JPH0795553A - Multi-spot pictorial communication system - Google Patents

Abstract

PURPOSE:To provide a video conference system, which unnecessitates any center equipment, as well by simultaneously observing the images of plural places at image display devices installed at the respective multiple spots connected in the shape of a loop. CONSTITUTION:For each terminal, an image display terminal is used so as to exchange encoded image data by adopting an encoding system to perform encoding for each of image data displayed in a small area while dividing the display picture into plural small areas, the image data from the upstream terminal are displayed in the plural small areas consisting of one picture by spots, data corresponding to any specified small area are deleted from those image data, and image data generated at the present terminal are inserted in place of those deleted data and sent to the downstream side terminal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multipoint image communication system in which a plurality of points are connected in a loop and communication using images is performed between the points.

More specifically, the present invention relates to any desired point among a plurality of points connected by a loop-shaped transmission line,
If an image display terminal is provided and image data from another upstream point transmitted via the transmission line is received,
While displaying this on the display screen of the terminal and adding the image data of its own point to the received image data, it is transmitted to another point downstream via a transmission path, thereby providing a point equipped with the image display terminal. The present invention relates to a multipoint image communication system for performing image communication between devices.

[0003]

2. Description of the Related Art A conventional videophone, when viewed as an image communication system, can perform only one-to-one counter communication. Also, in a video conference system which is a system for performing image communication, a multipoint connection is realized by connecting a multipoint in a star shape via a center device.

In a star-type connection type video conference system using a center device, since images of all points are concentrated on the center device, switching control is performed to determine which point each image is to be distributed to. Can be done easily. However, the star-type multi-point video conference system has a drawback that a large-scale and expensive center device is necessarily required.

Therefore, a method of connecting a plurality of terminals in a loop is conceivable as a method of realizing multipoint connection without requiring a center device. This loop connection method also has an advantage that the number of channels required for connection may be smaller than that of the star type.

[0006]

In the loop type connection system, unlike the star type connection system, there is no node (point) where images at all points are concentrated. Therefore, it is difficult to collect (edit) and distribute images from each point, and it seems that there is no other way than to send the image from only one point.

However, in this method, even though communication is being carried out between a plurality of points, only one of the points can be viewed, and, in particular, as in a conference, a plurality of points can be used. It is inconvenient if the images at a plurality of points cannot be viewed at the same time when such a statement is made.

In order to solve the above problems, it is an object of the present invention to provide a multipoint image communication system of a loop type connection system in which all terminals can simultaneously see a plurality of images of the ground. .

[0009]

In order to achieve the above object, a first aspect of the present invention provides an encoding method in which a display screen of a terminal is divided into a plurality of small areas and each small area is encoded. A terminal capable of transmitting and receiving image data is arranged at a plurality of points, and they are connected in a loop through a transmission line to form a multipoint image communication system. Image data deleting means for deleting data corresponding to a specific display position (small area) from the image data, and image data generated in the terminal itself are inserted into the received data as data corresponding to the specific display position (small area). And an image data inserting means for sending the image data.

In the second aspect of the invention, similarly, the multipoint image communication system as described above is constructed, and each terminal has the image data deleting means and the image data inserting means as described above.
In addition to the above, the display area changing means for rewriting the data portion expressing the display position (small area to be displayed) of the received image data is provided.

Further, in the third invention, the multipoint image communication system as described above is similarly constructed, and each terminal has the image data deleting means and the image data inserting means as described above.
In addition to being equipped with, each terminal at a different point on the loop,
When deleting the image data corresponding to a specific small area from the received image data by the image data deleting means, the corresponding small area to be deleted is made different for each point, and the specific small area is deleted by the image data inserting means. When inserting the image data corresponding to, the corresponding small area to be inserted is provided with a point-by-point insertion / deletion area designating unit that makes it possible to make it different for each point.

Further, in the fourth invention, the above-mentioned first to third
In the multipoint image communication system according to each invention,
At least one terminal includes a pattern generating unit that generates a specific image pattern as a background pattern, and the image data inserting unit inserts the image data generated by the own terminal at a specific display position (small area). The background pattern generated by the pattern generating means can be inserted into a display position (small area) different from that.

Further, in the fifth invention, the above-mentioned first to third
In the multipoint image communication system according to each invention,
At the time of loop formation (connection), in order of calling and connecting at each point,
We decided to determine the positioning of each small area in the display screen of each terminal. In the sixth invention, the positioning is performed clockwise or counterclockwise with respect to the own terminal on the loop, in the order of the terminals located in that order.
I decided to do it.

Further, in the seventh invention, in the multipoint image communication system according to each of the first to sixth inventions, processing such as deletion or insertion of received image data is performed at each point on the loop. Instead, the received image data is displayed on the screen as it is, and there is at least one point that has only a terminal that sends the image data as it is.

[0015]

In the multipoint image communication system according to the first aspect of the present invention, the terminal at each point on the loop displays the received image data, and the image data deleting means causes a specific display area (small area) from the received image. ) Is deleted, and the image data insertion means inserts the image data generated in the own terminal into a specific display area (small area), so that the entire display area is divided into several small areas. By dividing and displaying images of different points in combination with each small area, one screen in which images of a plurality of points are combined is configured. As a result, it is possible to improve the display man-machine interface of the multipoint image communication system and improve the sense of presence during image communication.

In the multipoint image communication system according to the second aspect of the present invention, the terminal at each point on the loop displays the received image data, and at the same time, the image data deleting means causes a specific display area (small area) from the received image. Image data corresponding to the area), the display area changing means changes the display position (small area) of the image of the different ground (point), and then the image data inserting means causes the image generated in the terminal itself. By inserting data, the entire display area is divided into several small areas, and images at different points are combined and displayed in each small area to form one screen that combines images from multiple points. Not only can you

For example, if the image of the own terminal is deleted and then the image of the other terminal is inserted, only the image of the other terminal excluding the image of the own terminal is divided into small areas on each small area. It is possible to display on the screen, and even if there is one more point on the loop than the number of divisions of the display screen (the number of small areas), the images of all terminals other than the own terminal are displayed on one screen. Since it can be displayed, it can be displayed without a sense of incongruity (the image of the terminal itself does not have to be always displayed. When necessary, it can be displayed by superimposing it on the display surface with PinP (Picture in Picture)).

In the multipoint image communication system according to the third invention, in addition to the function of the multipoint image communication system according to the first aspect, image data corresponding to the deleted small area is generated in the own terminal. By inserting the image data, it becomes possible to display split screens having the same content on terminals at all points on the loop.

In the multipoint image communication system according to the fourth aspect of the present invention, when the number of divided areas (the number of small areas) on the display screen of the terminal is larger than the number of points (terminals) on the loop, By displaying a specific image pattern as a background pattern in the vacant small area and eliminating the blank small area, the man-machine interface of the display can be improved.

Further, in the multipoint image communication system according to the fifth and sixth inventions, a loop is formed in the display position of the image on the display screen (the order of allocation of each small area constituting the display screen to each terminal). The display position (display position of each small area) and the terminal (the display position of each small area) and the terminal ( By associating the position with the position on the loop, it is possible to further improve the realism during image communication.

Further, in the multipoint image communication system according to the seventh invention, when the number of divisions of the small area (the number of small areas) on the display screen is smaller than the number of points (terminals) on the loop, the received image By only displaying the data, sending the received image data as it is, and providing the point (terminal) where the image of the own terminal does not flow on the loop, the number of screen divisions (the number of small areas) and the point on the loop ( The restrictions between the number of terminals) can be removed.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The image communication system according to the embodiments of the present invention will now be described in accordance with CCITT Recommendation H.264 as an image encoding system. 261
The description will be made assuming that the image data that is encoded and transmitted by the encoding method according to (Recommendation number) is used and the ISDN basic interface is used as the transmission line, but before that, CCITT Recommendation H.264. The hierarchical structure of encoded image data according to H.261 will be described.

FIG. 21 shows CCITT Recommendation H.264. FIG. 26 is an explanatory diagram showing a hierarchical structure of encoded image data according to H.261. As can be seen in the figure, CCITT Recommendation H.264. In 261
One frame of data that makes up one screen is converted into 12 GOBs.
Divided into (Group Of Block), each GOB has 3
It is divided into 3 macroblocks, and each macroblock is
It consists of 6 blocks, each block consisting of 8 × 8 pixels. Encoding is performed in units of macroblocks.

Expressing it differently, one frame of data constituting one screen consists of 12 GOBs.
GOB numbers 1 to 12 can be attached to each GOB as illustrated. Since one GOB consists of 33 macroblocks, macroblock numbers 1 to 33 can be assigned to each macroblock. 1 macroblock is 6
The luminance signal (Y) is represented by 1 to 4 blocks, and the color signal (Cb,
Cr).

In this way, H.264 The encoding method of H.261 is
This is also an example of an encoding method in which one screen is divided into a plurality of areas (GOB) and encoding is performed for each area. In addition, JPEG (Joint Photographic Coding Experts Grou
p), MPEG, etc. are also examples of methods for performing coding for each area.

Next, FIG. [Fig. 26] Fig. 26 is an explanatory diagram showing a format of a transmission frame of image data encoded by adopting the encoding method of H. The encoded data is framed in units of GOB in FIG.

In FIG. 22, PSC is a frame start code, followed by TR (frame number) and PTYP.
E (type information), PEI (extension data insertion signal),
... PSPARE (preliminary information), PEI (expansion data insertion signal), and GOB data. This GOB data continues as many times as necessary. One GOB data is GBS
C (GOB start code), GN (GOB number), GQUA
NT (quantization characteristic information), GEI (extension data insertion signal), ... GSPARE (preliminary information), GEI (extension data insertion signal), and macroblock data.

FIG. 1 is an explanatory diagram showing an example of multipoint connection in the multipoint image communication system as an embodiment of the present invention. As is well known, in the basic interface of ISDN, two B channels in one line (the B channel is
User information transfer channel) can be used at the same time, and
, And a loop of one B channel is formed as a whole.

FIG. 1A shows an example of connection of four terminals. Terminal A at point A, terminal B at point B, terminal C at point C,
When the terminal D at the point D and the terminal D are connected in a loop by an ISDN line, the terminal A is one of the two B channels, the terminal D on the upstream side, and the terminal B on the downstream side, Two
The other B channel is connected to the other B channel, and the same applies to other terminals. If the ISDN line is not used, the same connection can be made by using two telephone lines.

FIG. 1B shows a connection example of 5 terminals, FIG. 1C shows a connection example of 3 terminals, and FIG. 1D shows a connection example of 6 terminals. In any connection example, each terminal displays the image data received from the upstream on its own terminal, deletes some image data from the received image data, inserts the image data generated at its own terminal, and The image data will be sent to the downstream terminal.

In each terminal, the screen is divided into a plurality of small areas, and the image data from each upstream terminal is displayed in each of these small areas. Image communication becomes possible. An image generated in the terminal itself can be displayed in one of the small areas of the display screen of each terminal, or it can be not displayed. In addition, various modified examples are possible. Hereinafter, they will be sequentially described. Since the present invention focuses only on the image data, it does not touch on the transmission of audio signals necessary for general communication.

FIG. 2 is a block diagram showing an example of the configuration of the image display terminal provided at each point in FIG. 1 according to the present invention. In FIG. 2, 1 is a network interface unit, 2 is a multiplexing / demultiplexing unit, 3 is an image display unit, 4 is an image decoding unit, 5 is an image input unit, 6 is an image encoding unit, 7 is an image data deleting unit, Reference numeral 8 is an image data insertion unit, and 9 is a control unit. A bus connection is provided between the control unit 9, the network interface unit 1, the multiplexing / demultiplexing unit 2, the image data deleting unit 7, the image data inserting unit 8, and the image encoding unit 6.

Referring to FIG. Network interface section 1
Receives the data and call control information sent from the other terminal (upstream terminal) via ISDN, and separates the data on the B channel from the call control signal on the D channel. The multiplexing / separating unit 2 separates the data on the B channel into image data and other data (for example, audio data), and sends only the image data to the image data deleting unit 7 and the image decoding unit 4. It should be noted that voice data will not be described because it is not directly related to the present invention.

Since the present image communication system has a looped connection form as shown in FIG. 1, the flow of image data is unidirectional. In this example, for convenience, (a) in FIG.
, The direction is A → B → C → D → A → ...
Therefore, in the multiplexing / demultiplexing unit of the terminal A, the data from the B channel connected to the terminal D which is the upstream terminal is used as the reception data, and the transmission data is set to the B channel connected to the terminal B which is the downstream terminal. Will be sent.

The image data deleting section 7 has a function of deleting the data corresponding to a specific display position (small area) on the display screen from the image data from the multiplexing / separating section 2. H.
In the encoding method of 261, each position of the image described in FIG. 21 (GOB number 1 in one frame constituting one screen is 1
The GOB data corresponding to the small areas indicated by 12 to 12 are transmitted by being carried on the transmission frame shown in FIG. Therefore, for example, when deleting the data that should be displayed in the lower right quarter of the screen, the image data deletion unit 7 deletes the data of GOB numbers 8, 10, and 12 in the transmission frame of FIG.

The image encoding unit 6 receives an input image from an image generation source (not shown) generated by this terminal, according to CCITT Recommendation H.264. Encoding is performed according to H.261. The image decoding unit 4
The image data from the demultiplexing / demultiplexing unit 2 is transferred to CCITT Recommendation H.264. Decoding according to 261.

The image data inserting section 8 inserts the data from the image encoding section 6 into the data from the image data deleting section 7. For example, in the image data deletion unit 7, the lower right 1 /
When the data corresponding to the display position of No. 4 is deleted, the image data insertion unit 8 replaces the data from the image encoding unit 6 with G
It is inserted as data of OB numbers 8, 10, and 12. CCITT Recommendation H.264. 261, the number 1 shown in FIG.
A format called QCIF (using GOB1, 3, 5) having a resolution of 1/4 of the frame image is also defined, and if it is used, the image data insertion unit 8
Only reassign OB numbers. The inserted image data is multiplexed with other data (for example, audio data) by the multiplexing / separating unit 2 and then sent to the network interface unit 1.

The control unit 9 instructs the image data deleting unit 7 to perform GOB to be deleted, or uses the signal from the image data deleting unit 7 as a trigger to instruct the image encoding unit 6 to perform encoding, and The image data inserting unit 8 is instructed to insert the image data from the image encoding unit 6. Also, ISD
N call control and H.N. Control such as capacity exchange prescribed by 242 etc. is also performed. The image display unit 3 is a monitor that displays the image decoded by the image decoding unit 4. The image input unit 5 is a camera that inputs an image into the image encoding unit 6.

Next, referring to FIG. 2, the image coding / decoding section is instructed by CCITT Recommendation H.264. Using the H.261 compliant CODEC, the lower right quarter area of the received image (G in FIG.
OB8, 10, 12) will be deleted and the image data generated in the own terminal will be inserted therein, and the operation of each unit will be specifically described.

The received image data has the frame structure shown in FIG. 22, which is sent to the image data deleting unit 7 and the image decoding unit 4 as already described. The image decoding unit 4 decodes it as FCIF data. In the image data deleting unit 7, the header other than the GOB data and the GOB instructed by the control unit 9 (GOBs 8, 10,
GOB data other than 12) is transferred to the image data insertion unit 8 as it is. The GOB instructed by the control unit 9 is deleted. Please refer to the operation flow of the image data deleting unit 7 shown in FIG.

Note that the PSC reception is notified to the control unit 9 in this flow because it is used as a trigger for the control unit 9 to instruct the image encoding unit 6 to perform encoding. If you notify only once for the one frame shown,
Not limited to PSC reception, other events may be used as a trigger.

The image data coding unit 6 performs coding by QCIF according to an instruction from the control unit 9, and transfers the coded data to the image data insertion unit 8. The format at this time is the frame shown in FIG. 22, and GOB data is GOB data.
Only 1, 3, 5 are available. The image data inserting unit 8 combines the data from the image data deleting unit 7 and the data from the image encoding unit 6 to reconstruct the frame shown in FIG. Please refer to the operation flow of the image data insertion unit 8 shown in FIG.

In the flow of FIG. 4, since the data from the image coding unit 6 has a header such as PSC in addition to the data of GOB1, 3, 5, it is necessary to delete the header (image data insertion). When combined with the data from 7 in part 8, it will be double).

Next, GOB number (GN in FIG. 22)
Are rewritten from 1, 3, 5 to 8, 10, 12, respectively. In addition, the image encoding unit 4 adjusts the time for completing the encoding and the reception time from the image data deleting unit 7 to PSC to PSPARE, and H.264. Since the coding method of H.261 is variable length coding, the length of the data deleted by the image data deleting unit 7 and the length of the GOB from the image coding unit 6 do not always match. They require frame assembly or buffering.

In the control unit 9, the notification of the PSC reception from the image data deletion unit 7 is used as a trigger to give the image coding unit 6 a coding instruction. Please refer to the operation flow of the control unit shown in FIG.

In the above example, CCITT Recommendation H.264. 261
Using the difference in the resolutions of FCIF and QCIF, the screen is divided into four small areas, and one of the lower right ¼ images is deleted / inserted. Image coding unit 6
It is possible to use a screen division number other than 4 by using a non-standard one. In that case, the image encoding unit 6 encodes the input image of the image input unit 5 to a required resolution. For example, if two GOBs are coded, the screen can be divided into six (6 small areas) for use. Further, the position (which small region) to delete / insert an image can be set to an arbitrary position (arbitrary small region) only by changing the GOB number.

FIG. 6 shows the image data deleting section 7 in FIG.
3 is a block diagram showing the details of the configuration of FIG. In FIG.
Reference numeral 71 is a FIFO buffer, 72 is a PSC (frame start code) detection unit, and 73 is a GOB data deletion unit. FI
The FO buffer 71 receives the data from the multiplexer / demultiplexer 2. If there is received data, the PSC detector 7
2 is notified, and the data is read from the PSC detection unit 72.

When the PSC detection section 72 is notified by the FIFO buffer 71 that there is data, the FIFO
The data is read from the buffer 71. When the PSC (frame start code) is detected from the read data, the control unit 9 and the GOB data deletion unit 73 are notified. Then, the data is sent to the GOB data deleting unit 73.

The GOB data deleting section 73 detects GBSC (GOB start code) and GN (GOB number) from the data received from the PSC detecting section 72. If the detected GN is a value preset by the control unit 9, the G
GOB data including N is deleted (whether the deletion stop condition is to detect the next GBSC or receive a notification from the PSC detection unit). The data that is not deleted is transferred to the next block as it is.

FIG. 7 shows the image data inserting section 8 in FIG.
3 is a block diagram showing the details of the configuration of FIG. In FIG.
81 is a GOB header detecting unit, 82 is a FIFO buffer A, 83 is a header deleting unit, 84 is a GOB number replacing unit, 8
Reference numeral 5 is a FIFO buffer B, and 86 is an input selection unit.

In FIG. 7, the GOB header detector 81
Receives data from the preceding block. Although the former stage is the image data deleting unit 7, other display position changing units shown as the former stage will be described later. GBSC (GOB start code) is detected from the received data. G
The input selection unit 86 is notified that the BSC has been detected. Then, the data is transmitted to the FIFO buffer A 82.

The FIFO buffer A 82 receives the data from the preceding block via the GOB header detector 81. Then, the data is read from the input selection unit 86. The header deletion unit 83 receives the data from the image coding unit 6. Received data (format of FIG. 22)
To GOB data (from PSC to data immediately before GBSC) are deleted. Then, the data is transmitted to the GOB number substitution unit 84.

The GOB number replacing section 84 detects GN (GOB number) from the data received from the header deleting section 83. The detected GN is rewritten to a value designated by the control unit 9 in advance. Data other than GN is unchanged, G
N sends the rewritten data to the FIFO buffer B85. Input selection section 8 when there is no data to process
Notify 6.

The FIFO buffer B85 receives the data from the GOB number replacing unit 84. And the input selection section 8
Data is read from 6. In the input selection unit 86, G
A notification has been received from the OB number substitution unit 84, and GOB
When the GOB detection notification is received from the header detection unit 81,
Read data from the FIFO buffer B85 (GOB
Insertion). The data is transmitted to the subsequent block.

Next, as shown in (b) of FIG.
In the image communication system in which the five terminals are connected in a loop, and in each terminal, as in the case of the terminal in FIG.
FIG. 8 shows a configuration example of an image display terminal that can be suitably used when there are only four small display areas on one screen.

The block diagram shown in FIG. 8 differs from that shown in FIG. 2 in that a display position changing unit 10 is added. The display position changing unit 10 has a function of rewriting the data portion representing the display position (display small area) of the data from the image data deleting unit 7, that is, the GOB number.

In the terminal shown in FIG. 2, when the display data in the lower right ¼ area on the screen of the received data is deleted / inserted, the received data is transmitted as it is to the other display small areas. . However, the display position changing unit 10 can rearrange the display position of the received data (change the display small area). In the block diagram of FIG. 8, the functions of the parts other than the display position changing unit 10 are the same as those of FIG.

Next, referring to FIG. 8, CCITT Recommendation H.264 is applied to the image coding / decoding unit. When the display screen of each terminal (A to E in (b) of FIG. 1) is as shown in FIG. 9 using a 261 compliant CODEC (that is, no terminal displays image data of its own terminal, In the case of displaying the image data of 4 terminals in 4 small areas that compose one screen) as an example,
The operation of each unit will be specifically described.

Now, referring to FIG. 8, the image data deleting unit 7
Operates similarly to the case of the terminal in FIG. 2, except that the data transfer destination is the display position changing unit 10 instead of the image data inserting unit 8. In this example, GOB instructed by the control unit 9
Data is GOB1, GOB3, GOB5 on all terminals.
Is.

The display position changing unit 10 changes the GOB numbers in all terminals as follows. That is, GOB2 → GOB1 GOB4 → GOB3

GOB6 → GOB5 GOB7 → GOB2 GOB8 → GOB7

GOB9 → GOB4 GOB10 → GOB9 GOB11 → GOB6 GOB12 → GOB11

The operation flow of the display position changing unit 10 is shown in FIG.
Please refer to the above. The image data insertion unit 8 operates similarly to the case of the terminal shown in FIG. 2, except that the receiving destination of the image data is the display position changing unit 8 instead of the image data deleting unit 7. In this example, the data from the image encoding unit 6 is inserted as the image data of GOB8, GOB10, GOB12.

In this example, as shown in FIG. 9, on the loop ((B) in FIG. 1), the image data of each terminal are arranged in the counterclockwise order in the four small areas constituting one screen. Although the display positions are changed so that they are arranged side by side, the display positions of the image data can be arbitrarily arranged by changing the correspondence of the GOB numbers in the display position changing unit 10. In addition, in this example, since each terminal does not include the image data of its own terminal in the signal from the image decoding unit 4 and therefore does not display the image on the image display unit 3, the number of display points can be increased by 1 (at 4 points). There are merits (it can be set to 5 points).

When it is necessary to display the image data of the own terminal,
By using the PinP (picture-in-picture) method, it is possible to solve the problem by directly displaying an image from the image input means of the own terminal on an arbitrary part of the screen.

Next, FIG. 11 is a block diagram showing details of the configuration of the display position changing unit 10 in FIG. In FIG. 11, 101 is a GN detection unit, 102 is a GN rewriting unit, and 103 is a FIFO buffer unit.

Referring to FIG. The GN (GOB number) detection unit 101 receives data from the preceding block.
GN (GOB number) is detected from the received data. G
The FIFO buffer unit 103 is notified that N has been detected. Then, data other than GN is transferred to the FIFO buffer unit 10
Send to 3. The GN is transmitted to the GN rewriting unit 102.

In the GN rewriting unit 102, the GN detecting unit 1
Receive data from 01. GN is rewritten to a value preset by the control unit 9. And the data is F
It is transmitted to the IFO buffer unit 103. FI the end of transmission
Notify the FO buffer unit 103.

The FIFO buffer unit 103 is normally GN.
Data is received from the detection unit 101. When a signal is received from the GN detection unit 101, the GN rewriting unit 102
Receive signals from. When the signal is received from the GN rewriting unit 102, the signal is received from the GN detection unit 101.
Then, the data is transmitted to the next block.

Next, another operation mode of the image communication system according to the present invention will be described. A shown in FIG.
An example is a system in which four terminals D to D are connected in a loop. The configuration of the terminal is the same as that shown in FIG.
CCITT Recommendation H.264 is applied to the image encoding unit / decoding unit. The operation of each unit when the display screen of each terminal is as shown in FIG. 12 (that is, the display screen is the same for all terminals) using a 261 compliant CODEC will be specifically described. Note that, here, the operation different from the operation described above with reference to FIG. 2 will be mainly described.

Referring to FIG. The operation of the image data deletion unit 7 is as in the flow of FIG. 3 described above, but the GOB data to be deleted, which is instructed by the control unit 9, differs depending on the terminal. I.e.

The image data of the terminals A GOB1, GOB3 and GOB5 are deleted. The image data of the terminals B GOB2, GOB4, GOB6 are deleted. The image data of the terminals C GOB7, GOB9, GOB11 are deleted. The image data of the terminals D GOB8, GOB10, GOB12 are deleted.

The operation of the image data insertion unit 8 is also as in the flow of FIG. 4 described above, but the GOB data to be inserted, which is instructed by the control unit 9, differs depending on the terminal. I.e.

It is inserted as image data of the terminals A GOB1, GOB3, GOB5. Inserted as image data of terminals B GOB2, GOB4, GOB6. It is inserted as image data of the terminals C GOB7, GOB9, GOB11. It is inserted as image data of the terminals D GOB8, GOB10, GOB12.

When performing the loop connection shown in FIG. 1A, the terminal A is the first calling terminal at the time of the loop connection, and the terminal A is the terminal B, the terminal B is the terminal C, and the terminal C is the terminal. When C makes a call to the terminal D and the terminal D makes a call to the terminal A one after another to form a loop, in this example, the display small area is positioned in the order of the calling and connection (terminal). Has been decided, and it is possible to enhance the sense of presence during image communication.

Next, an image communication system according to another embodiment of the present invention will be described. Three terminals A to C
1 has a loop-like connection form as shown in FIG. 1C, and each terminal has CCITT recommendation H.264 as an image encoding unit / decoding unit in the same manner as that shown in FIG. A case where a CODEC compliant with H.261 is used will be described.

As described above, H.264. In the two resolutions recommended by H.261, the QCIF is 1/4 the resolution of FCIF, so the screen is divided into 4 (divided into 4 small areas) and the images with the resolutions equivalent to 4 QCIF are combined. It is natural to display and compose one screen. However, in practice, the number of points (terminals) connected on the loop and to be displayed on the screen may be smaller than the four. As an example of such a case, the number of terminals is 3 here.
Two cases will be described. That is, although there are four small areas that form one screen, the number of points (terminals) to be displayed is three, so that one small area is generated. The problem is how to handle this empty small area.

FIG. 13 is a block diagram showing the configuration of an image display terminal that can be suitably used in such a case. FIG.
2, the same parts as those in FIG. 2 are designated by the same reference numerals. In addition, 11 is a background pattern generation unit, and 12
Is a background pattern insertion part. For example, (c) in Figure 1
As shown in FIG. 3, there are three terminals, terminal A, terminal B, and terminal C, of which terminal A is a terminal having the configuration shown in FIG. 13 and the other two are terminals having the configuration shown in FIG. If so, the image data deletion unit of each terminal operates as follows. I.e.

Terminal A GOB1, GOB3, GOB5, GOB8, G
The image data of OB10 and GOB12 is deleted. The image data of the terminals B GOB2, GOB4, GOB6 are deleted. The image data of the terminals C GOB7, GOB9, GOB11 are deleted.

The background pattern generation unit 11 of the terminal A generates the blue back coding pattern as the background pattern to be displayed in the empty small area, and the background pattern insertion unit 12
Transfer to. The background pattern insertion unit 12 of the terminal A operates as follows. It is inserted as image data of the terminals A GOB1, GOB3, GOB5. Blueback image data is inserted into GOB8, GOB10, and GOB12.

Further, the image data inserting sections of the terminals B and C operate as follows. Inserted as image data of terminals B GOB2, GOB4, GOB6. It is inserted as image data of the terminals C GOB7, GOB9, GOB11.

The display screen of each terminal in this example is shown in FIG. The display area (small area) indicated by diagonal lines in the figure indicates a blue background (background pattern). In this way, a blue background (background pattern) is displayed in the display area (small area) that is originally blank.
Is displayed to eliminate the blank area, thus improving the man-machine interface of the display.

In the case of the image communication system using the image display terminal having the configuration shown in FIG. 8, for example, when the display image of each terminal is displayed as shown in FIG. 15, the image data deleting unit 7 of the terminal A is GOB1, GOB3, GOB5, GOB
7, GOB8, GOB9, GOB10, GOB11, G
The image data of OB12 is deleted, and the image data deletion unit 7 of terminals B and C deletes the image data of GOB1, GOB3, and GOB5. Then, the display position changing unit 10 changes the GOB number as follows. I.e.

GOB2 → GOB1 GOB4 → GOB3 GOB6 → GOB5

The image data inserting section 8 of each of the terminals B and C transfers the data from the image encoding section 6 to GOB2, GOB4, GOB.
6 as image data. The background pattern insertion unit (image data insertion unit) 8 of the terminal A performs the operations of the image data insertion unit 8 of the terminals B and C, as well as GOB7 and GOB.
Blueback encoded data is transmitted as data of 8, GOB9, GOB10, GOB11, and GOB12.

Further, in the case of the image communication system using the image display terminal having the configuration shown in FIG. 8, GOB1, GOB2, GOB3, GOB5, G
OB7, GOB9, GOB10, GOB11, GOB1
2 deletes the image data, and the image data deletion unit 7 of the terminals B and C deletes the image data of GOB3, GOB5, GOB7,

In the display position changing unit 10, GOB4 → GOB3 GOB6 → GOB5 GOB8 → GOB7 and GOB numbers are replaced,

The image data inserting section 8 of each of the terminals B and C transfers the data from the image encoding section 6 to GOB4, GOB6, GOB.
8 as the image data, and the background pattern insertion unit (image data insertion unit) of the terminal A performs the operations of the image data insertion units of the terminals B and C as well as GOB1, GOB2, GO.
Blueback encoded data is transmitted as data of B9, GOB10, GOB11, and GOB12. By this operation, the display screen on each terminal can be made as shown in FIG.

In the example shown here, the case where the blue background is used as the background pattern is shown, but the same operation is possible even if other patterns are used.

Next, FIG. 17 is a block diagram showing details of the configuration of the background pattern inserting section 12 in FIG.
In FIG. 17, reference numeral 121 is a GOB header detection unit, and 122.
Is a FIFO buffer A, 123 is a header deletion unit, 124
Is a GOB number replacement unit, 125 is a FIFO buffer B, 1
26 is a GOB header addition unit, 127 is a FIFO buffer C, and 128 is an input selection unit.

Referring to FIG. GOB header detector 1
21 receives the data from the previous block (the image data deleting unit or the display position changing unit). GBSC (GOB start code) is detected from the received data. GBSC
The input selection unit 128 is notified of the detection of. Also F
The data is transmitted to the IFO buffer A122.

The FIFO buffer A122 receives the data from the previous block (GOB header detection section 121). Then, the data is read from the input selection unit 128. The header deletion unit 123 receives the data from the image coding unit. All but the GOB data (from the data immediately before PSC to GBSC) is deleted from the received data (format of FIG. 22). And the data is GOB number substitution unit 1
Send to 24.

GOB number replacing section 124 detects GN (GOB number) from the received data. GN detected
Is rewritten to a value designated by the control unit 9 in advance. The GN transmits the rewritten data to the FIFO buffer B125 without changing the data other than the GN. When there is no more data to process, the input selection unit 128 is notified.

The FIFO buffer B125 receives the data from the GOB number replacing unit 124. Input selection unit 128
Data is read from. Then, the GOB header adding unit 126 receives the encoded data of the background pattern from the background pattern generation unit. GOB header with GN pre-specified by the control unit 9 (from GBSC to GEI)
Is added to the received data. Then, the data is transmitted to the FIFO buffer C127. GOB of the above display position
Repeat for the number of times. The input selection unit 128 is notified of the end of the processing.

The input selection unit 128 uses the GOB number substitution unit 1
24 has been notified, and GOB header detection unit 1
When the notification of GOB detection is received from 21, the data is read from the FIFO buffer B125 (insertion of the image of the own terminal). Next, when the notification is received from the GOB header adding unit 126, the data is read from the FIFO buffer C127 (insertion of the background pattern). FIF other than the above
Data is read from the O buffer A122. Send data to the next block.

Next, an image communication system as still another embodiment of the present invention will be described. The case where the six terminals A to F are connected in a loop as shown in FIG. Since there are 6 terminals, each terminal has 6 small areas (at least 5
If not, the screen data of all terminals (5 terminals except the terminal itself) cannot be displayed. However, among the 6 terminals, the image data is not generated by the terminal itself, and therefore the image data received from the upstream terminal is displayed without processing the image data such as deleting the image data or inserting the image data. However, there may be a terminal which sends the data to the downstream terminal as it is. If there is at least one such terminal, other terminals need only have four small areas that form one screen.

FIG. 18 shows the configuration of such an image display terminal (a terminal that does not generate image data at its own terminal and therefore does not perform image data processing such as image data deletion or image data insertion). It is a block diagram.

In the terminal shown in FIG. 18, the received image data is sent from the demultiplexing / separating unit 2 to the image decoding unit 4, and at the same time, multiplexed / demultiplexed to the next terminal on the loop loop.
It is transferred via the separation unit 2 and the network interface unit 1.
That is, this terminal displays the received image data, but does not send the image data of its own terminal.

FIG. 19 shows terminals A, B, C and E on the loop.
Is a terminal having a configuration as shown in FIG.
FIG. 19 is an explanatory diagram showing a display screen example of each terminal in the case of the terminal having the configuration shown in FIG. 18. Terminals A, B, C, D,
All of E and F are the image data of terminals A, B, C and E,
You can see that they are displayed equally.

Further, FIG. 20 shows that terminals A, B, and
C, E, and F are terminals having the configuration shown in FIG.
FIG. 19 is an explanatory diagram showing a display screen example of each terminal in the case of the terminal having the configuration shown in FIG. 18. It will be appreciated that all terminals are displaying the image data of the other four terminals except the terminal itself and the terminal D.

[0101]

As described above, according to the present invention,
There is an advantage that it is possible to provide a multipoint image communication system of a loop type connection system in which all terminals can simultaneously view a plurality of images of the ground. The multipoint image communication system according to the present invention can be used not only by being installed in a video conference system, but also by using a multipoint monitoring system (for example, connecting unmanned departments of a bank in a loop form, It can be used by mounting it on (or monitoring), and there are various possible uses.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a multipoint connection example of a multipoint image communication system as an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of an image display terminal provided at each point in FIG. 1 according to the present invention.

FIG. 3 is a flowchart showing an operation flow of an image data deleting unit 7.

FIG. 4 is a flowchart showing an operation flow of an image data insertion unit 8.

FIG. 5 is a flowchart showing an operation flow of the control unit 9.

FIG. 6 is a block diagram showing a configuration of an image data deleting unit 7.

FIG. 7 is a block diagram showing a configuration of an image data insertion unit.

8 is a block diagram showing another configuration example of the image display terminal provided at each point in FIG. 1 according to the present invention.

FIG. 9 is an explanatory diagram showing a screen display example of each terminal.

10 is a flowchart showing an operation flow of the display position changing unit 10. FIG.

11 is a block diagram showing a configuration of a display position changing unit 10. FIG.

FIG. 12 is an explanatory diagram showing another screen display example of each terminal.

13 is a block diagram showing still another configuration example of the image display terminal provided at each point in FIG. 1 according to the present invention.

FIG. 14 is an explanatory diagram showing still another screen display example of each terminal.

FIG. 15 is an explanatory diagram showing another screen display example of each terminal.

FIG. 16 is an explanatory diagram showing still another screen display example of each terminal.

FIG. 17 is a block diagram showing a configuration of a background pattern insertion unit 12.

18 is a block diagram showing another configuration example of the image display terminal provided at each point in FIG. 1 according to the present invention.

FIG. 19 is an explanatory diagram showing still another screen display example of each terminal.

FIG. 20 is an explanatory diagram showing still another screen display example of each terminal.

FIG. 21 CCITT Recommendation H.264 FIG. 26 is an explanatory diagram showing a hierarchical structure of encoded image data according to H.261.

FIG. 22 CCITT Recommendation H.264 [Fig. 26] Fig. 26 is an explanatory diagram showing a format of a transmission frame of image data encoded by adopting the encoding method of H.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Network interface part, 2 ... Multiplexing / separating part, 3 ... Image display part, 4 ... Image decoding part, 5 ... Image input part, 6 ... Image coding part, 7 ... Image data deletion part, 8 ... Image data Inserting unit, 9 ... Control unit, 10 ... Display position changing unit, 11 ... Background pattern generating unit, 12 ... Background pattern inserting unit.

Claims (7)

[Claims] 1. An image display terminal is provided at an arbitrary desired point among a plurality of points connected by a loop-shaped transmission line, and an image from another upstream point is transmitted through the transmission line. When the data is received, it is displayed on the display screen of the terminal, and after the image data of its own point is added to the received image data, the image is displayed by transmitting it to another point downstream via a transmission path. In a multipoint image communication system adapted to perform image communication between points provided with terminals, the image display terminal divides its display screen into a plurality of small areas, and displays each image data displayed in the small areas. An image display terminal capable of transmitting and receiving image data encoded by adopting an encoding method for encoding, wherein the encoding method from another upstream point received via a transmission line is Picture to be taken Image display means for displaying data in each of a plurality of small areas of the display screen on a point-by-point basis, and image data adopting the encoding method from another point on the upstream side received via a transmission line. Image data deleting means for deleting image data corresponding to the specific small area, and image data generated at its own point as image data corresponding to the specific small area after being deleted by the image data deleting means. Image data inserting means for inserting the received image data into the received image data and transmitting the image data to another downstream point via a transmission path. 2. An image display terminal is provided at an arbitrary desired point among a plurality of points connected by a loop-shaped transmission line, and an image from another upstream point is transmitted through the transmission line. When the data is received, it is displayed on the display screen of the terminal, and after the image data of its own point is added to the received image data, the image is displayed by transmitting it to another point downstream via a transmission path. In a multipoint image communication system adapted to perform image communication between points provided with terminals, the image display terminal divides its display screen into a plurality of small areas, and displays each image data displayed in the small areas. An image display terminal capable of transmitting and receiving image data encoded by adopting an encoding method for encoding, wherein the encoding method from another upstream point received via a transmission line is Picture to be taken Image display means for displaying data in each of a plurality of small areas of the display screen on a point-by-point basis, and image data adopting the encoding method from another point on the upstream side received via a transmission line. Image data deleting means for deleting the image data corresponding to the specific small area, and the received image data after being deleted by the image data deleting means, of the image data corresponding to the specific small area on the display screen, A display area changing means for changing the display area when rewriting the data portion representing the corresponding small area and displaying the same on the display screen, and image data generated at its own point are displayed as an image corresponding to the specific small area. Image data to be transmitted to another downstream point via a transmission path after being inserted as received data into the received image data whose display area has been changed by the display area changing means. Multipoint video communication system characterized by comprising a data inserting means. 3. An image display terminal is provided at an arbitrary desired point among a plurality of points connected by a loop-shaped transmission line, and an image from another upstream point is transmitted through the transmission line. When the data is received, it is displayed on the display screen of the terminal, and after the image data of its own point is added to the received image data, the image is displayed by transmitting it to another point downstream via a transmission path. In a multipoint image communication system adapted to perform image communication between points provided with terminals, the image display terminal divides its display screen into a plurality of small areas, and displays each image data displayed in the small areas. An image display terminal capable of transmitting and receiving image data encoded by adopting an encoding method for encoding, wherein the encoding method from another upstream point received via a transmission line is Picture to be taken Image display means for displaying data in each of a plurality of small areas of the display screen on a point-by-point basis, and image data adopting the encoding method from another point on the upstream side received via a transmission line. Image data deleting means for deleting image data corresponding to the specific small area, and image data generated at its own point as image data corresponding to the specific small area after being deleted by the image data deleting means. Image data inserting means for inserting the image data into the received image data, and then transmitting the image data to another point downstream via a transmission line, and by the image data deleting means in the image display terminal for each point provided with the screen display terminal. In the image data corresponding to the specific small area to be deleted, the corresponding small area to be deleted is made different, and the specific small area to be inserted by the image data inserting means is specified. The image data corresponding to the region,
An inter-multipoint image communication system comprising: a point-by-point insertion / deletion area designating unit that allows different corresponding small areas to be inserted. 4. The multipoint image communication system according to claim 1, 2, or 3, wherein an image display terminal at at least one point is provided with a pattern generation unit that generates a specific image pattern as a background pattern, The image data inserting means not only inserts the image data generated at its own point into the received image data after being deleted by the image data deleting means as image data corresponding to the specific small area, The background pattern generated by the pattern generation means is an image data corresponding to the specific small area, and the insertion means is capable of inserting the background pattern in a corresponding small area different from that of the image data generated at its own point. Characteristic multi-point image communication system. 5. The multipoint image communication system according to claim 1, 2, or 3, wherein image data that has been encoded by the encoding method is received from another point upstream through a transmission path,
When the image display means displays points by point in each of a plurality of small areas on the display screen of the terminal, in the process of forming a loop of the loop-shaped transmission line, a call is made and a connection is made at each point. The multi-point image communication system is characterized in that the image data is arranged so that a small area to be displayed is determined based on a certain rule in the order of the call and connection points. 6. The multipoint image communication system according to claim 5, wherein the fixed rule comprises a fixed rule of turning clockwise or counterclockwise with respect to the own terminal. Multipoint image communication system. 7. The multipoint image communication system according to claim 1, 2, 3, 4, 5 or 6, wherein the display screen is divided into a plurality of small areas, and each piece of image data displayed in the small area. An image display terminal capable of transmitting and receiving image data encoded by adopting an encoding method for encoding, wherein the encoding method from another upstream point received via a transmission line is Only an image display terminal that has image display means for displaying the image data to be taken in each of the plurality of small areas of the display screen, and does not have a means for performing processing such as deletion or insertion of the image data. An inter-multipoint image communication system, wherein at least one of the points possessed as a device is included in the plurality of points connected by a loop-shaped transmission path.