JP2987562B2 - Multipoint image transfer method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multipoint image transfer method, and more particularly to a method for transmitting image data to a plurality of image receiving apparatuses at multiple points via a connection-oriented communication network system such as an ATM network system. The present invention relates to a multipoint image transfer method for transferring.

[0002]

2. Description of the Related Art Generally, ATMs (Asynchronous Transfe
r Mode) When performing communication on a network system, it is necessary to take a connection setup procedure in order to secure communication paths and resources in the network prior to actual data transfer. It is called an oriented communication network system. This connection setup is performed when a device that wants to send data sends a connection setup message to the network.

[0003] The connection setup message includes communication quality parameters such as a data receiving destination, a maximum transfer rate, and a transfer rate to be secured at a minimum (minimum allowable transfer rate). Network components such as an ATM switch include: Various network resources represented by buffers are allocated to individual connections based on the communication quality parameters. Conventionally, it has been proposed that the communication quality parameters such as the maximum transfer rate be calculated based on reception environment information such as a display screen resolution notified from the image receiving apparatus prior to data transfer and a maximum allowable transfer time. When transferring image data to a plurality of image receiving apparatuses at multiple points, a multi-point image transfer method using this method can be considered.

[0004]

However, in a conventional multi-point image transfer method using such a communication quality parameter calculation method, an image is transferred based on individual reception environment information notified from a plurality of image receiving apparatuses. It is necessary to establish connections for the number of receiving devices, and a lot of communication resources from the image transmitting device to the image receiving device are occupied. Therefore, there is a problem that the connection to some image receiving apparatuses cannot be established due to a shortage of the band, and the probability that such broadcast-type communication is incomplete is increased. In addition, it is considered that a band that can be used by another communication is squeezed, which causes a reduction in communication speed and a failure in connection establishment. The present invention has been made to solve such a problem, and an object of the present invention is to provide a multipoint image transfer method capable of efficiently using communication resources.

[0005]

In order to achieve such an object, a multi-point image transfer method according to the present invention comprises a method for transmitting an image between an image transmitting apparatus and an image receiving apparatus for each of a plurality of image receiving apparatuses. At least one image quality management server is provided, the image transmission device transmits an environment information request to each image reception device prior to transmission of image data, and the image quality management server transmits the environment information request from the image transmission device. Receives the environment information notification returned from any of the image receiving devices according to the received environment information of each image receiving device stored in the environment information notification. Aggregates the multiple connections that can be aggregated into one, notifies the environment information of the remaining unaggregated connections, and generates new environmental information for the new connection obtained by aggregation. The image transmission device calculates a communication quality parameter based on the obtained environmental information notification, and transmits image data between itself and the image quality management server according to the communication quality parameter. The image quality management server makes a request for establishing a transfer connection, and the image quality management server establishes a connection for image data transfer between itself and the image transmission device, and then communicates based on the reception environment of each image reception device that has received the environment information notification. A quality parameter is calculated, and a request for establishing a connection for image data transfer between itself and each image receiving apparatus is made in accordance with the communication quality parameter.

Therefore, the environment information notice returned from each image receiving apparatus in response to the environment information request from the image transmitting apparatus is received by the image quality management server, and each image receiving apparatus stored in these environment information notices is received. The plurality of connections that can be aggregated among the connections to each image receiving apparatus are aggregated into one based on the reception environment information of, the environment information notification of the remaining unaggregated connections, and a new connection obtained by the aggregation The new environment information notification generated for the connection is transferred to the image transmission device. Further, based on the communication quality parameters calculated in response to these environmental information notifications, the image transmission device is requested to establish a connection for image data transfer with the image quality management server, after this connection is established, The image quality management server issues a request for establishing a connection for image data transfer with each image receiving device according to the communication quality parameter calculated from the reception environment of each image receiving device that has received the environment information notification. .

After the image data transfer connection to each image receiving apparatus is established, the image transmitting apparatus sequentially transfers the contour data constituting each image data or each image data unit to the image quality management server in a predetermined order. The image quality management server sequentially transfers the contour data or each image data unit from the image transmitting device to each image receiving device in a predetermined order based on the receiving environment information of each image receiving device that has received the environmental information notification. It is something to do. Therefore, after a connection for transferring image data to each image receiving device is established, the contour data or each image data unit constituting the image data is sequentially transferred from the image transmitting device to the image quality management server in a predetermined order, and The quality management server sequentially transfers the contour data or each image data unit from the image transmission device to each image reception device in a predetermined order based on the reception environment information of each image reception device.

Further, the image quality management server receives the environment information notification returned from any of the image receiving devices in response to the environmental information request from the image transmitting device, and receives the image information stored in the environment information notification. The communication provided by the communication network system based on the received reception environment information of each image receiving device after storing the reception environment information of the reception device and establishing the image data transfer connection between itself and the image transmission device. A quality parameter is calculated, and a request for establishing a connection for image data transfer between itself and each image receiving apparatus is made in accordance with the communication quality parameter. Therefore, the reception environment information of each image reception device stored in the environment information notification is stored in the image quality management server, and is stored after the image data transfer connection between the image quality management server and the image transmission device is established. A request for establishing a connection for image data transfer between the image quality management server and each image receiving device is made according to the communication quality parameter calculated based on the received reception environment information.

[0009] The image quality management server transfers the contour data indicating the contour of the image or a part of the image data among the reception environment information included in the environment information notice received from each of the image receiving apparatuses. Whether connection aggregation is possible or not is determined based on a combination of at least two of the availability, the maximum allowable transfer time allowed by the receiving side as the image data transfer time, and the display screen resolution of the receiving side when displaying image data. It is like that. Therefore, whether or not the receiving side can transfer the outline data or a part of the image data indicating the outline of the image, the maximum allowable transfer time allowed by the receiving side as the image data transfer time, and the display screen resolution of the receiving side when displaying the image data The image quality management server determines whether connection aggregation is possible based on a combination of any two or more of the above.

The information notified by the environmental information request and the environmental information notification includes the length of the entire image data to be transmitted and the length of the contour data. After the connection for image data transfer is established, a communication quality parameter is calculated based on the reception environment of each image receiving apparatus, the length of the entire image data, and the length of the contour data. A request for establishing a connection for image data transfer with the image receiving apparatus is made.
Therefore, by requesting environmental information and notification of environmental information,
The image quality management server is notified of the total length of the image data to be transmitted and the length of the contour data via the image transmission device and the image reception device. After the connection for image data transfer is established, a communication quality parameter is calculated based on the reception environment of each image receiving device, the length of the entire image data, and the length of the contour data. A request for establishing a connection for image data transfer between the image receiving apparatus and each image receiving apparatus is made.

Further, the image transmitting apparatus transmits the image data when the next image data unit is transmitted for each image quality management server based on the time actually required for transmitting the contour data or the image data unit. Calculate the total transfer time from the start to the end of transmission of the image data unit, and calculate the total transfer time and the maximum allowable transfer time requested by the respective environment information notifications as the transfer time of the image data according to the result of comparison. Thus, it is determined whether the next image data unit can be transferred to each image quality management server. Therefore, for each image quality management server, the total transfer time from the start of transfer of image data to the end of transmission of the image data unit, calculated from the time actually required to transfer the contour data or image data unit, The image transmission device compares the transfer time of the image data with the maximum allowable transfer time requested by the notification of each environment information, and determines whether the next image data unit can be transferred to each image quality management server.

In addition, the image quality management server transmits the next image data unit for each image receiving apparatus that has received the environmental information notification, based on the time actually required to transfer the contour data or the image data unit. In this case, calculate the total transfer time from the start of image data transfer to the end of transmission of the image data unit, and calculate the total transfer time and the maximum allowable transfer time requested by the respective environmental information notifications as the image data transfer time. According to the result of the comparison, it is determined whether or not the next image data unit can be transferred to each image receiving apparatus. Therefore, for each image receiving device, the total transfer time from the start of transfer of image data to the end of transmission of the image data unit, calculated from the time actually required to transfer the contour data or image data unit, and The image quality management server compares the data transfer time with the maximum allowable transfer time requested by the notification of each environment information, and determines whether the next image data unit can be transferred to each image receiving apparatus.

[0013]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a multi-point image transfer system according to an embodiment of the present invention, showing an example realized by using an ATM network system constituted by ATM switches 104 interconnected by an ATM link 105. I have. In order to perform server-client type image communication using an ATM network system, the image transmitting apparatus 101 and each image receiving apparatus 102 need
It is connected to the TM switch 104.

An image quality management server 103 is connected to, for example, each site of the communication network system in such a manner that a plurality of image receiving apparatuses 102 are aggregated. The image quality management server 103 includes a network access controller 109, a CPU 106,
10, and a memory 107 stores a quality management program 108 for executing the operation of the image quality management server described above.

Next, the operation of the present invention will be described with reference to FIG. When an image transfer request is issued from the image transmitting apparatus 101 to the plurality of image receiving apparatuses 102, the image transmitting apparatus 101 requests all of the image receiving apparatuses 102 to be received to notify the receiving environment information. The reception environment information referred to here is information relating to the operation environment of the reception side such as whether or not image outline or partial reception is possible, the resolution of the display screen, and the maximum allowable transfer time. The characteristics may be unique to the device 102 or may be set by a user using the individual image receiving device 102.

The image quality management server 103 collects the reception environment information notifications from the respective image receiving apparatuses 102, determines whether a plurality of connections among the connections corresponding to these notifications can be consolidated into one connection, and makes it possible. If so, the reception environment information notifications corresponding to the plurality of connections are re-created as one notification indicating a new connection. The operation of re-creating one notification will be described later.
The recreated reception environment information notification is transmitted from the image quality management server 103 to the image transmission device 101. In addition,
The reception environment information obtained from each image receiving apparatus 102 is stored in the image quality management server 103 corresponding to each image receiving apparatus 102 in preparation for transferring the image data to each image receiving apparatus 102 later. You.

The image transmitting apparatus 101 that has received the reception environment information notification from each image quality management server 103 establishes one or a plurality of connections to the image quality management server 103 based on the received reception environment information notification. The image quality management server 103, which has received the image data from the image transmission apparatus 101, determines the image quality management server and the individual image reception based on the size of the image data and the reception environment information stored corresponding to each image reception terminal. A communication quality parameter used between the devices is calculated.

The information on the size of the image data is included in a request message transmitted from the image transmitting apparatus 101 at the time of the request for the reception environment information. The information is copied to a notification message and transferred to the image quality management server 103.
As a result, the information regarding the size of the image data is stored by the image quality management server 103 that has received the environment information notification message, and is used for calculating the communication quality parameter. The communication quality parameters include a maximum transfer speed, a communication band that must be secured at a minimum, and the like.

Thereafter, the image quality management server 103 establishes connections to the individual image receiving apparatuses 102 based on the calculated parameters, and sets one of the image data sequentially transmitted from the image transmitting apparatus 101 after each connection is established. All or a part of the image data is transferred from itself to each image receiving apparatus 102 on the downstream side based on the respective reception environment information. As a result, in each of the image receiving apparatuses 102, the reception image quality differs depending on the individual reception environment conditions.

FIG. 2 is an explanatory diagram showing the structure of image data transferred from the image transmitting device to the image receiving device. The image data 201 is composed of outline data 202 that can independently display the outline of the image, and a plurality of image data units 203 that can independently display a part of the image. It is assumed that the image data units 203 are arranged in an important order in image display in advance. Since the image data 201 has such a structure, it is possible to display an outline by only partially transferring the image data.

Next, the image quality management server will be described with reference to FIG. FIG. 3 is a functional block diagram of the image quality management server. The reception environment information notification messages from the plurality of image receiving apparatuses 102 are collected by the message collection unit 312 via the communication control unit 313. For the collection of this message, timeout control using the collection monitoring timer 308 is performed. After the target receiving environment information notification messages are collected, the contents are extracted, and control is transferred to the message merging (aggregation) availability determination unit 309.

At this point, the image quality management server 103 stores the reception environment information and the information on the size of the image data obtained from the individual image reception apparatuses 102 in the reception environment database 307 corresponding to the image reception apparatuses. deep.
The information on the size of the image data includes the length of the outline data representing the outline of the image and the length of the entire image data. When the merging permission / non-permission determining unit 309 determines that the connection can be aggregated, the message generating unit 310 generates a new reception environment information notification.
This new reception environment information notification message is transmitted to the communication control unit 3
13 is transmitted to the image transmitting apparatus 101.

Upon receiving the reception environment information notification message, the image receiving apparatus 101 establishes a connection with the image quality management server 103. When the connection control unit 306 recognizes that the connection has been established, the connection control unit 306 obtains the reception environment information and the size of the image data corresponding to each image receiving apparatus from the reception environment database 307, and transmits them to the communication quality mapping unit 305. The communication quality mapping unit 305 determines each image receiving device 1 from the obtained information.
The communication control unit 306 calculates communication parameters suitable for communication with the image receiving apparatus 02, and establishes a connection corresponding to each image receiving apparatus.

At this time, the connection management database 3
If it is determined from step 11 that a connection having equivalent quality to the corresponding image receiving apparatus 102 has already been established, a new connection is not established. On the other hand, image data from the image transmitting apparatus 101 is received by the image data receiving unit 304 via the communication control unit 313. The received image data is sent to the data transfer unit 301, and the data transfer unit 301 starts communication in consideration of the quality of each image receiving device.

The transmission of image data via the image data transmission unit 303 is started from the contour data 202 for each image receiving apparatus 102 using the connection already established to each image receiving apparatus 102. Each time the contour data 202 is transmitted, or each image data unit 203 is transmitted, the transfer time is measured by the transfer time measuring unit 302,
It is always checked whether the maximum allowable transfer time required by the image receiving apparatus 102 can be satisfied even when the next image data unit 203 is transmitted.

Here, the maximum allowable transfer time is the time required by the receiving side (image receiving apparatus or its user) as the time required to transfer the image data, and the maximum allowable transfer time cannot be satisfied. At this point, transmission is stopped, and a stop message is transmitted to the image receiving apparatus 102. The image quality management server 103 performs such processing from connection establishment to transmission of image data for each image receiving apparatus. It should be noted that such transfer permission / inhibition determination processing for the subsequent image data unit is similarly performed in the image transmission device.

FIG. 4 is a sequence diagram showing an operation of transferring an image from an image transmitting apparatus to two image receiving apparatuses via an image quality management server. In this case, first, the image transmitting apparatus 101 transmits an environment information request message 401 to each of the image receiving apparatuses A and B. The environment information request message 401 includes information on the size of image data to be transmitted, in addition to an identifier indicating that environment information is requested from each of the image receiving apparatuses A and B. Here, the information relating to the size of the image data includes the length of the outline data representing the outline portion of the image and the length of the entire image data.

In response to this message, an environmental information notification message is transmitted from each of the image receiving apparatuses A and B to the image quality management server 103. Note that the environment information notification message 403 from the image receiving device A includes the environment information 1
One is a maximum allowable transfer time, and here, it is assumed that 0.3 seconds is set as the maximum allowable transfer time. On the other hand, it is assumed that 0.1 second is set as the maximum allowable transfer time of the environment information notification message 402 from the image receiving device B.

The environment information notification messages 402 and 4
03, information on the size of image data included in the environment information request message 401 received by each of the image receiving apparatuses A and B is copied. Image quality management server 103
Collects the environmental information notification messages from the image receiving apparatuses A and B, and
And transmits the image data to the image transmitting apparatus 101. The maximum allowable transfer time at this time is 0.3 seconds at the maximum and 0.1 seconds at the minimum.

Although the environment information notification messages 402 and 403 from the image receiving apparatuses A and B indicate only one maximum allowable transfer time, the message format is the environment information notification message from the image quality management server 103. Similarly to 404, the maximum value and the minimum value are transmitted with the same value. Further, the image quality management server 103 transmits the information on the maximum allowable transfer time and the size of the image data included in the received environment information notification message to each image receiving apparatus in order to establish a data transfer connection with each image receiving apparatus. Is stored in correspondence with.

The image transmitting apparatus 101 that has received the environment information notification message 404 from the image quality management server 103
Is the MCR (Minimum) of the connection for image data transfer.
CellRate: calculates the minimum cell rate. MCR is a cell transfer rate that the network wants to secure at a minimum.
The actual transfer rate varies depending on the network load with the lower limit of the MCR and the upper limit of another quality parameter, PCR (Peak Cell Rate).

The image transmission apparatus 101 transmits the cell rate (the ATM cell transmitted per second) required to transmit the contour data of the image within the minimum value of the maximum allowable transfer time in the received environment information notification message 404. Number) and calculate this as M
CR. An ATM connection establishment process 405 is performed using the obtained MCR as one of the ATM communication quality parameters. In the example of FIG. 4, the required MCR is a speed at which the contour data can be transmitted within 0.1 second.

After a connection has been established between the image transmission apparatus 101 and the image quality management server 103, connection establishment processing 407 and 406 between the image quality management server 103 and each of the image reception apparatuses A and B are started. You. The MCR requested at this time is the maximum allowable transfer time (0.3 seconds and 0.1 seconds respectively) and the size of the image data in the environment information notification messages 403 and 402 received and stored from each image receiving apparatus. The image quality management server 103 decides based on the information about the image quality. After the connection to the image receiving apparatuses A and B is established in this way, the image transmitting apparatus 101 starts transferring the image data in order from the contour data 408. This is transferred to the image quality management server 10
3 and transfer them to the connections established for each of the image receiving apparatuses A and B.

After transmitting the contour data, the image transmitting apparatus 101 determines whether or not the next image data unit can be transmitted based on the transmission time. More specifically, the total transfer time when the next image data unit is transmitted is estimated, and this is the maximum value of the maximum allowable transfer time in the environment information notification message 404 received from the image quality management server 103 (see FIG. It is determined whether it exceeds 0.3 seconds in the example of FIG. If not, the next image data unit is transmitted. This determination is made for each transmission of the image data unit. If there is a possibility that the maximum allowable transfer time exceeds the maximum value (0.3 seconds), the transmission is stopped and the end notification message 411 is transmitted.

The same judgment processing as the above-described judgment processing in the image transmitting apparatus 101 is also executed in the image quality management server 103. In this case, the transfer determination of the next data unit is performed for each of the image receiving apparatuses A and B. In the transfer of the image data to the image receiving apparatus A, the transfer is continued as long as the estimated total transfer time at the time of transmitting the next data unit does not exceed 0.3 seconds, and the end notification message 412 is transmitted when it is determined that the transfer is exceeded. To end the transfer.

In the transfer of the image data to the image receiving apparatus B, the transfer is continued unless the estimated total transfer time at the time of transmission of the next data unit exceeds 0.1 second. The message 410 is transmitted, and the transfer ends. Upon receiving the end notification message, the image receiving apparatuses A and B regard the transfer of the image data as having ended, and end the receiving process.

FIGS. 5A and 5B are explanatory diagrams showing a state of a connection established between the image transmitting apparatus, the image receiving apparatus, and the image quality management server. FIG. 5A shows a physical arrangement, and FIG. It shows the corresponding connection. In the figure, the numbers drawn for each connection represent the occupied bandwidth. The five image receiving apparatuses 102 respectively have bands “10”, “5”, “3”, “2”, and “2”.
It is assumed that environmental information that requires is notified.

The environmental information is stored in two image quality management servers 10.
3 to be notified to the image transmitting apparatus 101,
As a result, the connections of the bands “10” and “3” respectively correspond to the image transmitting apparatus 101 and the image quality management server 103.
Will be put in between. As shown in FIG. 5B, a connection is established from the image quality management server 103 to each image receiving apparatus 102 based on individual environmental information. FIG.
(B) The lower two image receiving apparatuses 102 have both notified environmental information that requires the band “2”, and connections to these are one-to-many as shown in FIG. Connection may be established.

FIG. 6 is an explanatory diagram showing the aggregation (merge) judgment of the environment information in the image quality management server 103 and the MCR value of the connection established by the image transmitting apparatus 101 based on the aggregated environment information notification. Here, the environment information indicates whether contour transfer is possible or not and the maximum allowable transfer time. This is because the transfer of only the outline of the image data is not always accepted due to the environment in which the image receiving apparatus 102 is used or the request of the user. It is thought that. Note that the sequence shown in FIG.
It is based on the merging of two environment information.

Two pieces of environmental information (the two maximum allowable transfer times are A and B and A> B) in which the outline transfer is possible and the maximum allowable transfer time is designated are the outline transfer possible and the maximum allowable transfer time. The maximum value of the transfer time is merged into one environment information of A and the minimum value of the transfer time is B. The image transmitting apparatus 101 that has received the environment information establishes a data transfer connection with the image quality management server 103. At this time, the target MCR can transmit contour data within “B” with “target”. The speed “minimum” is the speed at which the contour data can be transmitted within A.

Here, “target” and “m” are added to the MCR.
initum ", but this is an ATM
The communication parameter is defined as a communication parameter, and it is possible to have a certain width when establishing a connection. That is, the connection is initially established by the “target” MCR, but there is not enough free space in the network and the “target” MCR
If the quality cannot be assured as the actual MCR, "mi
The network selects an MCR that can be set to the lower limit of “nimum” MCR and determines the connection establishment request source as the MCR.
Is to be notified. Note that “target” M is included in the MCR at the time of connection establishment described in FIG.
Only CR is described.

If contour transfer is possible and one of the maximum allowable transfer times is A and one is not specified, that is, if there is a receiving apparatus that can wait for image reception for a long time, the two environment information indicates that the contour transfer is possible and the maximum allowable transfer time is Maximum transfer time is blank,
The minimum value is merged into one piece of environmental information of A. The MCR requested by the image transmitting apparatus for a connection established based on this environment information is such that “target” can transmit contour data within A, and “minimum” is 0.

On the other hand, environmental information that enables contour transfer,
Merging of the environment information in which contour transfer is not possible is performed only in a case where the bandwidth required by the contour transfer incapable information is clearly high. That is, when both of the maximum allowable transfer times are specified, merging is performed only when the maximum allowable transfer time associated with the environment information indicating that contour transfer is not possible is shorter. At this time, the contour transfer is merged with blank environment information. Merge is also performed when the maximum allowable transfer time is specified only for the information indicating that the contour transfer is not possible, or when the maximum allowable transfer time is not specified for both, and the merge result and the MCR value as shown in FIG. 6 are obtained. Merging of contour transfer enable / disable environment information having other conditions is not performed.

Further, if contour transfer is not possible and one of the maximum allowable transfer times is A and the other is B (A> B), the two environment information are that the contour transfer is not possible and the maximum value of the maximum allowable transfer time is Are merged into one environment information of A and the minimum value is B. The MCR requested by the image transmitting apparatus for a connection established based on this environment information is “target”
"t" is the speed at which the entire image can be transmitted within B, "mini
“mum” is the speed at which the entire image can be transmitted within A.

If contour transfer is not possible and one of the maximum allowable transfer times is A and one is not specified, that is, if there is a receiving device that can wait for a long time to receive an image, these two environment information indicate that contour transfer is not possible. The maximum value of the maximum allowable transfer time is merged into one environment information of blank and the minimum value is merged into one environment information of A. The MCR requested by the image transmitting apparatus for a connection established based on this environment information is such that “target” can transmit the entire image within A and “minimum” is 0.

Next, the processing operation of the image quality management server will be described with reference to FIG. FIG. 7 is a flowchart showing the processing operation of the image quality management server. The image quality management server 103 first starts the image receiving apparatus 102
Environment information notification messages from the server (step 70)
1) It is determined whether these messages need to be merged (step 702). Merging is performed on the message determined to be necessary for merging, and an environment information notification message reflecting this result is created again (step 70).
3).

Thereafter, the created information notification message is transmitted to the image transmitting apparatus 101 (step 704).
The connection is set up according to the request from the image transmitting apparatus 101 (step 705). When image data starts to be received from the image transmitting apparatus 101, an image message transfer subroutine (step 706) is called for each image receiving apparatus, and the transfer processing ends.

In the image message transfer subroutine, as shown in FIG. 8, first, the contour data received from the image transmitting device is transferred to the image receiving device (step 801). After the transfer is completed, the transfer time of the contour data is measured (step 802), and from this time and the length of the next image data unit, the total transfer time when the next image data unit is transferred (transfer start of the contour data) From the time until the transfer of the next image data unit is completed), and it is checked whether or not this time exceeds the maximum allowable transfer time set for each image receiving apparatus (step 803).

If the maximum allowable transfer time has not been exceeded (step 803: YES), it is determined that the next image data unit needs to be transferred, and the next image data unit is transferred (step 804). Thereafter, while the estimated total transfer time does not exceed the maximum allowable transfer time, step 802 is performed.
Repeat ~ 804. When the estimated total transfer time exceeds the maximum allowable transfer time (step 803: NO), it is determined that transfer of the next image data unit is unnecessary, and an end message is transmitted to the corresponding image receiving apparatus to perform image transfer processing. The process ends (step 805).

As described above, the image quality management server 103 is provided between the image transmitting apparatus 101 and the image receiving apparatus 102, and all of the image receiving apparatuses 102 to be transmitted from the image transmitting apparatus 101 before transmitting the image data. , An environment information request message 401 is transmitted to the image quality management server 103. In response to this, the image quality management server 103 receives environment information notification messages 402 and 403 returned from the respective image receiving apparatuses 102. , 403, receiving environment information of each image receiving apparatus 102,
For example, it is determined whether or not the connection can be integrated into one connection from the outline of the image or the possibility of partial reception, the display screen resolution, the maximum allowable transfer time, and the like. A notification message 404 is generated and transferred to the image transmitting apparatus 101, and in response to this, the image transmitting apparatus 101 calculates a communication quality parameter provided by the communication network system and issues a network connection establishment request. It is.

Therefore, as compared with the conventional case where the connections for the number of image receiving apparatuses are established based on the individual receiving environment information notified by the plurality of image receiving apparatuses,
Since the communication resources from the image transmitting device to the image receiving device are no longer occupied, the connection to some image receiving devices cannot be established due to insufficient bandwidth, and the probability that such broadcast-type communication will be incomplete In addition to solving the problem of increasing the communication bandwidth, it is also possible to avoid a reduction in communication speed and failure in establishing a connection without squeezing the bandwidth available for other communication, and to efficiently use communication resources. it can.

After the image data transfer connection to each image receiving apparatus 102 is established, the image transmitting apparatus 10
1, the contour data 202 or each image data unit 203 constituting the image data 201 (see FIG. 2) are sequentially transferred to the image quality management server 103 in a predetermined order, and the contour data or each image data unit is received by each image. Since the image data is sequentially transferred to each image receiving apparatus 102 in a predetermined order based on the reception environment information of the apparatus 102, the image data from the image transmitting apparatus is managed by the image quality management based on the image quality requested from each image receiving apparatus. The data can be transferred from the server to each image receiving device.

In the image quality management server 103, the environment information notification message 40 from the image receiving apparatus 102 is provided.
2, 403 (see FIG. 4), the reception environment information of each image receiving apparatus 102 and the information on the length of the image data stored in the message are individually stored, and the image transmitting apparatus In response to a request from 101, connection setup is performed on the basis of the stored reception environment information of each image receiving apparatus 102 and information on the length of image data.
When setting up a connection, the image receiving device 1
It is not necessary to obtain the reception environment information and the information on the length of the image data from the 02 side again, and the time required for the setup process can be reduced.

As connection aggregation processing in the image quality management server 103, whether or not the receiving side can transfer outline data indicating an outline of an image or a part of the image data, the maximum allowable transfer time allowed by the receiving side as the image data transfer time Since the connection aggregation is determined based on a combination of any two or more of the display screen resolutions on the receiving side when displaying image data, the user who uses each image receiving apparatus 102 It is possible to more accurately determine whether or not connection aggregation can be performed according to the request, and to realize image data transfer to multiple points using communication resources efficiently without giving a sense of discomfort to the user.

The length of the entire image data to be transmitted and the length of the outline data are determined from the image transmitting apparatus 101 to each image receiving apparatus 1 by an environmental information request and environmental information notification.
02, the image quality management server 103 establishes a connection for image data transfer between itself and the image transmission device, and then establishes the reception environment of each image reception device and the image to be transmitted. A communication quality parameter is calculated based on the length of the entire data and the length of the contour data, and a request for establishing a connection for image data transfer between itself and each image receiving apparatus is made in accordance with the communication quality parameter. Therefore, when setting up an image data transfer connection between the image quality management server 103 and each image receiving apparatus 102, the image quality management server 1
It is not necessary to inquire the image transmitting apparatus 101 of the total length of the image data to be transmitted and the length of the outline data from 03, and the time required for the setup processing can be reduced.

The image transmitting apparatus 101 and the image quality management server 103 transmit the image data when the next succeeding image data unit calculated from the time actually required for transferring the contour data or the image data unit is transmitted. Depending on the result of comparing the total transfer time from the start of transfer to the end of transmission of the image data unit with the maximum allowable transfer time requested in the notification of each environment information as the image data transfer time, the individual image quality Since it is determined whether or not the next image data unit can be transferred to the management server 103 or the individual image receiving apparatuses 102, the transfer failure of the subsequent image data can be accurately predicted, and the transfer failure is reliably avoided. It is possible to suppress various troubles caused by the transfer failure.

[0057]

As described above, according to the present invention, one or more image quality management servers are provided between an image transmitting apparatus and an image receiving apparatus for each of a plurality of arbitrary image receiving apparatuses. In the management server, based on the reception environment information stored in the environment information notification from each image receiving device, a plurality of connections that can be aggregated among the connections to each image receiving device are aggregated into one, and the aggregation is performed. The environment information notification of the remaining connections that did not exist and the new environment information notification generated for the new connection obtained by aggregation are transferred to the image transmitting device, and the communication quality parameter calculated based on these environment information notifications is transferred. The image transmission device requests the image quality management server to establish a connection for image data transfer, and then the image quality management server According to the communication quality parameter calculated based on the reception environment of the apparatus, in which to perform the establishment request for image data transfer connection between the image receiving apparatus.

Therefore, as compared with the conventional method in which the image transmitting apparatus and all the image receiving apparatuses are individually connected based on the receiving environment of each image receiving apparatus, the image transmitting apparatus can transmit the image from the image transmitting apparatus. The communication resources up to the receiving device can be used efficiently, and the connection to some image receiving devices cannot be established due to insufficient bandwidth, and the probability that such broadcast-type communication will be incomplete In addition to solving the problem of increase, it is possible to avoid a failure that occurs due to the transfer of image data, for example, a compression of a band available for other communication, a reduction in communication speed, or a failure in connection establishment. .

After the image data transfer connection to each image receiving apparatus is established, the image transmitting apparatus sequentially transfers the contour data constituting the image data or each image data unit to the image quality management server in a predetermined order. The contour data or each image data unit is sequentially transferred to each image receiving device in a predetermined order based on the reception environment information of each image receiving device, so that the image quality requested by each image receiving device can be obtained. The image data from the image transmitting device can be transferred from the image quality management server to each image receiving device.

The image quality management server stores the reception environment information of each image reception device and the information on the size of the image data stored in the environment information notification, and stores the information between the image quality management server and the image transmission device. After establishing the image data transfer connection between the image quality management server and each image receiving device according to the communication quality parameters calculated based on the stored reception environment information and the information on the size of the image data. Since the image quality management server establishes a connection to each image receiving device, the image receiving device again needs to establish individual reception environment information and the size of the image data. The need to collect information on the connection, simplifying the connection establishment request processing and the time required for processing Can be shortened, it is possible to greatly shorten the time until the start of transmission of image data as a whole.

Also, whether or not the receiving side can transfer the outline data indicating the outline of the image or a part of the image data, the maximum allowable transfer time allowed by the receiving side as the transfer time of the image data, and the receiving side when displaying the image data. Based on a combination of any two or more of the display screen resolutions,
Since it is determined whether connection aggregation is possible or not, it is possible to more accurately determine whether connection aggregation is possible according to a request of a user using each image receiving device, without giving a sense of incongruity to the user, Image data transfer to multiple points using communication resources efficiently can be realized.

The length of the entire image data to be transmitted and the length of the contour data are transferred from the image transmitting apparatus to the image quality management server via each image receiving apparatus in response to an environmental information request and environmental information notification. The quality management server is used to establish a connection for image data transfer with each image receiving apparatus based on the receiving environment of each image receiving apparatus and the total length of image data to be transmitted and the length of contour data. Since the communication quality parameter is calculated, when setting up the connection between the image quality management server and each image receiving device, the length of the entire image data and the length of the contour data transmitted to the image transmitting device are set. Therefore, it is not necessary to inquire about the time, and the time required for the setup process can be reduced.

Further, when the next image data unit is transmitted, which is calculated from the time actually required for transferring the contour data or the image data unit, from the start of the image data transfer to the end of the transmission of the image data unit Depending on the result of the comparison between the total transfer time of the image data and the maximum allowable transfer time requested by the respective environmental information notifications as the transfer time of the image data, the next image for each image quality management server or each image receiving device Since the transfer of the data unit is determined, the transfer failure of the subsequent image data can be accurately predicted, and the transfer failure can be reliably avoided. Defects can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a multipoint image transfer system according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the structure of image data transferred from an image transmitting device to an image receiving device.

FIG. 3 is a functional block diagram of an image quality management server.

FIG. 4 is a sequence diagram illustrating an operation of transferring an image from an image transmitting device to two image receiving devices via an image quality management server.

FIG. 5 is an explanatory diagram showing a connection established between an image transmitting device, an image receiving device, and an image quality management server.

FIG. 6 is an explanatory diagram showing an environment information merge determination table of the image quality management server.

FIG. 7 is a flowchart illustrating a processing operation of the image quality management server.

FIG. 8 is a flowchart showing an image message transfer subroutine of the image quality management server.

[Explanation of symbols]

101: Image transmitting device, 102: Image receiving device, 103
... Image quality management server, 104 ... ATM switch, 10
5 ATM link, 106 CPU, 107 memory
108: quality management program, 109: network access controller, 110: internal bus, 201: image data, 202: image contour data, 203: image data unit, 301: image transfer function, 302: transfer time measurement function, 303 ... Image data transmission function, 304: Image data reception function, 305: Communication quality mapping function, 3
06: Connection control function, 307: Communication quality management database, 308: Message collection timer, 309:
Message merge availability determination function 310 Message creation function 311 Connection management database 31
2 Message collection function, 313 Communication control function, 40
1 ... Environment information request message, 402-404 ... Environment information notification message, 405-407 ... Connection setup processing, 408 ... Outline data, 409 ... Image data unit, 410-412 ... End notification message, 5
01 ... Connection, 701-706 ... Steps in the operation flow of the image quality management server, 801-805 ... Steps in the image message transfer subroutine of the image quality management server.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) H04L 21/28 G06F 13/00 355 H04N 7/173

Claims (7)

(57) [Claims] 1. A connection is established in accordance with a reception environment of each image receiving device arranged at multiple points, and image data is transferred from the image transmitting device to each image receiving device via these connections. In the multi-point image transfer method, an image quality management server is provided between the image transmitting apparatus and the image receiving apparatus for each of a plurality of arbitrary image receiving apparatuses, and the image transmitting apparatuses transmit the image receiving apparatuses before transmitting the image data. The image quality management server receives the environmental information notification returned from any image receiving device in response to the environmental information request from the image transmitting device, and stores it in these environmental information notifications. The plurality of connections that can be aggregated among the connections to each of the image receiving apparatuses are determined based on the reception environment information of each of the image receiving apparatuses.
And transferring the environment information notification of the remaining connections that have not been aggregated and the new environment information notification generated for the new connection obtained by the aggregation to the image transmitting device side. A communication quality parameter is calculated based on the obtained environment information notification, and a request for establishing a connection for image data transfer between itself and the image quality management server is made according to the communication quality parameter. After establishing a connection for image data transfer between itself and the image transmitting apparatus, a communication quality parameter is calculated based on the receiving environment of each of the image receiving apparatuses that has received the environmental information notification, and the communication quality parameter is calculated according to the communication quality parameter. A request for establishing an image data transfer connection between the image receiving apparatus and each of the image receiving apparatuses. 2. The multi-point image transfer method according to claim 1, wherein the image transmission device establishes an image data transfer connection to each image reception device, and thereafter, the outline data or each image data unit constituting the image data. Are sequentially transferred to the image quality management server in a predetermined order. Based on the reception environment information of each image reception device that has received the environment information notification, the image quality management server transmits the contour data or each image data unit from the image transmission device. Are sequentially transferred to each of the image receiving apparatuses in a predetermined order. 3. The multi-point image transfer method according to claim 1, wherein the image quality management server receives an environment information notification returned from any of the image receiving apparatuses in response to an environmental information request from the image transmitting apparatus. And stores the reception environment information of each image receiving device stored in the environment information notification, and establishes a connection for image data transfer between itself and the image transmitting device, and then stores the stored information of each image receiving device. A communication quality parameter provided by the communication network system is calculated based on the reception environment information, and a request for establishing a connection for image data transfer between itself and each of the image receiving apparatuses is made according to the communication quality parameter. Multi-point image transfer method. 4. The multi-point image transfer method according to claim 1, wherein the image quality management server includes a contour indicating the contour of the image among the reception environment information included in the environment information notification received from any of the image receiving apparatuses. Two or more of the following: transfer enable / disable of the data or part of the image data on the receiving side, maximum allowable transfer time allowed by the receiving side as the transfer time of the image data, and display screen resolution of the receiving side when displaying the image data. A multi-point image transfer method, which determines whether connection aggregation is possible or not based on a combination of the above. 5. The multipoint image transfer method according to claim 1, wherein the information notified by the environmental information request and the environmental information notification includes a total length of image data to be transmitted and a length of contour data, and the image quality management. After establishing a connection for image data transfer between itself and the image transmitting device, the server calculates a communication quality parameter based on the receiving environment of each image receiving device, the length of the entire image data, and the length of the contour data. A request for establishing a connection for transferring image data between the image receiving apparatus and the image receiving apparatus in accordance with the communication quality parameter. 6. The multi-point image transfer method according to claim 2, wherein the image transmitting apparatus is configured to perform the following for each image quality management server based on the time actually required to transfer the contour data or the image data unit. When the image data unit is transmitted, calculate the total transfer time from the start of the image data transfer to the end of the transmission of the image data unit, and request the total transfer time and the image data transfer time in the respective environmental information notifications. A multi-point image transfer method, which determines whether or not the next image data unit can be transferred to each image quality management server according to a comparison result with the maximum allowable transfer time. 7. The multi-point image transfer method according to claim 2, wherein the image quality management server comprises:
Based on the time actually required to transfer the contour data or image data unit, calculate the total transfer time from the start of image data transfer to the end of transmission of the image data unit when the next image data unit is transmitted. According to the comparison result between the total transfer time and the maximum allowable transfer time requested in each environmental information notification as the transfer time of the image data, it is determined whether or not the next image data unit can be transferred to each image receiving apparatus. A multi-point image transfer method.