JPH0399593A - Picture data transmission system for inter-multipoint video conference system - Google Patents

Abstract

PURPOSE:To eliminate unnatural picture display in an inter-multipoint video conference system by providing a picture data selecting means and a selection instructing means. CONSTITUTION:Only one of picture data sent from plural 1st terminal equipments 111 being talkers and participants is selected by a selecting means 131 and sent to a 2nd terminal equipment 121. A selection instructing means 141 controls the selection operation of the selecting means 131 and applies the control of selecting a 1st terminal equipment 111 being normally a talker and only when a picture data from any of the 1st terminal equipment 111 being a participant exceeds a prescribed value, the control selecting the terminal equipment 111 is applied. Normally only the picture from the 1st terminal equipment 111 being a talker is selected normally and sent and the picture data from the 1st terminal equipment 111 being a participant other than the talker is selected and sent only when a prescribed quantity is exceeded, unnatural movement based on the picture data with less information quantity is eliminated and the unnaturality of picture display is improved.

Description

[Detailed Description of the Invention] [Summary] Improvement of unnaturalness in image display regarding an image data transmission method of a multipoint video conference system that controls the transmission and reception of video information between video conference stations installed at multiple points. In an image data transmission method for a multipoint video conference system that transfers image data input from a plurality of first terminals serving as speakers and participants to a second terminal, the first
a selection means for selectively selecting and outputting manually input image data from each of the terminals; and selection instruction means for sending an instruction to select the first terminal to the selection means only when the image data sent from any one of the terminals exceeds a predetermined amount.

[Industrial application field]

The present invention relates to an image data transmission method for a multipoint video conference system that controls the transmission and reception of video information between video conference stations installed at multiple points.

[Conventional technology]

There is a video conference system that connects two conference halls located at remote locations through a communication line and exchanges image signals and audio signals with each other. This video conference system has the advantage of saving travel time for both conference participants and ensuring a good atmosphere in the conference hall.

FIG. 6 shows a schematic configuration of the point-to-point video conference system described above. In the figure, the video conference station 61
1 includes a video codec 613 that encodes and decodes video images, and a camera 615 that photographs videos to be transmitted.
It also includes a monitor device 617 that displays the received video. Similarly, the video conference station 621 uses a video codec 623 . Camera 625. A monitor device 627 is provided.

The video conference stations are connected, for example, via transmission paths each having a line capacity of 384 Kbps in both directions, and image data encoded with high efficiency using moving image codecs 613 and 623 is sent and received. Inter-frame/intra-frame encoding is commonly used as this high-efficiency encoding method, and inter-frame encoding is normally performed, and intra-frame encoding is performed only when there is a large difference between consecutive frames, that is, when there is intense movement. I do.

The configuration of the multipoint videoconferencing system when such a point-to-point videoconferencing system is extended to multiple points is described in the seventh section.
As shown in the figure.

In the figure, 711, 713, 715, and 71'7 represent video conference stations, and 721 represents a multipoint connection device, respectively. Multiple video conference stations 71
1. ... are connected via a multipoint connection device 721, and each video conference station and the multipoint connection device 72
For example, a transmission line with a line capacity of 384 Kbps is used for connection with 1.

In addition, each video conference station is equipped with a camera to take images on its own device and multiple monitor devices to display images sent from other video conference stations, and is constantly connected to multiple points. Images are exchanged between them.

In such a multipoint video conference system, for example, if video conference station 711 is a speaker and other video conference stations are participants (listeners),
Images are sent and received, mainly image data of the speaker. Each participant receives image information of the speaker and participants other than its own device at a ratio of n:1, for example, the image of the speaker is
After updating the image, update one image of the participant.

In addition, as a publicly known example of a point-to-point video conference system or a multi-point video conference system, there is
-43954 publication, JP-A-60-79886 publication,
JP-A-63-280558, JP-A-63-302
There are publications such as No. 685.

[Problem to be solved by the invention]

By the way, in the above-mentioned multipoint video conference system, since the ratio of image information between speakers and participants is fixed, the amount of information for both speakers and participants is limited.
In particular, there was a problem in that images of participants with a small amount of information were discontinuous and unnatural due to delays. For example, if the ratio of speakers to participants is 8:1 and the number of video conference stations is 4, then 1/10 of the line capacity
(approximately 38 Kbps) is allocated to the images of the participants, making it impossible to send the amount of information necessary for displaying natural moving images.

In addition, if we increase the amount of information for participants in an attempt to improve the unnaturalness of their movements, the movements of the speaker, who normally moves a lot, will become unnatural, so the amount of information for participants will be minimized. It is normal to do so.

The present invention was created in view of the above points, and an object of the present invention is to provide an image data transmission method for a multipoint video conference system that improves the unnaturalness of image display. .

[Means to solve the problem]

FIG. 1 is a block diagram of the principle of the image data transmission method of the multipoint video conference system of the present invention. In FIG. In the image data transmission method of the multipoint video conference system for transferring to the second terminal 121, the selection means 131 alternatively selects and outputs the image data input from each of the first terminals 111.

The selection instruction means 141 normally selects the first terminal 1 which is the speaker.
11 is sent to the selection means 131, and an instruction to select this first terminal 111 is sent only when the image data sent from any of the first terminals 111 that are participants exceeds a predetermined amount. It is sent to the selection means 131.

Therefore, overall, the image data from participants other than the speaker is configured to be transferred only when a certain amount is exceeded.

[Function] Image data sent from a plurality of first terminals 111 serving as speakers and participants is input to the selection means 131, and only one of the first terminals 111 is selected and the image data is It is sent to the second terminal 121.

The selection instruction means 141 controls the selection operation of the selection means 131, and normally selects the first terminal 1 that is the speaker.
Control is performed to select 11.

In addition, only when the image data sent from any of the first terminals 111 that are participants exceeds a predetermined amount, the first terminal 111
control to select the terminal 111 of.

In the present invention, the first terminal 111 which is usually the speaker
The image data sent from the first terminal 111, which is a participant other than the speaker, is selected and sent only when the amount exceeds a certain amount. This eliminates unnatural image display based on image data with a small amount of information.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 2 shows the configuration of a multipoint video conference system in an embodiment of the present invention. Further, FIG. 3 shows the configuration of a multipoint connection device according to an embodiment, and FIG. 4 shows the configuration of a video conference station.

Here, the correspondence relationship between the embodiment of the present invention and FIG. 1 is shown (.

The first terminal 111 is a video conference station 2'll
, 221, 241.

The second terminal 121 corresponds to a video conference station 231.

The selection means 131 corresponds to the selector 321.

The selection instruction means 141 corresponds to the control circuit 311.

Examples of the present invention will be described below assuming that the correspondence relationship as described above exists.

As shown in FIG. 2, the multipoint video conference system of the embodiment includes four video conference stations (hereinafter simply referred to as stations) 2 each installed at a remote location.
11, 221, 231, 241, and a multipoint connection device 251 that connects each station. Each station and the multipoint connection device 251 are connected, for example, by a bidirectional transmission line with a line capacity of 384 Kbps.

Also, one station (e.g. station 231
) The detailed configuration of the multipoint connection device 25I is shown in FIG. 3. In the figure, 311 is a control circuit, 32 is a control circuit, and 32 is a control circuit.
1 indicates a selector, and 331 indicates a multiplexing section.

Stage buttons 211, 221, and 241 perform inter-frame encoding or intra-frame encoding as necessary (when there is intense movement) to transfer image data to the multipoint connection device 25.
I am sending it to 1. The control circuit 311 normally performs control to select only the image data of the speaker from among the image data sent from the above-mentioned stage engines, and only when the participant's movements become violent, the control circuit 311 selects the image data of the participant. Controls the selection of image data.

The selector 321 actually selects image data under the control of the control circuit 311, and the selected image data is sent to the station 231 after being multiplexed with control data in a multiplexer 331.

Note that the configuration of the multipoint connection device 251 described above is a configuration for sending image data of other stations to the station 231, and
The multipoint connection device 251 is assumed to have a similar configuration for transmitting image data to each of the 41, and illustration and detailed description thereof will be omitted.

Further, FIG. 4 shows the configuration of image data transmission and reception at each station. Each station uses video codec 4
11, a camera 431 for inputting images, and three monitor devices 441, 443 and 445 for displaying images corresponding to each of the other stations.

The video codec 411 encodes the video signal captured by the camera 431, and also encodes the video signal captured by the camera 431.
It performs an operation of decoding the image data sent from 51 and sending it to the corresponding monitor devices 241 to 245. Specifically, an encoding unit 413 that performs interframe encoding or intraframe encoding as necessary, a decoding unit 415 that decodes encoded data, and three monitor devices 441 to 44.
The image memories 417, 418, and 419 store decoded data corresponding to each image memory 417, 418, and 419, respectively. When image data is sent from the multipoint connection device 251 and decoded by the decoding unit 415, the corresponding image memory is updated, and only the display on the monitor device connected to this image memory is updated. It has become.

Next, the operation of the embodiment of the present invention described above will be explained.

FIG. 5 shows the operating procedure in the multipoint connection device 251 of the embodiment.

Now, with the configuration shown in FIG.
Let us consider the case where station 211 sends image data from other stations, and in particular, consider the case where station 211 is the speaker and the other stations are participants.

Normally, the multipoint connection device 251 sends image data of the station 211, which is the speaker, to the station 231 (step 511).

The control circuit 311 selects input terminal A from the three input terminals of the selector 321 to
Only 11 image data are input to the multiplexing section 331. The multiplexer 331 applies this input image data to the control circuit 3.
The control data (station identification data, etc. corresponding to image data) inputted from the station 11 is multiplexed and sent to the station 231 .

The station 231 decodes this image data, determines based on the multiplexed control data that the image data is from the station 211, updates the image memory 417 based on the decoded data, As a result, the display on the monitor device 441 corresponding to the station 211 is updated.

The control circuit 311 also determines whether there is a participant who is performing intraframe encoding (step 512).
, if the determination is negative, the process of step 511 is repeated.

When the movement of images at the stations 221 and 241 increases, the video codec 411 in each station shifts from interframe encoding to intraframe encoding and performs encoding. Image data containing the information is sent.

The control circuit 311 makes an affirmative determination in step 512 by detecting this image data, and then determines that the source of the image data in the intra-frame encoding mode is station 2.
21 (step 513). When the judgment is affirmative, the selector 321 is switched and the image data from the station 221 input to the input terminal B (
image data by intra-frame encoding) is selected (step 514). The selected image data is further sent to the stage generator 231 via the multiplexer 331, and the image memory 418 corresponding to the station 221, that is, the display on the monitor device 443 is updated.

If the determination in step 513 is negative, it is determined that the station 241 is the source of the image data in intraframe encoding mode. Therefore, the control circuit 311 switches the selector 321 to select the image data of the station 241 input to the input terminal C (step 515). This selected image data is further sent to the station 231 via the multiplexing section 331, and the display of the image memory 419 corresponding to the station 241, that is, the monitor device 445 is updated.

When the transmission of the image data of the participants in the intraframe encoding in step 514 or step 515 is completed, the control circuit 311 switches the selector 321 to select the station 211 that is the speaker (step 516). Thereafter, the process returns to step 511 and station 2, which is the speaker,
11 image data is sent to station 231.

In this way, the multipoint connection device 251 normally sends only the image data from the station 211, which is the speaker, to the station 231, and the images at the other participants, stations 221 and 241, change rapidly. Only when switching to intra-frame coding mode, image data in this intra-frame coding mode is transferred to the station 23.
Make sure to send it to 1.

Therefore, the station 231 normally receives only the image data of the speaker and updates the display on the monitor device, and only receives the image data of the participant and updates the display on the monitor when the movement becomes intense. The display of the corresponding monitor device is updated. Therefore, it is possible to prevent unnatural image display caused by sending a limited amount of information from each participant, and since the image data of only the speaker is normally received, the movement of the speaker can be prevented. Become natural.

In reality, since the speaker changes fairly regularly, it can be said that there is no particular problem in fixing the image of the participant who does not move much during that time.

Note that in the embodiment of the present invention, the station 231
Although we have considered the case where image data is sent to another station, the same applies to the case where image data is sent to other stations.

Further, in the embodiment, the case where the station 211 is the speaker is considered, but if the speaker changes, for example, if the station 221 becomes the speaker, the control circuit 3
11 performs speaker detection, and then station 21
Similar processing may be performed using 1,241 as a participant. Regarding this speaker detection, the prior art was developed in Japanese Patent Application Laid-open No. 60-4.
This is a known technique as disclosed in Japanese Patent No. 3954, etc., and its explanation will be omitted.

〔Effect of the invention〕

As described above, according to the present invention, only the image data that is normally sent from the first terminal that is the speaker is selected and transmitted, and the first terminal that is the participant other than the speaker By selectively transmitting the image data sent from the system only when the amount exceeds a certain amount, it is possible to eliminate unnatural movements based on image data with a small amount of information and improve the unnaturalness of the image display. Therefore, it is extremely useful in practical terms.

[Brief explanation of drawings]

Fig. 1 is a principle block diagram of the image data transmission method of the multipoint video conference system of the present invention, Fig. 2 is a block diagram of the multipoint video conference system of the embodiment, and Fig. 3 is the multipoint connection of the embodiment. A configuration diagram of the device, FIG. 4 is a configuration diagram of a video conference station according to an embodiment, FIG. 5 is an explanatory diagram of the operation of the embodiment, FIG. FIG. 1 is a configuration diagram of a teleconference system. In the figure, 111 is a first terminal, 121 is a second terminal, 131 is a selection means, 141 is a selection instruction means, 211, 221, 231, 241 are video conference stations, 251 is a multipoint connection device, 311 is a control circuit, 321 is a selector, 331 is a multiplexing unit, 411 is a video codec, 413 is an encoding unit, 415 is a decoding unit, 417, 418, 419 are image memories, 431 is a camera, 441 443, 445 is a monitor device be. Higashishitake, J's lazy color, F', fl TV meeting, person ψ I, Atonement BA CA, figure 2, roasting example, 397 L, the laziness of the enemy, figure 3, money spinning, TV d Kaijin Station's A% attack 24th figure Shun Matsuho's movement tFL mouth day ward 2b Iroto, Mimiko Shiji' Rei transfer Shijin tem's clear figure Figure 6 Shio Iba, Kama Brevi ° Kaigi System σ, #Swim Chart Figure 7

Claims (1)

[Claims] (1) A plurality of first terminals (111
) In an image data transmission method of a multipoint video conference system that transfers image data input from a second terminal (121) to a second terminal (121), the image data input from each of the first terminals (111) is selected. selection means (131
), and an instruction to select the first terminal (111) that will normally be a speaker is sent to the selection means (131), and an instruction is sent from any of the first terminals (111) that will be a participant. This first terminal (11
1) selection instruction means (141) for sending an instruction to select the selection means (131);