JPH02101884A - Picture signal transmission system and video conference system - Google Patents

Abstract

PURPOSE:To attain the transmission and reception of broad band information other than conference information by decomposing a picture signal into 1/n sampling data and transmitting the result to a line of 1/n band respectively. CONSTITUTION:A picture signal digitized by a demultiplexer DMUX 200 controlled by a control circuit 230 at a transmission side is separated by FIFO 210-213 at every sampling point of ABCD. A multiplexer MUX 120 multiplexes signals in the FIFO 210-213 to time slots 1-4 of a time division transmission line. Thus, 1/4 sampling picture data are sent through one line and a conference by 4 parties is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a video conferencing system in a broadband I5DN.

(Prior Art) As a conventional image conference system, the one described in "Electronic Information and Communication Handbook" edited by the Institute of Electronics, Information and Communication Engineers (published by Ohmsha), pages 2595 to 2597 is known.

FIG. 5 is a block diagram showing the configuration of a conventional image conference system. As shown in FIG. 5, in the conventional image conference system, operation terminals 500 to 503
, video cameras 520-523, monitor TVs 510-5
13.Multiplexer (MUX/
An image conference terminal consisting of DMUX) 530 to 533 is connected to an exchange 540 through a communication path having a transmission speed for moving images. Furthermore, the image conference trunk 550 is
40, and edits image signals from each terminal and distributes them again to each terminal. Further, a control circuit 560 of the image conference trunk 550 is connected to the exchange 540, and the image conference trunk 550 is controlled by control signals from each terminal.
Controls 0.

A case will be described in which an image conference is held using the system configuration shown in FIG. 5. Members participating in the conference control the exchange and set up one uplink and one downlink line between the terminal and the video conference trunk. After that, a line is set up between the operating terminal and the control circuit 560, and the image conference trunk 550
It controls the terminals to perform processing such as combining image signals from the terminals, distributes the signals to each terminal, and displays them on the terminals.

(Problems to be Solved by the Invention) According to the image conference system according to the prior art shown in FIG. They could not be sent at the same time. An object of the present invention is to provide a system that can simultaneously transmit broadband information other than moving image information while saving line capacity.

(Means for solving the problem) According to the present invention, n is a natural number of 2 or more, an image signal is decomposed into n series of 1/n subsampled image signals, and each of the 1/n subsampled image signals is An image signal transmission system is obtained which is characterized in that the image signal is transmitted through a line having a band that is 1/n of the band of the entire image signal.

Furthermore, an image signal transmission system is obtained, which is characterized in that the number of lines for transmitting and receiving 1/n subsampled image signals is controlled to a desired number.

Further, m is a natural number of 1 or more and An image signal transmission system characterized by selecting and using one of the conversion procedures is obtained.

Furthermore, n is a natural number of 2 or more, the image signal is decomposed into n series of 1/n subsampling image signals, and the 1/n
a transmitter for transmitting each sub-sampled image signal to a line having a band of 1n of the entire image signal band; a means for controlling the number of lines for sending and receiving 1/n sub-sampling image signals to a desired number; A natural number greater than or equal to n and less than or equal to 1
Or 1/n of m lines received from multiple image conference terminals
a plurality of image conference terminals each having one or more signal conversion means for constructing a full screen from a subsampled image signal and having a signal receiving section that selects and uses one of the signal conversion means; A video conferencing system is obtained which is characterized by comprising an exchange that connects multiple signals in a desired form under control of the above, and a multiple signal transmission line that connects the exchange.

(Function) By decomposing the image signal into n series of 1/n subsampled data and transmitting each to a line having a band of 1/n of the entire image signal, while holding a conference using subsampled images, Broadband information other than conference information can be sent and received. Furthermore, line capacity can be saved by transmitting and receiving sub-sample images.

(Example) The operation of the image conference system of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention;
FIG. 2 is a block diagram showing the configuration of the transmitting side of the line terminating device shown in FIG. 1, and FIG. 3 is a block diagram showing the configuration of the receiving side of the line terminating device. According to FIG. 1, the embodiment of the present invention includes operating terminals 100 to 103 and a video camera 120.
-123, monitor TVIIO-113, operation terminals 100-103, video cameras 120-123, line termination devices 130-133 to which monitors TV110-113 are connected to their respective terminal boats, and a control circuit 150. A control circuit 150 is connected to a control terminal, and an exchange 140 is connected to first to fourth terminals to which line ports of line termination devices 130 to 133 are connected.

Furthermore, as shown in FIG. 2, the transmission side of the line termination device 130 shown in FIG. 1 includes a control circuit 230 and a demultiplexer (
DMUX) 200 and each human power is DMUX 200
first-in-first-out memories (FIFOs) 210 to 213 connected to the first to fourth outputs of the first to fourth outputs;
~Consists of a multiplexer (MUX) 220 whose fourth input is connected to FIFOs 210-213, respectively.

Furthermore, the receiving side of the line termination device 130 shown in FIG.
As shown in Figure 3, a demultiplexer (DMUX) 3
00, and each input is the 1st to 4th of DMUX300.
a multiplexer (MUX) 320 whose first to fourth inputs are connected to the FIFOs 310 to 313, respectively, and whose output is connected to the control input of the MUX 320. control circuit 330.

A case will be described in which four people conduct an image conference according to this embodiment. Members participating in the conference first set up a line between their respective operation terminals 100 to 103 and the control circuit 150. Depending on the configuration of the image conference, exchange 1
40, and connects and sets as many multiplex lines as necessary for uplink and downlink desired transmission/reception signals between the image terminals 120 to 123, respectively. In this case, if necessary, a branch connection such as one to three is also performed. After that, each video camera 220-22
The image signals from 3 are multiplexed onto the line by the line termination devices 230 to 233, distributed to each terminal by the multiplex line set by the exchange 240, and the signals from the lines are reconfigured into image signals by the line termination devices 230 to 233. and display it on the terminal to conduct an image conference.

Next, the operation of the line termination device will be explained. On the transmitting side shown in FIG. 2, a DMUX 20 controlled by a control circuit 230
The image signal digitized by 0 is separated into PIFs 0210 to 213 at each sampling point of ABCD. MUX 120 multiplexes the signals input into FIFOs 210 to 213 into time slots 1 to 4 of the time division multiplex transmission path, respectively.

Also, as shown in Figure 3, on the receiving side of the line termination device,
The DMUX 300 sends the image signals multiplexed to time slots 1 to 4 of the input time division multiplex transmission path to FIFO 3, respectively.
10-313 Separate. The signals separated into FIFOs 310 to 313 are sent to 5EL3 controlled by a control circuit 330.
20, it is reconstructed into a desired image signal.

Next, a description will be given of what kind of image conference is conducted in this embodiment. FIG. 4 shows the mode of image conference carried out in this embodiment. - As an example, assume that 1/4 subsampled image data is sent over one line and a conference is held with four people.

If you want to display the image signal monitor screens of terminals 1 to 4 participating in the image conference on terminal 1 divided into four parts,
Each of the four transmitting sides transmits a 1/4 subsampled image signal using one line. The exchange 140 connects terminals 1 to
Connect all lines from 4 to terminal 1.

On the receiving side of the terminal equipment, the signals of each line are separated into FIFOs 310 to 313 as shown in FIG.
The signal is reconfigured so that it is displayed in four parts and displayed on a monitor.

If you want to display the image from terminal 1 on terminal 2 without reducing the definition, the transmitting side of the terminal equipment sends out four different 1/4 subsampled image signals using four lines. All four lines from terminal 1 are connected to terminal 2. On the receiving side of terminal 2, the 5EL 340 reconstructs the image signals of the four lines into the original image signal and displays it on the monitor.

If the terminal 3 wants to use only one line for the image signal in order to send data other than the image signal, the transmitting side of the terminal 3 uses one line to send out the 1/4 subsampled image signal. Exchange 140 connects one line from terminal 1 to terminal 3. On the receiving side of the terminal 3, as shown in FIG. 3, a control circuit 330 controls the 5EL 320, reconfigures the signal so that the terminal operator's signal is displayed, and displays it on the monitor. This allows the three lines to be used for other purposes.

As explained above, by combining various ways of using lines and displaying images on terminals, it is possible to send and receive broadband information other than conference information while holding a conference, and to save line capacity. be able to. Furthermore, since an image conference can be held by simply performing simple image processing on the terminal, there is an advantage that an image conference trunk is not required.

However, it is, of course, also possible to connect a conference trunk to the exchange 140 and perform a branch connection or the like using the conference trunk, as in the conventional example.

(Effects of the Invention) As described above, according to the present invention, it is possible to obtain an image conference system that can transmit and receive broadband information other than image conference information while holding a conference, and can save line capacity. .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of the transmitting side of the line terminating device shown in FIG. 1, and FIG. 3 is a receiving block diagram of the line terminating device shown in FIG. 1. FIG. 4 is a schematic diagram showing a connection type that can be performed in the embodiment shown in FIG. 1, and FIG. 5 is a block diagram showing the configuration of a conventional image conference system. In the figure, 101-103.500-503...operation terminal, 110-113.510-513-, Mo:
Data TV, 120-123.520-523...Video camera, 130-133...Line termination device, 53
0~533-MUX/DMUX, 140.340-...
Exchange, 150°560, 230.330...Control circuit, 550...Conference trunk, 200°300/DM
UX 1220・MUX, 320・SEL, 210
~213°310~313... FIFO is shown respectively.

Claims (4)

[Claims] (1) Let n be a natural number of 2 or more, and the image signal is 1 of n series.
An image signal transmission system characterized in that the image signal is decomposed into 1/n subsampled image signals, and each of the 1/n subsampled image signals is transmitted through a line having a band of 1/n of the band of the entire image signal. (2) The image signal transmission system according to claim 1, wherein the number of lines for transmitting and receiving 1/n subsampled image signals is controlled to a desired number. (3) where m is a natural number from 1 to n, and has one or more signal conversion procedures for constructing the entire screen from 1/n subsampling image signals of m lines received from one or more signal sources; 3. The image signal transmission system according to claim 2, wherein one of the signal conversion procedures is selected and used. (4) Let n be a natural number of 2 or more, and the image signal is 1 of n series.
a transmission unit that decomposes the 1/n subsampled image signals into 1/n subsampled image signals and sends the 1/n subsampled image signals to a line having a band of 1/n of the entire image signal; Means for controlling the number of lines to a desired number, and signal conversion for constructing a full screen from 1/n subsampling image signals of m lines received from one or more image conference terminals, where m is a natural number from 1 to n. a plurality of image conference terminals each having one or more means and having a signal receiving section that selects and uses one of the signal conversion means, and connecting multiple signals into a desired form under control from the image conference terminal. A video conferencing system comprising an exchange and a multi-signal transmission path connecting the exchange.