JPH05336517A - Video conference device - Google Patents

Abstract

PURPOSE:To improve the man-machine interface of the video conference device by improving the access time of still picture information and document informa tion. CONSTITUTION:This video conference device is provided with a storage part for still images and documents, a low-speed transmission channel which exerts no influence of the transmission of a speech and a moving picture on a multiplexing part 16. The still pictures to be used for a conference are previously stored in a storage device 15 and still picture data base of both terminals are mutually transmitted and exchanged by utilizing the free time right after the conference starts. When the image data bases which are made common are retrieved, an identification number is only transmitted to call and display an image from the storage part of each terminal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a videophone or a videoconference device that simultaneously transmits voice information, document information, still image information, and moving image information using a telephone line or the like.

[0002]

2. Description of the Related Art 64 Kbps or 128 Kb such as ISDN
Videophones and videoconferencing devices that transmit voice and images using a narrow band transmission line such as ps divide a transmission line into a plurality of channels using a multiplexing device, and a moving image compressed and encoded in each channel. Also, real-time transmission of voice and images is realized by efficiently allocating voice and control signals. Furthermore, by splitting part of the audio and image signals,
By providing a channel for multiplexing low-bit-rate signals here, it is possible to multiplex the signals of still images and documents to enable multimedia transmission without apparently affecting audio or moving images. Are known.

[0003]

The transmission of still images and documents does not have the time constraint that several frames must be transmitted per second, unlike the transmission of moving images.
Transmission at low bit rates is possible. However,
In the case of high-resolution documents and high-definition still images, the amount of data is large, and even if the data is compressed it occupies a considerable amount of data. The conference is interrupted and the man-machine interface is adversely affected.

In order to reduce the waiting time, there is a method of temporarily interrupting the transmission of a moving image, allocating still image and document data to a moving image signal transmission channel, and transmitting at high speed. There is an inconvenience that the moving image stops.

There is also a method of newly connecting a line and allocating one line for the transmission of still images and documents and performing high-speed transmission. However, in this case, the line usage fee is high and the number of line contracts is high. There is a problem that an additional line cannot be physically connected when the number is small.

[0006]

In order to solve the above problems, a video conference apparatus according to the present invention includes an input unit for inputting each information of voice information, document information, still image information, and moving image information, and the input unit. An encoder for compressing / combining each information, an output unit for displaying or outputting each information, a signal of each encoder and a control signal for control are multiplexed and multiplexed. It comprises a multiplexing unit having a switching unit for switching and selecting the information, a line interface unit serving as an input / output interface between the multiplexing unit and a transmission line, and a control unit for performing various controls. In a video conferencing apparatus that communicates information with each other, an identification for identifying still image information or document information used in a conference among the information, respectively. A still image information or document information and the identification information are stored in the image storage unit in advance before line connection, and the still image information or document information is stored simultaneously with the transmission line connection. Document information and the identification information are transmitted to each other using a low-speed transmission channel, and the still image information or the document information and the identification information received from the other terminal are accumulated in the image storage unit, and after the mutual transmission is completed. When a request to use the still image information or the document information is issued, only the identification information is transmitted to the other terminal, and the terminal receiving the identification information, based on the identification information, outputs the still image from the image storage unit. It is configured to have a control unit for searching and displaying information or document information.

Further, in the video conference apparatus, when the mutual transmission is not completed at the time when the use request of the still image information or the document information is generated,
It is configured to have a control unit for temporarily allocating still image information or document information and identification information to the high-speed transmission channel of the multiplexing unit and transmitting the information.

[0008]

The still image or document used for the conference is created in advance and registered and stored in the image storage unit. Immediately after the line connection, the control unit uses a multiplexing device to search for still images or documents by using a low-speed transmission channel that does not affect the signals in addition to the transmission of moving images and audio. It is transmitted together with the identification information. The receiving terminal receives the information and stores it in the image storage unit.

After the data exchange of the still image or the document is completed, when the terminal operator requests the display of the still image, the control unit retrieves the still image from the image storage unit based on the identification number of the image, While displaying on the display unit of the terminal, only the identification information is sent to the other party terminal, and the other party terminal receiving this retrieves the corresponding image information from the image storage section on the other party terminal side based on the identification information, Display a still image on the display.

If the conference starts before the completion of the database exchange, the high-speed moving image transmission channel is preferentially assigned to the transmission of the still image or the document, and the exchange process is completed quickly.

[0011]

1 is a diagram showing an embodiment of a video conference apparatus of the present invention. Reference numeral 1 is a tablet for inputting handwritten characters and device operation, 2 is a camera for inputting moving images, 3 is a display device such as a color display for displaying moving images or still images, and 4 is a camera or scanner for inputting still images. Reference numeral 5 is a document display, 6 is a document scanner, 7 is a speaker for outputting voice, 8 is a microphone for inputting voice, 9 is a display control unit (independent) for controlling display of moving images and still images. This is not necessary if a display device is provided) 10 is a system control unit that controls the entire system, 11 is a moving image encoder that compresses / decodes moving images, 12
Is a still image encoder that compresses / decodes a still image, 13 is a document encoder (binary image encoder) that compresses / decodes a document, 14 is a voice encoder that compresses / decodes audio,
15 is a storage device for storing still images and documents, 1
6 is a multiplexer for multiplexing image signals, audio signals, control signals, etc., 17 is a line interface, 18 and 19 are switches for selecting signal allocation, 20 is a line, 2
1, 22, 23 and 24 are terminals connected to the switch 18, and 25, 26 and 27 are terminals connected to the switch 19.

The moving image captured by the camera 2 is compression-encoded by the moving image encoder 11, and the terminal 21 and the switch 1 are used.
8, output to the line 20 via the multiplexer 16 and the line interface 17. On the contrary, when the compressed moving image data is received, the original image signal is decoded through the procedure reverse to the above, and the data is displayed on the color display 3 by the display controller 9.

The still image input from the camera or color scanner 4 is compressed and encoded by the still image encoder 12 and output. Conversely, when still image compressed image data is received, it is combined with the original image and displayed on the color display 3.

The image read by the document scanner 6 is compression encoded by the document encoder 13 and output. Conversely, when the compressed document data is received, it is decoded into the original image and displayed on the document display unit 5. The color display 3 and the document display 5 can be shared.

The multiplexer 16 multiplexes image signals, audio signals, control signals and the like. CCITT Recommendation H.
A multiplexing device conforming to 221 can be applied. An example of a video conference apparatus using this apparatus and ISDN 2B channel (128 Kbps) is shown below.

The 128 Kbps transmission path is divided into 48 Kbps as a voice transmission channel, 14.4 Kbps for a low speed transmission channel such as a control signal, 62.4 Kbps for a high speed image transmission channel, and 3.2 Kbps for other frame synchronization signals in a multiplexer. Since the output of the audio encoder 14 is connected to the audio transmission channel (48 Kbps) and the output of the moving image encoder 11 is connected to the high-speed image transmission channel (62.4 Kbps), bidirectional audio and image transmission can be performed. , A video conferencing device can be realized.

Furthermore, a low speed transmission channel (14.4 Kb)
ps), the still image and the document can be transmitted by multiplexing and transmitting the control signals from the still image encoder 12, the document encoder 13, and the system control unit 10 when necessary.

H. With a 221 compliant multiplexer,
Since the transmission channels can be dynamically assigned, the transmission channels can be opened only when sending a still image or document signal. When not sent, it can be assigned to image channels. Since the allocation of signals can be freely selected, the switches 18 and 19 are included in the multiplexer.

For a multiplexer in which the transmission channel cannot be changed dynamically, switches 18 and 19 are used to connect terminals 21 to 27 to change the signal allocation. The signals multiplexed by the multiplexing unit 16 are connected to the telephone line 20 through the line interface 17 so that the signals can be communicated with a remote party's terminal.

FIG. 2 shows the flow of data during the transmission of a still image of this device. The data flow is the same for documents. FIG. 3 is a diagram showing an example of signal allocation. The symbols from to in FIGS. 2 and 3 correspond to each other.

In FIG. 2, 102 is a video conference terminal A,
101 is a display device, 103 is a storage device, 105 is a video conference terminal B, 106 is a display device, 107 is a storage device, 1
A telephone line (transmission line) 04 connects the terminals A and B.

The data flow of the conventional video conference apparatus will be described. 2 shows an example of signal allocation at the time of connecting a normal video conference apparatus. At this time, the switch 18 of FIG. 1 is connected to the terminal 21, and voice, moving image, and control signals are flowing.

In the conventional video conference apparatus, when the tablet 1 shown in FIG. 1 instructs the system control unit 10 to transmit a still image, the switch 18 shown in FIG. 1 is connected to the terminal 22 to temporarily stop the transmission of the moving image. Transmission of still images begins.

The image on the display device and the image being read by the scanner are sent to the still image encoder 12 and encoded,
It is transmitted to the other terminal using the high speed transmission channel.
On the receiving side, this signal is decoded and displayed on the display device so that the screens of both terminals become the same. In this case, the image identification number is not transmitted and the received image is not stored.

The method of the present invention is exactly the same as the conventional method when a still image is not handled, but when a still image or a document is handled, image data such as a still image or a document created in advance is temporarily stored in a storage device. An image identification number is attached to 103 and is stored. The operation for such storage is usually performed before line connection.

In FIG. 2, image identification numbers "still image 1" and "still image 2" and corresponding image data "still D1" and "still D2" are displayed on the terminal A side, and "still image 3" is displayed on the terminal B side. ",
The image identification number "still image 4" and the corresponding image data "still D3" and "still D4" are stored in the storage devices 103 and 10, respectively.
Suppose that it is accumulated in 7. This is represented by the "original image" in FIG.

When the line is connected in this state, the channels of the multiplexing unit are in the state shown by in FIG. 2, and the image identification numbers of "still image 1" and "still image 2" are displayed from the terminal A side.
The image data of “Still D1” and “Still D2” are the same as the image identification numbers of “Still Image 3” and “Still Image 4” and “Still D” from the terminal B side.
The image data of "3" and "static D4" are automatically transmitted using low-speed transmission channels, respectively.

At this time, since the moving image and the sound are hardly influenced, it is not known to the participants of the video conference that the still image is transmitted. When the transmission is completed, the contents of the image databases in the storage devices of both terminals become equal. That is,
As can be seen from the “original image” and the “incoming image” in FIG. 2, the database contents in both storage devices are the same. Also, the transmission channel returns to the state shown by in FIG.

When the terminal A selects the image of "still image 1" in this state, "still D1" which is the image data of "still image 1" is read from the storage device 103 and the still image encoder 1 is read.
After being decoded by 2, it is displayed on the display device 101. At the same time, the state of the transmission channel becomes the state shown in FIG. 2, and the terminal A transmits the “still image 1” which is the image identification signal to the partner terminal B.

When the terminal B receives the image identification number "still image 1", the storage device 107 receives the image identification number based on the image identification number.
The target image data "static D1" is searched from within, decoded by the still image encoder 12, and then displayed on the display device.

Since the image identification number is a signal of several bytes, it can be transmitted in an instant, the target image is called up at both terminals almost at the same time, the timing deviation and the waiting time due to the transmission time are eliminated, and the man-machine interface is remarkably Be improved.

Although the video conference has already been started at the beginning of communication or the like, but when the image database cannot be standardized as described above, the transmission of still images is prioritized. The transmission channel at this time is in the state shown by in FIG.

Suppose that when "still picture 2" was selected at terminal A, "still picture 2" had not yet been transmitted to terminal B. At this time, the terminal A calls "still D2" which is the data of "still image 2" from the storage device 103, decodes it by the still image encoder, and then displays it on the display device. At the same time, the switches 18 of both terminals are connected to 24, and the transmission of the moving image is stopped.

Instead, "still image 2" which is the image identification number
The image data “static D2” corresponding to is transmitted. Terminal B
Then, the received data is decoded by the still image encoder 12 and then displayed on the display device 106. The data and the image identification number received at the same time are stored in the storage device 107, and will be used in a method of calling the data from the storage device without retransmitting from the next access.

After the transmission is completed, the transmission channel returns to the state shown by in FIG. Even when a new image needs to be transmitted immediately during the conference, the method of prioritizing the transmission of a still image as described above is adopted. At this time, the data flow is almost the same as the state shown in FIG. 2, but the image identification number and the image data are stored in the storage device of the transmission side terminal at the same time as the transmission, and can be used from the next access.

[0036]

According to the video conference apparatus of the present invention, a multiplexing unit is utilized by utilizing a free time such as a greeting at the beginning of a meeting immediately after connecting a line, a meeting progress or meeting contents, and a time of advance negotiation. Using the low-speed transmission channel of, the still images and documents used for the conference are sent, and the image data and the image identification number are stored in the storage device of the video conference device at each conference site, so that the still image can be used during the subsequent conferences. When displaying images and documents, you can access them at high speed and instantly display them on each terminal.

Since this transmission uses the low-speed transmission channel, it does not adversely affect the moving image or voice during the still image transmission. When a still image is accessed, the image identification number is only transmitted to the other terminal, and the target image is displayed on the screen almost at the same time. It is possible to realize a video conference device with a significantly improved man-machine interface for access.

Further, even if the conference starts before the still image database is sufficiently shared, or if a new still image or document is needed during the conference, the high speed transmission channel transmits the still image. Since it is preferentially allocated to, the waiting time at the time of transmitting a still image can be reduced as much as possible.

Further, once the images are exchanged, the accumulated database can be used from the next access, so that it is not necessary to transmit the images every time, and the line use time can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a video conference device according to an embodiment.

FIG. 2 is a diagram illustrating a data flow in this embodiment.

FIG. 3 is a diagram showing an example of allocation of transmission signals.

[Explanation of symbols]

 1 Tablet 2 Camera 3 Color Display 4 Camera / Color Scanner 5 Document Display 6 Scanner 7 Speaker 8 Microphone 9 Display Control Unit 10 System Control Unit 11 Moving Image Encoder 12 Still Image Encoder 13 Document Encoder 14 Voice Encoder 15 Storage Device 16 Multiplexing device 17 Line interface 18, 19 Changeover switch 20 Line 21, 22, 23, 24, 25, 26, 27 Connection terminal

Claims (2)

[Claims] 1. An input unit for inputting each information of audio information, document information, still image information, moving image information, an encoder for compressing / combining the input information, and each information. An output unit for displaying or outputting, and a multiplexing unit that has a switching unit that multiplexes the signals of the respective encoders and a control signal for control and that switches and selects the information to be multiplexed, In the video conferencing apparatus, which comprises a line interface unit that serves as an input / output interface between the communication unit and the transmission path, and a control unit that performs various controls, and that communicates the information with each other via the transmission path, An image storage unit that stores and stores still image information or document information used in a meeting together with identification information for identifying the information, Document information and the identification information are stored in the image storage unit in advance before the line connection, and at the same time when the transmission line is connected, the still image information or the document information and the identification information are transmitted between terminals using a low-speed transmission channel. However, while accumulating the still image information or the document information and the identification information received from the partner terminal in the image accumulating unit, and when a request for using the still image information or the document information is generated after the mutual transmission ends, the It is characterized in that only the identification information is transmitted to the counterparty terminal, and the terminal receiving the identification information has a control unit for searching and displaying the still image information or the document information from the image storage unit based on the identification information. Video conferencing equipment. 2. The video conference apparatus according to claim 1, wherein when the mutual transmission is not completed at the time when the request for using the still image information or the document information is issued, it is identified as the still image information or the document information. A video conference apparatus having a control unit for temporarily allocating and transmitting information to a high-speed transmission channel of a multiplexing unit.