JPH05111019A - Image signal multiple point connecting device - Google Patents

Abstract

PURPOSE:To obtain an image signal multiple point connecting device capable of being simply constituted of a common interface corresponding to respective function components and preventing the deterioration of a signal due to processing. CONSTITUTION:Components 21a to 21c are prepared correspondingly to synthesizing, switching and distributing functions included in the image signal multi-point connecting device 21 and interfaces among respective components are used in common so that respective components can execute the processing of digital image signals having a common intermediate format(CIF). When respective communication terminals 11 to 13 are not provided with functions for converting and inversely converting image signals based upon a prescribed signal type into CIF image signals, an image signal conversion part 21d for converting and inversely converting a prescribed signal type image signal into a CIF image signal is connected to the signal I/O point of the device 21 to convert prescribed signal type image signals inputted from respective communication terminals 11 to 13 to CIF digital image data. Then respective components 21a to 21c execute processing and the conversion part 21d inversely converts processed results into prescribed signal type image signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal multipoint connection device, and more particularly to an image signal multipoint connection device for a system for mutually communicating image signals between communication terminals provided at multiple points.

[0002]

2. Description of the Related Art In a system for communicating image signals between communication terminals respectively provided at multiple points, for example, in a video conference system, image signals are mutually communicated via an image signal multipoint connection device provided at a center or the like. To do.

The image signal multipoint connection device is designed individually according to the mode of use of the multipoint connection communication service, and there are no definitive methods depending on the scale and concept of the number of terminals used. Is the current situation. For example, in a video conference system, a display screen of each communication terminal is divided into a plurality of display screens, and a first method (screen combining method) for displaying a conferee or a meeting scene at each point on each divided screen, a display of each communication terminal. The second method (screen switching method) that displays the speaker or the meeting scenery on the speaker side on the screen, and the third method (combined method) that uses the above two methods together
There are advantages and disadvantages of each, and there is no definitive method at present.

In FIG. 8A, the images Ia, Ib, Ic, and Id from the communication terminals at the points a, b, c, and d are combined by the combining unit IMC as shown in FIG. 8B, and distributed. It is a block diagram of an image signal multipoint connection device IMPC which realizes a screen synthesizing method in which a synthetic image IM is sent from a part IMD to a communication terminal at each point.
This screen synthesis method can grasp the atmosphere of the entire conference to some extent, but since the image is divided and displayed, it becomes small and it is difficult to capture the expression of the speaker.

FIG. 9 shows an image I from each point a, b, c, d.
An image signal that realizes a screen switching method in which a desired image is selected from a, Ib, Ic, and Id by the switching unit ISW, and the distribution unit IMD sends the image Is output from the switching unit ISW to the communication terminal at each point. It is a block diagram of the multipoint connection device IMPC. This screen switching method can grasp the expression of the speaker,
There is a problem that the atmosphere of the whole meeting cannot be grasped.

In FIG. 10, a switching unit ISW selects and outputs a desired image from the images Ia, Ib, Ic, Id from the points a, b, c, d or the composite image IM synthesized by the synthesizing unit IMC.
It is a block diagram of the image signal multipoint connection apparatus IMPC which implement | achieves the combined system which sends out the image Is output from the switching part ISW in the distribution part IMD to the communication terminal of each point, This 3rd system is 1st, 1st, Although the problem of the method 2 can be solved, control of the switching timing of the display image becomes troublesome, and there is an operational problem.

[0007]

From the above, there is no definitive method as an image signal multipoint connection device, and therefore,
In the future as well, every time various needs arise, various image signal multipoint connection devices must be developed, which causes problems in terms of development cost and development period.

The image signal systems currently used are roughly classified into three types (N
There are TSC system, PAL system and SECAM system). And since these signals are not compatible as they are,
In order to carry out international communication, it is necessary to convert these image signals into a predetermined signal format in the image signal multipoint connection device, which causes a problem that the device becomes complicated.

For example, as shown in FIG. 11, the image signal multipoint connection device IMPC has three components A, B,
When C is provided, the input image signal is input to the interface a ′, b ′,
It is necessary to convert the image formats of the components A, B, and C at c'and d ', respectively, which complicates the configuration. Further, as shown in FIG. 12, even if each of the components A, B, and C is made into a common image system (for example, NTSC system) and is shared by the interface e, the image signal is analog and signal deterioration occurs in each process. However, there is a limit to the circuit integration.

In view of the above, the object of the present invention is to reduce the development cost of the image signal multipoint connection device, shorten the development period, and further to make it possible to provide a simple structure in which each functional component is standardized. An object of the present invention is to provide an image signal multipoint connection device without signal deterioration due to processing.

[0011]

FIG. 1 illustrates the principle of the present invention. In FIG. 1 (a), 11 to 13 are communication terminals provided at respective points, and 11c to 13c are provided in the respective communication terminals, and image data of a predetermined image signal system is used in a common intermediate format, for example, CIF (Common Intermediate). Form
image signal conversion unit for converting into a digital image signal of (at) and converting from CIF into a predetermined image signal system, 21 is an image signal multipoint connection device, and 21a to 21c are functions provided in the image signal multipoint connection device. The first to third components provided in.

In FIG. 1 (b), 11 to 13 are communication terminals provided at respective points, 21 is an image signal multipoint connection device,
Reference numerals 21a to 21c denote first to third components provided for each function of the image signal multipoint connection device, and 21d converts image data of a predetermined image signal system into a common intermediate format, for example, a digital image signal of CIF. ,And,
An image signal conversion unit that converts the signal system of the communication terminal from the CIF.

[0013]

Functions: Functions of the image signal multipoint connection device 21
For example, first to third components 21a to 21c are provided for each basic function such as distribution, switching, and composition, and each component is configured to process a digital image signal of a common intermediate format (CIF). Common interface between them. By doing so, each of the communication terminals 11 to 13 can operate in the predetermined signaling system (NTSC,
PAL, SECAM) image signal to CIF digital image data and has a function of inverse conversion (FIG. 1 (a)), the image signal multipoint connection device 21 receives the CIF digital image data. Image data can be output by performing synthesizing processing, switching processing, distribution processing, etc. without any conversion processing, and standardized CIF interface components are used to easily digitally configure multi-point image signal points. The connection device can be created, the development cost can be reduced, the development period can be shortened, and the digital configuration prevents signal deterioration due to processing.

As shown in FIG. 1B, the communication terminal 11
13 to 13 are predetermined signal systems (NTSC, PAL, SECA
When the image signal of M) does not have a function of converting the image signal into digital image data of CIF and the inverse conversion, the image of the common intermediate format (CIF) is provided at the signal input / output point of the image signal multipoint connection device 21. An image signal conversion unit 21d that converts and reverses a signal is provided. The image signal converter 21d
Predetermined signal system (N
(TSC, PAL, SECAM) image signals are converted into CIF digital image data, and thereafter, the components 21a to 21c perform combination processing, switching processing, distribution processing, etc., and the image signal conversion unit 21d sets the processing result to a predetermined value. The signal is converted back into a signal type image signal and transmitted to the communication terminals 11 to 13. With this configuration, even when the communication terminal does not have a function of converting to and from CIF, the standardized CIF interface component can be used to simply and digitally configure the image signal multipoint connection device. Can be created, the development cost can be reduced, the development period can be shortened, and the digital configuration does not cause signal deterioration due to processing.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (a) Overall configuration of the first embodiment of the present invention FIG. 2 is a configuration diagram of the first embodiment of the present invention applied to a video conference system.
This is a case where it has a function of converting an image signal of C, PAL, SECAM) into digital image data of CIF and inverse conversion.

In the figure, 11 to 12 are communication terminals provided at respective points, 21 is an image signal multipoint connection device, and 31 is an ISD.
N is a digital network, 41 is a compressed image data by a predetermined encoding method, for example, a high efficiency encoding method such as DPCM, MC or DCT, or the compressed image data is the original image data. It is a codec (CODEC) for decoding into. Although only two communication terminals are shown in FIG. 2 for convenience of description, actually three or more communication terminals are connected to the image signal multipoint connection device 21 via a digital network.

Communication terminals Communication terminals 11 and 12 are television cameras for picking up an image of a conference participant,
Although a television (display device) for displaying an image, an operation unit, and the like are provided, in FIG. 2, only the image pickup system is shown in the communication terminal 11 and only the image receiving system is shown in the communication terminal 12. In the communication terminal 11, 11a is a television camera, 11b is an AD converter for converting an image pickup signal into a digital signal, 11c
Is a predetermined image signal system (NTSC, PAL, SECA
M) image signal is a common intermediate format CIF (Comm
on Intermediate Format) CIF converter for converting into digital image data, 11d is a codec for compressing and encoding CIF image data, and 11e is a line interface. In the communication terminal 12, 12a is a line interface, 12b is a codec that decodes CIF image data, 12c is a CIF converter that converts common intermediate format CIF digital image data into a predetermined signal system image signal, and 12d is A DA converter 12e for converting an analog image signal is a television.

Image signal multipoint connection device When the image signal multipoint connection device is analyzed in consideration of the form of the conventional multipoint connection service and the form of use which will be needed in the future, the following three basic Functional component, (1) distribution (or branch) functional component,
(2) Switching (or selection) functional components and (3) Combined (or combined or mixed) functional components can be roughly classified, and an image signal multipoint connection device of any form can be configured by combining them.

Therefore, in the image signal multipoint connection device 21, 21a to 21c are the first to third components for executing the above-mentioned functions, and the respective components 21a to 21c.
1c is a common intermediate format such as CIF (Common
It is configured to be able to perform processing according to Intermediate Format). That is, the image signal multipoint connection device 2
1st to 3rd component 21 for each basic function of 1
a to 21c are provided so that each component can perform processing with a common intermediate format CIF interface, whereby the interface between each component is made common.

In FIG. 2, three components are shown, but there may be two components or four or more components depending on the form of the image signal multipoint connection device.

CIF (Common Intermediate Format) NTSC system used in Japan and the US and European P
There is no compatibility between the AL / SECAM systems, and it is not possible to see the image of the other television system. However, in a television conference system or the like, it is necessary to globally receive and process images from various points in the world so that they can be viewed on a television. It's a problem if you can't see. Therefore, at present, the signals of the television system of each country are once converted into a video signal common throughout the world, and by encoding / decoding the signals, communication can be performed without being aware of the television system of the other party. ing.
This intermediate format CI has a common video signal
FIG. 3 shows an application example of CIF, which is a video signal compliant with F.
FIG. 4 is a table for explaining CIF parameters. In FIG. 3, 101 is a PAL → CIF converter, and 102 is a CI.
F → PAL converter, 103 is NTSC → CIF converter, 104 is CIF → NTSC converter, 105
Is a codec including a coding unit COD and a decoding unit DEC.

In FIG. 4, QCIF is a common intermediate format (Quarter CIF) in which the resolution is halved both horizontally and vertically, and in the present invention, CIF,
Either QCIF can be used.

Overall operation The image signal of the conference person or the conference scene imaged by the television camera 11a of the communication terminal 11 is converted into digital, converted into CIF image data by the CIF converter 11c, and encoded by the codec 11d. Then, it is sent to the digital network 31 toward the image signal multipoint connection device 21 via the line interface 11e.

The image data output from the digital network 31 is decoded by the codec 41 provided at the entrance of the image signal multipoint connection device 21 and input to the image signal multipoint connection device 21. Similarly, although not shown, image signals from other communication terminals are also input to the image signal multipoint connection device 21 via the digital network 31 and the codec 41.

Each of the components 21a to 21c of the image signal multipoint connection device 21 synthesizes, switches, and distributes the CIF digital image data sent from each of the multipoint communication terminals, and distributes them to a predetermined communication terminal (for example, a communication terminal). 12) Send to the side. The CIF image data sent from the image signal multipoint connection device 21 is compression encoded by the codec 51 and sent to the communication terminal 12 via the digital network 31.

The communication terminal 12 fetches the CIF image data via the interface 12a, and the codec 12b
Then, the CIF converter 12c converts the image data into image data of its own image signal system, and then converts it into analog data for display on the television 12e.

As described above, in the case where each of the communication terminals 11 to 13 has a function of converting an image signal of a predetermined signal system (NTSC, PAL, SECAM) into digital image data of CIF and vice versa, a large number of image signal is transmitted. Point connection device 21
Can transmit the image data by performing a combining process, a switching process, a distribution process, etc. on the received CIF digital image data without performing any conversion process.

(B) Overall configuration of the second embodiment of the present invention FIG. 5 is a configuration diagram of the second embodiment of the present invention applied to a video conference system, in which each communication terminal uses a predetermined signal system (NTS).
This is a case where there is no function of converting (C, PAL, SECAM) image signals into CIF digital image data and vice versa. The same parts as those in the first embodiment of FIG. 2 are designated by the same reference numerals.

The difference from FIG. 2 is that (1) each communication terminal 11,
12 ... has no CIF converter,
(2) The image signal multipoint connection device 21 has a predetermined image signal system (NTSC, PAL, CI) on the input side and the output side, respectively.
The image signal conversion unit 21d for converting the image data of F) into the image data of the common intermediate format CIF, and the predetermined image signal system (NTSC, PAL,
CIF) image signal conversion unit 21 for inverse conversion into image data
This is the point where d'is provided.

Overall operation The image signal of the conference person or the conference scene imaged by the television camera 11a of the communication terminal 11 is converted into a digital signal, coded by the codec 11d, and transmitted through the line interface 11e. Point connection device 21
Are sent to the digital network 31 for

The image data output from the digital network 31 is decoded by the codec 41 provided at the entrance of the image signal multipoint connection device 21 and input to the image signal multipoint connection device 21. Similarly, although not shown, image signals from other communication terminals are also input to the image signal multipoint connection device 21 via the digital network 31 and the codec 41.

The image signal conversion section 21d of the image signal multipoint connection device 21 converts the input image data into digital image data of CIF, and each of the components 21a to 21.
c is the image data (C
(IF digital image data) are combined, switched, distributed, and input to the image signal conversion unit 21d '. Image signal converter 21
d'converts the input CIF image data into the image signal system of the receiving side communication terminal, and the communication terminal (for example, the communication terminal 1
2) Send to the side.

The image data of the predetermined signal system output from the image signal multipoint connection device 21 is compression-encoded by the codec 51 and sent to the communication terminal 12 via the digital network 31. The communication terminal 12 is the interface 12
CIF image data is loaded via a and codec 1
It is decoded by 2b, converted into analog after that, and displayed on the television 12e.

As described above, even when the communication terminals 11, 12, ... Have no function of converting the image signal of the predetermined signal system (NTSC, PAL, SECAM) into digital image data of CIF and inverse conversion. , The CIF image signal converter 21 at the signal input / output point of the image signal multipoint connection device 21.
If d and 21d 'are provided, each of the components 21a to 21c in the middle can perform a combining process, a switching process, a distributing process and the like according to the common interface.

(C) Application example of the present inventionConstitution FIG. 6 shows the present invention applied to a screen-switching type video conference system.
It is a block diagram of the image signal multipoint connection device when used,
61-63 are conference terminals (communication terminals) provided at each point
Then, each TV camera TLCM₁~ TLCM₃, Tele
Vision TLV ₁~ TLV₃, Switching operation part OPP₁~ OP
P₃Is equipped with. 71 is a conversion component or distribution code
Image signal composed of components and switching components
It is a multi-point connection device. Each conference terminal 61-63
End of NTSC system, PAL system and SECAM system respectively
In addition, each conference terminal 61-63 and image signal
Although not shown between the point connection devices 71, a digital network
It is designed to communicate data via the network.

In the image signal multipoint connection device 71, 7
1a is NTSC output from the TV camera TLCM _1.
CIF converter for converting a standard image to CIF, 71
b is a CIF converter for converting CIF image data into the NTSC system and inputting it to the television TLV ₁ , 71c
Is a CIF converter for converting PAL image data output from the TV camera TLCM ₂ into CIF, 71
d is a CIF converter for converting CIF image data into a PAL system and input to the television TLV ₂ , 71e A CIF converter for converting SECAM system image data output from the television camera TLCM ₃ into a CIF, 71
Reference numeral f is a CIF converter for converting the CIF image data into the SECAM system and inputting it to the television TLV ₃ .

Further, 71g is a distribution unit for distributing the image from the conference terminal 61 to the conference terminals 62 and 63, 71h is a distribution unit for distributing the image from the conference terminal 62 to the conference terminals 61 and 63, and 71i is the conference. The image from the terminal 63 is displayed on the conference terminal 6
1, 62, and a switching operation unit OP.
A switching unit that selectively outputs one of the images input from the distribution units 71h and 71i according to an instruction from P ₁ , and 71k selects one of the images input from the distribution units 71g and 71i according to an instruction from the switching operation unit OPP _2. Output switching unit, 71m
The distribution unit 71g, in response to an instruction from the switching operation unit OPP ₃ ,
A switching unit that selectively outputs one of the images input from 71h.

Each distribution unit 71g-71i and each switching unit 71
j to 71m is a common intermediate format such as CIF
The image data on the double line in the figure is CIF image data.

Operation Television camera TLCM ₁ of each conference terminal 61-63
~ NTSC image, PAL image, SEC from TLCM ₃
The AM image is input to the image signal multipoint connection device 21,
The CIF converters 71a, 71c, and 71e convert the image data into CIF image data, and the distribution units 71g to 7g.
It is input to 1i. Each of the distribution units 71g to 71i branches the input CIF image data into two and inputs the CIF image data to the switching unit on the other conference terminal side, and the switching units 71j, 71k, and 71m switch from the switching operation units OPP _{1 to} OPP _3. A predetermined CIF image data is selected according to the operation instruction, and the CIF converter 71 is selected.
b, 71d, 71f, and each CIF converter 71
b, 71d and 71f are CIF image data NT
Converted to SC image, PAL image, SECAM image and input to the conference terminals 61 to 63, and the televisions TLV _{1 to} TL.
Display on V ₃ .

(D) Configuration of Application Example of the Present Invention FIG. 7 is a configuration diagram of an image signal multipoint connection device when the present invention is applied to a video conferencing system video conference system.
Reference numerals 81 to 83 are conference terminals provided at the respective points, and are television cameras TLCM _{1 to} TLCM ₃ and television TL, respectively.
It has V _{1 to} TLV ₃ . Reference numeral 91 is an image signal multipoint connection device including a conversion component, a synthesis component, and a distribution component. In addition, each conference terminal 81
~ 83 are NTSC system, PAL system, SEC
It is assumed that the terminal is an AM system, and each of the conference terminals 81 to 83
Although not shown, data communication is performed between the image signal multipoint connection device 91 and the image signal multipoint connection device 91 via a digital network.

In the image signal multipoint connection device 91, 9
1a is NTSC output from the TV camera TLCM _1.
CIF converter for converting a standard image to CIF, 91
b is a CIF converter for converting PAL image data output from the TV camera TLCM ₂ into CIF, 9
1c is SECA output from the TV camera TLCM _3.
A CIF converter for converting image data of the M system into CIF, 91d is a synthesizing unit for synthesizing images output from each CIF converter, 91e is a distributing unit for branching the synthesized image output from the synthesizing unit into three, and 91f is a CIF. A CIF converter for converting the composite image data into the NTSC system and inputting it to the television TLV ₁ , 91g is a CIF converter for converting the CIF composite image data into the PAL system and inputting it to the television TLV ₂ , and 91h is a CIF composite image. Data is converted to SECAM format and converted to television TLV ₃
It is a CIF converter for inputting to.

The synthesizing unit 91d and the distributing unit 91e have a common intermediate format, for example, CIF (Common Intermediate).
It is configured to perform processing according to (Format),
In the figure, the image data on the double line is CIF image data.

Operation Television camera TLCM ₁ of each conference terminal 81-83
~ NTSC image, PAL image, SEC from TLCM ₃
The AM image is input to the image signal multipoint connection device 21,
The CIF converters 91a, 91c, and 91e convert the image data into CIF image data and input the image data into the combining unit 91d. The synthesizing unit 91d synthesizes the images input from the conference terminals and inputs the images to the distributing unit 91e. The distribution unit 91e splits the CIF composite image data into three and inputs the CIF converters 91f, 91g, and 91h, and the CIF converters 91f, 91g, and 91h respectively convert the CIF image data into an NTSC image, a PAL image, and a SECAM image. Input to the conference terminals 81 to 83 and the television TLV ₁ to
Display the composite image on TLV ₃ .

The present invention has been described above with reference to the embodiments.
The present invention can be variously modified according to the gist of the present invention described in the claims, and the present invention does not exclude these modifications.

[0045]

As described above, according to the present invention, a component is provided for each function of the image signal multipoint connection device, for example, for each basic function such as distribution, switching, and combining, and each component has a common intermediate format (CIF). In the case where each communication terminal has a function of converting an image signal of a predetermined signal system into digital image data of CIF and vice versa because the interface between the components is made common so as to be able to process the digital image signal. In addition, the image signal multipoint connection device can output the image data by performing a combining process, a switching process, a distribution process, etc. on the received CIF digital image data without performing any conversion process.
Moreover, the standardized CIF interface component can be used to easily create an image signal multipoint connection device with a digital configuration, which can reduce the development cost and the development period. There is no signal deterioration due to.

Further, according to the present invention, when the communication terminal does not have the function of converting the image signal of the predetermined signal system into the digital image data of CIF and the inverse conversion, the signal of the image signal multipoint connection device is used. Since the image signal conversion unit for converting and converting back to the common intermediate format (CIF) image signal is provided at the input / output point, even if the communication terminal does not have the function of converting to CIF and reverse conversion. , Standardized C
Using the IF interface component, you can easily create an image signal multipoint connection device with a digital configuration,
The development cost can be reduced and the development period can be shortened.
Furthermore, since it has a digital configuration, there is no signal deterioration due to processing.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a configuration diagram of an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a CIF application example.

FIG. 4 is a chart for explaining CIF parameters.

FIG. 5 is a configuration diagram of another embodiment of the present invention.

FIG. 6 is a configuration diagram showing an application example of the present invention.

FIG. 7 is another configuration diagram showing an application example of the present invention.

FIG. 8 is an explanatory diagram of a screen synthesizing method of a conventional image signal multipoint connection device.

FIG. 9 is a configuration diagram of a screen switching system of a conventional image signal multipoint connection device.

FIG. 10 is a configuration diagram of a combined system of conventional image signal multipoint connection devices.

FIG. 11 is an explanatory diagram of a first problem of the conventional image signal multipoint connection device.

FIG. 12 is a diagram illustrating a second problem of the conventional image signal multipoint connection device.

[Explanation of symbols]

 11-13..communication terminal 11c to 13c..image signal converter 21..image signal multipoint connection device 21a to 21c..first to third component 21d..image signal converter

Claims (3)

[Claims] 1. An image signal multipoint connection device (21) for an image signal multipoint connection device of a system for mutually communicating image signals between communication terminals provided at multiple points via the image signal multipoint connection device (21). ) Is made a component for each function provided in the apparatus, and each component (21a to 21c) is configured to process a common intermediate format digital image signal, and the interface between the components is made common. An image signal multipoint connection device characterized by the above. 2. The components (21a to 21c) are components for distributing or branching image signals, components for switching or selecting image signals, and outputting them.
2. The image signal multipoint connection device according to claim 1, further comprising a component for combining or mixing a plurality of image signals. 3. A conversion component (21d) for converting an image signal of a common intermediate format on a signal input side, and a conversion component (21d 'for converting an image signal of a common format on a signal output side to an image signal of a predetermined system. The image signal multipoint connection device according to claim 2, further comprising: