JP3342069B2 - Image transmission system, image transmission device, and image reception device - Google Patents

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 compressing and transmitting image information, and an image transmitting apparatus and an image receiving apparatus.

[0002]

2. Description of the Related Art In a conventional image transmission system for compressing and transmitting image information, a compression ratio of image information is determined by an image transmission side regardless of a purpose of use on an image reception side.

[0003]

However, image output devices such as printers and monitors are supplied with various resolutions or image qualities. Therefore, as an image transmission system, it is not only possible to assume a situation where the resolution or image quality of the image output device is different depending on the device configuration of the image transmission device, and a plurality of monitors having different resolutions are connected to the receiving terminal, It is also conceivable that an image receiving side intends to select a monitor to output an image.

In the conventional example, since the image receiving side unilaterally determines the compression ratio, a compression ratio that does not match the resolution or image quality required by the image receiving side may be selected. Had occurred.

That is, in the case of a compression ratio of an image quality exceeding the image quality required by the image receiving side, unnecessary portions are included in transmission data, and for example, there is a problem that an unnecessarily long transmission time is required.

On the other hand, in the case of a compression ratio of an image quality that does not reach the image quality required by the image receiving side, the image receiving side may endure the image quality of the received image or re-execute at a lower compression ratio by telephone or the like. The transmission is requested to the image transmission side.

An object of the present invention is to provide an image transmission system, an image transmission device, and an image reception device that do not cause such inconveniences.

[0008]

An image transmission system according to the present invention is an image transmission system for compressing and transmitting image information, wherein an image receiving side transmits usage purpose information to an image transmitting side prior to image transmission. The image transmitting side compresses and transmits an image to be transmitted according to the use purpose information.

[0009] The image transmitting apparatus according to the present invention is characterized by comprising a receiving means for receiving the purpose information from the image receiving side, and a compressing means for compressing and transmitting an image to be transmitted in accordance with the purpose information. And

An image receiving apparatus according to the present invention is an image receiving apparatus of an image transmission system for compressing image information and transmitting the compressed image information. The transmitting apparatus transmits usage purpose information of an image to be received before transmitting the image information. Means are provided.

[0011]

According to the above means, the image receiving side can receive image information of a required resolution or image quality. Therefore, inconveniences such as an unnecessarily long transmission time, poor image quality, and a request for retransmission at another compression rate are eliminated.

[0012]

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

FIG. 1 is a block diagram showing a schematic configuration of a communication terminal apparatus according to an embodiment of the present invention.

Reference numeral 10 denotes a CPU for controlling the whole. 12
Is an R that stores fixed data and a program of the CPU 10.
OM, 14 is a RAM for temporarily storing various data and programs, 16 is an operation device having key switches for giving various instructions to the CPU 10, such as dial keys, transmission keys, reception keys, and multi-image display keys, 18 Is a display device that displays various state information by a liquid crystal display panel, a light emitting diode, or the like.

The ROM 12 stores a correspondence table TBL12a between the number of multi-picture screens and the compression ratio. Generally, a multi-image is defined as a plurality of images (for example,
4, 9, 16, or 25) are combined so as to be displayed simultaneously. In this embodiment, one image is displayed on one screen.
An image display is also included in the multi-image as a special example of the multi-image. In the RAM 14, an image buffer 14a for temporarily storing the transmitted compressed image information and the received compressed image information is set.

Reference numeral 20 denotes an image input / output device including an image input unit such as a video camera or an image scanner and an image output unit such as a video monitor or a printer. 22 temporarily stores an image to be transmitted and a received image. Image memory, 2
Reference numeral 4 denotes a compression / decompression circuit for compressing and encoding an image to be transmitted and decompressing received compressed image information. Reference numeral 26 denotes a communication control circuit (CC) for controlling communication via a communication line such as ISDN.
U).

Each of the above elements 10 to 26 includes a control bus 28,
They are interconnected via an address bus 30 and a data bus 32.

FIG. 3 shows an operation flowchart for transmitting an image. First, the line is connected by the CCU 26 (S
1), receiving the number of multi-images from the image receiving side (S)
2). The compression ratio is determined by applying the number of received images to the table 12a (S3). The specified number of images are fetched from the image input / output device 20 into the image memory 22 and combined into a multi-image. The combined multi-picture is compressed by the compression / decompression circuit 24 (S4).

The compression information is transferred to the CCU 26 via the image buffer 14a of the RAM 14,
Transmits the compression information to the communication partner (S5). After transmitting necessary information, the CCU 26 disconnects the line (S
6).

FIG. 4 shows an operation flowchart when receiving an image. The line is connected by the CCU 26 (S11),
The number of multi-images is input from the operation device 16 (S1).
2). The number of input images is transmitted to the image transmitting side (S1).
3) Receive compressed image information compressed at a compression rate corresponding to the number of images (S14). The received compressed image information is transferred to the compression / decompression circuit 24 via the image buffer 14a, decompressed and stored in the image memory 22 (S1).
5).

The received image stored in the image memory 22 is read out, supplied to the image input / output device 20, and displayed on the monitor screen of the image input / output device 20 as a multi-image (S1).
6). Upon completion of reception of necessary compressed image information or termination of communication, the CCU 26 disconnects the line (S17).

In FIGS. 3 and 4, the number of images constituting a multi-picture is used as a means for specifying the compression ratio, but the compression ratio itself may be specified. FIG. 5 shows an operation flowchart for transmitting an image. First, the line is connected by the CCU 26 (S21), and compression ratio information is received from the image receiving side (S22). The image information is taken into the image memory 22 from the image input / output device 20, and the image data in the image memory 22 is compressed by the compression / expansion circuit 24 at the compression rate of the received compression rate information (S23).

The compressed image information is transferred to the CCU 26 via the image buffer 14a of the RAM 14,
U26 transmits this compression information to the communication partner (S2).
4). After transmitting necessary information, the CCU 26 disconnects the line (S25).

FIG. 6 shows an operation flowchart for receiving an image. The line is connected by the CCU 26 (S31),
The number of images of the multi image is input from the operation device 16 (S3
2). With reference to the table 12a, the compression ratio for the input number of images is determined (S33) and transmitted to the image transmitting side (S34). The compressed image information compressed at the transmitted compression ratio is received (S35). The received compressed image information is transferred to the compression / decompression circuit 24 via the image buffer 14a, decompressed and stored in the image memory 22 (S3).
6).

The received image stored in the image memory 22 is read out, supplied to the image input / output device 20, and displayed on the monitor screen of the image input / output device 20 as a multi-image (S3).
7). The CCU 26 disconnects the line when the reception of the necessary compressed image information is completed or the communication is completed (S38).

Although transmission of a multi-image consisting of a predetermined number of images has been described as an example, it goes without saying that the same applies to normal image transmission. Although the embodiment in which the image receiving side transmits the compression ratio to the image transmitting side has been described, other information related to compression such as quantization step size information, horizontal and vertical resolution, and band may be used.

[0027]

As can be easily understood from the above description, according to the present invention, image information can be transmitted at the required resolution or image quality on the image receiving side. Therefore, disadvantages such as unnecessarily long transmission time, poor image quality, and requesting retransmission at another compression ratio are solved.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of an embodiment of the present invention.

FIG. 2 is a correspondence table between the number of images of a multi-image and a compression ratio.

FIG. 3 is an operation flowchart of an image transmission side.

FIG. 4 is an operation flowchart corresponding to FIG. 3 on the image receiving side.

FIG. 5 is another operation flowchart on the image transmission side.

6 is an operation flowchart corresponding to FIG. 5 on the image receiving side.

[Explanation of symbols]

10: CPU 12: ROM 12a: Table 1
4: RAM 14a: Image buffer 16: Operation device 18: Display device 20: Image input / output device 22:
Image memory 24: Compression / expansion circuit 26: Communication control circuit (CCU) 28: Control bus 30: Address bus
32: Data bus

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-105965 (JP, A) JP-A-3-60268 (JP, A) JP-A-2-104078 (JP, A) JP-A-4- 167664 (JP, A) JP-A-63-237660 (JP, A) JP-A-3-248672 (JP, A) JP-A-1-198176 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 1/00-1/00 108 H04N 1/32-1/36 H04N 1/42-1/44

Claims (10)

(57) [Claims] An image transmission system for compressing and transmitting image information, wherein prior to image transmission, an image receiving side transmits usage purpose information to an image transmission side, and the image transmission side transmits the usage purpose information in accordance with the usage purpose information. An image transmission system, wherein an image to be transmitted is compressed and transmitted. 2. The image transmission system according to claim 1, wherein the use purpose information is information indicating whether or not the image is a multi-image. 3. The image transmission system according to claim 1, wherein the image transmission side has a correspondence table of the number of images constituting the multi-image and the compression ratio, and the use purpose information is information on the number of images of the multi-image. 4. The image receiving side has a correspondence table of the number of images constituting a multi-image and a compression ratio, and the image receiving side determines a compression ratio by applying the designated number of images of the multi-image to the correspondence table. 2. The image transmission system according to claim 1, wherein information on the determined compression ratio is transmitted to the image transmission side. 5. An image transmitting apparatus comprising: receiving means for receiving use purpose information from an image receiving side; and compression means for compressing and transmitting an image to be transmitted according to the use purpose information. 6. The image transmitting apparatus according to claim 5, wherein the use purpose information is information indicating whether or not the image is a multi-image. 7. The image transmitting apparatus according to claim 5, further comprising a correspondence table of the number of images constituting the multi-image and the compression ratio, wherein the use purpose information is information on the number of images of the multi-image. 8. An image receiving apparatus of an image transmission system for compressing image information and transmitting the compressed image information, wherein transmission means for transmitting usage purpose information of an image to be received is provided prior to transmission of the image information. Image receiving device. 9. The image receiving apparatus according to claim 8, wherein the compression information is information indicating whether or not the image is a multi-image. 10. The image processing apparatus according to claim 1, further comprising a correspondence table of the number of images constituting the multi-image and the compression ratio, wherein said transmitting means uses information of the compression ratio corresponding to the designated number of images of the multi-image as said use purpose information. The image receiving device according to claim 8, wherein the image is transmitted.