JPH01160281A - Still picture video telephone communication system - Google Patents

Abstract

PURPOSE:To command the stop of transmission at an optional point of time during picture transmission by inserting a cancelling flag at a prescribed interval in a picture data sent in the transmission of the picture data and expressing the presence of a cancel command by means of the flag. CONSTITUTION:When a transmission button in a key pad 9 is set, a data in a picture memory 16 is extracted one by one line each and one flag is inserted for 96 data. When a cancel button 18 is not depressed, '1' is set to the flag and when the button 18 is depressed, a flag of '0' level is added after the data by one line and the resulting data is transferred to the reception side. The picture data is divided into one line each to check the flag at the reception side and when the flag '0' is identified, the reception of the picture data is stopped and a matrix switch 6 is switched from the position of a modulation- demodulation circuit 13 into an analog circuit 4 to restore the system into the voice communication.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a still image videophone communication system, and particularly to an improvement in transmission termination processing during communication of image data.

[Prior Art] There is a demand for videophones that simultaneously transmit audio and images using telephone communication lines, but in reality, current telephone communication lines cannot continuously transmit dynamic images that require a huge amount of data. Since it is difficult to send and receive a still image to the other party during a call, still image videophones are being put into practical use.

This still image videophone allows you to
It is possible to temporarily interrupt this call and send a desired still image, such as the speaker's face, a photo screen or a picture depending on the content of the call, or the like.

Therefore, with such a still image videophone, it is possible to send and receive images over a telephone line, which was previously impossible, and the amount of data processing is limited because only one still image is sent each time. This had the advantage that it was easy to put videophones into practical use.

A videophone capable of transmitting such still images is shown, for example, in the October 1986 issue of Foreign Communication Technology.

FIG. 5 is a circuit diagram of the simple static+L-screen TV filling machine. In the figure, (1) is a handset, (2) is a microphone, (3) is an audio input/output circuit, (4) is an analog circuit, (5) is a matrix switch, (6) is a telephone interface circuit, and (7) is a is the telephone line connection terminal, (8) is the speaker, (9) is the keypad, (10) is the input/output board, (11) is the CPU, (12) is the program memory,
(13) is a modulation/demodulation circuit, (14) is a television camera, (1
5) is an image controller, (16) is an image memory,
(17) is a display.

Next, the operation of transmitting audio and image signals of this conventional video telephone will be explained based on FIGS. 5 to 9.

In Figure 5, a voice call is made from a handset (1) or microphone (2) to a telephone line via an audio input/output circuit (3), an analog circuit (4), a matrix switch (5), and a telephone interface circuit (6). Connection terminal (7)
sent to. Further, an audio signal from the other party is reproduced by the handset (1) or the speaker (8) via a path opposite to the above-mentioned signal path.

Here, when transmitting an image signal, as shown in Figure 6, in order to confirm whether the communication partner is a video phone that has the ability to communicate image data in the same data format, an ID code containing data about the ability, etc. is sent. Then, after receiving the ID code returned from the other party and confirming that the other party has similar capabilities, the image data is transmitted.

That is, in FIG. 5, when the keypad (9) is used to instruct image transmission, the CPU (11) detects this via the input/output port (10), and the program memory (
12), the ID code is sent to the modulation/demodulation circuit (13) according to a program stored in advance. After modulating this ID code into an analog signal, it is sent out from the telephone line connection terminal (7) via the matrix switch (5).

The ID code from the communication partner passes through a path opposite to the above-mentioned signal path, and the CPU (11) confirms the code, etc.

Meanwhile, the image captured by the television camera (14) during this period is quantized by the image controller (15), stored in the image memory (16), and sequentially derived and displayed on the display (17). The image is output from the image memory (16) to the telephone line connection terminal (7).

Note that a header indicating data length, etc. is added to this image data.

When the ID code is input from the other party, the matrix switch (5) recognizes that image data reception is about to begin, and uses the carrier signal received by the matrix switch (5) to determine the destination by transmitting the received signal from the telephone interface circuit (6). is switched from the analog circuit (4) to the modulation/demodulation circuit (13). After the received signal is demodulated by the modulation/demodulation circuit (13), the CPU (11) returns the ID code or stores the data in the image memory (16), and the image controller (15) converts the self-image data and the other party's image data. It is derived one by one and displayed on the display (17).

Note that when the transmission and reception of images is completed and the carrier signal from the modulation/demodulation circuit (13) disappears, the matrix switch (5
) is the telephone interface circuit (6) and the analog circuit (4).
) to restore voice calls.

Furthermore, if the response from the receiving side is to be omitted, information regarding the omission is included in the ID code or header, and the image data is transmitted following the header.

The above-described operations of the still image video telephone device on the transmitting side and the receiving side are shown in FIGS. 7 and 8.

[Problems to be Solved by the Invention] As described above, in the conventional Q still image videophone communication system, the image length is identified by the ID code or header,
Communication of image data could not be completed until image data of this length was completed. For this reason, there is a problem in that even if the sending side accidentally sends an image that it does not want to send, it cannot be canceled midway through.

The present invention has been made to solve these problems, and an object of the present invention is to provide a still image videophone communication system that allows an instruction to stop transmission at any time during image transmission.

[Means for solving the problem] In a still image videophone communication system in which a desired still image is transmitted and received during a call using a telephone communication line, when image data is transmitted from the transmitting side, the image data to be transmitted is A cancellation flag is inserted at a predetermined interval in the image data, and when there is a cancellation instruction, this is expressed in the flag.The receiving side constantly monitors this flag, and when the cancellation instruction of this flag is confirmed, the image data is The feature is that the reception of the information is discontinued.

[Operation] When transmitting image data from the transmitting side, a cancellation flag is inserted into the image data at predetermined intervals. Then, on the transmitting side, when the transmission of image data is to be canceled midway through, an instruction to cancel is transmitted to the CPU. And the CPU
expresses a cancellation instruction using a cancellation flag. The receiving side checks the cancellation flag inserted at a predetermined position in the image data, and stops receiving the image data when it identifies a cancellation instruction.

In this way, cancellation of image data during communication can be performed.

Embodiment] Hereinafter, an embodiment of the present invention will be described based on the drawings.

In FIG. 1, (1) to (17) are the same components as those in the conventional example shown in FIG. 5, and their explanation will be omitted.

A feature of this embodiment is that a cancel button (18) is provided. Note that this cancel button (18) may be in any format and may be included in the keypad (9) as long as it can transmit an instruction to cancel transmission from the speaker on the transmitting side to the CPU (11). .

On the other hand, in this embodiment, as shown in FIG.
When creating image data in U (11), flags are inserted at predetermined intervals, in this example, for each row of image data. That is, when receiving a transmission instruction, the CPU (11) reads image data from the image memory (16), converts it into serial image data, and inserts a flag after one line of image data. The data with the flag inserted in this way is supplied to the modulation/demodulation circuit (13).

At this time, the CPU (11) also adds a header for identifying the start of the image data. Further, the insertion interval of this flag may be set at an appropriate interval instead of every line.

Here, the procedure for canceling image data transmission on the transmitting side will be explained based on FIG. 3.

When the send button in the keypad (9) is turned on, first connect the matrix switch (5) to the analog switch (
4) to the modulation/demodulation circuit (13). This means that voice communication has been switched to image data transmission. Then, the image obtained by the television camera (14) is sent to the image memory (16) via the image controller (15).
Incorporate into.

Next, the model of the other party is confirmed by exchanging ID codes, and after confirming that the receiver is ready, the image data is sent. In this embodiment, the data in the image memory (16) is extracted line by line. That is, if the image data corresponds to 96×96 pixels, one flag is inserted for each 96 pieces of data. In this embodiment, data of "0" and "1" are used as flags. That is, the cancel button (18)
When is not pressed, "1" is added as a flag and data for the next row is fetched.

If the cancel button (18) is not pressed and the end of the image data is reached, the matrix switch (5) is pressed.
is switched from the modulation/demodulation circuit (13) to the analog circuit (4) and returns to voice communication.

At this point, press the cancel button (18) while sending the image data.
) is pressed, the CPU (11) adds a flag of "0" after one line of data, transfers this to the receiving side, and returns to voice communication.

On the other hand, on the receiving side, image data is received using the procedure shown in FIG.

After receiving the ID code response and header, the image data is received. In this embodiment, the image data is divided into rows and flags are checked. In other words, the cancel button (18) is not pressed on the sending side, and “
If the 0° flag is not transmitted, one line of data is sequentially stored in the image memory (16), and the transmitted image is displayed on the display (17). This process is repeated until the image data ends, and when the end of the image data is identified, the matrix switch (5) is switched to return to voice communication.

Here, if the cancel button is pressed on the sending side, a flag of '0' is sent.
When the PU (11) identifies this "0" flag (if the flag is not set), it stops receiving the image data and switches the matrix switch (5) from the modulation/demodulation circuit (13) to the analog (4 ) to return to voice calls.

Note that the cancellation identification flag is "0°."

Not limited to "1", various types of data can be used.

[Effects of the Invention] As described above, according to the still image videophone communication system according to the present invention, even if a transmission cancellation instruction is given at any timing during the transmission of image data, the next flag will not indicate this cancellation. This allows both the sending and receiving sides to reliably return to voice communication.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a still screen videophone device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the structure of image data in the same embodiment, and FIG. 3 is a transmission diagram in the same embodiment. FIG. 4 is a flowchart showing the reception operation of the same embodiment. FIG. 5 is a block diagram showing the configuration of a conventional still image videophone device. FIG. 6 is an image of the conventional videophone device. Sequence diagram showing transmission procedure, No. 7
FIG. 8 is a flowchart showing the transmission operation in the conventional example, and FIG. 9 is a flowchart showing the receiving operation in the conventional example. In the figure, (1) is a handset, (5) is a matrix switch, (11) is a CPU, (13) is a modulation/demodulation circuit, (
18) is a cancel button. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent Patent attorney Masuo Oiwa (and 2 others) Cr% Ro He - Figure 2 Figure 6 Video phone Switchboard Video phone Figure 9

Claims (1)

[Claims] (1) In a still image videophone communication system that transmits and receives desired still images during a call using a telephone communication line, the sending side inserts a cancellation flag into the image data to be transmitted at predetermined intervals, and A still picture television characterized in that when there is a cancellation instruction, this is expressed in a flag, and the reception side stops receiving image data by identifying this flag and confirming the cancellation instruction of this flag. Telephone communication method.