JP2005269272A - Image data transmitting method and image data transmitting/generating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the processing load of a network band occurring when image data are distributed to a plurality of client devices from a lecturer side terminal 1 in real time in a remote lecture and a seminar or the like by computers using the Internet. <P>SOLUTION: The image data of a frame successively acquiring the image data are divided into a plurality of preset areas in main body devices 1, 2. Divided image data in each divided area are stored by making them correspond to the divided areas. The image data of a frame to be inputted next are divided into a plurality of the preset areas. The divided image data in each divided area are stored by making them to correspond to the divided areas. The image data inputted first and the image data inputted next in the same divided area are compared with each other. The processing load of the band required for transmitting the image data can be reduced by making only the changed divided image data to be displayed by the client device 3 when there is a change in the image data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method or system for displaying image data on a remote display device. In detail, presentation images such as lecture materials and conference materials, concise images captured by surveillance cameras, etc. are displayed on a remote computer or device, or E-learning, seminars at remote locations, display of online help desks, etc. The present invention relates to a display method or system that can be used for image display in the care of a subject or object located in a remote place, display of a monitoring camera image, and the like.

With the development of networks such as the Internet, many terminals can now share images while in remote locations. The use of Internet services is also widespread in companies, schools, public facilities, and the like. In addition, in companies and the like, leased line communication in which communication apparatuses existing in remote places are connected by a dedicated line to perform communication is also widespread.
Along with the development of these networks, various courses such as manner training, English conversation learning, information technology qualification acquisition courses, etc. that use the communication are being conducted not only for individuals but also for companies, schools, public facilities, etc. . This is so-called E-learning. Typical examples of these E-Learning programs include manner training, English learning, and distance learning to acquire information engineer qualifications. In the E-learning system, the video shot of the lecturer and the lecture slide material are synchronized and distributed via the Internet.
That is, the video data of the lecturer that has been photographed and the slide video data used for the lecture are stored in advance in a distribution server for distributing to the terminal side, which is the student. The accumulated data becomes a distribution target to the user as content, that is, content data. The stored content data is generally used on demand, in which the content data is distributed to the terminal and viewed according to an instruction from the terminal as a student.

In recent years, networks such as the Internet have dramatically increased in communication speed due to the continuous connection and the spread of broadband. As a result, many terminals can now share images while in remote locations. The use of Internet services is also widespread in companies, schools, public facilities, and the like. In addition, in companies and the like, leased line communication in which communication apparatuses existing in remote places are connected by a dedicated line to perform communication is also widespread.
The spread of these high-speed networks has made it possible to provide images in real time. As a result, on-demand use has been limited to providing pre-stored data, but it provides data that changes sequentially, such as university lectures and seminars held in real time between remote locations and the headquarters. Requires real-time image data communication. In this real-time communication, such as a seminar, the learner can immediately ask the instructor where he / she does not understand. Like the conventional group education, the instructor and the learner can share time and information and feel a sense of unity. Can be maintained, and more efficient lectures are possible.

In lectures conducted in real time in these remote locations (hereinafter referred to as real-time remote lectures), in addition to the instructor's face video and audio, the free speed of free entry space such as a blackboard or white board written by the instructor, and the speed of document slides, etc. Etc. are important factors. In this real-time remote lecture, the lecture is progressed through a network connection due to the relationship between the lecturer server and the client student.
In the above real-time remote lecture, not only the prepared slide image of the document is provided, but also the video written in the free entry space and other web pages may be displayed as necessary. May be advanced. That is, for example, a server that is an instructor is a board writing tool (hereinafter referred to as a small tool with a single function) that is a dedicated application for writing in a free space such as a blackboard or white board while displaying a slide slide image on the client. This is a case where an image that is freely entered in (1) is sent to a client who is a student. In such a case, a system in which the server and all clients prepare a common application in advance, and a system for switching so that the frame image displayed by the server is displayed in synchronization with the client is necessary.

However, the application software is very limited, and there is a problem that it is difficult for each client to prepare, and real-time remote lecture cannot be easily realized.
As software that can solve the problem, conventionally, as means for providing a frame image such as a material slide created by an arbitrary application in real time in a one-to-one correspondence via a network, for example, an application screen or Windows (registered) There is a synchronous remote type real-time screen sharing tool that uses software for sharing a desktop screen of a trademark between a server and a client. That is, a remote desktop sharing tool. As the remote desktop sharing tool, some software exists as software operating on Windows (registered trademark) which is an operation system.

However, the remote desktop sharing tool that operates on Windows (registered trademark) must be prepared by all the servers and clients to be used, and there is a problem that it takes time and money to distribute software. It was. Furthermore, there is a restriction that the environment in which the tool operates is only on Windows (registered trademark), and all of the server as a lecturer and all the clients as students must set the OS to Windows (registered trademark). did not become.
Furthermore, since the tool is a tool for one-to-one communication, information cannot be simultaneously distributed from one server to a plurality of clients, and there are more than 100 clients such as university lectures. There is a problem that large-scale one-to-multiple communication cannot be performed.

On the other hand, there is a Web system as a system that does not require common application software for all clients and can be used by a plurality of clients. The Web system can be used if the client has a Web browser and is not affected by the OS. Therefore, it is easier to prepare a user environment than a remote desktop sharing tool, and the cost for deploying services can be greatly reduced.
However, since the HTTP system does not support push delivery, the Web system has a problem that information cannot be pushed from a web server to a plurality of clients.

Therefore, in order to solve the above problems, the inventor periodically and automatically inquires the web server from the client side, and only when the data transmitted from the web server is changed, the web server to the client. To build a data transfer system (as a QuickBoard system, research papers have been published).
That is, in the Web server, the display scene of the terminal used by the instructor is stored in the image file as a snapshot image. The Web server has a function capable of transmitting the stored snapshot image to a plurality of clients. Accordingly, when there is an inquiry automatically and periodically from the client, the Web server responds to the inquiry and sends a snapshot image to the inquired client. A snapshot image is sent to the client, and a pseudo push delivery service is realized using the HTTP protocol that does not support push delivery. This makes it possible to distribute images displayed on the lecturer terminal from the Web server to a plurality of clients.

  In addition to these, there is a compression technique for image data used for the purpose of compressing a moving image and enabling distribution via a network. When providing an image in real time, moving image data to be distributed Because of its large size, image data compression technology was indispensable, leading to the development. Conventionally used image data compression techniques include compression techniques such as MPEG2 and MPEG4. A compression technique such as MPEG2 or MPEG4 (hereinafter simply referred to as MPEG compression technique) is a technique for providing a compressed movie or a natural image in general. Each image pixel of a frame image constituting a computer screen, that is, an image, is provided. Compares the same frame image pixel of the previous frame image, extracts only the changed image pixel and replaces only the changed image pixel with the previous image pixel when displaying the current frame image. Is configured and displayed.

However, since the pseudo push type distribution system distributes the entire display screen of the lecturer terminal that is the distribution service target, there is a problem that the volume of image data to be distributed increases. In particular, when a large number of terminals of 100 or more such as university lectures attend at the same time, it causes a significant increase in network traffic, which may cause delays in data transfer at the time of distribution and obstacles to other services. It had the problem that it might end.
Therefore, in order to compress the image data to be transferred in the pseudo push type distribution system, it is conceivable to apply an image compression technique such as MPEG2 or MPEG4.
However, since the image compression technique is intended for compression of moving images whose images are constantly rewritten, that is, video, when the same screen as a material slide used for a lecture is displayed for a relatively long time. In addition, since the data is always compressed and distributed, the amount of data to be distributed can be reduced, but a large amount of data must be transferred.
Specifically, when the image data of the lecturer terminal is compressed and transferred, a network area of 4 Mbps to 6 Mbps is required for one client. That is, if the number of clients is 100, the band of 400 Mbps to 600 Mbps is occupied, and real time distribution is extremely difficult because the area is always used.
Furthermore, when using an image compression technique such as MPEG2 or MPEG4, a tool is required for the client to decompress the compressed image data, which limits the operating environment of the client terminal. Had.

Therefore, the inventor has continually changed the image in units of pixels even though a moving image such as a natural image or a movie distributed using the compression technology is a still image. In presentation images such as lecture slides distributed from terminals, we focused on the fact that the images used for display as still images do not change in pixel units. Similarly, changes in image display such as instructor writing or the addition of new materials are intended for the entire display screen (ie, the entire screen is rewritten), but in many cases Noted that the change is limited to a partial region by writing or the like.
Based on these facts, it is possible to reduce the network bandwidth when transmitting to a plurality of clients by transferring a change in a partial area to a client without using a compression technique that looks at a change in pixel units. did.

So this invention is
Sequentially acquiring the image data, dividing the image data of the acquired frame into a plurality of predetermined regions, storing the divided image data of each divided region corresponding to the divided region,
Next, the image data of the input frame is divided into a plurality of predetermined areas, and the divided image data of each divided area is stored in correspondence with the divided areas.
Comparing the first input image data and the next input image data in the same divided area, and when the image data is changed, the changed divided image data is output. Image data transmission method,

  as well as,

A display means, a data output means, an image data storage means, and a control means, wherein the control means divides the image data of the frame displayed by the display means into a plurality of divided image data obtained by dividing the frame input before and after A main unit capable of outputting divided image data by comparing each other;
The main unit is connected to the main unit so as to be able to communicate data, and is provided so as to be able to receive data from the main unit. The divided image data is input by the data input means, and comprises a client device that outputs the image data from the data output means so as to be displayed at a predetermined divided position.
In the main unit, the control means divides the image data of the frame displayed by the display means into a plurality of predetermined areas, and the divided image data of each divided area is stored in the image data storage means corresponding to the divided areas, and the display means Divides the image data of the frame to be displayed next into the plurality of predetermined areas, stores the divided image data of each divided area in the image data storage means in association with the divided areas, and precedes the divided same area. The displayed image data and the next displayed image data are compared with each other, and when there is a change in the image data, the changed divided image data is output from the data output means to the client device,
In the client device, the control unit inputs the updated divided image data received from the main body device from the data input unit, stores the input divided image data in the image data storage unit, and stores it in the image data storage unit. An image data transmission and generation system characterized by outputting image data that can constitute a frame by the latest data of each divided image data;

  as well as,

A display means, a data output means, an image data storage means, and a control means, wherein the control means divides the image data of the frame displayed by the display means into a plurality of divided image data obtained by dividing the frame input before and after A main unit capable of outputting divided image data by comparing each other;
A data input means, a data output means, an image data storage means, and a control means are connected to the main apparatus so as to be able to communicate with data, and the data input means inputs the divided image data output from the main apparatus, and the predetermined division is performed. It consists of a client device that outputs image data from the data output means to be displayed at a position,
In the main unit, the control means divides the image data of the frame displayed by the display means into a plurality of predetermined areas, and stores the divided image data of each divided area in the image data storage means in correspondence with the divided areas, and displays them. The means divides the image data of the frame to be displayed next into the plurality of predetermined areas, and stores the divided image data of each divided area in the image data storage means in association with the divided areas. The image data displayed on the screen and the next displayed image data are compared with each other. If there is a change in the image data, the latest divided image data in which the changed divided image data is updated in the image data storage means is displayed. When the information for inquiring the presence / absence of divided image data that has not yet been transmitted from the client device to the client device is received, the untransmitted divided image data is received. It is capable of outputting the data from the data output means to the client apparatus,
In the client device, the control unit inputs the updated divided image data received from the main body device from the data input unit, stores the input divided image data in the image data storage unit, and stores it in the image data storage unit. Output image data that can form a frame with the latest data of each divided image data, and output to the main unit information that inquires about the presence or absence of updated divided image data that is newer than the currently stored divided image data. An image data transmission generation system characterized in that a frame is always constituted by the latest divided image data;

  as well as,

A display means, a data output means, an image data storage means, and a control means, wherein the control means divides the image data of the frame displayed by the display means into a plurality of divided image data obtained by dividing the frame input before and after A main unit capable of outputting divided image data by comparing each other;
It is connected to the main unit so as to be able to communicate with data, and includes a data input unit, a data output unit, an image data storage unit, and a control unit. The divided image data is input by the data input means, and comprises a client device that outputs the image data from the data output means so as to be displayed at a predetermined divided position.
In the main unit, the control means divides the image data of the frame displayed by the display means into a plurality of predetermined areas, and stores the divided image data of each divided area in the image data storage means in correspondence with the divided areas, and displays them. The image data of the frame to be displayed next is divided into a plurality of predetermined areas, and the divided image data of each divided area is stored in the image data storage means in correspondence with the divided areas, The image data displayed on the screen and the next displayed image data are compared with each other, and if there is a change in the image data, the updated divided image data is updated to the image data storage means. An HTML file that is stored as image data and that constitutes a frame from the latest divided image data is generated, and the HTML file generated from the client device is output. Can be output from the data output means to the client apparatus, and when the information desired to output desired divided image data is received from the client apparatus, the data is output from the data output means to the client apparatus. ,
In the client device, the control means outputs information for requesting the output of the HTML file to the main device, receives the HTML file, and among the divided image data described in the received HTML file, its own image data. The presence / absence of divided image data not stored in the storage means is determined, and if there is divided image data not stored in its own image data storage means, information for outputting the data to the main unit is output, and the data When the input means receives the divided image data from the main unit, the image can be stored in the image data storage means as updated divided image data, and a frame can be configured by the latest data of each divided image data stored in the image data storage means An image data transmission generation system characterized by being capable of outputting data,
I will provide a.

In the above method and each system,
Image data transmission generation method and image data transmission generation system in which image data of divided frames is all or part of a screen to be displayed,
I will provide a.

Furthermore, in the above method and each system,
When the main unit is used for multitasking, the main unit generates an image data transmission generation system that handles the display area of the currently used application as the image data of the divided frames.
Provide

An image data transmission generation system that includes a pointing device, and that treats an image area designated by the pointing device as image data of a frame to be divided,
I will provide a.

Therefore, according to the present invention, in the main device, the main device divides a frame to be displayed on the client device, and the client device acquires only the divided image data of the updated divided area and displays it on the client device. Since the client device can display the updated frame on the main device, it can display the entire image of the changed frame on the client device by communicating only the divided image data of the updated divided area. Become.
Accordingly, it is possible to perform communication in a band that is smaller than the band used for communication performed between the client apparatus and the main apparatus as compared with the case where the entire frame is transmitted.
Thereby, the number of client devices connectable to the main device can be increased.

Furthermore, according to the present invention, a Web browser which is a non-push type distribution system that is currently most frequently used can be used for image transfer as a pseudo push type distribution system.
As a result, a pseudo push distribution system from the main device can be constructed by the most commonly used browser.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic explanatory diagram of an image data transmission generation system, FIG. 2 is an explanatory diagram of divided areas in the embodiment of the present invention, and FIG. 3 is an explanatory diagram of update comparison of divided areas in the embodiment of the present invention. 4 is an explanatory diagram of an HTML file in the first embodiment, FIG. 5 is an explanatory diagram of update comparison of the divided areas, FIG. 6 is an explanatory diagram of the HTML file, and FIG. FIG. 8 is an explanatory diagram of the HTML file, FIG. 9 is an explanatory diagram of the HTML file in the second embodiment, and FIG. 9 is an explanatory diagram of the HTML file in the second embodiment. FIG. 10 is an explanatory diagram illustrating the Java (registered trademark) SCRIPT, FIG. 11 is an explanatory diagram illustrating the third embodiment, and FIG. When implemented in a text editor It is an explanatory view of FIG. 13 is a diagram of the split state of the divided regions.

  Reference numeral 1 denotes an image data transmission generation system that transmits image data generated and used by a lecturer to students who are a plurality of clients when the lecturer lectures. The image data transmission generation system 1 includes a lecturer-side terminal 2 used by a lecturer, a Web server 3, and a client device that can receive and view data and audio necessary for a lecture such as image data transmitted from the Web server 3. It consists of four. The instructor-side terminal 2 and the Web server 3 are connected via a VPN so as to be communicable, and the Web server 3 and the client device 4 are connected so as to be able to exchange information via the Internet. Each device is connected as described above, but the instructor terminal 2 and the Web server 3 may be connected by the Internet, and the Web server 3 and the client device 4 are connected by wired or wireless VPN. May be connected to each other, or may be connected by LAN instead of VPN. The image data transmission generation system 1 efficiently displays the image data displayed on the instructor side terminal 2 on each client device 4.

A first embodiment using the above devices will be described below.
The first embodiment is an example in which the desktop screen of the instructor side terminal 2 is distributed to a plurality of client devices 4 in real time. In each embodiment, the instructor side terminal 2 and the web server 3 form a main body device. However, the instructor side terminal 2 and the web server 3 are not separately provided, but the main body device is provided as the instructor side terminal 2. And the web server 3 may be integrated, and the image data may be transmitted to the client device 4 by direct operation by the lecturer.

  The instructor side terminal 2 is a notebook computer in this embodiment, and uses a so-called notebook personal computer. The instructor-side terminal 2 includes a standard pointing device 23 such as a mouse, a keyboard 24, and other input means, and a liquid crystal display unit 21 that is a display means. Further, the instructor side terminal 2 includes a control means 22 such as a CPU and a memory. Further, the instructor side terminal 2 includes image data storage means 25 capable of storing image data. And the control means 22 of the lecturer side terminal 2 is provided with the function which can divide | segment the frame which the liquid crystal display part 21 displays into predetermined plurality, and can acquire the division | segmentation image data which are the image data of each area | region. In this embodiment, the frame is divided into 25 areas as shown in FIG. The divided divided image data is sent to the Web server 3 and stored. Needless to say, the instructor side terminal 2 includes data input means and data output means that can communicate with the Web server 3 by VPN. When outputting data or inputting data from the Web server 3, the communication means is used for communication according to a predetermined procedure.

  The Web server 3 includes a data storage unit 31 and a display unit 32, and also includes a data input unit 33 and a data output unit 34 for inputting / outputting data to / from the client device 4, and controls each unit. The control means 35 is provided. Then, the Web server 3 receives the divided image data divided from the instructor-side terminal 2, and stores the data by associating the time when each divided image data input under the control of the control unit 35 is input with the divided position. Store in the means 31.

The client device 4 comprises a personal computer such as a desktop computer or a laptop computer, and a plurality of clients can be connected to the Web server 3 via the Internet. The client device 4 includes a mouse and a keyboard that are provided as standard, and includes a display unit 41 that is a display unit. Here, the display unit 41 included in the client device 4 displays image data output from the data output unit of the client device, but outputs data to a display unit as another device that is not provided integrally with the client device 4. The means may be capable of outputting and displaying data. Further, the client device 4 includes data input means 42 that can input data from the Web server 3, and also includes control means 43 that includes a CPU, a memory, and the like, and image data storage means 44 that can store the input data. Is provided. The client device 4 can display the divided image data divided from the Web server 3, thereby displaying the frame image generated by the instructor-side terminal 2 and the Web server 3 on the display unit 41.
In this embodiment, the Web server 3 and the client device 4 are provided with a Web browser and communicate using the Internet, and can communicate images, sounds, and the like by HTML. However, communication by means of other browsers or the like is possible. It may be possible, as long as the client device 4 can display the image data acquired from the Web browser by communicating at least.

By each device configured as described above,
1. The instructor-side terminal 2 divides all or part of its desktop screen into a plurality of parts, creates divided image data, stores the divided image data in the image data storage means 25, and transmits the updated divided image data to the Web server 2 2 . 2. The Web server 3 stores the acquired divided image data in the public directory in association with the created time and the divided position. 3. When the divided image data is transmitted from the Web server 3 to the client device 4, the updated divided image data that has not yet been transmitted to the client device 4 is transmitted. The client device 4 can store each divided image data received from the Web server 3 and can form and display a frame image using each stored divided image data. Installed.

Details of the first embodiment will be described below.
In this embodiment, the instructor-side terminal 2 and the Web server 3 function as a main body device through cooperative operation.
The control means 22 of the instructor terminal 2 divides the frame image displayed on the liquid crystal display unit 21 shown in FIG. 2A into a predetermined number, that is, 25 shown in FIG. Divided image data is generated for each divided image area. At this time, each divided image data is generated so as to recognize the position and time of the image by associating the time generated by the division and the divided image position. The generation timing of the divided image may be every predetermined time interval. In this embodiment, the divided image is generated every 5 seconds. If this time interval is shorter, the time alignment of the display images displayed on the instructor side terminal 2 and the client device 4 can be taken. If the time interval is longer, the image displayed on the client device 4 is the image displayed on the instructor side terminal 2. Therefore, it may be determined as appropriate depending on the communication line between the client device 4 and the Web server 3, the number of client devices 4, and the like. In addition, some timings may be selected in advance in the instructor side terminal 2. In the description of this embodiment, since the display unit 41 of the client device 4 displays an image of the entire liquid crystal display unit 21 of the instructor terminal 2, the entire screen is divided into 25 as shown in FIG. The application program screen currently used by the side terminal 2 can be divided, and in this case, the window of the application program designated and activated by the pointing device 23 provided in the lecturer side terminal 2 is framed. The frame may be divided into a predetermined number, for example, 25. Furthermore, switching to activate the application program may be performed by inputting a predetermined specific key without depending on the pointing device 23, or may be performed by any other method. Furthermore, a shortcut key may be determined in advance, and an area of an application window in which the pointing device 23 such as a mouse is placed when the shortcut key is pressed may be used as a frame area for generating divided image data. The image of the frame displayed on the liquid crystal display unit 21 of the instructor side terminal 2 generated at the timing is stored in the image data storage unit 25 of the instructor side terminal 2.
Similarly, at the next timing, the divided image data of each divided image region is stored in the image data storage unit 25 in association with the time and the image region. Accordingly, at least two identical divided image data are stored in the image data storage means 25 at different times.

  The control means 22 of the instructor side terminal 2 has a function of comparing the same divided image data stored at the different times. Then, the control means 22 compares the divided image data stored earlier in the same image area with the divided image data stored next, whether or not the data has changed in pixel units.

Hereinafter, the comparison of the divided image data performed by the control means 22 will be described in detail with reference to FIG. In the following description, an example of a case where the image of the frame to be divided is four areas of area 1-1, area 2-1, area 1-2, and area 2-2 shown in FIG. Explained.
The image of the frame shown in FIG. 3 is an image displayed side by side on the liquid crystal display unit 21 of the instructor side terminal 2. For the sake of explanation, each pixel in each image region is the uppermost pixel from the left. P00, the adjacent pixel is P10, and subsequently P20... Pm0, the next pixel is P01, P11, P21... Pm1 from the left. The steps are P0n, P1n, P2n,... Pmn from the left.
Using these pixel displays, the divided image data comparison before and after the same image area performed by the control unit 22 of the instructor side terminal 2 will be described. The control unit 22 of the instructor side terminal 2 stores in the image data storage unit 25 first. Divided image data 1-1_0.. Stored previously among the divided image data of the area 1-1. The pixel data of the P00 pixel of P00 is compared with the pixel data of the P00 pixel of the next recorded divided image data 1-1_1. If there is a difference in the data of the P00 pixel, the count is performed. do not do. Next, similarly, the divided image data 1-1_0. png and divided image data 1-1_1. The pixel data of Png P10 pixels are compared with each other, and if there is a difference, it is counted, and if there is no difference, it is not counted. Accordingly, when there is a difference in the P00 pixel data, the count is “1”, and when there is also a difference in the P10 pixel data, the count is further incremented to “2”. The counting may be performed using a counting method performed in a normal program, and is sequentially added and temporarily stored.

  Next, the divided image data 1-1_0. png and divided image data 1-1_0. Png P20 pixel data are compared with each other, and similarly, if there is a difference, it is counted, and if not, it is not counted. When the comparison for each pixel is finished up to Pm0, the divided image data 1-1_0. png and divided image data 1-1_1. The pixel data of png pixels are compared, and if there is a difference, the pixel counts up. Similarly, P02 to Pm2, which are the next stages, are compared, and finally the divided image data 1-1_0. png and divided image data 1-1_1. Png pixel data is compared with each other and counted.

  The control means 22 compares the previous divided image data 1-1_0 of the divided image data 1-1 with the next divided image data 1-1_1 as described above, and the count value finally stored is “0”. If not, it is determined that the image data of the divided image data 1-1 has been updated, and the control unit 22 transmits the data of the divided image data 1-1_1 to the Web server 3. The display of “1-1_0” representing the divided image data is such that the “1-1” portion represents the position of the divided image area, the numerical value before “−” is the row number, and the numerical value after “−” is Represents a column number. In addition, since the numerical value after “_” indicates the timing at which an image is generated, that is, the value corresponding to the time, the numerical value after “_” is set at every set time interval for generating divided image data. is increasing. Since the image data 1-1_0 and the image data 1-1_1 have the same “1-1”, they are data in the same area, and the generated time indicates that “_1” is generated after “_0”. ing. Therefore, when the file name of the divided image data is stored as “1-1_0.png” when stored in the Web server 3, the image area and the image generation time of the divided image data can be specified. The image area and the image generation time are stored in association with each other.

In the comparison of the divided image data described above, the cursor is not present in the divided image area to be compared. However, when the cursor is present and blinking, the number of pixels required for blinking the cursor, for example, A threshold value for a count value of 500 pixels (which may be set as appropriate depending on the size of the cursor or pointer) may be provided, and the count value may be determined to be updated when the count value exceeds the threshold value. Further, when the divided image data is stored, whether or not a cursor or pointer exists in the divided image area is determined in advance, and divided image data for storing the presence or absence of the cursor or pointer is included. When the control unit 22 compares the previous divided image data with the next divided image data, the cursor or pointer exists by referring to the data on the presence or absence of the cursor or pointer. When the divided image data is updated based on whether or not the count value exceeds the threshold value, the count value is set to the threshold value if there is no cursor or pointer. It may be set to “0”.
The control means 22 compares all the pixels. However, when the counter value exceeds the threshold value, the comparison operation may be terminated and the divided image data may be stored. If the threshold value is compared with the count value and the count value exceeds the threshold value, the step of storing the divided image data may be executed by the determination step.

When it is determined that the result of the comparison as described above exceeds the threshold value and the divided image data has been updated, the control means 22 determines the time and the divided region at which the updated divided image data was acquired. It transmits to Web server 3 so that it may associate and memorize. Of course, the linking may be linking by the file name as in the above example.
Furthermore, in the lecturer side terminal 2, when the client apparatus 4 and the Web server 3 communicate by HTML, the HTML file for enabling the client apparatus 4 to acquire the divided image data updated from the Web server 3 is obtained. Create automatically. This is a means for making the Web server 3 that is not originally a push type pseudo-push. The image data transmission generation system 1 may be configured to transmit only the updated divided image data from the Web server 3 to each client device 4 in the push type. In this case, when the Web server 3 acquires the updated divided image data from the instructor side terminal 2, the control unit 35 of the Web server 3 transmits the data to each client device 4 by the data output unit 34. The transmission method only needs to be performed based on the protocol used in the image data transmission generation system 1.

The automatically generated HTML file is prepared in advance as shown in FIG. 4, for example, in the case of four divisions as shown in FIG. The HTML file is finally transmitted to the client device 4. The client device 4 inquires the Web server 3 for the divided image data that is not in its own cache among the divided image data represented in the HTML file, and obtains it by communication. Thus, the client device 4 acquires all the divided image data and displays them on the display unit 41.
That is, the image shown in FIG. 3 is the earliest image, and the divided image data in the area 1-1 is default image data before the image is present, and is controlled by the control means 22 of the instructor terminal 2. It is determined that there has been an update as a result of the comparison between the divided image data described above, and the updated divided image data is generated as a “1-1_0.png” file and transmitted to the Web server 3. Similarly, the “2-1 — 0. png”, “1-1 — 0. png”, and “2-2 — 0. png” files are transmitted to the divided region 2-1, the divided region 1-2, and the divided region 2-2, respectively. The Web server 3 stores each input divided image data.

On the other hand, an HTML file capable of displaying an image in HTML is generated from each of the divided image data. The automatic generation of the HTML file will be described below.
In the teacher side terminal 2, an HTML file described in the HTML format as shown in FIG. 4 is prepared in advance, and “./1-1 — 0. png” written in the fourth line is a divided area 1-1. It is described as a variable representing the divided image data. Similarly, “./2-1 — 0. png” written in the fifth line is “./1-2 — 0. png” written in the eighth line as a variable representing the divided image data of the divided area 2-1. "Is described as a variable representing the divided image data of the divided area 1-2, and" ./2-2_0.png "written in the ninth line is described as a variable representing the divided image data of the divided area 2-2. Yes. If the divided image data is updated as a result of the comparison of the divided image data with respect to the HTML file described in this manner, the control means 22 represents the area of the updated divided image data. An HTML file is automatically generated by substituting the newly generated divided image data into a variable. The generated HTML file is transmitted from the Web server 3 by the control means 22 by the data output means, like the updated divided image data. In the example illustrated in FIG. 4, each of the divided image data “1-1_0.png”, “2-1_0.png”, “1-1_0.png”, and “2-2_0” updated to the previously described variable of the divided image data. .Png "represents the result of substitution.
Accordingly, the lecturer-side terminal 2 generates each piece of divided image data at the above timing and sequentially transmits it to the Web server 3.

As described above, the updated divided image data and the HTML file transmitted from the instructor terminal 2 via the VPN are received by the Web server 3.
That is, when the divided image data is transmitted from the instructor-side terminal 2, the Web server 3 causes the control unit 35 to store the data in the data storage unit 31. Therefore, the data storage unit 31 stores “1-1_0.png”, “2-1_0.png”, “1-1_0.png”, and “2-2_0.png”. Each stored divided image data is stored in a public directory so that it can be transmitted to the client device 4 by an inquiry from the client device 4. Similarly, the HTML file received from the instructor terminal 2 is also stored in the data storage unit 31 so as to be transmitted to the client device 4 by an inquiry from the client device 4. The stored HTML file is always updated and stored. As described above, the divided image data and the HTML file input from the data input unit 33 by the control unit 35 are stored in the data storage unit 31. When the control unit receives an acquisition request from the client device 4, the HTML file stored in the data storage unit 31 can be output from the data output unit 34.

When the divided image data is transmitted from the instructor terminal 2 to the Web server 3, the file size of the divided image data is almost directly proportional to the network transfer amount, so that the image file format with a high compression rate, for example, a Web browser is used. It is desirable to reduce the burden on the network by using a PNG image format that is reversible compression that can be displayed. Of course, other compression such as GIF compression or JPEG compression may be used, and transmission may be performed without compression if it does not cause a burden.
In this embodiment, the public directory of the data storage means 31 of the Web server 3 for storing the divided image data is installed inside the firewall so that the VPN accessed from the instructor terminal 2 can exceed the firewall. It is desirable to keep security. By applying security in this way, it becomes impossible to write to the public directory of the Web server 3 except for the instructor-side terminal 2, and safety is ensured.

In the client device 4, the control unit 43 has a function of inquiring the Web server 3 periodically at predetermined intervals in advance. The inquiry function may be included in the client device 4 from the beginning, and when the client device 4 is connected to the Web server 3 for the first time, the Web server is periodically updated every predetermined time prepared in the Web server 3 in advance. This may be realized by downloading a Java (registered trademark) SCRIPT procedure for inquiring to 3. Note that the interval that is regularly determined every predetermined time is determined as appropriate depending on the environment in which the Web server 3 and the client device 4 are connected, such as every 5 to 10 seconds, and the frame that is actually required for the lecture. If it is enough.
In the client device 4, the control unit 43 can request acquisition of an HTML file from the Web server 3 via the Internet using the data input unit 42, and can acquire the HTML file. That is, when the control unit 43 of the client apparatus 4 outputs an HTML file acquisition request from the data output unit 45, when the HTML file is output from the Web server 3, the control unit 43 recognizes and receives the file and receives the image data. It can be stored in the storage means 44. A series of these file acquisitions is communication performed by a Web browser that is generally performed.
When the client device 4 receives an HTML file, it performs communication and image display based on HTML based on the description of the file. In other words, when the HTML file is received, the control means 43 causes the client 43 to display the respective divided image data described in the fourth, fifth, eighth, and ninth lines shown in FIG. It is determined whether or not the image can be acquired from the local cache of the Web browser of the device 4, and if it can be acquired, the image can be acquired by displaying it in the display area of the divided image data using the divided image data of the local cache. For example, the control unit 43 downloads to the public directory provided in the data storage unit 31 of the Web server 3 by the data output unit 45 and acquires it.

In this embodiment, the screen display by HTML using a Web browser is adopted, so that it becomes a pseudo push type distribution system, and the inquiry of the divided image data is made from the client device 4 side to the Web server 3. When the push type distribution system is used, when the updated divided image data is transmitted from the instructor terminal 2 to the Web server 3 by the same method as described above, the control means 35 of the Web server 3 updates the updated divided image data. This can be realized by storing the divided image data in the data storage means 31 and controlling the stored divided image data to be distributed to all connected client devices 4.
In the push-type distribution system, the connection condition with the client device 4 connected to the Web server 3, that is, the data communication speed (capacity for data communication per unit time) is registered in the Web server 3 in advance. Alternatively, if the Web server 3 can automatically determine the speed at which the data communication can be performed and transmits the data to the client apparatus 4 at a time interval corresponding to the communication speed, it differs for each client apparatus 4. Data communication can be performed at time intervals, and both the Web server 3 and the client device 4 can perform efficient data communication. In the pseudo push type distribution system as in the present embodiment, the speed at which data communication is possible (capacity for data communication per unit time) is registered in the client apparatus 4 or the speed at which the client apparatus 4 itself can perform data communication is set. By making the determination possible automatically, it is possible to make an inquiry from the client device 4 to the Web server 3 at time intervals corresponding to the communication speed. In this case, it is possible to rewrite the inquiry timing described in the Java (registered trademark) SCRIPT procedure.

Next, a procedure for updating the frame by actually distributing only the update divided image data will be described.
First, a frame image shown in FIG. 3 is displayed on the client device 4 by the divided image data of each divided area. At this time, the client device 4 obtains the HTML file shown in FIG. 4 by making an inquiry to the Web server 3, and “1-1_0.png”, “2-1_0.png”, and “1-2_0.png” described in the HTML file. “2-2_0.png” is obtained from the Web server 3. The image data acquired at this time is all data for composing all the frames, but is necessary for initial display, in other words, because the divided areas of all the divided image data are communicated from the default state. is there.
When the frame shown in FIG. 3 is displayed, the divided image data “1-1_0.png”, “2-1_0.png”, “1-2_0.png”, and “2-2_0.png” are already stored in the local cache of the Web browser, That is, it has been acquired and stored in the image data storage means 44 in the client device 4.

On the display screen shown in FIG. 3, the lecturer adds an image change for the area 2-1 as shown in FIG.
Then, the instructor side terminal 2 acquires each divided image data at the next timing when the change is made, and stores them in the image data storage means 25 as “1-1_1.png”, “2-1_1.png”, and “1-2_1. Png "" 2-2_1.png ", which is stored as divided image data linked to the acquisition time, that is, the timing and the divided area. In other words, the divided image data of the divided area 2-1 to which the change has been made is stored in the divided image data storage unit 25 as divided image data different from the divided image data before the change is added. Is stored in the file. The divided image data of other areas are “1-1_1.png”, “1-2_1.png”, and “2-2_1.png”, although the timing at which the divided image data is acquired is different. The divided image data as information is stored as the same content.
Then, a step of determining whether or not each divided image area is updated is performed at a timing after the stored divided area 2-1 is changed.
That is, the previously created divided image data “1-1 — 0. png” in the area 1-1 and the “1-1_1. Png” similar to the previous image acquired and recorded when this comparison is performed. As described above, the pixel data at the same position of the divided image data that is drawn and is not changed is sequentially compared from P00 to Pmn as described above, and counted when there is a change. Then, since the divided image data of “1-1 — 0. png” and the divided image data of “1-1 — 1 .. png” are the same, the value obtained by counting the presence or absence of the change is “0”, which is below the threshold value. The control unit 22 does not transmit the generated divided image data “1-1_1.png” to the Web server 3.

Next, the divided image data “2-1 — 0. png” already created in the region 2-1 and the previous “2-1_1. Png” obtained and recorded when this comparison is made are changed. The pixel data at the same position in the divided image data is sequentially compared from P00 to Pmn as described above, and the presence or absence of a change is counted.
Then, since the change is added in the area 2-1, the divided image data “2-1 — 0. png” and the divided image data “2-1_1. Becomes a numerical value such as “833” instead of “0”, which exceeds the threshold.
In the control means 22 of the instructor side terminal 2, since the count value exceeds the threshold, the divided image data “2-1_1.png” newly stored in the image data storage means 25 is sent to the Web server 3 via the data output means. Send to.
Then, the region 1-2 and the region 2-2 are also compared in units of pixels. Since each region is the same image as the region 1-1, the count value is equal to or smaller than the threshold value and the newly stored “1-21_1. “png” and “2-2_1.png” are not transmitted to the Web server 3.
And in the lecturer side terminal 2, the control means 22 adds the change for specifying "2-1_1.png" which is the divided image data in the all divided image data in the HTML file shown in FIG. Send to server 3. That is, as shown in FIG. 6, by replacing the file name specifying the image data of the area 2-1 described in the fifth row by giving the file name “2-1_1.png” to the variable as described above. Rewrite the HTML file. Note that the underline in FIG. 6 is only displayed to indicate the fifth level and is not in the actual HTML file.

In the Web server 3, the divided image data “2-1_1.png” whose image has been updated is transmitted from the instructor side terminal 2 and an HTML file as shown in FIG. 6 is transmitted. Then, the control unit 35 of the Web server 3 stores the divided image data “2-1_1.png” transmitted from the instructor side terminal 2 via the data input unit 33 in the data storage unit 31 and has been changed. The HTML file is stored in the data storage means 31.
In this way, the Web server 3 stores the updated divided image data “2-1_1.png” and the HTML file and makes them public to the client device 4.

On the other hand, the client device 4 makes an inquiry to the Web server 3 at the timing of the Java (registered trademark) SCRIPT procedure acquired in advance after the divided image data “2-1_1.png” and the HTML file are stored and released on the Web server 3. . That is, since a predetermined time has elapsed from the time when the inquiry was made last time, the control means 43 desires to make an inquiry to the Web server 3 via the data output means 45 in order to display the frame image again, that is, obtain an HTML file. Then, since the control unit 35 inquires from the client device 4 in the Web server 3, the HTML file is output from the data output unit 34. Then, the client device 4 acquires an HTML file and stores it in the image data storage unit 44.
Next, in the client device 4, the control unit 43 analyzes the HTML file, and checks whether the data “1-1 — 0.png” representing the divided image data shown in the fourth line in FIG. 6 exists in its own local cache. Judge whether or not. Since the divided image data “1-1_0.png” already exists in the local cache, the control unit 43 displays “1-1_0.png” stored in the local cache in the area 1-1 of the display unit 41.

Next, similarly, the control unit 43 analyzes the HTML file and determines whether or not the divided image data “2-1_1.png” shown in the fifth line in FIG. 6 is stored in the local cache. Since the divided image data “2-1_1.png” is new divided image data that has not yet been displayed and does not exist in the local cache, the control unit 43 determines that the divided image data “2_1. -1_1.png "is output from the data output means 34. Then, since the control means 35 of the Web server 3 receives the information for obtaining the divided image data “2-1_1.png” from the client device 4, the divided image data “2-1_1.png” is provided to the client device 4. To do. In the client device 4, the control unit 43 acquires the divided image data “2-1_1.png” via the data input unit 42 and stores it in the local cache of the image data storage unit 44, and the data “2-1_1.png”. Is displayed in the area 2-1 of the display unit 41.
Next, the control means 43 analyzes the HTML file and determines whether or not the data “1-2 — 0.png” representing the divided image data shown in the eighth line in FIG. 6 exists in its own local cache. To do. Since the divided image data “1-2_0.png” already exists in the local cache, the control unit 43 displays “1-2_0.png” stored in the local cache in the area 1-2 of the display unit 41.
Next, the control means 43 analyzes the HTML file and determines whether or not the data “2-2 — 0. png” representing the divided image data shown in the ninth line in FIG. 6 exists in its own local cache. To do. Since the divided image data “2-2 — 0.png” already exists in the local cache, the control unit 43 displays “2-2 — 0.png” stored in the local cache in the area 2-2 of the display unit 41.

As described above, the client device 4 makes an inquiry to the Web server 3 at the next timing when the divided image data “2-1_1.png” and the HTML file are stored in the Web server 3. The display change similar to the display of the instructor side terminal 2 in which the change is made to the display unit 41 of the client device 4 is performed only by acquiring the image data and the HTML file of the area 2-1 where the change has been made.
Even when the instructor-side terminal 2 is not changed, the client device 4 makes an inquiry to the Web server 3 in the same manner as described above at the timing described in the Java (registered trademark) SCRIPT procedure. The HTML file acquired from the Web server 3 is the same as the previously acquired HTML file because no changes have been made to the divided areas, so the fourth, fifth, eighth, and ninth lines of the HTML file are the same. Since each divided image data described in the eye is stored in the local cache which is the image data storage means 44, the divided image data is displayed on the display unit 41 without acquiring the divided image data from the Web server 3. As a result, the client device 4 also displays the same frame image on the display unit 41 as the frame image of the instructor terminal 2.

  The instructor-side terminal 2 performs the same comparison at a predetermined time interval even when the display is not changed. However, since the count value of each divided image data is equal to or less than the threshold value, the Web server 3 However, the divided image data is not updated.

Next, when the change as shown in FIG. 7 is further made to the instructor side terminal 2, the instructor side terminal 2 performs the same pixel unit comparison.
That is, the instructor changes the image for the area 1-1 as shown in FIG. 7 at the instructor side terminal 2 on the display screen shown in FIG.
Then, the instructor-side terminal 2 acquires each divided image data at the next timing when the change is made, and sends them to the image data storage unit 25 as “1-1_2.png”, “2-1_2.png”, “1-2_2. Png "" 2-2_2.png ", which is stored as divided image data linked to the acquisition time, that is, the timing and the divided area. That is, the divided image data of the divided area 2-1 to which the change has been made is stored in the divided image data storage unit 25 as the divided image data different from the divided image data before the change. Is stored in the file. The divided image data of the other areas are “2-1_2.png”, “1-2_2.png”, “2-2_2.png”, although the timing of acquiring the divided image data is different. The divided image data as information is stored as the same content.

Then, a step of determining whether or not each divided image area is updated is performed at a timing after the stored divided area 1-1 is changed.
In other words, the divided image data “1-1_1.png” already created in the area 1-1 and the previous “1-1_2.png” obtained and recorded when this comparison is made are changed. The pixel data at the same position in the added divided image data is sequentially compared from P00 to Pmn as described above, and the presence or absence of a change is counted.
Then, since the change is made in the area 1-1, the divided image data “1-1_1.png” is different from the divided image data “1-1_2.png”. Becomes a numerical value such as “7326” instead of “0” and exceeds the threshold value.
Next, in the control means 22 of the instructor terminal 2, since the count value exceeds the threshold value, the divided image data “1-1_2.png” newly stored in the image data storage means 25 is sent to the Web via the data output means. Send to server 3.

Next, the divided image data “2-1_1.png” already created in the area 2-1 and the same image as the previous one “2-1_2.png” acquired and recorded when this comparison is performed. As described above, the pixel data at the same position of the divided image data that is drawn and is not changed is sequentially compared from P00 to Pmn as described above, and counted when there is a change. Then, since the divided image data “2-1_1.png” and the divided image data “2-1_2.png” are the same, the value of whether or not there is a change is “0”, which is below the threshold value. The control unit 22 does not transmit the generated divided image data “2-1_1.png” to the Web server 3.
Subsequently, the area 1-2 and the area 2-2 are also compared in units of pixels. Since each area is the same image as the area 2-1, the count value is equal to or less than the threshold value and the newly stored “1-21_2. “png” and “2-2_2.png” are not transmitted to the Web server 3.

  And in the lecturer side terminal 2, the control means 22 adds the change for specifying "1-1_2.png" which is the divided image data which has changed in all the divided image data in the HTML file shown in FIG. Send to server 3. That is, as shown in FIG. 8, the file name specifying the image data of the area 1-1 described in the fourth row is replaced by giving the file name “1-1_2.png” to the variable as described above. Rewrite the HTML file. Note that the underline in FIG. 8 is only displayed to indicate the fourth level and is not in the actual HTML file.

In the Web server 3, the divided image data “1-1_2.png” whose image has been updated is transmitted from the instructor-side terminal 2 and an HTML file as shown in FIG. 8 is transmitted. Then, the control unit 35 of the Web server 3 stores the divided image data “1-1_2.png” transmitted from the instructor side terminal 2 via the data input unit 33 in the data storage unit 31 and has been changed. The HTML file is stored in the data storage means 31.
In this way, the Web server 3 stores the updated divided image data “1-1_2.png” and the HTML file and makes them public to the client device 4.

  On the other hand, the client device 4 makes an inquiry to the Web server 3 at the timing of the Java (registered trademark) SCRIPT procedure acquired in advance after the divided image data “1-1_2.png” and the HTML file are stored and released on the Web server 3. . That is, since a predetermined time has elapsed from the time when the inquiry was made last time, the control means 43 desires to make an inquiry to the Web server 3 via the data output means 45 in order to display the frame image again, that is, obtain an HTML file. Then, since the control unit 35 inquires from the client device 4 in the Web server 3, the HTML file is output from the data output unit 34. Then, the client device 4 acquires an HTML file and stores it in the image data storage unit 44.

  Next, similarly, the control means 43 analyzes the HTML file and determines whether or not the divided image data “1-1_2.png” shown in the fourth line in FIG. 8 is stored in the local cache. The divided image data “1-1_2.png” is new divided image data that has not yet been displayed, and therefore does not exist in the local cache. Therefore, the control unit 43 determines that the divided image data “1_1. -1_2.png "is output from the data output means 34. Then, since the control means 35 of the Web server 3 receives the information for obtaining the divided image data “1-1_2.png” from the client device 4, the divided image data “1-1_2.png” is provided to the client device 4. To do. In the client device 4, the control unit 43 acquires the divided image data “1-1_2.png” via the data input unit 42 and stores it in the local cache of the image data storage unit 44, and the data “1-1_2.png”. Is displayed in the area 2-1 of the display unit 41.

Next, in the client device 4, the control unit 43 analyzes the HTML file, and whether “2-1_1.png” data representing the divided image data shown in the fifth line of FIG. 8 exists in its own local cache. Judge whether or not. Since the divided image data “2-1_1.png” already exists in the local cache, the control unit 43 displays “2-1_1.png” stored in the local cache in the area 1-1 of the display unit 41.
Next, the control means 43 analyzes the HTML file and determines whether or not the data “1-2_1.png” representing the divided image data shown in the eighth line in FIG. 8 exists in its own local cache. To do. Since the divided image data “1-2_1.png” already exists in the local cache, the control unit 43 displays “1-2_1.png” stored in the local cache in the area 1-2 of the display unit 41.
Next, the control unit 43 analyzes the HTML file and determines whether or not the data “2-2_1.png” representing the divided image data shown in the ninth line in FIG. 8 exists in its own local cache. To do. Since the divided image data “2-2_1.png” already exists in the local cache, the control unit 43 displays “2-2_1.png” stored in the local cache in the area 2-2 of the display unit 41.

  As described above, in the instructor-side terminal 2, the divided image data of the divided image area that is always changed is stored in the Web server 3 so that the client device 4 can acquire it at the timing after the instructor makes a change to the frame. Since the HTML file is updated and stored together with the client device 4, when the display update of the client device 4 is performed at the timing after the updated divided image data and the HTML file are stored in the Web server 3, the update is performed. A frame similar to the frame changed in the instructor terminal 2 is displayed only by acquiring the divided image data and the HTML file.

Next, a second embodiment will be described.
Unlike the first embodiment, the second embodiment creates an HTML file once when the instructor-side terminal 2 sets an image area where a snapshot of all or part of its desktop screen should be acquired. Transmit to Web server 3. On the other hand, the Web server 3 transmits the HTML file to the client device 4 when the client device 4 first connects to the Web server 3 and acquires a shared frame designated by the lecturer-side terminal 2. Thereby, the client device 4 obtains an HTML file when the communication is started and the screen is shared. Then, once the Web server 3 transmits the HTML file to the client device 4, if any of the divided image data in the image area of the screen to be shared is updated, unlike the first embodiment. The Web server 3 does not re-create the HTML file one by one, and the updated divided image area and the information that can specify the divided image data in the same area are updated every time the client apparatus 4 makes an inquiry to the Web server 3. Output from the server 3 to the client device 4.

  That is, in the second embodiment, as in the first embodiment, when the instructor-side terminal 2 is designated as a whole area of its own desktop screen or a partial area designated by the instructor operating the instructor-side terminal 2. The control unit 22 recognizes the area as a frame shared with the client apparatus 4 and, as in the first embodiment, compares each divided image data to determine whether or not each divided image data has been updated. Data is stored in the image data storage means 25. At the time of initial activation, the control means 22 first compares the divided image data by dividing the frame and compares the divided values with the currently displayed divided image data. Data is stored in the image data storage means 25. Further, the control means 22 automatically generates an HTML file as shown in FIG. 9A at the time of activation and transmits it to the Web server 3. In this embodiment, the control means 22 compares the default value at startup with the currently displayed divided image data, and is configured to acquire the currently displayed divided image data at startup and use it as an initial value. In this case, before the control unit 22 starts comparing the divided image data described above, a step of acquiring the divided image data and storing it in the image data storage unit 25 is performed. Further, in the instructor side terminal 2, when the control means 22 compares the divided image data and determines that the divided image data has been updated, the updated divided image data list file shown in FIG. Is automatically generated by the control means 22 and transmitted to the Web server 3.

  Specifically, if there is an updated divided image as a result of comparing the divided image data, the control unit 22 sets the file name as the divided image data updated as in the first embodiment. It is automatically assigned and transmitted to the Web server 3. Then, the X and Y position (cell position) of the divided image in which the divided image area is obtained can be acquired to specify the X and Y position (cell position), and the file name of the updated divided image data at the same position An updated image list (a file in which cell positions and file attributes are described) capable of specifying (automatically assigned file names) is automatically generated and transmitted to the Web server 3. That is, in the automatically generated HTML file, the coordinate information of each cell is specified as the name attribute, as shown in the fourth, fifth, eighth, and ninth lines in FIG. The file name of the initial image to be displayed in each cell is designated as the Src attribute. By generating the HTML file in this way, the client device 4 that has received the HTML file acquires the divided image data acquired from the desktop screen of the lecturer terminal 2 and stored in the Web server 3 as in the first embodiment. And displayed on its own display unit 41. In this example, the HTML file is displayed in a window called mainwindow. Therefore, in addition to the divided image data, the instructor terminal 2 transmits an HTML file for displaying the divided image area to the transmission Web server 3 when the divided image area is designated, and thereafter, the divided division is updated. The divided image data of the image area and the updated image list file that can specify the divided image area and the divided image data are transmitted.

In the Web server 3, the HTML file and the divided image data transmitted from the instructor-side terminal 2 are stored in the data storage unit 31 and can be provided in response to an inquiry from the client device 4. In the second embodiment, the Web server 3 is the same as the first embodiment except that the updated image list file is stored in the data storage means 31 in addition to the HTML file.
Thus, in the second embodiment, even if the counter value exceeds the threshold as a result of the comparison of the divided image data, the HTML file is not recreated. Instead, in the second embodiment, as a result of the comparison of the divided image data, if the counter value exceeds the threshold, a list of updated divided image data shown in FIG. 9B is automatically created. The list of the divided image data created at this time associates the file name of the divided image data that the client apparatus 4 should newly acquire from the Web server 3 with the coordinate information (position of the divided image region) of the image data. Exist.

On the other hand, the client device 4 acquires an HTML file when initially connected to the Web server 3. The acquisition of the HTML file is the same as in the first embodiment. The initial client device 4 makes an inquiry to the Web server 3 based on the acquired HTML file based on the description of the HTML file to acquire each piece of divided image data as in the first embodiment. Each divided image data represented in the 4th line, 5th line, 8th line, and 9th line of the HTML file shown in (a) is acquired from the Web server 3. The acquisition of these divided image data is the same as that in the first embodiment.
Further, in the client device 4, as in the first embodiment, the Web server 3 is inquired about the presence or absence of the updated divided image data every predetermined time. The inquiry is the same as in the first embodiment. However, in the second embodiment, unlike the first embodiment, the client apparatus 4 obtains an updated image list file shown in FIG. 9B by making an inquiry to the Web server 3.

When the updated image list file is acquired, the client device 4 dynamically creates Java (registered trademark) SCRIPT as shown in FIG. 10 based on the list. That is, Java (registered trademark) SCRIPT as shown in FIG. 10 is prepared in advance in the control means 43 of the client apparatus 4, and the update acquired earlier after “images” of the Java (registered trademark) SCRIPT. By substituting “1” and “1” representing the X and Y positions in the image list file before and after “_” of “[” _ ”]”, a “[“ 1_1 ”]” portion is generated and Java ( The Java (registered trademark) SCRIPT shown in FIG. 10 is generated by substituting the “src =”. 1-1_1.png ”portion in the updated image list file acquired previously in the subsequent part of the registered trademark SCRIPT. The control means 43 temporarily holds the Java (registered trademark) SCRIPT generated in this way, and is stored in the image data storage means 44 and is displayed in the HTML file (main window) shown in FIG. 9A. The Java (registered trademark) SCRIPT is executed on the divided image data on the display unit 41 specified and displayed by (). As a result, the HTML file that specified the currently displayed image rewrites the divided image data in the divided area corresponding to the description portion that specifies the image to be displayed at the same cell position as the updated image in the table. The That is, with reference to the description of a specific HTML file, “<IMgsrc =” ./ 1-1_1.png “name” 1_1> ”shown on the fourth line in FIG.
The part is “<IMgsrc =” ./ 1-1_2. Png “name” 1_1> ”
The image is displayed on the display unit 41 corresponding to the above.

In the client device 4, the control unit 43 causes the display unit 41 to display it as if it is displayed based on the HTML file generated by automatically rewriting as described above. At this time, as in the first embodiment, the client device 4 has already acquired each divided image data represented by the fourth row, the fifth row, the eighth row, and the ninth row in FIG. If there is image data that has not yet been acquired, the Web server 3 is inquired to acquire the divided image data from the Web server 3, and income is obtained from the Web server 3. The divided image data is displayed in the divided image area. If already acquired (already displayed), the already acquired divided image data is used as it is and displayed on the display unit 41.
As described above, according to the second embodiment, it is possible to display and update only the image of a specific divided image area (cell) without changing or recreating the HTML file acquired from the Web server 3. Accordingly, even a type of Web browser that cannot use the local cache function can be used as the client device 4.

When the client device 4 makes an inquiry as to whether or not the divided image data has been updated, instead of creating and outputting a list of updated divided image data, the Web server 3 as shown in FIG. Java (registered trademark) SCRIPT may be directly generated based on the information of the updated divided image data acquired from the instructor side terminal 2, and may be output to the client device 4. In this case, the Web server 3 does not create an updated image list file, and Java (registered trademark) SCRIPT shown in FIG. 10 is prepared in advance in the control means 35, and a predetermined location of the Java (registered trademark) SCRIPT is prepared. Is generated by substituting “src =” ./ 1-1_2.png ”for specifying the X and Y positions and the divided image data of the updated divided image data acquired from the instructor-side terminal 2.
The time interval for inquiring whether the client device 4 has the updated divided image data to the Web server 3 is the same as the time interval for comparing whether the instructor-side terminal 2 has updated the divided image data. By doing this, even when there is a change in another divided image area following the update of certain divided image data of the lecturer side terminal 2, the same image as the update comparison result of the lecturer side terminal 2 can be displayed.
The rest of the second embodiment is the same as that of the first embodiment.

Next, a third embodiment will be described.
The third embodiment is configured in advance so that an application used by a lecturer can be registered in the lecturer side terminal 2 in advance. For example, when the application used by the lecturer in the lecturer-side terminal 2 can be acquired from information on the OS side by the OS in the multitask window format, the window area of the acquired application is transferred to the client device 4. This is a case of dividing as a frame.

That is, A and B among the three types of applications A, B, and C are registered in the instructor-side terminal 2 in advance. Of course, the number of applications that can be registered may be different depending on the performance of the instructor terminal 2 and the client device 4.
Then, as shown in FIG. 11, among the registered applications, an application that is activated by an operation by the instructor of the instructor side terminal 2, that is, an application that is moved to the forefront and displayed is a frame to be transferred to the client device 4 Treat as an area.
Specifically, in the state where the instructor-side terminal 2 is shown in FIG. 11A, since the activated application is C, it is necessary to transfer, that is, it is not necessary to transfer the frame to the client device 4. 22 judges. Therefore, nothing is done.

On the other hand, as shown in FIG. 11B, when the instructor side terminal 2 is active and the frontmost application is A, the control means 22 of the instructor side terminal 2 determines that the window of A is based on the information on the OS side. It is determined that the frame is to be transferred to the client device 4. Then, the window of application A is divided into a predetermined number of divided areas.
That is, the range of the XY coordinates on the liquid crystal display unit 21 of the window of the application A is acquired from the information on the OS side, and the acquired XY coordinates are divided and divided so as to have a predetermined number of divided areas. For example, if the range of the XY coordinates is 500 on the X side and 250 on the Y side, and 5 × 5 25 divisions, each divided area on the application A window is 100 pixels on the X axis side and 50 pixels on the Y axis side. It is determined that each area is a divided area to be transmitted to the client device 4. Then, as a frame for transmitting the window of the application A to the client apparatus 4, the same processing as that of the first embodiment is performed on the frame.
Further, as shown in FIG. 11C, when the active application is changed to B, a divided area is newly set with the window of application B as a frame to be divided, and the same processing as in application A is performed. .

  In the third embodiment, the number of divisions is not determined in advance, but the size of the rectangular area to be divided is determined in advance, and the control means 35 determines the window area of application A acquired from the OS side as the rectangular area. Each area size is divided in the XY-axis direction, and a portion that becomes a fraction less than the size of the rectangular area is programmed in advance to be a rectangular area that becomes the fraction, and each rectangular area is divided into divided areas. As in the first embodiment, it is possible to perform the same processing as in the first embodiment. Furthermore, when registering an application, it is possible to identify the type of application, for example, whether it is a text editor or image editing software that performs image processing. It is also possible to set the divided image areas by changing the ratio of the sizes in the XY axis direction. For example, in the case of a text editor, the horizontally divided divided image areas (1) to (6) are used (see FIG. 12). In the case of horizontal writing, only the almost same area is treated as an update target, and the divided image data accompanying the update can be efficiently transmitted to the client device 4.

  Furthermore, the embodiment shown in FIG. 13 is an example in which a divided region is set finely in the vicinity where the cursor exists, and other regions are not often updated, and thus are set as a large divided region. That is, in an application such as a text editor as shown in FIG. 13, image updating is always performed based on the cursor position. Therefore, at the position where the cursor exists based on the cursor position, the divided area is set to about one line of text lines. The width in the axial direction and the width in the X-axis direction are divided by a width that divides the window region into three, and the other upper and lower regions are in a wide range as shown as region (1) or region (5) in FIG. It can also be an area.

  In the description of each of the above embodiments, a pseudo-push distribution system has been described by using an example using the most widely used web browser. However, when a push distribution system is used, The control unit 43 of the client device 4 does not make an inquiry to the Web server 3. The Web server 3 can be realized by delivering the updated divided image data to each client device 4 at every predetermined time or whenever the updated divided image data is provided from the instructor side terminal 2. . In this case, the Web server 3 needs to recognize all the connected client devices 4 and transmits to the recognized client device 4, that is, the registered client device 4. On the other hand, in the client device 4, when the updated divided image data is transmitted from the Web server 3, the control unit 43 receives the divided image data transmitted via the data input unit 45 and updates the divided region. The image data is displayed in the divided area of the display unit 41.

In each of the above embodiments, the main body apparatus is configured by the instructor side terminal 2 and the Web server 3. However, it goes without saying that the main body apparatus can be implemented even if it is composed of one apparatus.
Furthermore, in each of the above embodiments, the client device 4 has been described as a personal computer terminal, but a ubiquitous device such as a PDA or a mobile phone may be used.

In the present invention configured as described above, a frame image supply side and a client that displays the frame, such as a lecture or in-house training performed by a lecturer and a student sharing a screen, have a frame as an image. When sharing, image sharing is possible with a small communication band, which is effective.
In other words, it can be applied to devices that send presentation slides, intermittent images taken by surveillance cameras, etc. to remote computers and devices for remote display and playback. E-learning, remote seminars, online help desks, remote healthcare, It can be applied to applications such as remote fault diagnosis and surveillance cameras. In addition, since it is an open system in which the use of a specific operation system is not compulsory, it can also be used for the above-described applications such as E-learning using a ubiquitous device such as a personal computer, PDA, or mobile phone as a client device.

Schematic explanatory diagram showing the configuration of the present invention Explanatory drawing of the division area in the Example of this invention Explanatory drawing of the update comparison of the division area in the Example of this invention Explanatory drawing of the HTML file in the first embodiment Explanatory drawing of update comparison of the same segment Explanatory drawing of the same HTML file Explanatory drawing of update comparison of the same segment Explanatory drawing of the same HTML file (A) is explanatory drawing of the HTML file in 2nd Example, (b) is explanatory drawing showing the update image list file which instruct | indicates the updated data Explanation of Java (registered trademark) SCRIPT Explanatory drawing showing the third embodiment Explanatory diagram when implemented in the same text editor Explanatory drawing showing the division state of the same divided area

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image data transmission production system 2 Instructor side terminal 21 Liquid crystal display part 22 Control means 23 Pointing device 24 Keyboard 25 Image data storage means 3 Web server 31 Data storage means 32 Display means 33 Data input means 34 Data output means 35 Control means 4 Client Device 41 Display unit 42 Data input means 43 Control means 44 Image data storage means 45 Data output means

Claims (7)

Sequentially acquiring the image data, dividing the image data of the acquired frame into a plurality of predetermined regions, storing the divided image data of each divided region corresponding to the divided region,
Next, the image data of the input frame is divided into a plurality of predetermined areas, and the divided image data of each divided area is stored in correspondence with the divided areas.
Comparing the first input image data and the next input image data in the same divided area, and when the image data is changed, the changed divided image data is output. Image data transmission method. A display means, a data output means, an image data storage means, and a control means, wherein the control means divides the image data of the frame displayed by the display means into a plurality of divided image data obtained by dividing the frame input before and after A main unit capable of outputting divided image data by comparing each other;
The main unit is connected to the main unit so as to be able to communicate data, and is provided so as to be able to receive data from the main unit. The divided image data is input by the data input means, and comprises a client device that outputs the image data from the data output means so as to be displayed at a predetermined divided position.
In the main unit, the control means divides the image data of the frame displayed by the display means into a plurality of predetermined areas, and the divided image data of each divided area is stored in the image data storage means corresponding to the divided areas, and the display means Divides the image data of the frame to be displayed next into the plurality of predetermined areas, stores the divided image data of each divided area in the image data storage means in association with the divided areas, and precedes the divided same area. The displayed image data and the next displayed image data are compared with each other, and when there is a change in the image data, the changed divided image data is output from the data output means to the client device,
In the client device, the control unit inputs the updated divided image data received from the main body device from the data input unit, stores the input divided image data in the image data storage unit, and stores it in the image data storage unit. An image data transmission and generation system characterized by outputting image data capable of constituting a frame by the latest data of each divided image data. A display means, a data output means, an image data storage means, and a control means, wherein the control means divides the image data of the frame displayed by the display means into a plurality of divided image data obtained by dividing the frame input before and after A main unit capable of outputting divided image data by comparing each other;
A data input means, a data output means, an image data storage means, and a control means are connected to the main apparatus so as to be able to communicate with data, and the data input means inputs the divided image data output from the main apparatus, and the predetermined division is performed. It consists of a client device that outputs image data from the data output means to be displayed at a position,
In the main unit, the control means divides the image data of the frame displayed by the display means into a plurality of predetermined areas, and stores the divided image data of each divided area in the image data storage means in correspondence with the divided areas, and displays them. The means divides the image data of the frame to be displayed next into the plurality of predetermined areas, and stores the divided image data of each divided area in the image data storage means in association with the divided areas. The image data displayed on the screen and the next displayed image data are compared with each other. If there is a change in the image data, the latest divided image data in which the changed divided image data is updated in the image data storage means is displayed. When the information for inquiring the presence / absence of divided image data that has not yet been transmitted from the client device to the client device is received, the untransmitted divided image data is received. It is capable of outputting the data from the data output means to the client apparatus,
In the client device, the control unit inputs the updated divided image data received from the main body device from the data input unit, stores the input divided image data in the image data storage unit, and stores it in the image data storage unit. Output image data that can form a frame with the latest data of each divided image data, and output to the main unit information that inquires about the presence or absence of updated divided image data that is newer than the currently stored divided image data. An image data transmission generation system characterized in that a frame is always constituted by the latest divided image data. A display means, a data output means, an image data storage means, and a control means, wherein the control means divides the image data of the frame displayed by the display means into a plurality of divided image data obtained by dividing the frame input before and after A main unit capable of outputting divided image data by comparing each other;
It is connected to the main unit so as to be able to perform data communication, and includes a data input unit, a data output unit, an image data storage unit, and a control unit. A frame can be configured based on the description of the HTML file and is output from the main unit. The divided image data is input by the data input means, and comprises a client device that outputs the image data from the data output means so as to be displayed at a predetermined divided position.
In the main unit, the control means divides the image data of the frame displayed by the display means into a plurality of predetermined areas, and stores the divided image data of each divided area in the image data storage means in correspondence with the divided areas, and displays them. The image data of the frame to be displayed next is divided into a plurality of predetermined areas, and the divided image data of each divided area is stored in the image data storage means in correspondence with the divided areas, The image data displayed on the screen and the next displayed image data are compared with each other, and if there is a change in the image data, the updated divided image data is updated to the image data storage means. An HTML file that is stored as image data and that constitutes a frame from the latest divided image data is generated, and the HTML file generated from the client device is output. Can be output from the data output means to the client apparatus, and when the information desired to output desired divided image data is received from the client apparatus, the data is output from the data output means to the client apparatus. ,
In the client device, the control means outputs information for requesting the output of the HTML file to the main device, receives the HTML file, and among the divided image data described in the received HTML file, its own image data. The presence / absence of divided image data not stored in the storage means is determined, and if there is divided image data not stored in its own image data storage means, information for outputting the data to the main unit is output, and the data When the input means receives the divided image data from the main unit, the image can be stored in the image data storage means as updated divided image data, and a frame can be configured by the latest data of each divided image data stored in the image data storage means An image data transmission generation system characterized in that data can be output. 5. The image data transmission method according to claim 1 or the image data transmission generation system according to claim 2, wherein the image data of the divided frames is all or part of a screen to be displayed. 5. The image data transmission and generation system according to claim 4, wherein when the main device is used for multitasking, the main device treats the display area of the currently used application as image data of a divided frame. 5. The image data transmission generation system according to claim 4, wherein the main body apparatus includes a pointing device and handles the image area designated by the pointing device as image data of a frame to be divided.