JPH0526397B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a still image is converted into a digital signal on a transmitting side and transmitted via a communication line, and on a receiving side, this signal is once stored in a memory, and the contents are divided into digital signals, for example, by the number of scanning lines. The present invention relates to a still image teleconferencing device that displays images on various small and medium-sized CRT displays with approximately 525 images, and exchanges this image information between the transmitting and receiving sides to realize remote conferences, etc.

Conventionally, in this type of remote conference device, the receiving side stores the sent digital signal as an image signal in the form of one still image frame in a memory. Alternatively, if a compressed code is used on the transmitting side, the receiving side decodes it back to an image signal and stores it in memory. This memory can be expanded with a regular large CRT or projection CRT display device, so that multiple people can view it at the same time, or multiple CRTs can be lined up to create a kind of multi-screen display.

In such a method, even if a detailed image is sent as a still image, the scanning line as described above on the receiving side
A normal CRT with about 525 lines could not display detailed images and it was difficult to see a wide range of conditions. Furthermore, even when transmitting text drawings such as documents and blackboards, the display range and resolution of the normal CRT are not good, so there is a big difference from actually viewing printed matter.

In order to eliminate these drawbacks, the present invention calculates how many pages the entire conference image information or the document information of the front body corresponds to on a normal CRT with about 525 scanning lines, and calculates the equivalent. Send multiple pages to the receiving side. On the receiving side, all this
The receiving conference participant can store this information anywhere in the entire RAM memory.
By extracting and viewing pages on your own CRT,
The purpose is to improve the convenience of still image video conferencing.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a conceptual diagram for explaining an embodiment of the present invention. For example, pages A to D of RAM memory 1 are color images of the arrangement of people at the other party's meeting, which can normally be displayed in its entirety on one CRT page. The E of RAM memory 2 is expressed as a side-by-side shape.
Pages from page H to page H are similarly color images, but four pages are used to display the entire image as double the density of the normal image, and are used for sending and receiving real images with gradations or color photographs. Furthermore, pages I to X of the RAM memory 3 are dedicated to black and white binary documents, and are allocated for documents or electronic blackboards. If allocated as documents, 4 each
It may be configured as one document with pages as an entire image and used for a total of four pages, or it may be used for two pages in portrait orientation. As an electronic blackboard, four documents may be arranged horizontally and used horizontally. The method of allocating the RAM memory 3 mentioned above and whether or not to rewrite the above image with new contents each time are all controlled by the sending side. usually using
Each CRT page is monitored, and if it is determined that it is OK to send, the frame memory is fixed and the digital image information is sent to the transmission line. Next, operate the camera, monitor the next image, and send it again.

FIG. 2 shows the configuration of the transmitting section of the present invention, in which 4 is a color monitor, 5 is a color vidicon camera, and 6 is a camera movement control section. Move the step. 7 is a camera control circuit, and 8 is an A/D converter that converts one page of a normal CRT into, for example, 400 (number of horizontal dots on a normal CRT) x 300 (number of vertical dots on a normal CRT) x 8.
(Color specification) Convert to 960K bits and write the contents to frame memory 9. Regarding the black and white binary blackboard information, the blackboard information is read out by accurately moving frame by frame memory by the operator's button control using the black and white vidicon camera 10 and the movement control unit 11.
12 is a camera control circuit, 13 is an A/D converter, 1
4 is digital 1 frame memory, 400 (CRT
(number of horizontal dots) x 300 (number of vertical dots on CRT) x
A memory capacity of 1 (color specification) bit = 120k bits is sufficient. Furthermore, since much of the information in black and white is written on paper, a mechanism 15 similar to a facsimile transmitter is used to read out the document line by line using a one-dimensional sensor (8 lines per mm). dot) This is stored in the image memory 16. At this time, the black and white information of 8 dots per mm is reduced to about half by appropriate sample processing, and one line is 400 x 2.
= Stored as 800 bits of memory. That is, 1
The screen usually accumulates as the width of two CRT pages.
The transmitting side operator transmits one of the frame memory 9, digital 1 frame memory 14, image memory 16, etc., through the switch 17, but when the transmission model 18 is in black and white binary, Alternatively, when the image is a color image, it is transmitted via either coder 19 or 20 in order to compress the amount of information to be transmitted. Immediately before transmission, information such as when to update this frame memory is sent from the operation unit 21 to the receiving side.

Next, the operation on the receiving side will be explained with reference to FIG. The signal received from the modem 22 is sent to the control unit 23
decipher the location and nature of the image information that should arrive. Accordingly, the data 24 or decoder 25 is connected to restore the incoming signal to the original image signal. The memory 26 uses the restored one-page memory to store the person in the meeting (RAM
1), a general color memory (RAM memory 2), a blackboard memory (RAM memory 3), and which part of it it is, and then drives the address control 27 to input the contents to a predetermined location. Write in place. On the other hand, each conference participant on the called side is individually equipped with a normal CRT 28, and the memory group 1,
2 and 3, one page's worth of memory information is read from any location in the memory group as a starting point via the starting point address buffer 30 using the up/down movement keys and left/right movement keys of each console 29. Then, it is written into the self-CRT memory 31 and repeatedly displayed on the CRT. self console 29
is equipped with a lamp display that shows the status of the entire memory being written, the group of memories that are currently being updated, etc., and conference participants can call up any memory by operating the keys. You can search left and right, up and down, just like you would with the naked eye. Furthermore, by keying in the name of a speaker who is a remote conference participant, the name can be displayed on the receiving side console 29 or superimposed on the CRT 28 by keying in the name from the console operation section 21 .

As explained above, the present invention is effective for a conference system using a plurality of still images, and the transmission time for one page of color images is 960 kb/s with a compression rate of 1/2 using a 64 kb/s digital line. 64kb×1/2
≒8 seconds, and one black and white page is compressed at 1/5
120kb/64kb×1/5≒0.4 seconds, and efficient transmission characteristics can be obtained. Furthermore, if a general telephone line is used, the transmission time is 9.6 kb/s, which is seven times the above-mentioned transmission time, but in this case, it is practically appropriate to convert the color image to monochrome.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram for explaining an embodiment of the present invention, FIG. 2 is a block diagram of a transmitter of the present invention, and FIG. 3 is a block diagram of a receiver of the present invention. 1, 2, 3...RAM memory, 4...Color monitor, 5...Color vidicon camera, 6...Camera movement control section, 7, 12...Camera control circuit,
8, 13...A/D conversion unit, 9...Frame memory, 10...Black and white bidicon camera, 11...Movement control unit, 14...Digital 1 frame memory,
15... Transmission mechanism, 16... Image memory, 17...
...Switch, 18...Transmission modem, 19,20...
...Coder, 21...Operation unit, 22...Modem, 2
3...Control unit, 24...Data, 25...Decoder, 26...Memory, 27...Address control, 28...Normal size CRT, 29...Console, 30...Start point address buffer, 31...
...Memory for CRT.

Claims (1)

[Claims] 1. In a still image teleconferencing device that transmits and receives a plurality of still images as digital signals and plays and displays them on the receiving side, a person, etc. who can display the entire image on a normal one-page CRT screen sent from the transmitting side. It receives a still image signal 1 such as 1 and a control signal 1 for controlling the still image signal 1, has a capacity capable of storing at least one page worth of the still image signal 1, and stores the still image based on the control signal 1. A memory means 1 configured to suppress accumulation of the signal 1, and a memory means 1 configured to suppress accumulation of the signal 1;
A still image signal 2 such as a color photograph having gradations that cannot be displayed as an entire image on a CRT 1-page screen and a control signal 2 for controlling this still image signal 2 are received, and the control signal 2 for controlling the still image signal 2 is received for at least the divided pages. a memory means 2 having a capacity capable of storing still image signals 2 of 2 and configured such that storage of the still image signals 2 is controlled based on the control signal 2; usually
The entire image cannot be displayed on a CRT 1-page screen2
Still image signal 3 consisting of value information and this still image signal 3
The still image signal 3 is configured to receive a control signal 3 for controlling the still image signal 3, to have a capacity capable of storing at least the divided still image signals 3 for the plurality of pages, and to control the storage of the still image signal 3 based on the control signal 3. and display means for electrically cutting out and displaying the still image information stored in the memory means 1, 2, and 3 at will by each receiving conference participant on his/her own ordinary CRT. A still image video conference device characterized by the following.