JPH07250322A - Image coder and remote supervisory system using it - Google Patents

Abstract

PURPOSE:To obtain an image coder and a remote supervisory system allowing a user to simply control information at a remote location without taking notice of a delay through transmission or the like. CONSTITUTION:Upon the receipt of control information to a camera 9 and a PAN head 15 from a supervisory side image communication terminal equipment, a control section 19 supervises its control content to operate the camera 9 and the universal head 15 and to use a format conversion section 17 to reduce the resolution of an coded image signal coded by an image coding section 18, and the coding control method for the image coding section 18 is revised to make quantization of each frame rough. Thus, the transmission information quantity is reduced to increase the number of frames to be sent to the supervisory side thereby sending the received image without a delay and without deframing along with the operation of the camera 9 and the PAN head 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to controlling the imaging function such as position, focus, aperture or zoom in a camera section of a remote device, or fast-forwarding during playback, reverse-reverse during playback in an image recording device such as a VTR. When controlling the function of, for example, in the image input means in which the state of the image signal is controllable, the image information input by the controlled image input means is encoded and transmitted, and with respect to the transmitted image information amount,
An image coding apparatus preferably used when controlling the image input means while monitoring the image information transmitted from the control side using a line having a relatively low transmission speed, and a remote using the image coding apparatus. It concerns a surveillance system.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional image coding apparatus,
An example of controlling a camera unit at a remote place will be shown. The figure shows an example in which image information at a remote place is monitored using transmission of image information using an N-ISDN network or the like. In the figure, 30 is an image communication terminal device on the monitoring side, and 40
Is an image coding and transmitting device on the monitored side, and is the ISDN network 5
The image information is encoded via 0 and transmitted to the image communication terminal device 30 on the monitoring side.

In the image communication terminal device 30 on the monitoring side,
Reference numeral 1 is a monitor for monitoring image information of a remote place on the monitoring side. In the image communication terminal device 30, the ISDN interface unit 6 receives the image information from the monitored side received via the ISDN network 50, the demultiplexing unit 5 separates the image information, and the image decoding unit 4 thereafter. Decoding to obtain a digital image signal. In order to convert the obtained digital image information into an image signal that can be displayed on the monitor 1, after the format is inversely converted by the format inverse converter 3, the D / A
The conversion unit 2 converts the analog image signal and displays it on the monitor 1. Further, when controlling a camera at a remote location on the monitored side, the operating direction of the camera at the remote location is designated by the operation unit 7 while monitoring the image on the monitor 1. This control information is transmitted by the control unit 8 to the image encoding device 40 on the monitored side via the demultiplexing unit 5. Also, the image information sent from the camera controlled on the monitored side is monitored by the monitor 1, the stop position is instructed by the operation unit 7, the control unit 8,
It is transmitted to the monitored side via the demultiplexing unit 5.

The image coding apparatus 40 on the monitored side has a camera 9 as an image input means, and an image signal input by using the camera 9 is converted into a digital image signal by an A / D converter 10 to be formatted. After being converted into an image signal to be encoded by the conversion unit 11, the image encoding unit 1
It is encoded with 2. After that, the signals are multiplexed by the demultiplexing unit 13 and transmitted to the image communication terminal device 30 on the monitoring side by the ISDN network 50 via the ISDN interface unit 14. A control signal from the monitoring side, such as the direction of the camera 9, is separated by the demultiplexing unit 13 and sent to the control unit 16. The control unit 16 receives instructions from the monitoring side such as control of the camera platform 15 that can change the direction of the camera 9 according to the received camera control information and control of focus, aperture, zoom, etc. of the camera 9. The control of the following camera operation is executed.

[0005]

However, in the conventional example, when the camera unit on the monitored side is controlled and operates according to the control information, the image coded by the image coding unit in the image coding apparatus on the monitored side. Since the signal resolution and the encoding control method are fixed, if abrupt conversion of the image signal occurs due to the operation of the camera unit, the image signal encoded when transmitting and encoding the input image information There was a problem that delay and frame drop occurred, the change of the screen of the image signal input by operating the camera part was not immediately and completely transmitted from the monitored side to the monitoring side, and it became difficult to monitor. . This problem occurs due to the following reasons.

There are the following problems in using the moving image coding system. In the video coding system, IT is used as a coding system for videophone / videoconference.
In the U-TS, H.264. The H.261 coding system is recommended. In these moving image coding methods, the correlation between input frames is used to predict the image signal of the next encoded frame from the image signal of the previously encoded and transmitted frame. The prediction error is encoded and transmitted. As a result, a large compression effect can be obtained. When such an encoding method is used, the image signal input by the operation of the camera unit changes greatly in units of frames, and the image signal of the previously encoded frame is encoded next. Even if the image signal of the frame is predicted, it cannot be predicted well, and the coding efficiency is significantly deteriorated. Therefore, the amount of coded image coded data increases, and coding transmission delay occurs. Also, 1
Since the coding amount of the frame increases, the frame is thinned out (dropped) and transmitted as compared with the normal case.

There are the following problems in using the still image coding system. In the still image coding system, a still coding system called JPEG is recommended in ISO as a coding system for still image services such as color facsimiles. In these still image coding methods, since the information in the frame is coded in input frame units, the code amount due to the loss of inter-frame prediction as described in the case of using the moving image coding method The problems of increase and transmission delay are not significant. However, in the still image encoding method, the encoding efficiency is not originally high, and even if the encoding is continuously performed, the frame information cannot be transmitted to follow the movement of the camera unit,
It is not possible to monitor the image information according to the movement of the camera unit, which causes a problem in control.

The present invention has been made in view of the above points, and eliminates the above-mentioned drawbacks and allows a user to easily control information at a remote location without being aware of delays or dropped frames in transmission or the like. It is an object of the present invention to provide an image coding apparatus that can be used and a remote monitoring system using the same.

[0009]

In order to achieve the above object, the present invention is an image coding device for coding and transmitting image information of an input image signal, and an image input means capable of controlling the state of the input image signal. And control means for monitoring the control content for the image input means and reducing the amount of information to be encoded when the control content is an instruction to change the state of the input image signal.

In the configuration of the above-mentioned image coding apparatus, as the control means for reducing the amount of information, in the invention of claim 2,
The means for reducing the resolution of the image information to be encoded by thinning is used, and the invention of claim 3 uses the means for changing the encoding control information for the means for encoding the image information to roughen the quantization.

As the image input means, an image photographing device is used in the invention of claim 4, and an image recording device whose control content relates to reproduction is used in the invention of claim 5.

Further, according to the invention of claim 6, when the above-mentioned image coding apparatus stores the image information to be coded and transmitted in a buffer and carries out the transmission, the control means for reducing the amount of information, When reducing the amount of information to be encoded, the degree of reduction of the amount of information is changed with reference to the open state of the buffer.

According to the invention of claim 7, in addition to the configuration of the image coding apparatus described above, there is provided control information receiving means for receiving control information for the image input means from the outside, and control means for reducing the amount of information. However, the control content of the received control information is monitored, and when the control content is an instruction to change the state of the input image signal, the amount of information to be encoded is reduced.

According to the present invention of claim 8, in addition to the above image coding apparatus, there is an operating means for instructing control of the image input means, and the control means for reducing the amount of information is the instructed control. When the content is monitored and the control content is an instruction to change the state of the input image signal, the amount of information to be encoded is reduced.

Further, in the invention of claim 9, in addition to the configuration of the above-mentioned image encoding device, the monitored side has an image code having a control information receiving means for receiving control information for the image input means from the outside. And a means for decoding and displaying the image information transmitted from the image coding apparatus, a means for issuing control information to the image input means of the image coding apparatus, and the control unit on the monitoring side. A remote monitoring system is configured by arranging an image communication terminal device having a means for transmitting information to a control information receiving means of the image encoding device through a transmission path.

[0016]

When the position, focus, aperture, zoom, etc. of the image photographing device such as a camera at a remote place are controlled from a remote place, or when functions such as fast-forwarding during playback, reverse return, etc. in an image recording device such as a VTR are controlled. When the state of the image signal of the image input means is controllable, it is necessary to control the image input means such as the camera and the image recording device without delay. Therefore, in the image coding apparatus of the present invention and the remote monitoring system using the same, when the control information of the image input means is received, the control content is monitored and the image coding section performs the coding together with the operation of the image input means. Frames that can be transmitted by reducing the amount of transmission information by reducing the resolution of the image signal to be encoded or changing the encoding control method of the image encoding unit to roughen the quantization of each frame. Increase the number. By increasing the number of frames that can be transmitted in this way, it is possible to monitor or search input image information according to the operation of the image input means without delay and without dropping frames even at a remote place.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the present invention. In the figure, 30 is an image communication terminal device arranged on the monitoring side, 41 is an image coding device arranged on the monitored side, and 50 is the image communication terminal device 30 and the image coding device 4.
It is an ISDN network that connects 1 to each other. Here, as a component of the image communication terminal device 30, 1 is a monitor, 2 is a D / A conversion unit, 3 is a format reverse conversion unit, 4 is an image decoding unit, 5
Is a demultiplexing unit, 6 is an ISDN interface unit, 7 is an operation unit, and 8 is a control unit. Further, as the components of the image encoding device 41, 9 is a camera, 10 is an A / D conversion unit, 13 is a demultiplexing unit, 14 is an ISDN interface unit, 15 is a platform for moving the position of the camera 9, and 17 is A format conversion unit, 18 is an image encoding unit, and 19 is a control unit.

In this embodiment, as compared with the conventional example of FIG.
The monitoring-side image communication terminal device 30 has the same configuration, and the monitored-side image coding device 41 has the image resolution and coding control for coding the format conversion unit 17 and the image coding unit 18, respectively. The method can be changed, and the control unit 19 monitors the contents of the control information received by the ISDN interface unit 14 and separated by the demultiplexing unit 13 for the image input means of the camera 9 and the platform 15 on the own device side, and receives them. If the content of the control signal indicates the operation of the image input means, the resolution of the image to be format-converted by the format conversion unit 17 on the device side or the code to be encoded by the image encoding unit 18 The transmission control amount is to be reduced by changing the computerization control method or both of them. Specifically, the resolution of the image is changed by performing filtering processing or the like and then reducing the resolution by thinning out pixels or lines. Further, the coding control method is changed by changing the coding control information to roughen the frame quantization.

The operation of the first embodiment having the above configuration will be described. In FIG. 1, the same numbers as those in FIG.
Since the operation is the same as, the description thereof will be omitted. The control information of the camera sent from the monitoring side is received by the control unit 19 through the ISDN interface unit 14 and the demultiplexing unit 13, and the operation of the camera 9 requested by the monitoring side is performed. Further, the resolution of the image signal being communicated, that is, the operation format in the format conversion unit 17, which can change the format, can be changed under the control of the control unit 19 or the control of the control unit 19 can change the operation format. The coding control method of the image coding unit 18 that can change the coding control method of the image coding is changed to roughen the quantization of the frame to be transmitted. By this operation, the camera 9
Changes its position due to the operation of the platform 15, or when the focus, aperture, zoom, etc. of the camera 9 are operated, and so on, there is a large change in the input image signal. If you want to monitor the input image without dropping large frames, the resolution and coding control method are controlled in the direction of increasing the number of frames to be coded, and the control of camera movement, focus, aperture, zoom, etc. is adjusted. If you want to
That is, before these operations, the image signal of each frame is controlled to be transmitted in more detail than the number of frames. In the above, when changing the encoding control method,
Since the existing function of the encoding unit can be used, the present invention can be easily implemented, but the effect of reducing the amount of transmitted information is relatively small. On the other hand, when the resolution of the image information to be encoded is reduced, it is necessary to add a new circuit, but the effect of reducing the amount of transmitted information is great.

In the present embodiment, the image coding apparatus used in the remote image monitoring system has been described, but it goes without saying that it may be used in other applications. For example, when transmitting a medical image using a document camera or the like, it can be used for an application such as controlling a transmitting camera from a remote place and specifying an observed position.

Next, a second embodiment of the image coding apparatus of the present invention will be shown. FIG. 2 is a block diagram showing the configuration.
Compared with the first embodiment of FIG. 1, this embodiment has a similar configuration for the image communication terminal device 30 on the control side corresponding to the monitoring side, and the image on the controlled side corresponding to the monitored side. With respect to the encoding device 42, the camera and the platform which are the image input means are the image recording device 20 such as a VTR, and the control unit is received by the ISDN interface unit 14 and is received by the demultiplexing unit 13 as in the first embodiment. The content of the control information for the separated image recording apparatus 20 on the apparatus side is monitored, and if the content of the received control information indicates the operation of the image input unit, the format conversion unit 17 on the apparatus side. The control unit 21 reduces the amount of transmission information by changing the image resolution for format conversion, the encoding control information encoded by the image encoding unit 18, or both.

The operation of the second embodiment having the above configuration will be described. In the same figure, those with the same numbers as in FIG.
Since the operation is similar to, the description will be omitted. FIG. 2 shows an embodiment in which the image information stored in the image recording device 20 such as a VTR at a remote place is searched by a process such as fast-forwarding during playback or reverse return. The control information of the image recording device 20 sent from the image communication terminal device 30 on the control side passes through the ISDN interface unit 14 and the demultiplexing unit 13 to the control unit 2.
The image recording device 20 received in No. 1 and requested by the control side
During playback, perform fast forward, reverse, etc. operations. Further, similarly to the first embodiment, by the control from the control unit 21, the resolution of the image signal during communication, that is, the operation format in the format conversion unit 17 capable of changing the format is changed, or the control unit 21 is changed. Control of the image coding unit 18 that can change the coding control method of the image coding during communication to roughen the quantization of the frame to be transmitted. Due to this operation, when the image recording apparatus 20 is controlled to fast forward or reverse during reproduction, there is a large variation in the input image signal, and when it is desired to see the input image from the image recording apparatus 20 on the control side without dropping a large frame. Similarly to the first embodiment, when the resolution and the encoding control method are controlled in the direction in which the number of frames to be encoded increases, and the movement of the image recording apparatus 20 is desired to be adjusted, that is, before those operations are performed. Is controlled so that the image signal of each frame can be transmitted in more detail than the number of frames.

The present embodiment can be used for recording monitoring information in a VTR or the like at a remote place for later timely observation or for retrieving image information at a remote place.

Next, a third embodiment of the present invention will be shown. FIG. 3 is a block diagram showing its configuration. This embodiment is different from the first embodiment in FIG. 1 in that the image coding device 43 on the monitored side is
An operation unit 23 is provided in the control unit 22, and the control unit 22 supplies control information for the camera 9 and the platform 15 to the control unit 22. In the case of instructing the operation of No. 15, the transmission information is changed by changing the image resolution for format conversion by the format conversion unit 17 or the encoding control method for encoding by the image encoding unit 18 or both of them. The amount should be reduced. Therefore, the operation unit and the control unit of the image communication terminal device 31 on the monitoring side may be omitted.

According to the present embodiment, the camera 9 on the monitored side is
When controlling the camera platform 15, the resolution of the image signal encoded by the image encoding unit 18 is reduced along with the operation thereof, thereby reducing the amount of transmission information and increasing the number of frames that can be transmitted, By changing the coding control method of the image coding unit and roughening the quantization of each frame,
Since the number of frames that can be transmitted is increased, it is possible to appropriately transmit the input image according to the operation of the camera 9 and the platform 15 to the remote monitoring side without delay and without dropping frames.

Next, a fourth embodiment of the present invention will be shown. FIG. 4 is a block diagram showing the configuration. This embodiment is different from the second embodiment in FIG. 2 in that the image encoding device 44 on the controlled side is
An operation section 23 is provided in the control section 24, and control information for the image recording apparatus 20 is given from the operation section 23 to the control section 24. In the case of instructing a reproduction operation such as reverse playback, the image resolution to be format-converted by the format conversion unit 17 on the device side, the encoding control method for encoding by the image encoding unit 18, or both of them are changed. This will reduce the amount of information sent.
Therefore, also in this embodiment, the operation unit and the control unit of the image communication terminal device 31 on the control side may be omitted.

According to the present embodiment, when the controlled side performs reproduction control such that the input image signal of the image recording device 20 fluctuates abruptly, it is encoded by the image encoding section 18 together with the operation. Format conversion unit 1 for image signal resolution
7, the number of frames that can be transmitted can be increased by reducing the amount of transmission information, or the encoding control method of the image encoding unit 18 can be changed to roughen the quantization of each frame for transmission. Since the number of frames is increased, the camera 9 and the platform 1
It is possible to appropriately transmit the input image according to the operation of No. 5 without delay and without dropping frames.

When the image information to be encoded and transmitted by the image encoding device is stored in a buffer for transmission, the control unit encodes the image signal by reducing the resolution of the image signal or changing the encoding method. When performing control for reducing the amount of information to be performed, it is possible to change the degree of reducing the amount of information with reference to the open state of the buffer. In this case, if the buffer is available, the resolution can be increased and the number of frames that can be transmitted can be increased without causing transmission delay or dropping of frames. Further, according to the present invention, a rapidly changing input image can be transmitted without delay and without dropping frames. Therefore, while monitoring the monitor screen on the monitoring side or the control side, various controlled objects on the monitored side or controlled side at a remote place can be obtained. It can also be suitably used when operating or controlling.

[0030]

As described above, when the image coding apparatus of the present invention is used, information that requires a relatively long transmission time, such as image information, is transmitted to monitor or retrieve image information with a remote location. In addition, it is possible to appropriately encode the image information according to the operation requested by the image input means and to transmit the image information without delay or frame drop.

According to the second aspect of the invention, particularly when the input image information fluctuates greatly, the amount of transmission information can be greatly reduced, and the delay and the dropping of frames can be further eliminated.

According to the third aspect of the invention, in particular, the function of the existing encoding device can be utilized to simplify the implementation.

According to the invention of claim 4, since the image photographing device is used as the image input means, it is suitable for immediate monitoring and control of a remote place.

According to the fifth aspect of the invention, since the image recording device is used as the image input means, it is suitable for timely monitoring of remote places and retrieval of image information.

According to the sixth aspect of the invention, in particular, even when the state of the input image signal greatly changes, the resolution of the input image signal to be transmitted is increased or the number of frames to be transmitted is increased according to the situation. be able to.

According to the invention of claim 7 or claim 9,
In particular, when transmitting information that requires a relatively long transmission time, such as image information, to control it with a remote place, the image information is appropriately displayed according to the operation requested from the monitoring side of the remote place, etc. Since it can be encoded and transmitted without delay or dropping of frames, operation delay does not occur and the control desired by the operator can be executed conveniently.

According to the invention of claim 8, particularly when operating the image input means on the monitored side or the like, the image is appropriately encoded according to the movement of the image input means without delay or dropping of frames. You can send.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the present invention.

FIG. 3 is a block diagram showing a third embodiment of the present invention.

FIG. 4 is a block diagram showing a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a conventional image encoding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Monitor 2 ... D / A conversion part 3 ... Format reverse conversion part 4 ... Image decoding part 5 ... Demultiplexing part 6 ... ISDN interface part 7 ... Operation part 8 ... Control part 9 ... Camera 10 ... A / D conversion part 13 Demultiplexing unit 14 ISDN interface unit 15 Platform 17 Format conversion unit 18 Image coding unit 19, 21, 22, 24 Control unit 20 Image recording device 23 Operating unit 30, 31 Image communication terminal Device 41, 42, 43, 44 ... Image coding device 50 ... ISDN network

Claims (9)

[Claims] 1. An image encoding apparatus for encoding and transmitting image information of an input image signal, comprising: an image input means capable of controlling a state of the input image signal; and a control content for monitoring the control content for the image input means. An image coding apparatus comprising: a control unit that reduces the amount of information to be coded when instructing an operation of changing the state of the input image signal. 2. The image coding apparatus according to claim 1, wherein the control means for reducing the amount of information is means for reducing the resolution of the image information to be coded by thinning out. 3. The image code according to claim 1, wherein the control means for reducing the amount of information is a means for changing the coding control information for the means for coding the image information to roughen the quantization. Device. 4. The image encoding device according to claim 1, wherein the image input means is an image capturing device. 5. The image coding apparatus according to claim 1, wherein the image input means is an image recording apparatus, and the control content thereof is related to reproduction. 6. When the image coding apparatus according to claim 1 stores image information to be coded and transmitted in a buffer and performs the transmission, the control means for reducing the amount of information codes the information to be coded. When reducing the amount, the image encoding device is characterized in that the degree of reducing the information amount is changed with reference to the open state of the buffer. 7. The image coding apparatus according to claim 1, further comprising a control information receiving means for receiving control information for the image input means from the outside, wherein the control means for reducing the amount of information receives the received control. An image encoding device characterized by monitoring the control content of information and reducing the amount of information to be encoded when the control content instructs an operation of changing the state of an input image signal. 8. The image coding apparatus according to claim 1, further comprising an operation unit for instructing control of the image input unit, wherein the control unit for reducing the information amount monitors the instructed control content. An image coding apparatus, characterized in that, when the control content is an instruction to change the state of an input image signal, the amount of information to be coded is reduced. 9. The monitored side is provided with the image encoding device according to claim 7, and the monitored side is provided with means for decoding and displaying image information transmitted from the image encoding device, and the image. An image communication terminal device having a means for issuing control information to the image input means of the encoding device and a means for transmitting the control information to the control information receiving means of the image encoding device via a transmission path is provided. Remote monitoring system characterized by.