JPH09238322A - Image transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly send image data with high definition and to reduce the transmission time of the image data by sending in parallel the image data to image transmitters with a multi-point control unit. SOLUTION: Image data by the HDTV system are outputted onto a network line from an image transmitter 110. The image data are sent from the transmitter 110 to a multi-point control unit MCU 301. The MCU 301 stores the image data to a storage device, then the CPU of the MCU 301 reads out the stored image data and sends the data to an image transmitter 120 and then sends the same image data to an image transmitter 130 and the repeats the operation above to image transmitters 140-190 sequentially. Thus, the image data sent from the transmitter 110 are sent to the other transmitters 120-190.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image transmission system for transmitting input image data to another place.

[0002]

2. Description of the Related Art Conventionally, images and sounds are sent to a remote place,
A system is used in which a conference is held between distant points by displaying and reproducing them at a remote place. In a conventional system, an NTSC television signal is often used as an image signal to be transmitted.

[0003]

As in the prior art, NTS
The resolution of an image that can be transmitted by a C-type television signal is not high. Therefore, even if an image such as a slide photograph (for example, an image taken with a microscope) used in a research group or an academic conference in the fields of medical care, chemistry, etc. is transmitted, the image quality is sufficient for the other party to understand. It didn't look like a picture.

For such applications, transmission of high definition images is required. Therefore, an image transmission system that can use high-definition images in a conference at a plurality of distant points is required. However, since a high-definition image has a large amount of image data, it takes time to transmit. Images used in a conference are often transmitted to the image display devices of all conference participants. If there are many participants in the conference and many image display devices, the image transmission time is very long. In addition, there is a problem that the transmission path is occupied for a long time for transmitting the image data.

In view of the above problems, it is an object of the present invention to provide an image transmission system capable of shortening the transmission time of image data and reducing the load on the transmission path.

[0006]

Means for Solving the Problems To solve the above problems,
According to the present invention, a plurality of image transmission devices capable of transmitting or receiving data and a control unit which is connected to the plurality of image transmission devices and manages data transmission between the plurality of image transmission devices are network-connected. In the transmission system, the control unit includes an input unit for inputting image data from the image transmission device, an image data storage unit for storing the image data, and the stored image data for another image transmission device. And an image transfer means for transferring to the.

Also, the present invention is directed to a plurality of image transmission devices capable of transmitting or receiving data, and a plurality of control units connected to the image transmission devices and managing data transmission between the plurality of image transmission devices. And a network-connected transmission system, each of the plurality of image transmission devices is connected to any of the plurality of control units, the plurality of control units are network-connected, The control unit includes an input unit for inputting image data from the image transmission device or another control unit, an image data storage unit for storing the image data, and the stored image data for another image transmission device or another. An image transfer means for transferring to the control unit is provided.

The present invention is also directed to a plurality of image transmission devices capable of transmitting or receiving data, and a plurality of control units connected to the image transmission devices for managing data transmission between the plurality of image transmission devices. Is a network-connected transmission system, each of the plurality of image transmission devices is connected to one of the plurality of control units, and the control unit is transmitted from the connected image transmission device. Image data to be input, the image data is transferred to another control unit, and then the image data is transferred to another connected image transmission device.

The image transmission device is capable of transmitting a plurality of image data having different resolutions, and the control unit is
The transmission of the image data with the higher resolution may be controlled.

[0010]

FIG. 2 is a diagram showing the configuration of an image transmission system according to the first embodiment of the present invention. In FIG. 2, a multipoint control unit (MCU) 301 and image transmission devices 110 to 190 are connected via a network line. In this system, nine image transmission devices are connected via a network, but any number of two or more may be connected. The respective image transmission devices are installed at different points (remote locations).

FIG. 1 is a diagram showing the configuration of the image transmission apparatus 110. The other image transmission devices 120 to 190 have the same configuration. In FIG. 1, the CPU (central processing unit) 12 is
It is connected to the transmission control unit 112, and inputs high-definition digital image data sent from another image transmission device via the transmission control unit 112, or to another image transmission device via the transmission control unit 112. It also outputs high-definition digital image data. CP
A display device 13, a keyboard 14, and a storage device 15 are connected to U12. As the storage device 15, a device using a large-capacity storage medium such as a hard disk device or an optical disk device is used, and high-definition digital image data is stored therein. The operator operates the keyboard 14 while watching the contents displayed on the display device 13. In addition to the keyboard 14, a pointing device such as a mouse 25 is used as the input device. Also tablets
26 may be used. Note that, in FIG. 2, the transmission control unit connected to each image transmission device is omitted.

The HDTV camera 17 is a camera for capturing a high-definition image (image according to the HDTV system). The HDTV image signal (analog image signal) output from the HDTV camera 17 is the HDTV input / output device 16
Is input to The HDTV input / output device 16 converts the input analog image signal into digital image data and outputs CP.
Output to U12. Also, the HDTV input / output device 16 is a CP
The digital image data input from U12 is converted into an analog image signal and output to the switching device 22. The digital image data input to the HDTV input / output device 16 is temporarily stored in the frame memory 24. Then, the HDTV input / output device 16 reads the digital image data from the frame memory 24, converts it into an analog image signal, and outputs it.

The NTSC input / output device 18 is connected to the transmission control unit 111, and inputs NTSC digital image data sent from another image transmission device through the transmission control unit 111, and the transmission control unit 111. The NTSC digital image data is output to another image transmission device via 111. The NTSC I / O device 18
An NTSC camera 19, a speaker 20, and a microphone 21 are connected.

The NTSC camera 19 is a camera for capturing an NTSC image. The NTSC image signal (analog image signal) output from the NTSC camera 19 is NTS
It is input to the C input / output device 18. NTSC I / O device 18
Converts the input analog image signal into digital image data and outputs the digital image data to the transmission control unit 111. Microphone 21
The voice is input from. The input audio signal is NT
It is converted into digital audio data by the SC input / output device 18 and output to the transmission control unit 111 together with the digital image data.

The NTSC input / output device 18 converts the digital image data input from the transmission control unit 111 into an analog image signal and outputs it to the switching device 22.
The switching device 22 selectively outputs one of the analog image signals input from the HDTV input / output device 16 and the NTSC input / output device 18. The analog image signal output from the switching device 22 is input to the monitor display device 23. The monitor display device 23 displays an image on the screen according to the input analog image signal.

This system handles two types of image data (HDTV, NTSC) as described above. The HDTV image has a higher resolution than the NTSC image and is a high-definition image. When converting an image signal to digital data, in the case of an image based on the NTSC system, for example, 32
It is converted into image data consisting of pixel data of 0x250 pixels (80,000 pixels).
Converts to image data consisting of pixel data of 20 × 1024 pixels (about 2 million pixels). Since the image data of the HDTV system has a larger number of pixels, the data capacity becomes larger and it takes time to transfer the data.

Next, the multipoint control unit (MCU) 201
Will be described. As shown in FIG. 3, the MCU 301 is
It is composed of a CPU 31 and a storage device 33. CPU31
Is a transmission control unit 32 that controls transmission with other devices.
Is connected to Then, a command or image data sent from the image transmission device via the transmission control unit 32 is input. The input command and image data can be stored in the storage device 33. The MCU 301 performs a process of transmitting commands and image data sent from the connected image transmission devices 110 to 190 to an image transmission device other than the image transmission device that is the transmission source. The transmission control unit 32 is omitted in FIG.

Next, the operation of the system of this embodiment will be described. In FIG. 2, consider a case where high-definition image data based on the HDTV system is sent from the image transmission apparatus 110 to another image transmission apparatus. CPU 12 of the image transmission device 110,
Image data of the HDTV system is output to the network line via the transmission control unit 112. The image data is once transmitted from the image transmission device 110 to the MCU 301. The MCU 301 stores the transmitted image data in the storage device 33.
To memorize. After that, the CPU 31 of the MCU 301 reads the image data from the storage device 33 and transmits it to the image transmission device 120. When this transmission is completed, the same image data is then sent to the image transmission device 130. Then, this operation is sequentially repeated for the image transmission devices 140 to 190. In this way, the image data transmitted from the image transmission device 110 is sent to the other image transmission devices 120 to 190.

FIG. 4 is a diagram showing a lapse of time during the transmission operation of the image data. t1-M represents the transmission time of image data from the image transmission device 110 to the MCU 301. tM-2 to tM-9 represent transmission times of image data from the MCU 301 to the image transmission devices 120 to 190, respectively. The time for transmitting the image data to all the image transmitting devices is the sum of the time for transmitting the image data to each image transmitting device.

Next, an image transmission system according to the second embodiment will be described. FIG. 5 shows an image transmission system including three MCUs and nine image transmission devices.
The MCU 301 controls data transmission with the image transmission devices 110, 120 and 130, the MCU 302 controls data transmission with the image transmission devices 140, 150 and 160, and the MCU 303 controls the image transmission device 17.
Controls the transmission of data with 0, 180, 190. And M
CU301 is connected to MCU302, and MCU302 is MCU303
Is connected to The MCUs 302 and 303 have the same configuration as the MCU 301.

The following rules of priority are provided in the order of image transmission by the MCU. That is, the MCU that receives the image data transmits the image data to another MCU before the image transmission device under control.
Similar to the case of the first embodiment, consider a case where image data is transmitted from the image transmission device 110 to another image transmission device. The time course of image transmission in this case is shown in FIG.
It is. The time notation is the same as that described above, t1-M
Is the transmission time of image data from the image transmission device 110 to the MCU 301, and tM-2 to tM-9 are transmission times of image data from the MCU to the image transmission devices 110 to 190, respectively. That is, tM-2, tM-3 are transmission times of image data from the MCU 301 to the image transmission devices 120, 130, respectively, tM-4, tM-5, t.
M-6 is the image transmission device 140, 150, 16 from the MCU 302, respectively.
The transmission time of image data to 0, tM-7, tM-8, and tM-9 are transmission times of image data from the MCU 303 to the image transmission devices 170, 180, and 190, respectively.

Then, T1-2 is from MCU301 to MCU302
Image data transmission time to T2-3 from MCU302 to MC
This is the transmission time of image data to U303. Image transmission device 1
Upon receiving the image data from 10, the MCU 301 temporarily stores the image data in the storage device 33 and then transmits the image data to the MCU 302. After that, CPU31 of MCU301
Reads the image data from the storage device 33 and transmits the image data to the image transmission devices 120 and 130. The MCU 302, to which the image data is transmitted from the MCU 301, stores the image data in the storage device 33 and then stores the image data in the same manner as the MCU 301.
Image transmission device 140, 150, 160
Transmit to Similarly, the MCU 303 also transmits the transmitted image data to the image transmission devices 170, 180 and 190. In this way, the image data transmitted from the image transmission device 110 is sent to all the other image transmission devices, and the image data transmission process ends.

As shown in FIG. 6, in a system having a plurality of MCUs, image data transmission from each MCU to the image transmission device under its control is processed in parallel.
It can be seen that the transmission time of the entire system is shortened as compared with FIG. In this way, by connecting a plurality of multipoint control units (MCU), the work of image transmission is shared, the time for transmitting image data to all image transmission devices is shortened, and the transmission path The load is also reduced.

[0024]

As described above, according to the present invention, the provision of the control unit enables smooth transmission of high-definition image data. Further, by providing a plurality of control units, the transmission time of image data can be shortened.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an image transmission device according to first and second embodiments of the present invention.

FIG. 2 is a diagram showing a configuration of an image transmission system according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a multipoint control unit (MCU) according to the first and second embodiments of the present invention.

FIG. 4 is a diagram showing a transmission time of image data in the image transmission system according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of an image transmission system according to a second embodiment of the present invention.

FIG. 6 is a diagram showing a transmission time of image data in the image transmission system according to the second embodiment of the present invention.

[Explanation of symbols]

2; network line, 12; CPU, 13; display device, 14; keyboard, 15; storage device, 16; HDTV input / output device, 17; HDTV camera, 18; NTSC input / output device, 19; NTSC camera, 20; speaker , 21; Mike,
22; Switching device, 23; Monitor display device, 24; Frame memory, 25; Mouse, 26; Tablet, 31; CP
U, 33; storage device, 110, 120, 130, 140, 150, 160, 17
0, 180, 190; image transmission device, 111, 112, 121, 122, 13
1, 132, 32; transmission control unit, 301, 302, 303; multipoint control unit (MCU).

Claims (4)

[Claims] 1. A network connection of a plurality of image transmission devices capable of transmitting or receiving data, and a control unit connected to the plurality of image transmission devices and managing data transmission between the plurality of image transmission devices. The control unit includes an input unit for inputting image data from the image transmission device, an image data storage unit for storing the image data, and another image transmission for the stored image data. An image transmission system comprising: an image transfer means for transferring to an apparatus. 2. A network connection of a plurality of image transmission devices capable of transmitting or receiving data, and a plurality of control units connected to the image transmission device and managing data transmission between the plurality of image transmission devices. In the transmission system, each of the plurality of image transmission devices is connected to one of the plurality of control units, the plurality of control units are network-connected, the control unit, Input means for inputting image data from the image transmission device or another control unit, image data storage means for storing the image data, and transfer the stored image data to another image transmission device or another control unit. And an image transfer means for performing the image transfer. 3. A network connection of a plurality of image transmission devices capable of transmitting or receiving data, and a plurality of control units connected to the image transmission device and managing data transmission between the plurality of image transmission devices. In the transmission system, each of the plurality of image transmission devices is connected to any of the plurality of control units, and the control unit controls the image data sent from the connected image transmission device. An image transmission system characterized by inputting, transferring the image data to another control unit, and then transferring the image data to another connected image transmission device. 4. The image transmission device is capable of transmitting a plurality of image data having different resolutions, and the control unit controls transmission of image data having a higher resolution. The image transmission system according to claim 2 or 3.