JPH05344317A - Picture transmission system - Google Patents

Abstract

PURPOSE:To suppress the deterioration in a picture quality, to compress data amounts, and to shorten a transmitting time by reconstituting a multi-screen based on picture data at each unit screen received based on auxiliary data. CONSTITUTION:The outside input of one of outside input terminals T1-T3 is selected by a selector 1, the picture signal is amplified by an amplifier 2, amplified by an A/D converter 3, and supplied to a selector 4. At the time of recording, the picture data from the selector 4 are temporarily stored in an RAM 7. The picture data read from the RAM 7 at the time of receiving the timing control of a system control circuit 13, are transmitted through a selector 8 to a compressing and expanding unit 9, and a prescirbed compressing processing is operated. And also, at the time of reproduction, the data inputted to the RAM 7 are transmitted through the selector 4 to a reproducing process part 5, and a prescribed reproducing processing is operated. Then, the data are converted into an analog signal by a D/A converter 6, and outputted to a video output terminal. Thus, the constitution of the multi-screen, the compression of the data amounts, and the shortening of the transmitting time can be attained.

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, and more particularly to an image transmission system which reduces the transmission image data amount and transmission time.

[0002]

2. Description of the Related Art For example, when transmitting image data via a telephone line, compression of the amount of image data to be transmitted and reduction of transmission time are extremely important problems. Therefore, usually, the image data is digitized, and the image amount is reduced by using the data compression technique, so that the transmission time is shortened. A multi-screen obtained by dividing a monitor screen into a plurality of sub-screens is widely used because it is easy to compare a plurality of frame screens, and in this case, a data compression technique is also used. At this time, the child screen has a reduced screen configuration by compressing one screen. As an example of a multi-screen configuration,
As shown in FIG. 7A, one screen is divided into four child screens # 1 to # 1.
There is a screen configuration in which the screen is divided into # 4, and as shown in FIG. 7B, the sub-screen # 6 is placed in a part of the background screen # 5.

In the conventional multi-screen transmission, for example, as shown in FIG. 8, after the communication destination is called and confirmed by a terminal such as a telephone (step S101), uncompressed data (usually about 7) is transmitted.
40K bytes) are transmitted in multi-screen (step S102).

[0004]

When transmitting a modified screen such as this screen, if the multi-screen is further compressed and transmitted, the amount of image data is compressed, but decompression processing is required after compression. In the end, since the compression and the decompression processing are performed twice, there is a problem that the image quality is greatly deteriorated. Further, a storage medium for storing the compressed processed image data is also required, and the hardware becomes large. On the other hand, if the multi-screen image data is transmitted in a non-compressed state, the image data amount becomes large and the transmission time becomes long, which is contrary to the original purpose.

Therefore, an object of the present invention is to provide an image transmission system capable of compressing the transmission image data amount and shortening the transmission time while suppressing the deterioration of the image quality.

[0006]

In order to solve the above-mentioned problems, the image transmission system according to the present invention provides an image data for each unit screen which has been compressed and represents a plurality of images constituting the multi-screen, and the above-mentioned image data. First means for sequentially sending auxiliary data representing a configuration of a multi-screen from the transmission side system, and an image for each compressed unit screen sent from the transmission side system by the first means Second means for reconstructing a multi-screen based on the image data of each unit screen received by receiving the data and the auxiliary data by the receiving side system and relying on the auxiliary data. .

[0007]

In the present invention, the transmitting side sequentially sends each unit compressed image data of a plurality of images forming a multi-screen and auxiliary data indicating a configuration mode of the multi-screen, and the receiving side relies on the received auxiliary data. By reconstructing a multi-screen based on the image data of each received unit screen, the amount of transmitted image data is compressed and the transmission time is shortened.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an image transmission system according to the present invention. In this embodiment, the telephones 100 and 200 are used as terminals, and the recording / reproducing devices 120 and 13 are used.
0 and modems 110 and 210 are used to send and receive image data via a telephone line, and monitor 130 and 23 respectively.
This is an example of reproducing a multi-screen on 0. Modem 110
A normal call line is formed between the telephones 100 and 200 via the and 210. The recording / reproducing devices 120 and 220 record image data transmitted from the other party via the modem 110 or 210 and reproduce it on a monitor, or transmit the reproduced image data to the other party via a telephone line.

An example of the structure of the recording / reproducing devices 120 and 220 is shown in FIG. The external input terminals T1, T2, and T3 have RGB signals, S signals, and NT signals conforming to the TV standard.
The SC signal is input, and the selector 1 selects one of the external inputs. The image signal selected by the selector 1 is amplified by the amplifier 2, amplified by the A / D converter 3, and supplied to the selector 4.

At the time of recording, the image data from the selector 4 is temporarily stored in the RAM 7. The image data read from the RAM 7 under the timing control from the system control circuit 13 is sent to the compression / expansion unit 9 via the selector 8 and subjected to predetermined compression processing. The DCT / IDCT circuit 91 of the compression / expansion unit 9 is a discrete cosine transform / inverse discrete cosine transform circuit, and performs orthogonal transform processing on the block data for data compression. The transform coefficient obtained by the orthogonal transform is quantized by the quantization / inverse quantization circuit 92, and then encoded by the encoding / decoding circuit 93. Processing such as encoding in the compression / expansion unit 9 is controlled by the encoding control circuit 14 based on an instruction from the system control circuit 13. The image data thus compressed is recorded in the IC card memory 12 via the selector 10 and the card interface circuit 11. The image data from the RAM 7 via the selector 8 and the compressed image data via the selector 10 are supplied to the magneto-optical disk drive 18 via the system control circuit 13 and recorded on the magneto-optical disk 19. The serial interface circuit 17 is connected to a telephone line via a modem (110 and 210 in FIG. 1). The LCD 15 displays the operating status of the apparatus.

At the time of reproduction, RA is made by the route opposite to that at the time of recording.
The image data entered in M7 is sent to the reproduction process unit 5 via the selector 4 and subjected to a predetermined reproduction process.
The analog signal is converted by the D / A converter 6 and output to the video output terminal.

The operation unit 20 is for instructing the operation of this apparatus, and is provided with various keys. For example, a start key 20A for instructing operations such as recording and erasing, 20B for instructing a recording preparation state, and a key 20 for selecting a screen such as a reproduction screen.
C, 20D, a key 20E for instructing reproduction, a key 20F for instructing the erasing preparation state, a key 20 for instructing a recording mode
G, a key 20H for instructing a stop operation, a key 20I for instructing a multi-screen (for example, 2 × 2 screen configuration), and a key 20J for instructing transmission are provided.

Now, in the above-mentioned structure, the operation of this embodiment will be described with reference to FIG. 3. First, the REC key is "O".
It is determined whether or not N is set (step S1), and "O"
If it is N ″, a recording operation described later is executed (step S
5) Return to the process of step S1. If it is not “ON”, it is determined in the next step S2 whether or not another key is “ON”. Perform an action. Then, in step S3, it is determined whether or not the multi-screen reproduction key 19I is "ON".
Here, if the multi-screen playback key 19I is "ON", the multi-screen process described later is executed and the process returns to step S1 (step S6). In step S3,
If the multi-screen playback key 19I is not "ON", it is determined whether or not the transmission key 19J is "ON". If it is "ON", the transmission operation described later is executed (step S7), and the process of step S1. When the transmission key 19J is not "ON", the process directly returns to step S1.

In the recording operation in step S5, as shown in FIG. 4, the non-compressed external input is temporarily stored in the RAM 7 (step S51), and the compression / expansion unit 9 performs the compression process (step S52) to compress it. The image data is written in the IC card memory 12 which is a storage medium (step S53).

FIG. 5 shows the multi-screen reproduction processing procedure in step S6. This processing is an example of processing for a multi-screen configuration of 2 × 2 screens. First, the parameter N designating the frame numbers # 1 to # 4 is set to the initial value “1” (step S61), and the IC card memory is set. The compressed data stored in 12 is read out, and the compression / decompression unit 9
In, the data is expanded, reduced to 1/4, and written in the RAM 7 (step S62). Next, N is incremented by 1 to specify the next frame number (step S63),
It is determined whether N has reached the final frame number 4 (step S64). If N is not larger than 4, step S6
The same operation is repeated by returning to the processing of 2. If N is larger than 4, the process ends.

FIG. 6 shows a multi-screen transmission process (step S
The processing procedure of 7) is shown. After confirming the communication destination (step S7)
1), of the multi-screens, the first screen (# 1) transmits compressed data (about 60 KBytes), and then the second screen similarly.
The third screen and the fourth screen are transmitted (steps S73 to S7).
5). After that, a command indicating the multi-screen is issued (step S76). In this way, after transmitting each screen of the multi-screen as compressed data, if the multi-screen command is issued, the receiving side reproduces the multi-screen by using these four sets of screens.

In the image transmission system according to the above-described embodiment, the image data of each screen of the multi-screen is individually transmitted as the compressed data, and the multi-screen command is transmitted. Therefore, the compression ratio of the image data is the uncompressed data. It is greatly improved compared to the case of transmission. For example, when the uncompressed data for one screen is about 740 KBytes, according to the present embodiment, the compressed data for each child screen is four times as large as about 60 KBytes, that is, about 240 KBytes.

[0018]

As described above, according to the image transmission system of the present invention, particularly in the multi-screen configuration,
It is possible to significantly reduce the amount of image data to be transmitted and significantly reduce the transmission time.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an image transmission system according to the present invention.

FIG. 2 is a block diagram showing a configuration example of a recording / reproducing apparatus in the embodiment of FIG.

FIG. 3 is a flowchart showing an operation processing procedure in the embodiment of the present invention.

FIG. 4 is a flowchart showing a recording operation processing procedure in FIG.

5 is a flowchart showing a multi-screen reproduction processing procedure in FIG.

6 is a flowchart showing a multi-screen transmission processing procedure in FIG.

FIG. 7 is a diagram showing an example of a multi-screen configuration.

FIG. 8 is a diagram showing an operation processing procedure of a conventional multi-screen image transmission system.

[Explanation of symbols]

 1, 4, 8, 10 Selector 2 Amplifier 3 A / D converter 5 Reproduction process section 6 D / A converter 7 RAM 9 Compression / expansion unit 11 Card interface circuit 12 IC card memory 13 System control circuit 14 Encoding control circuit 15 LCD 16 communication control circuit 17 serial interface circuit 18 magneto-optical disk drive 19 magneto-optical disk 20 operation unit 100, 200 telephone 110, 210 modem 120, 220 recording / reproducing device 130, 230 monitor

Claims (3)

[Claims] 1. A system for sequentially sending, from a system on the transmitting side, image data for each unit screen that has been compressed and that represents a plurality of images that form the multi-screen, and auxiliary data that represents a configuration mode of the multi-screen. 1 means, and the image data and auxiliary data for each compressed unit screen sent from the system on the transmitting side by the first means are received by the system on the receiving side and depended on the auxiliary data. A second means for reconstructing a multi-screen based on the image data for each unit screen received by the second transmission means, and an image transmission system comprising: 2. A means for sequentially transmitting image data for each unit screen that has been compressed and that represents a plurality of images that compose the multi-screen, and auxiliary data that represents a configuration mode of the multi-screen. An image transmission system characterized by. 3. Image data for each unit screen that has been compressed and that represents a plurality of images that form the multi-screen transmitted from the compatible image transmission system, and auxiliary data that represents a configuration mode of the multi-screen. An image receiving system comprising means for receiving and reconstructing a multi-screen based on the received image data of each unit screen based on the auxiliary data.