the main device. In normal times, a line is sequentially connected to each image transmitting apparatus to receive a still image. However, when a moving image transmission from each image transmitting apparatus is detected, the line connection with the image transmitting apparatus that outputs a moving image must be maintained. It is characterized by.

[0010] The remote monitoring device according to the present invention is also a remote monitoring device for transmitting an image of an image target area to a remote place via a network, comprising: image input means for photographing the target area; Means for converting the photographed image by means
Image conversion means for converting the information amount into one of the information amount and the second information amount larger than the first information amount; a transmission means for transmitting an output image of the image conversion means via the network; A state detection means for detecting a state of the target area; and a control means for controlling the image conversion means in accordance with a detection output of the state detection means. Is converted into the first amount of information by the image converting means, and the image information is transmitted. The image captured by the image input means is converted by the image converting means into the second state of the monitoring target area. 2
The information is converted to the information amount and the image is transmitted .
A first image size corresponding to the first information amount of the captured image;
And the second image size corresponding to the second information amount
It is characterized by having image size conversion means for converting the image size into one of them.

[0011] The remote monitoring device according to the present invention also includes a monitoring device.
Image input means for photographing an elephant area;
Abnormality detection means for detecting the amount of movement between screens;
Usually, according to the output of the informing means, the image input means
Image as a still image using intra-frame coding.
When the abnormality is detected by the abnormality detection means, the image is compressed.
The image captured by the image input means is subjected to inter-frame encoding.
Image compression means for compressing an image as a used moving image;
From the transmission means for transmitting the compressed data by the image compression means
It is characterized by becoming.

[0012] A control method of a monitoring device according to the present invention is a method for controlling a monitoring device.
An image input process for photographing the target area, and the monitoring target area
Abnormality detection process of detecting the amount of movement between screens by using
Usually, according to the output of the detection step, the image input means
Image as a still image using intra-frame coding
When the image is compressed and an abnormality is detected by the abnormality detection process,
Inter-frame encoding of the image captured by the image input process
An image compression step of compressing an image as a moving image using
Transmission process for transmitting compressed data by image compression process
It is characterized by comprising.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic block diagram showing an embodiment of the present invention. In FIG. 2, reference numeral 30 denotes a video input device that captures an image of a monitoring target area; 32, an intra-frame encoding / inter-frame encoding of an image captured by the video input device 10;
A video encoding circuit that performs compression encoding by an encoding method that uses both motion compensation and discrete cosine transform; a microphone that captures audio generated in the monitoring target area; and a voice encoding circuit that encodes the output of the microphone It is.

38 is a system control circuit for controlling the whole,
Reference numeral 40 denotes a terminal control signal generation circuit for generating a communication control signal required for image / audio transmission, and reference numeral 42 denotes a network control signal generation circuit for generating a network control signal for connecting to an ISDN network.

The reference numeral 44 determines whether or not the amount of motion is equal to or greater than a predetermined value based on the motion vector signal V output from the video encoding circuit 32. Is a motion detection circuit that supplies a selection signal S for coding and inter-frame coding and supplies a predetermined control signal to the system control circuit 38.

Reference numeral 46 denotes a transmission encoding unit which multiplexes the encoded image data, the encoded audio data, and the communication control signal from the video encoding circuit 32, the audio encoding circuit 36, and the terminal control signal generating circuit 40 to form a transmission frame. Circuit.

FIG. 3 shows a detailed circuit configuration of the video encoding circuit 32. In FIG. 3, reference numeral 50 denotes a motion amount detection circuit 4.
4 selects the intra-frame encoding and the inter-frame encoding in the circuit shown in FIG. 3 based on the intra-frame / inter-frame selection signal S and the internal count value, and outputs the intra-frame / inter-frame flag P according to the selection. Internal / interval control circuit, 5
2 is a subtractor that subtracts the motion-compensated prediction value of the inter-frame coding from the current video signal output from the video input device 30 and outputs a prediction error. Contact) or output of subtractor 52 (contact b)
Switch.

Reference numeral 56 denotes a DCT circuit which performs discrete cosine transform on the output of the switch 54 and outputs its frequency coefficient.
Reference numeral 8 denotes a quantization circuit that quantizes the frequency coefficient output from the DCT circuit 56 and outputs a quantization index Q.

Reference numeral 60 denotes an inverse quantization circuit for inversely quantizing the coefficient data quantized by the quantization circuit 58; 62, an inverse DCT circuit for performing an inverse discrete cosine transform of the output of the inverse quantization circuit 60; An adder 66 for adding the predicted value of the previous screen to the output of the inverse DCT circuit 62 is provided between the current video signal output from the video input device 30 and the output of the adder 64 (before the video output from the video input device 30). A motion compensation prediction circuit that detects a motion vector by performing block comparison with an image of a screen and performs motion compensation on the output of the adder 64 in accordance with the detected motion vector. Reference numeral 68 denotes a motion output from the motion compensation prediction circuit 66. This is a loop filter including a spatial low-pass filter that spatially limits the band of the compensated predicted value. The output of the loop filter 68 is applied to the subtractor 52 and the adder 64 as a predicted value.

Reference numeral 70 denotes a valid / invalid discrimination circuit for discriminating whether the coded image data output from the quantization circuit 58 is valid or invalid according to the output of the switch 54, the output of the DCT circuit 56, and the output of the quantization circuit 58. It is.

The intra-frame / inter-frame control circuit 50 indicates the intra-frame / inter-frame flag P, the valid / invalid discriminating circuit 70 indicates the valid / invalid flag T, the quantization circuit 58 indicates the quantization index signal Q, and the motion compensation prediction circuit 66 Outputs the motion vector V, and the loop filter 68 outputs the loop-back filter on / off signal F to the transmission coding circuit 46. The motion vector V is also applied to the motion amount detection circuit 44.

FIGS. 4 and 5 show operation flowcharts of this embodiment. The operation of this embodiment will be described with reference to FIGS. The system control circuit 38 secures a line with the main device (reception side monitoring device) via the network control signal generation circuit 42 (S1). Next, the intra-frame / inter-frame control circuit 50 switches the switch 54 to the contact a side (S2),
The image captured by the video input device 30 is compressed as a still image. That is, the image captured by the video input device 30 is a DCT
Intra-frame encoding is performed by the circuit 56 and the quantization circuit 58 (S3). The encoded image data is applied to the transmission encoding circuit 46 and the inverse quantization circuit 60 as a Q signal. At the same time, the audio encoding circuit 36 encodes the input audio signal from the microphone 34, and the transmission encoding circuit 46 encodes the encoded image data from the video encoding circuit 32, the encoded audio signal from the audio encoding circuit 36, and The terminal control signal from the terminal control signal generation circuit 40 is multiplexed and output to the receiving side monitoring device via the network (S4).

The encoded image data is decoded by the inverse quantization circuit 60, the inverse DCT circuit 62 and the adder 64 (S
5). The motion compensation prediction circuit 66 compares the current video signal from the video input device 30 with the decoded video signal, calculates a motion vector indicating the movement of an image between screens, and generates a motion vector as a V signal. And the motion amount detection circuit 44 (S6).

The motion amount detection circuit 44 calculates the motion vector V
When the motion amount is less than a certain amount (S7), an intra-frame selection signal instructing intra-frame encoding is output to the intra-frame / inter-frame control circuit 50, and the system control circuit 38 It does not output a motion detection signal indicating that the amount of motion is equal to or more than a certain amount. System control circuit 38
Since the motion detection signal is not input, the network control signal generation circuit 42 disconnects the line with the receiving side monitoring device (S8), and waits for a time for transmitting the monitoring image again by the timer provided therein (S9).

When the amount of movement is equal to or more than a certain value (S
7), the motion amount detection circuit 44 outputs the inter-frame selection signal instructing the inter-frame encoding to the intra-frame / inter-frame control circuit 50.
And outputs a motion detection signal to the system control circuit 38 (S10). The system control circuit 38 causes the terminal control signal generation circuit 40 to output the moving image transmission signal to the transmission encoding unit 108 according to the motion detection signal from the motion amount detection circuit 44 (S11). The in-frame / inter-frame control circuit 50
In accordance with the intra-frame / inter-frame selection signal S from the motion amount detection circuit 44, the switch 54 is switched to the contact b (S1).
2). Thereby, the video encoding circuit 32 encodes the captured image of the video input device 30 between frames. That is, the subtractor 52 calculates the motion-compensated predicted value from the video signal output from the video input device 30 (the output of the loop filter 68).
The DCT circuit 56 performs a discrete cosine transform of the prediction error by the subtracter 52, and the quantization circuit 58
6 (frequency coefficient data) and outputs a quantization index signal Q to the transmission coding circuit 46. The transmission encoding circuit 46 transmits the encoded image data together with the encoded audio data and the terminal control signal to the receiving side monitoring device via the network (S13).

At the time of inter-frame encoding in the video encoding circuit 32, the motion compensation prediction circuit 66
Is calculated by comparing the current video signal from the video signal with the video signal decoded by the circuits 60, 62 and 64, and outputs the calculated motion vector to the motion amount detection circuit 44 (S1).
4). The motion amount detection circuit 44 monitors the motion amount from the motion vector, and when the motion amount is equal to or more than a certain amount (S1).
5) Output an inter-frame selection signal to the intra-frame / inter-frame control circuit 50, and output a motion detection signal to the system control circuit 38 to continue image transmission (S13).

If the motion amount is less than the predetermined value (S15), the motion detection circuit 44 outputs the intra-frame selection signal
Output to the control circuit 50 and the system control circuit 3
8 does not output a motion detection signal. System control circuit 3
No. 8 receives no motion detection signal, so the network control signal generation circuit 42 disconnects the call with the receiving side monitoring device (S8).
The time for transmitting the monitoring image is again waited for by the internal timer (S9).

As described above, in this embodiment, the amount of movement between screens is monitored, and if there is no or little movement, intermittent still image transmission is performed, and if there is more than a certain amount of movement, moving image transmission is performed. To shorten the line usage time. As a result, the line cost can be significantly reduced while fulfilling the purpose of monitoring.

Next, a second embodiment of the present invention will be described. FIG. 6 shows a schematic block diagram of the second embodiment. In the present embodiment, a plurality of image transmitting apparatuses each including a video input apparatus are prepared, and each of the captured images of the plurality of image transmitting apparatuses is transmitted to one main apparatus (receiving apparatus) via a network to perform centralized monitoring. I do. In FIG. 6, 80 (80-1, 80-2, 80)
-3, 80-4) are the video input device 82 and the microphone 84
The transmission-side monitoring device having the transmission-side monitoring device 80
A monitoring device (main device) 88 for monitoring and outputting monitoring information according to the above is a network such as an ISDN for transmitting input information of the transmitting monitoring device 80 to the receiving monitoring device 86.

FIG. 7 is a detailed block diagram of the configuration of the transmission-side monitoring device 80. In the embodiment shown in FIG. 2, switching between still image transmission and moving image transmission is performed according to the amount of motion between screens.
In this example, still image transmission and moving image transmission are switched according to the volume. Reference numeral 90 denotes a video encoding circuit for compressing an image captured by the video input device 82 so as to match the line capacity, and the inside thereof is exactly the same as that in FIG.

Reference numeral 92 denotes an audio encoding circuit for converting an output audio signal from the microphone 84 into a digital audio signal; 94, a system control circuit for controlling the whole; 96, a terminal for generating a communication control signal required for image / audio transmission. Control signal generation circuit,
Reference numeral 98 denotes a network control signal generating circuit for generating a control signal for connecting to an ISDN line network or the like. 100 detects whether or not the audio captured by the microphone 84 is at or above a certain level. A volume detection circuit that outputs an intra / interframe selection signal to the encoding circuit 90 and outputs a predetermined control signal to the system control circuit 94;
2 coded audio data and terminal control signal generation circuit 9
6 is a transmission coding circuit that multiplexes the communication control signal from the communication control signal 6 to form a transmission frame.

FIG. 8 shows a transmission / reception sequence between the transmission-side monitoring device 80 and the reception-side monitoring device 86. First, the first transmission side monitoring apparatus (for example, 80-1) sets up a call with the reception side monitoring apparatus 86 by the network control signal generation circuit 98 and connects the line.

The video encoding circuit 90 of the transmission side monitoring device 80-1 compresses the image captured by the video input device 82 as a still image, and compresses the compressed data together with the audio encoded data and the communication control signal. 102 and network 88
Is transmitted to the receiving side monitoring device 86 via

The sound volume detection circuit 100 monitors the sound volume of the input sound from the microphone 84. If the sound volume is equal to or more than a predetermined amount, the sound volume detection circuit 100 sends a control signal for instructing the video encoding circuit 90 to perform inter-frame encoding, that is, a moving image transmission. , A volume detection signal is output to the system control circuit 94, and conversely, if the volume is less than a predetermined amount, a control signal for instructing intra-frame encoding, that is, still image transmission, to the video encoding circuit 90 is output. No volume detection signal is output to the control circuit 94. When a volume detection signal is not input from the volume detection circuit 100, the system control circuit 94 disconnects the call to the reception side monitoring device 86 by the network control signal generation circuit 98, and waits for a predetermined time by an internal timer.

In the same manner, the second transmitting side monitoring device 80-
2. The third transmission-side monitoring device 80-3 and the fourth transmission-side monitoring device 80-4 execute line connection and still image transmission in order. In this way, the input information from the four transmitting side monitoring devices 80 is cyclically transmitted to the receiving side monitoring device 86.

During such a transmission / reception sequence, for example, the voice detection circuit 100 of the second transmission side monitoring apparatus 80-2
Suppose that a volume equal to or higher than a certain value is detected. The system control circuit 94 of the device 80-2 causes the terminal control signal generation circuit 96 to output the moving image transmission signal to the transmission encoding unit 102 according to the volume detection signal from the volume detection circuit 100, and the video encoding circuit 90 Then, the captured image is inter-frame coded by the inter-frame selection signal from the volume detection circuit 100. The transmission encoding circuit 102 multiplexes the encoded image data from the video encoding circuit 90 with the encoded audio data from the audio encoding circuit 92 and the communication control signal from the terminal control signal generation circuit 96, and Transmit.

When the sound volume falls below a certain value, the sound volume detection circuit 100 outputs an in-frame selection signal to the video encoding circuit 90 and does not output a sound volume detection signal to the system control circuit 94. As a result, the system control circuit 94 disconnects the line with the receiving side monitoring device 86 by the network control signal generation circuit 98 and waits until the monitoring image is transmitted again by an internal timer.

In FIG. 7, the occurrence of an abnormality in the monitored place is determined by voice. Of course, the determination may be made based on the motion of the image. By transmitting a still image monitoring image to the transmission / reception side monitoring device 86 sequentially from the plurality of transmission side monitoring devices 80 at certain fixed time intervals while there is no abnormality, a plurality of points can be substantially used using only one line. It is possible to monitor. In addition, in normal times, still image transmission is used to shorten the line use time and reduce the line cost. If the volume is high, it is determined that an abnormality has occurred, and switching to moving image transmission enables to obtain necessary information.

It is apparent that an infrared sensor or a door switch may be used as a method for detecting the occurrence of an abnormality, and that the transmission of the still image and the transmission of the moving image may be switched based on the output of the infrared sensor or the door switch.

In FIG. 8, the transmission-side monitoring device 80 determines the start timing of the still image transmission of the monitoring image. However, if a plurality of transmission-side monitoring devices 80 independently determine the timing, a call is issued. May overlap. The transmission-side monitoring device 80 that has failed in the call setting may make a re-call, but in this case, the reception timing of the monitoring information is undefined on the receiving side. To prevent this, it is preferable that the receiving device controls the transmission timing of the transmitting device. That is, the receiving-side monitoring device 86 calls each of the transmitting-side monitoring devices 80 in order, receives a still image from a normal transmitting-side device, and receives a moving image from an abnormal transmitting-side device. Of course, if an abnormality occurs in the transmitting device, the transmitting device may be able to call the receiving monitoring device 86. In such a configuration, the receiving-side monitoring device 86 can normally obtain the images captured by the plurality of transmitting-side monitoring devices 80 in a predetermined order. An image from the location where the error occurred can be obtained as a moving image.

The next embodiment of the present invention will be described. FIG.
The schematic configuration block diagram is shown. In FIG. 9, 110
Is a video input device that captures an area to be monitored, 112 separates the output of the video input device 110 into a luminance component and a color component,
A Y / C separation circuit that outputs only the luminance component.
Output (a contact) of C separation circuit 112 or video input device 1
A switch 116 for selecting the output of No. 10 (contact b), 116
A video encoding circuit for compressing and encoding the video signal selected by the switch 114 by using an encoding method that uses both intra-frame encoding / inter-frame encoding, motion compensation, and discrete cosine transform. 118 is generated in the monitoring target area. A microphone 120 for taking in voice is a voice coding circuit for coding the output of the microphone 118.

Reference numeral 122 denotes a system control circuit for controlling the entire system, reference numeral 124 denotes a terminal control signal generation circuit for generating a communication control signal required for video / audio transmission, and reference numeral 126 denotes a network control signal for generating a network control signal for connecting to an ISDN network. It is a signal generation circuit.

The reference numeral 128 determines whether or not the amount of motion is equal to or more than a predetermined value based on the motion vector signal V output from the video encoding circuit 116.
14 is a motion amount detection circuit that controls the system control circuit 14 and supplies a predetermined control signal to the system control circuit 122.

Reference numeral 130 denotes a transmission encoding unit which multiplexes the encoded image data, the encoded audio data, and the communication control signal from the video encoding circuit 116, the audio encoding circuit 120, and the terminal control signal generating circuit 124 to form a transmission frame. Circuit.

FIG. 10 shows a detailed circuit configuration of the video encoding circuit 116. In FIG. 3, reference numeral 150 denotes an intra-frame / inter-frame control circuit that selects intra-frame encoding and inter-frame encoding based on the internal count value, and outputs an intra-frame / inter-frame flag P according to the selection.
Subtractor 15 for subtracting the motion-compensated prediction value of the inter-frame coding from the current video signal from 4 and outputting a prediction error;
Reference numeral 4 denotes a switch for selecting a video signal (a contact) from the switch 114 or an output (b contact) of the subtractor 52.

Reference numeral 156 denotes a DCT circuit that performs discrete cosine transform on the output of the switch 154 and outputs its frequency coefficient. 158 quantizes the frequency coefficient output from the DCT circuit 156 and outputs a quantization index Q. Circuit.

Reference numeral 160 denotes an inverse quantization circuit for inversely quantizing the coefficient data quantized by the quantization circuit 158, and 162 denotes an inverse quantization circuit.
An inverse DCT circuit 164 for performing an inverse discrete cosine transform on the output of the inverse quantization circuit 160 is an inverse DCT in intra-frame encoding.
The adder 166 which outputs the output of the circuit 162 as it is and adds the predicted value of the previous screen to the output of the inverse DCT circuit 162 in the inter-frame encoding is provided by the current video signal from the switch 114 and the output of the adder 164 (switch A motion compensation prediction circuit that detects a motion vector by performing block comparison with a video of the previous screen with respect to the output video of 114, and performs motion compensation on the output of the adder 164 according to the detected motion vector;
Reference numeral 168 denotes a loop filter including a spatial low-pass filter for spatially band-limiting the motion-compensated predicted value output from the motion-compensated prediction circuit 166.

A switch 169 applies a value of 0 to the adder 164 during intra-frame encoding, and applies an output (predicted value) of the loop filter 168 to the adder 164 during inter-frame encoding. . That is, the switch 169 is connected by the intra-frame / inter-frame control circuit 150 to the contact a during the intra-frame encoding and to the contact b (output of the loop filter 168) during the inter-frame encoding. In this way, the output of the loop filter 168 is used as the predicted value as the predicted value via the subtractor 52 and the switch 169 to adder 1
64.

The in-frame / inter-frame control circuit 150
The switch 154 is also controlled in the same manner. The switch 154 is connected to the contact a (output of the switch 114) during intra-frame coding, and the switch 154 is connected to contact b (output of the subtractor 152) during inter-frame coding. .

170 is an output of the switch 154, DCT
According to the output of the circuit 156 and the output of the quantization circuit 158,
This is a valid / invalid determination circuit that determines whether the encoded image data output from the quantization circuit 158 is valid or invalid.

The intra-frame / inter-frame control circuit 150 sets the intra-frame / inter-frame flag P, and the valid / invalid judgment circuit 170
The invalidation flag T, the quantization circuit 158 outputs the quantization index signal Q, and the motion compensation prediction circuit 166 outputs the motion vector V
The loop filter 168 outputs a loop-back filter on / off signal F to the transmission encoding circuit 130. The motion vector V is also applied to the motion amount detection circuit 128.

FIGS. 11 and 12 show operation flowcharts of this embodiment. The operation of the present embodiment will be described with reference to FIGS. The system control circuit 122 secures a line with the main device (reception side monitoring device) via the network control signal generation circuit 126 (S21), and the switch 11
4 is switched to the contact a side (S22). As a result, a monochrome image transmission mode is set.

The video encoding circuit 116 includes the video input device 1
The luminance signal of the captured image according to 10 is input, and the video encoding circuit 116 performs DCT conversion and quantization on the luminance signal to compress the image (S23). At the same time, the speech encoding circuit 12
0 encodes the input audio signal from the microphone 118, and the transmission encoding circuit 130 encodes the encoded image data from the video encoding circuit 116, the encoded audio signal from the audio encoding circuit 120, and the terminal control signal generation circuit 124. Are multiplexed and output to the receiving-side monitoring device via the network (S24).

The coded image data is supplied to an inverse quantization circuit 160,
Decoding is performed by the inverse DCT circuit 162 and the adder 164 (S25). The motion compensation prediction circuit 166 compares the current video signal from the video input device 30 with the decoded video signal, calculates a motion vector indicating the movement of an image between screens, and generates a motion vector as a V signal. And output to the motion amount detection circuit 128 (S26).

The motion amount detection circuit 128 monitors the motion amount based on the motion vector V. If the motion amount is less than a certain amount (S27), the process proceeds to S23, and the transmission of the monochrome moving image is continued.

When the amount of motion is equal to or more than a certain value (S2
7), the motion amount detection circuit 44 switches the switch 114 to the contact b (S28). As a result, a color moving image transmission mode is set. The system control circuit 122 causes the terminal control signal generation circuit 124 to output a signal indicating color video transmission to the transmission encoding circuit 130 according to the motion detection signal from the motion amount detection circuit 128. The video encoding circuit 116 performs color image compression of the signal from the switch 114, that is, the output of the video input device 110 (S29). The transmission encoding circuit 130 transmits the encoded color image data together with the encoded audio data and the terminal control signal to the receiving side monitoring device via the network (S30).

The motion compensation prediction circuit 166 calculates a motion vector between screens and outputs the calculated motion vector to the motion amount detection circuit 128 (S31). The motion amount detection circuit 128 monitors the motion amount from the motion vector. If the motion amount is equal to or more than a certain amount (S32), the process proceeds to S29, and the moving image transmission of the color image while maintaining the switch 114 is continued. Is smaller than the predetermined value (S32), the switch 114 is switched to the contact a (S33), and the process proceeds to S23 to switch to monochrome moving image transmission.

When there is a certain amount of movement between the screens,
It is assumed that some abnormality has occurred. From this point of view, in the present embodiment, the amount of movement between the screens is monitored. If there is no or little movement, the moving image is transmitted as a monochrome image, and if there is more than a certain amount of movement, the moving image is transmitted as a color image. This ensures that you get enough information when you need it. In this embodiment, the presence or absence of an abnormality is determined from the movement of an image. However, the presence or absence of an abnormality may be determined by sound (output of the microphone 118 or the like), and the presence or absence of an abnormality is determined by both sound and image. May be.

In this embodiment, the information amount of the transmitted image is switched between a normal image and an abnormal image, such as a monochrome image and a color image. However, the image compression ratio may be changed. FIG. 13 is a block diagram showing a schematic configuration of the image transmitting apparatus according to the embodiment. The same components as those in FIG. 9 are denoted by the same reference numerals. 172 compresses an image in the same manner as the video encoding circuit 116, but a video encoding circuit whose image compression ratio can be controlled from the outside.
From the motion vector output from the
8 is a motion amount detection circuit that detects a motion amount and outputs a predetermined motion detection signal for a certain abnormal motion amount.
Reference numeral 176 denotes a system control circuit for controlling the entire system. In addition to the function of the system control circuit 122, the system control circuit 176 has a function of controlling the compression ratio of the video encoding circuit 172 according to the output of the motion amount detection circuit 174.

FIG. 14 is a block diagram showing the configuration of the internal circuit of the video encoding circuit 172. Figure 1 shows the basic circuit configuration.
It is exactly the same as 0, but the output order of the frequency coefficient in the DCT is freely changeable, and is changed according to the amount of motion by a control signal from the system control circuit 176. That is, 178 is a DCT circuit that performs discrete cosine transform of the video signal supplied from the switch 154, and 180 is an inverse D that performs inverse discrete cosine transform of the output of the inverse quantization circuit 160.
These are CT circuits whose compression ratio is controlled by a compression ratio control signal from a system control circuit 176.

The system control circuit 176 initially has
The compression order in the video encoding circuit 172 is set large by reducing the output order of the DCT circuit 178. If the motion detection circuit 174 detects a motion equal to or greater than a predetermined value during image transmission in this state, the system control circuit 176 increases the output order of the DCT circuit 178 according to the output of the motion detection circuit 174, and The compression ratio in the encoding circuit 172 is reduced. Then, the system control circuit 176 keeps the compression ratio of the video encoding circuit 172 low while the motion equal to or more than the predetermined value is detected.

In FIG. 14, the compression ratio is adjusted by the output order of the DCT, but the compression ratio is changed by other factors of video compression, for example, intra-frame coding / inter-frame coding or quantization characteristics, or This and the change of the output order of the DCT may be used in combination.

As described above, in this embodiment, when the amount of motion of an image is small, the amount of transmission data is reduced. When the amount of motion of an image is large, there is a possibility that some abnormality has occurred. By reducing the ratio, a higher definition image is transmitted. As a result, even when recording is performed on a recording medium by the image receiving side device, the recording medium can be saved and used effectively.

In an abnormal situation, the photographed image may be transmitted at a normal image size or resolution, and at a normal time, the photographed image may be transmitted at a resolution smaller than the normal image size or lower than the normal resolution. FIG. 15 is a schematic block diagram of still another embodiment of the present invention. In this embodiment, an image captured by a video input device is transmitted at a normal image size smaller than the normal image size, and when an abnormality occurs. , Is transmitted in a normal image size.

Reference numeral 210 denotes a video input device for photographing the range to be monitored, 212 an A / D converter for converting the output of the video input device 210 into a digital signal, and 214 a temporary storage of the output of the A / D converter 212. Dual-port memory,
216, a D / A converter for converting data read from the dual port memory 214 into an analog signal;
A clock generation circuit 8 supplies a predetermined clock to the A / D converter 212 and the D / A converter 216. A memory control circuit 220 controls writing and reading of the dual port memory 214.

Reference numeral 222 denotes a video encoding circuit for encoding the output of the D / A converter 216, and its internal configuration is exactly the same as that of the video encoding circuit 116. Reference numeral 224 denotes a motion detection circuit that monitors the motion of an image according to the motion vector output from the video encoding circuit 222, and 226 denotes a system control circuit that controls the whole. A synchronization signal is input from the video input device 210 to the memory control circuit 220, and a control signal for turning on / off the reduced output of the image size is input from the motion amount detection circuit 224.

The other elements in FIG. 15 are the same as the elements shown in FIG. 9, and are denoted by the same reference numerals.

The operation of FIG. 15 will be described. The system control circuit 226 sets a line with the receiving side monitoring device by the network control signal generation circuit 126. Next, as an initial state, the memory control circuit 220 receives a D / A signal from the dual port memory 214 based on a signal from the motion amount detection circuit 224.
The image data having the reduced image size is output to the converter 216. Also, the system control circuit 226
Causes the terminal control signal generation circuit 124 to output the image size control signal to the transmission encoding circuit 130.

The video signal of the image captured by the video input device 210 is converted into a digital signal by the A / D converter 212 and is sequentially written in the dual port memory 214. The memory control circuit 220 has a dual port
The image data stored in the memory 214 is read out so as to have a predetermined reduced image size. The read image data is converted into an analog signal by the D / A converter 216 and input to the video encoding circuit 222.

The video encoding circuit 222 includes a D / A converter 2
16 and outputs encoded image data to the transmission encoding circuit 130. Transmission coding circuit 130
Multiplexes the encoded image data with the audio data from the audio encoding circuit 120 and the control signal from the terminal control signal generating circuit 124, and transmits the multiplexed image data to the receiving side monitoring device via the network.

The motion amount detection circuit 224 monitors the motion vector output from the video encoding circuit 222, and if the motion amount is less than a certain amount, the image transmission of the reduced image size is continued. When the motion amount of the dual port memory 21 is detected, the memory control circuit 220 outputs a control signal to the memory control circuit 220.
4 is switched from the reduced image size to the normal image size. Further, the system control circuit 226 causes the terminal control signal generation circuit 124 to output a size control signal of a normal image size to the transmission encoding circuit 130 according to the motion detection signal from the motion amount detection circuit 224.

As described above, when the movement of the image is small, it is considered that there is little change in the monitored place and no abnormality has occurred, and a moving image transmission with a small image size and a small data amount is performed. If the amount is large, it is considered that an abnormality has occurred, and the moving image transmission is performed with a normal image size. As a result, even when recording is performed on a recording medium by the image receiving side device, the recording medium can be saved and used effectively. Of course, an infrared sensor, a door switch, or the like may be used as a method for detecting occurrence of abnormality.

[0074]

As can be easily understood from the above description, according to the present invention, still image transmission is normally performed,
By transmitting a moving image at the time of an abnormality, it is possible to shorten the line use time and suppress the line cost. In addition, in a configuration in which a line is exchanged with a plurality of remote monitoring apparatuses on the transmission side, a plurality of points can be monitored with a small number of lines, for example, one line, and the use time and line cost of the line can be further reduced.

According to the present invention, there is also provided an image conversion means for changing the amount of transmitted information of a captured image for monitoring, so that an image is transmitted with a small amount of transmitted information in a normal state, and an image is transmitted with a larger amount of transmitted information in an abnormal state. , It is possible to obtain more information when needed. Further, the amount of recording medium used on the image receiving side can be reduced, and the use efficiency can be improved. According to the invention of claim 1, the abnormality is detected.
If not, make sure you don't overlook small changes.
Transfer still images using intra-frame coding that is easy to observe
Follow the movement on the screen when an error is detected
Video using inter-frame coding that is easy to observe
Can be transmitted. In particular, it detects the amount of movement between screens
Therefore, when the amount of motion was small, intra-frame coding was used.
When a still image is transmitted and the amount of motion is large,
Video using inter-frame coding that is easy to follow and observe
Monitoring system by configuring
Thus, a more appropriate configuration can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a conventional example.

FIG. 2 is a schematic block diagram of a first embodiment of the present invention.

FIG. 3 is a schematic configuration block diagram of a video encoding circuit 32 of FIG. 2;

FIG. 4 is a part of an operation flowchart of the embodiment shown in FIG. 2;

FIG. 5 is a part of an operation flowchart of the embodiment shown in FIG. 2;

FIG. 6 is a schematic configuration block diagram of a configuration in which a plurality of transmission-side devices are line-connected.

FIG. 7 is a schematic block diagram of the configuration of a transmission-side monitoring device 80 shown in FIG. 6;

FIG. 8 is an example of a transmission / reception sequence in the embodiment shown in FIG. 6;

FIG. 9 is a schematic block diagram of another embodiment of the present invention.

10 is a circuit configuration block diagram of a video encoding circuit 116. FIG.

FIG. 11 is a part of an operation flowchart of the embodiment shown in FIG. 9;

FIG. 12 is a part of an operation flowchart of the embodiment shown in FIG. 9;

FIG. 13 is a schematic block diagram of still another embodiment of the present invention.

FIG. 14 is a circuit configuration block diagram of a video encoding circuit 172.

FIG. 15 is a schematic block diagram of still another embodiment of the present invention.

[Explanation of symbols]

10: Video input device 12: Video coding circuit 14: Microphone 16: Audio coding circuit 18: System control circuit 20: Terminal control signal generation circuit 22: Network control signal generation circuit 24: Transmission coding circuit 30: Video input device 3
2: Video coding circuit 34: Microphone 36: Audio coding circuit 38: System control circuit 40: Terminal control signal generating circuit 42: Network control signal generating circuit 44: Motion detection circuit 46: Transmission coding circuit 50: In frame / Interval control circuit 52: subtractor 54: switch 56: DCT circuit
58: quantization circuit 60: inverse quantization circuit 62: inverse DC
T circuit 64: adder 66: motion compensation prediction circuit 6
8: Loop filter 70: Valid / invalid discrimination circuit 8
0 (80-1, 80-2, 80-3, 80-4): transmitting side monitoring device 82: video input device 84: microphone 8
6: receiving-side monitoring device (main device) 88: circuit network 90:
Video coding circuit 92: Audio coding circuit 94: System control circuit 96: Terminal control signal generation circuit 98: Network control signal generation circuit 100: Volume detection circuit 102: Transmission coding circuit 110: Video input device 112: Y / C Separation circuit 114: switch 116: video encoding circuit 1
18: Microphone 120: Speech coding circuit 122: System control circuit 124: Terminal control signal generation circuit 126:
Network control signal generation circuit 128: Motion amount detection circuit 13
0: Transmission coding circuit 150: In-frame / inter-frame control circuit 152: Subtractor 154: Switch 156: DCT
Circuit 158: Quantization circuit 160: Inverse quantization circuit 16
2: Inverse DCT circuit 164: Adder 166: Motion compensation prediction circuit 168: Loop filter 169: Switch 170: Valid / invalid discrimination circuit 172: Video encoding circuit 174: Motion amount detection circuit 176: System control circuit 178: DCT Circuit 180: Inverse DCT circuit 2
10: Video input device 212: A / D converter 214:
Dual port memory 216: D / A converter 21
8: Clock generation circuit 220: Memory control circuit 22
2: Video encoding circuit 224: Motion amount detection circuit 22
6: System control circuit

──────────────────────────────────────────────────続 き Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G08B 13/00-15/02 G08B 23/00-31/00 H04N 7/18

Claims (10)

(57) [Claims] 1. An image input means for photographing a monitoring target area, an abnormality detecting means for detecting occurrence of a predetermined abnormality in the monitoring target area, and the image input means is normally provided according to an output of the abnormality detecting means. The image captured by the means is image-compressed as a still image using intra-frame encoding, and when an abnormality is detected by the abnormality detection means, the image captured by the image input means is converted to a frame.
A remote monitoring device comprising: an image compression unit that compresses an image as a moving image using inter-coding; and a transmission unit that transmits data compressed by the image compression unit. 2. The transmission means connects a line at regular time intervals to transmit compressed data of a still image,
2. The remote monitoring apparatus according to claim 1, wherein when an abnormality is detected by the abnormality detecting means, the line is maintained in a connected state and the compressed data of the moving image is continuously transmitted. 3. A remote monitoring device comprising one main device and at least one image transmitting device connected to the main device via a line, wherein each of the image transmitting devices normally converts a captured image into a still image. As an intermittent transmission to the main device, and when a predetermined abnormality occurs in the monitoring target area in charge, transmitting a captured image as a moving image to the main device. A remote monitoring device characterized in that a line is sequentially connected to a device to receive a still image, but when detecting a transmission of a moving image from each image transmitting device, a line connection with an image transmitting device that outputs a moving image is maintained. 4. An image of an image target area is distant via a network.
A remote monitoring device for transmitting to a remote place, comprising: an image input unit that captures an image of a monitoring target area;
Either the information amount or the second information amount larger than the first information amount
Image conversion means for converting the image into one of them, and transmitting the output image of the image conversion means via the network
Transmitting means, a state detecting means for detecting a state of the monitoring target area, and the image converting means in accordance with a detection output of the state detecting means.
And control means for controlling the first state of the monitored area.
The image captured by the image input means
The image is converted into the first information amount by the image conversion means and transmitted.
Then, for the second state of the monitoring target area, the image input
The image taken by the means is converted to the second image by the image conversion means.
Image transmissionAnd The image conversion means converts the captured image to the first information amount.
Corresponding to the first image size and the second information amount
Image size converter for converting to one of the second image sizes
With steps A remote monitoring device, characterized in that: 5. The remote monitoring device according to claim 4, wherein the first state of the monitored area is a normal state, and the second state of the monitored area is an abnormal state. 6. The image conversion means according to claim 4, wherein said first compression means compresses the photographed image as a black and white image, and said second compression means compresses the photographed image as a color image.
The remote monitoring device according to claim 1. 7. The image conversion means comprises: first compression means for compressing a captured image to the first information amount; and second compression means for compressing the captured image to a second information amount. Item 5. The remote monitoring device according to Item 4. 8. The remote monitoring apparatus according to claim 7, wherein said first compression means is a binary image compression means, and said second compression means is a multi-valued image compression means. 9. An image input means for photographing an area to be monitored
When, Abnormality detection that detects the amount of movement between screens in the monitoring target area
Means, Usually, according to the output of the abnormality detection means, the image input
Still images using intra-frame coding for images captured by force means
Compress the image as an image and detect the abnormality by the abnormality detection unit
Sometimes, the image taken by the image input means is
Image compression means for compressing an image as a moving image using inter-coding
And transmission for transmitting compressed data by the image compression means.
And a remote monitoring device. 10. An image input step of photographing a monitoring target area
When, Abnormality detection that detects the amount of movement between screens in the monitoring target area
Process and Normally, according to the output of the abnormality detection step, the image input
Images taken by force means Stationary with intraframe coding
Compresses the image as an image and detects the abnormality by the abnormality detection process
Sometimes, the image captured by the image input process is
Image compression process to compress images as moving images using inter-coding
And transmitting the compressed data by the image compression process.
And a control method of the monitoring device.