JPH08317404A - System and method for image data transmission/reception - Google Patents

Abstract

PURPOSE: To provide a system and a method for image data transmission/ reception capable of reducing memory capacity and communication data quantity and improving the transmission efficiency of image data. CONSTITUTION: The image data conversion control part 10 of a client 1 samples blocked image data from the screen of a first display 4, and stores it in an image data storage part 11. Difference between sampled data and preceding image data stored in a preceding image data storage part 13 is sampled by a differential image data compression part 12, and the data is compressed, then, it is transmitted to a server 2. The image data expansion part 16 of the server 2 expands received compressed differential image data, and outputs a request to transmit the image data of the next block to the client 1 until an EOD that is the final block is received, and displays an image on the screen of a second display by an image data display part 17 when receiving EOD data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image data transmitting / receiving system and an image data transmitting / receiving method, and more particularly, to reducing the capacity of an image data storage device, reducing the capacity of an online data storage device, and improving transmission efficiency. A transmission / reception system and method.

[0002]

2. Description of the Related Art Conventionally, in transmitting / receiving image data between terminals of an image data storage device or between a host computer and a terminal, various image data transmission / reception has been performed in order to increase image data transmission efficiency and shorten response time. Method is used.

For example, Japanese Patent Application Laid-Open No. 61-48028 discloses an example of image data transfer transmission / reception method. In the image data transmission / reception method described in this conventional example, when a screen switching request is transmitted from the terminal to the host computer,
The host computer extracts only the difference image data between the image currently displayed on the terminal and the image of the previous screen stored in the previous screen image storage means and transmits it to the terminal. By this method, the data flowing on the online line is reduced and the transmission efficiency of transmission and reception is improved.

[0004]

However, in the above-mentioned image data transmitting / receiving method of the conventional example, it is necessary to prepare in advance a large-capacity storage device capable of storing all the image data currently displayed. Further, the difference between the image currently displayed and the image on the previous screen is different, the difference image data size increases closer to the image data size currently displayed. Therefore, there is a problem in that the data to be transmitted is not reduced and the transmission efficiency of transmission / reception does not increase.

It is an object of the present invention to provide an image data transmitting / receiving system and an image data transmitting / receiving method capable of reducing the storage capacity and the communication data amount and improving the image data transmission efficiency.

[0006]

To achieve the above object, in an image data transmitting / receiving system of the present invention, a client computer for transmitting image data and a server computer for receiving the image data are interconnected by a communication line. In the image data transmitting / receiving system, the client computer side divides the image information displayed on the screen of the client computer into blocks, and obtains image data, and image data conversion control means,
Image data storage means for storing the collected image data,
At the first image data transfer, the collected image data is stored as it is, and at the second and subsequent image data transfers, the previous image data is stored until the image data transmission process is performed, and the image data transfer is performed. A front image data storage means for storing the collected image data afterwards, a difference image data compression means for extracting and compressing difference image data between the image data to be transmitted and the previous image data, and communication And a first communication control means for controlling the above.
Compressed image data is expanded and the image data is blocked.
Image data expansion means for reassembling data, and image data for displaying the expanded and reassembled image data on the screen
And a second communication control means for controlling communication.

The image data transmission / reception method of the present invention is an image data transmission / reception method of transmitting / receiving image data between a client computer and a server computer, wherein the image data of one frame displayed on the client computer is divided into a plurality of blocks. One of image data dividing step of dividing, block image data collecting step of collecting image data of the divided predetermined block, image data storing step of storing the collected image data, and one of transmitted image data A previous image data storing step of storing previous previous image data, a differential image data extracting step of extracting image data of a difference between the image data and the previous image data, and a differential image data extracting step. A difference image data compression step of compressing the difference image data, An image data transmitting step of transmitting the processed difference image data, an image data receiving step of receiving the transmitted difference image data, and an image data block obtained by decompressing the received image data. It is characterized by including an image data expansion step of reassembling data and a step of displaying the expanded and reassembled image data on a screen.

[0008]

Therefore, according to the image data transmitting / receiving system and the image data transmitting / receiving method of the present invention, the division and compression processing of the image data held by the client computer is controlled, and the image data and the image are processed for image processing. The previous image data immediately before the data is stored. The difference image data between the stored image data and the previous image data is extracted and further compressed to obtain compressed image data.
This compressed image data is transmitted and received. Therefore, the difference data between the partial image data in the same frame is further compressed, and this difference compressed image data is transmitted and received between the client computer and the server computer.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image data transmitting / receiving system and an image data transmitting / receiving method according to the present invention will be described in detail with reference to the accompanying drawings. 1 to 4, there is shown an embodiment of an image data transmitting / receiving system and an image data transmitting / receiving method of the present invention. FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is a conceptual diagram of the processing contents in the image data transmitting / receiving system. 3 and 4 are flowcharts showing the operations of the client computer (hereinafter, also simply referred to as a client) side and the server computer (hereinafter, simply referred to as a server) side of the image data transmission / reception system of FIG.

Referring to FIG. 1, the image data transmitting / receiving system according to the present embodiment includes a client 1 for transmitting image data.
And a server 2 for receiving image data and a client 1
And a communication line 3 for connecting the server 2 and transmitting image data.

One of the clients 1 constituting the above-mentioned image data transmitting / receiving system includes a first display 4 and
An image data conversion control unit 10, an image data storage unit 11,
Difference image data compression unit 12 and previous image data storage unit 13
And a first communication control unit 14.

The other server 2 constituting the above image data transmitting / receiving system includes a second display 5, a second communication control section 15, an image data decompression section 16, and an image data display section 17. ing.

The first display 4 constituting the client 1 is a monitor display of image data on the client side.

The image data conversion control unit 10 is a circuit unit for controlling the conversion process of the image data displayed on the first display 4. The conversion process here is a process of dividing the image data displayed on the first display 4 into eight blocks, and a data compression process for each divided block of image data.

The image data storage unit 11 is a storage unit configured as a work area of the differential image data compression unit 12 and for storing the image data involved in the image data conversion processing. In the image data conversion process, the differential image data compression unit 12 executes the image data compression process using the image data storage unit 11 under the control of the image data conversion control unit 10.

The differential image data compression section 12 is a processing section for executing the conversion processing of image data. This process is executed under the control of the image data conversion control unit 10.

The previous image data storage unit 13 is a storage unit for storing and holding the blocked image data immediately before the completion of the image data conversion process. That is, it is a storage unit for storing the image data immediately before the block-processed image data that is currently undergoing the conversion process.

The first communication control unit 14 is an I / O unit of the client computer. First communication control unit 14
Is connected to the second communication control unit 15 which is the I / O unit of the server computer by the communication line 3 to exchange image data. Image data is transmitted / received for each frame in units of image data of 1 block with 1/8 frame as one block.

The second display 5 which constitutes the server 2
Is a monitor display of image information data on the server side.

The second communication control unit 15 is an I / O unit of the server computer. The second communication control unit 15 is connected to the first communication control unit 14 which is the I / O unit of the client computer via the communication line 3 and exchanges image data.

The image data expansion unit 16 is a processing unit for executing expansion conversion processing of image data.

The image data display unit 17 is a buffer memory unit for holding the image information data displayed on the second display 5.

The procedure of image data conversion processing in the client computer 1 and the server computer 2 configured by the above-mentioned respective parts will be described below with reference to FIG.

The image data currently being executed on the first display 4 of the client 1 is designated as "F". The image data of this frame is image data divided into eight blocks F1 to F8.

In the first image processing, the block F1
After storing the image data of No. 2 in the image data storage unit 11, the block F1 ′ of the previous image data storage unit 13 is initialized. Next, the difference image data compression unit 12 uses the two blocks F
The difference image data f1 of the image data of 1 and F1 'is
Extract as 1 '= f1 (C3). The acquired difference image data f1 is further compressed (C5) to obtain difference compressed image data δf1. The image data compression processing here is, for example, Huffman coding. In the server 2 which has received the differential compressed image data δf1, the image data decompression process,
The restoration process, F1 = F1 '+ f1 is executed. The image data of the block F1 is overwritten, that is, updated from the image data storage unit 11 to the previous image data storage unit 13 (C4). further,
The image data transfer processing from block F2 to block F8 is F
The same process as 1 is performed one after another, and the transmission of the image data of one frame is completed by the end of the image data transmission process of block 8.

In the second and subsequent image processing, after the image data of the block F1 is stored in the image data storage unit 11, the block F1 'of the previous image data storage unit 13 is not initialized and the differential image data is extracted. Compression of difference image data, server 2
The differential compressed image data is transferred to. Regarding the image data of the blocks F2 to F8, the blocks F2 'to F8' of the previous image data storage unit 13 are not initialized. The server 2 that has received the differentially compressed image data performs the same processing as the first image processing.

The process of transmitting / receiving image data between the client computer 1 and the server computer 2 will be described in time series with reference to FIGS. 3 and 4.

The image data conversion control unit 10 receives the image transmission request signal from the server 2. Request content is server 2
If it is determined that the request is not the next block transmission request transmitted from (step A1), the image information displayed on the screen of the first display 4 is divided into eight blocks F1 to F8 (step A2). The image data F1 of the first block of the divided image data is sampled, and the image data storage unit 11
(Step A3). When it is determined that the request content is the next block transmission request (step A1 / YE
S), the image data of the next block is collected (step A)
4). Next, when it is determined that there is no block to be sampled when the image data is sampled (eight blocks of data F8 have been sampled) (step A5 / YES), EOD (final data)
Is transmitted to the server 2 (step A12), and the server 2 is notified that the image data that can be collected is completed. Next, when the next screen transmission request is received from the server 2 (step A
13 / YES) returns to the first processing (returns to step A1), and when the end notification is received (step A14 / YE)
S) ends all the processes on the client 1 side. next,
When it is determined that the currently executed image information collection process is the first time, that is, the first execution (step A5 / YES), the block of the previous image data storage unit 13 corresponding to the currently collected block is initialized ( Step A7).

The difference image data compression unit 12 extracts the image data from the image data storage unit 11, extracts only the difference data from the previous image data held in the previous image data storage unit 13 (step A6), and compresses it. (Step A7), the image data size is reduced to create compressed differential image data.

The previous image data storage unit 13 overwrites the stored previous image data (step A8) and holds it as the previous image data for extracting the next difference data.

The first communication control unit 14 sends the compressed differential image data sent from the differential image data compression unit 12 onto the communication line 3 and sends it to the server 2.

Second communication control section 15 constituting the server 2
Receives the compressed difference image data transmitted from the client 1 (step B1).

If the compressed differential image data sent from the second communication control unit 15 is judged not to be EOD (step B2), the image data expansion unit 16 expands the differential image data (step B3) and temporarily stores it. The image data is sequentially stored in the buffer 18 (step B4). Next, a request for transmitting the image data of the next block is issued to the client 1 (step B5). On the contrary, when it is determined that the data is EOD data (step B2), the control is transferred to the image data display unit 17.

The image data display unit 17 includes a temporary buffer 1
The image data is taken out from within 8 (step B6) and displayed as an image on the screen of the second display 5 (step B7). Next, in the case of issuing the next image data transmission request (step B8 / YES), the next image transmission request is transmitted to the client 1, and the process returns to the first process (return to step B1). When issuing the end notification (step B10 / YES),
Send an end notification to the client 1 (step B1
1), all processing on the server 2 side is ended.

As described above, according to the present image data transmission / reception system, since the collected image data is processed in block units, the storage device for storing the image data is the image data currently displayed. It is sufficient to prepare a small-sized storage device whose size is divided by the number of blocks. Further, since the image data is reduced by the difference processing and the compression processing, the online line usage fee is reduced and the response time is improved, and the transmission / reception transmission efficiency is improved.

The above embodiment is one example of the preferred embodiment of the present invention, but the present invention is not limited to this and various modifications can be made without departing from the gist of the present invention.

[0037]

As is apparent from the above description, according to the image data transmission / reception system and the image data transmission / reception method of the present invention, the image data held by the client computer is divided and the divided images for image processing are divided. The data and the previous image data immediately before the image data are stored. The difference image data between the stored image data and the previous image data is extracted, further compressed to be compressed image data, and the compressed image data is transmitted and received. Therefore, the image data of the same frame is divided into blocks, the difference data between the blocked image data is further compressed,
This differential compressed image data is transmitted and received between the client computer and the server computer. The storage capacity of image data for this processing may be small, and the amount of image data transmitted / received is divided and compressed to be reduced. Therefore, the online line usage charge is reduced and the response time is improved, and the transmission / reception transmission efficiency is improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an image data transmitting / receiving system of the present invention.

FIG. 2 is a diagram conceptualizing an operation procedure on the client side in FIG.

FIG. 3 is a flowchart showing the operation on the client side in the system of the present invention.

FIG. 4 is a flowchart showing an operation on the server side in the system of the present invention.

[Explanation of symbols]

 1 Client Computer 2 Server Computer 3 Communication Line 4 First Display 5 Second Display 10 Image Data Conversion Control Section 11 Image Data Storage Section 12 Difference Image Data Compression Section 13 Previous Image Data Storage Section 14 First Communication Control Section 15 Second communication control unit 16 Image data expansion unit 17 Image data display unit

Claims (2)

[Claims] 1. An image data transmission / reception system in which a client computer transmitting image data and a server computer receiving the image data are interconnected by a communication line, wherein the client computer has a screen of the client computer. Image data conversion control means for collecting the image data by dividing the image information displayed above into blocks, image data storage means for storing the collected image data, and the above-mentioned collection for the first image data transfer. The stored image data is stored as it is, and when the image data is transferred for the second time and thereafter, the previous image data is stored until the process of transmitting the image data is performed, and the acquired image data is stored after the image data is transferred. Image data storage means and differential image data between the image data to be transmitted and the previous image data are extracted. And a first communication control means for controlling communication. The server computer side decompresses the compressed image data and is divided into blocks. Image data
Image data expansion means for reassembling data, image data display means for displaying the expanded and reassembled image data on the screen, and second communication control means for controlling communication. An image data transmission / reception system characterized by comprising. 2. An image data transmitting / receiving method for transmitting / receiving image data between a client computer and a server computer, the image data dividing step of dividing one frame of image data displayed on the client computer into a plurality of blocks. A block image data collecting step of collecting image data of the divided predetermined blocks; an image data storing step of storing the collected image data; and storing previous image data immediately before the transmitted image data. A pre-image data storing step, a differential image data extracting step of extracting differential image data between the image data and the previous image data, and compressing the differential image data extracted by the differential image data extracting step. Differential image data compression step for processing, and differential image data subjected to the compression processing An image data transmitting step of transmitting, an image data receiving step of receiving the transmitted difference image data, an image data for reassembling the block image data by expanding the received image data. An image data transmitting / receiving method, comprising: a data expanding step; and a step of displaying the expanded and reassembled image data on a screen.