JPH04223673A - Transmitting device - Google Patents

Abstract

PURPOSE:To attain transmitting the encoded data of respective bit rates or grouped encoded data using simultaneously the plural B channels of a connecting ISDN by sampling/encoding picture data form low resolution to high resolution in order by a hierarchical encoding system. CONSTITUTION:Hierarchical encoding processing is given to transmission picture data by an encoding/decoding part 8. The encoded data are transmitted, repeating the subsampling of an original picture, for each data of the respective bit rates of the least significant bit rate encoded data, the more significant bit rate encoded data and the much more significant or the most significant bit rate encoded data wherein the difference between a picture into which they are decoded and the original picture is encoded, in order from the data whose bit rate is lower to the data whose bit rate is higher, by using the plural B channels of a connecting ISDN simultaneously.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission apparatus for transmitting hierarchically encoded image data using an ISDN line.

0002

2. Description of the Related Art Conventionally, in a transmission device such as a facsimile device for transmitting images, the image data to be handled is sequentially encoded for one page. Therefore, it was sufficient to transmit such coded data through one communication channel. On the other hand, transmitting one page of encoded data in parallel through multiple communication channels to increase the image transmission speed has never been done in the past because it is difficult to select and control the division points of the encoded data. Therefore, the transmission speed of image data was limited to the transmission speed of one communication channel.

0003

[Problems to be Solved by the Invention] However, when encoding data using a layered encoding method, which is an effective encoding method for color multivalued images, etc., it is difficult to encode one page of image data from low resolution to high resolution. It is encoded independently for each bit rate. Therefore, there is no problem in transmitting encoded data of different bit rates in different communication phases.

[0004] Furthermore, with the spread of ISDN, it has become possible to easily communicate using multiple channels. Furthermore, due to advances in technology, facsimile devices do not encode images while reading them and transmit them in real time, but instead read images in advance, store the encoded data once, and then transmit the stored data. transmission methods are being adopted.

[0005] For this reason, an environment has been created that is not necessarily restricted to sequential image communication. especially,
When trying to transmit a color multilevel image, even if compression encoding is performed, the amount of data is still enormous compared to the black and white binary data handled by conventional facsimile machines, and there is a need for ways to improve communication speed. It was getting worse.

[0006]

[Means for Solving the Problems] The present invention has been made for the purpose of solving the above-mentioned problems, and has the following configuration as a means for solving the above-mentioned problems. That is, an encoding means for sequentially encoding image data from low resolution to high resolution using a hierarchical encoding method, an accumulating means for individually accumulating encoded data at each bit rate encoded by the encoding means, and and transmitting means for transmitting the encoded data stored in the storage means to another device using a connecting ISDN line, and the transmitting means is for transmitting encoded data of each bit rate or grouped encoded data. Multiple B channels of the connected ISDN are used simultaneously to send one image data.

[0007] For example, furthermore, using the user-to-user information of the communication protocol data unit of the D channel, the transmission means sends a message to the communication partner device using a plurality of B channels.
The apparatus includes notification means for notifying that image data of two documents will be transmitted. Furthermore, the communication partner device and the requested B
A switching means is provided for switching to transmit one document of encoded data using the number of established B channels when all calls on the channels cannot be established.

Alternatively, in response to an incoming call from a communication partner device, coded data received separately from a plurality of B channels may be combined into one
The apparatus includes a decoding means for decoding the image data of one document.

[0009]

[Operation] In the above configuration, the lower bit rate and the higher bit rate of hierarchically encoded data are
By providing a function for parallel transmission using a plurality of N B channels, the apparent communication speed is increased and the time required for communication is shortened.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing an example of the hardware configuration of an embodiment according to the present invention. In the figure, 1 is CP
For example, FIGS. 5 and 6 stored in ROM2
The entire embodiment is controlled according to the program shown in FIG. 2 is a ROM in which the above programs are stored, 3 is a CP
RAM that temporarily stores data for processing by U1
, and the user interface of the SETUP protocol described below.
It is also used when creating and analyzing user information. 4
A device controller controls a scanner 5 and a printer 6 under the control of the CPU 1, a scanner 5 is used to input image data of a document, and a printer 6 prints the image data.

7 is an image memory that temporarily stores image data or its encoded data when reading, printing out, transmitting, receiving, encoding, and decoding image data; 8 is a memory for storing image data; An encoding/decoding unit that performs encoding and decoding processing, 9 a hard disk interface (HDI/F) that controls a hard disk, and 10 a hard disk that is a large-capacity external storage device that stores encoded image data, etc. (HD), 11 is a communication control unit (CCU) that controls the interface with ISDN and controls the transmission and reception of encoded data.The CCU 11 controls the ISDN line 12, and has two B channels and one D channel. enable the use of

Reference numeral 13 denotes a system bus, which is a data bus used for exchanging data other than image data and its encoded data between elements constituting this system. 14 is an image data bus, which transfers image data or encoded data to the device controller 4, image memory 7, encoding/decoding section 8, HDI/F 9, and CC.
It is used to exchange image data or encoded data between U11. An outline of the image data transmission process in this embodiment having the above configuration will be described below.

First, a transmission original is set on the scanner 5, and the transmission original is read from the scanner 5. All the read image data for one transmission is stored in the image memory 7 via the device controller 4. After all the image data for one item is accumulated, the image data is read out at the time of transmission. The read image data is sent to the encoding/decoding section 8 and subjected to hierarchical encoding processing. The encoded data is classified and managed for each bit rate data, and the HDI/
It is stored in the HD 10 via F9.

FIG. 2 shows the storage format of hierarchically encoded document encoded data in the HD 10. As shown in Figure 2, the hierarchically encoded data consists of the lowest bit rate encoded data (D1), which is obtained by repeatedly subsampling the original image to reduce its resolution, and decoding the lowest bit rate encoded data. The encoded data (D2, D3) with a higher bit rate that encodes the difference between the image data and the image data obtained by subsampling the original image, and the difference between the decoded image and the original image are encoded. The encoded data (D4, D5) is encoded at a higher or highest bit rate.

The encoded data of each of the bit rates D1 to D5 are logically independent so that they can be decoded if the encoded data of each bit rate or lower is available. In normal communication, on the transmitting side, encoded data of each of these bit rates is transmitted in order from the lowest bit rate to the highest bit rate.

[0016] On the receiving side, the encoded data is sequentially decoded at the same time as it is received, and once the data of the required resolution is obtained, the reception of the encoded data of the higher bit rate can be stopped. It was developed so that it can be done. Therefore, the encoded data for each bit rate of D1 to D5 is stored separately for each bit rate, as shown in FIG. 2, so that it can be accessed in logically independent units. The data is configured such that it can be identified as encoded data.

In the case of a document consisting of a plurality of pages, D1 to D5 are created for each page, and this is repeated as many times as the number of pages. The encoded data stored in the HD 10 is transmitted to other destination devices via the ISDN line 12 according to a communication protocol controlled by the CCU 11. Since the control sequence of the communication protocol controlled by the CCU 11 is the core process of this embodiment, details will be described later with reference to FIG.

Next, an outline of the reception processing of this embodiment will be explained. Communication requests from the other device are sent via ISDN line 12 D.
Receive calls by channel. Therefore, when the CCU 11 detects an incoming call on the D channel, it establishes a call on the B channel. Subsequently, the encoded data is received by controlling the communication protocol of the B channel that established the call. The received encoded data is temporarily stored in the image memory 7.

When the received data is to be printed out immediately, the received encoded data temporarily stored in the image memory 7 is read out and decoded by the encoding/decoding section 8. The decoded image data is sent to the printer 6 via the device controller 4 and printed. On the other hand, if printing is not done immediately, the encoded data is read out from the image memory 7 as it is,
It is stored in the HD 10 via the HDI/F9.

The encoded data to the HD 10 is stored in the same format as the encoded data stored for transmission as shown in FIG. However, in the case of received data, which bit rate of encoded data exists depends on the document. The detailed operation of this embodiment for performing the above-described transmission and reception processing will be described below. ISD in this example
The N line has a basic interface and is connected to two B channels and one D channel. These two B channels are controlled and used so that one B channel transmits encoded data at a bit rate other than the highest, and the other B channel transmits encoded data at the highest bit rate.

[0021]The user-user information is used in the communication protocol data unit of the D channel in order to inform the receiving device of the other party that data of one document will be transmitted using two B channels. In addition, regarding the call origination sequence, the D channel is used to establish a call for the first B channel, and the communication for each B channel is started when the call setup for both B channels is confirmed. do.

FIG. 3 is a diagram showing an example of the communication control procedure of this embodiment controlled as described above. In FIG. 3, terminal A represents an image transmission device on the transmitting side, and terminal B represents an image transmission device on the receiving side. When a call request occurs at terminal A, a SETUP message P is sent from calling terminal A.
1 is sent. The SETUP message includes the called terminal number, subaddress, transmission capability, consistency confirmation information, etc., and can include user-to-user information in this embodiment.

FIG. 4 shows an example of the data format of this SETUP message. As shown in Figure 4, the protocol identifier, call number, and message type must be included in all messages of the D channel. identify things. Information ranging from transmission capability to higher layer compatibility is information used in the SETUP message, and is used to determine whether communication with the called terminal is possible.

[0024] User-to-user information is used for transmitting information between users. In this embodiment, this user-to-user information is used to notify that data of one document will be transmitted over two B channels. The contents of the user-to-user information include, first, a supplier code indicating the manufacturer of the image transmission device, that is, a manufacturer code, a model code indicating the model of this embodiment, and transmission using the communication method of this embodiment. Communication method information indicating whether or not the communication method is used is set. Subsequently, the oscillation date and time of the document and the document ID are set. The above contents are commonly set in the user information of all SETUP messages issued to perform data transmission of one document. The bit rate of the encoded data of the document is indicated by the data type. This data type is SETUP for setting up the first B channel call.
Not used in messages. This means that if the call setup for the second B channel cannot be established, all encoded data will be transmitted on the first B channel, and if the call setup for the second B channel is successful, the second B channel will be transmitted. This is because the information depends on the call setup of the second B channel, such as transmitting encoded data other than that transmitted by the first B channel.

Such a SETUP message is shown in FIG.
As shown in P1, from terminal A to the network (ISDN)
, the network sends a CALL PROCeed to terminal A, if the B channel is available at this time.
ing (Fig. 3P2) message is sent. At the same time, a SETUP message is delivered to terminal B. Terminal B
The SETUP message received by the user includes transmission capability, consistency confirmation information, and user/user information among the above-mentioned information. Therefore, terminal B that has received the AETPU message determines whether or not to respond based on the received information. Depending on the state of terminal B, it may not be able to respond immediately to the SETUP message. If terminal B cannot respond, AL is sent to notify this.
ERT(P3) is sent. When the network receives such an ALERT message, it sends this message to terminal A to inform terminal A that it is calling terminal B.
Send LERT message.

[0026] Here, if it is determined that communication is possible or if it becomes possible to respond, CONN(
P4) Send a message. This CONN message can also include user-user information. C.O.
The NNP4 message indicates that terminal B can accept the incoming call and requests communication path setup for accepting the incoming call.

The network sends this message to terminal A to notify that terminal B has responded and a communication path has been established. Also, for terminal B, CONN
Sends an ACK (P5) message. Terminal A looks at the user information in the received CONN message, and
Check whether the same communication method, transmission date and time, document ID, and data type as those set in the SETUP message are set. If these match, then it can be known that data communication based on the method of this embodiment is possible.

When the first B channel call is set up in this way, terminal A subsequently sends a SETUP message (P6) to set up the second B channel call. This SETUP message also has the same data format as shown in FIG. 4, and the same data as that set at the time of setting up the first B channel call is set in the user/user information transmission date and time and document ID. However, regarding the data type, data indicating that the second B channel transmits encoded information of the highest bit rate is set.

[0029] In response to this SETUP message, the network sends CALL PROCe to terminal A.
eding message (P7) to terminal B.
Sends a TUP message (P6). Terminal B examines the sent SETUP message. If the terminal cannot respond immediately, it sends an ALERT message (P8) in the same way as P3. If communication is possible,
A CONN message (P9) is sent. In this case, if it is determined that the communication method of this embodiment is possible, the CO
SET P6 in user/user information in NN message
Copy the user/user information data received in the UP message.

[0030] The network sends the CONN message (P
9), sends this CONN message (
P9) and sends a CONN ACK message (P10) to terminal B. Terminal A receives CON
Look at the user/user information in the N message and click the second B.
It is possible to know whether it is possible to transmit encoded data at the highest bit rate on the channel.

[0031] Thus, terminals A and B are in the transfer phase, and in the communication of the two B channels, D1 to D in FIG.
4 bit rate is transmitted. During such communication, if the communication is terminated and disconnected at P11 or P12, the call is released using the D channel as follows. That is, call release is performed by DISC P13,R
Each procedure of EL P14 and RELCOM P15 is performed, and one B channel call is released.

[0032] When the communication of the other B channel is completed, the D channel also transmits DISC P16, RE.
The call is released by each procedure of LP17 and RELCOM P18, and all communication procedures are completed. In this way, after the call release is completed, the state returns to the initial state, that is, the state before the start of call setup.

[0033] Through the communication procedure as explained above, 2
One document data is transmitted in parallel through the B channel of the book. The details of the processing sequence in the transmitting/receiving device for performing such processing will be further explained below using FIGS. 5 and 6. FIG. 5 shows the processing of this embodiment.
2 is a flowchart illustrating an example of a processing sequence performed by a transmitting device.

When the device detects a transmission processing request, first in step S1, it generates user-user information (UUI) in which the transmission date and time and document ID are set. Subsequently, in step S2, D is used to establish the first B channel call.
A channel SETUP message is sent to the ISDN via the CCU 11. Then, in step S3, the ISDN
It enters a state where it waits to receive a CONN message from the line. If the call setup fails, a REL message will be received, so in step S4, it is monitored whether or not a REL message is received.

If an REL message is received during the execution of steps S3 and S4,
The transmission ends. On the other hand, CONN from ISDN
If a message has been received, the B channel call has been established, so the process advances from step S3 to step S5, where the same origination date and time and document ID that were set in the UUI in step S1 are set in the UUI, and further data is set. Enter information indicating that it is the highest bit rate encoded data in the type field and set it.

[0036] In the next step S6, the D channel SETUP for establishing the second B channel call is set to IS.
Send it to the DN and include the UUI created in step S5.
include. Then, in steps S7 and S8 again, the device receives a CONN message from the ISDN line or a REL message similar to steps S2 and S3 described above.
The process moves to monitoring processing to determine whether or not a message has been received.

If a CONN message from ISDN is received during the execution of steps S7 and S8, the second B channel call has been established, and the process advances from step S7 to step S9. Step S
9. The process in step S10 is to transmit image data of one document in parallel through two B channels. First, in step S9, encoded data of bit rates other than the highest bit rate, that is, data D1 to D4 in FIG. 2, is transmitted through the first B channel. In the following step S10, the encoded data of the highest bit rate, that is, the data of D5 in FIG. 2, is transmitted through the second B channel.

When the transmission in either step S9 or step S10 is completed, the process advances to step S12, and the D channel is disconnected and released. Further, when the other transmission is completed, the D channel is disconnected and released in step S13. On the other hand, this step S7 and step S8
If a REL message is received during execution of the process, the process advances from step S8 to step S11. Step S11 is a sequence when only one B channel call can be set in a request for simultaneous use of two B channels. In this case, all encoded data of the document to be transmitted is transmitted using only one B channel, the first B channel. When the transmission of all encoded data is completed, the process advances to step S13, and the D channel is disconnected and released.

The transmitting side image transmission device operates according to the processing sequence described above. Note that steps S1 to S in FIG.
3 corresponds to P1 to P4 in FIG. 3, and includes step S5.
The processing from ~S7 corresponds to P6~P9 in FIG. Similarly,
Step S9 is P11, step S10 is P12, step S12 is P13-P15, and step S13 is P16.
~P18 respectively.

Next, referring to FIG. 6, a communication control sequence performed by the receiving side device in the communication system of this embodiment will be explained. In step S51, the receiving device monitors whether a SETUP message is received from the D channel. When the reception of the SETUP message is detected, proceed to step S.
Proceeding to step 52, the user-user information (UUI) in the SETUP message is analyzed. If it is determined that communication is possible as a result of the analysis, the D channel CON is turned on in the next step S53.
Send N messages. Furthermore, in step S54, reception processing for the B channel is started, and call setup for the D channel is completed.

[0041] In the following steps S55 and S56,
Regarding call setup for the other B channel, monitoring is performed to see if a SETUP message is received from the D channel and whether B channel communication has ended. During this monitoring, if the communication on the B channel set in step S54 is completed, the process proceeds from step S56 to reception processing.

On the other hand, during this monitoring, if reception of SETUP on the D channel is detected, the process advances from step S55 to step S57, and the UUI in the SETUP message is analyzed. Here, the contents of this UUI are
If the calling date and time and document ID are the same as those analyzed in step 2, it can be known that this call setup will be performed using the method of this embodiment to transmit encoded data. Therefore, U
If the contents of the UI are common, the process advances to step S59, where the encoded data of the highest bit rate of the document received by the first B channel is received by the next established B channel, Proceed to step S61.

If the contents of the UUI are not common, the process advances to step S60, and reception processing for the next established B channel is performed, assuming that communication is completely independent of the first B channel communication. Then, the process advances to step S61. In step S61, it is monitored whether communication of any B channel has ended. If it is recognized that the communication of either B channel has ended, the process advances to step S62, and it is determined whether or not the communication of both B channels has ended. If both have not been completed, step S61
Return to , and wait for the other B channel to complete communication.

[0044] If communication with both B channels has ended, the reception process is ended. The receiving side image transmission device operates according to the processing sequence described above. Note that the processing in steps S51 to S53 in FIG. 6 corresponds to P1 to P4 in FIG. 3, and the processing in steps S55 to S58 corresponds to P6 to P9. Similarly, step S54 is P11, step S59 is P11, and step S59 is P11.
12. Steps S61-S62 correspond to P13-P18.

As explained above, according to this embodiment, hierarchically encoded image encoded data can be transmitted over multiple ISDN B channels, making it possible to shorten communication time. The implementation of the communication system according to this embodiment has a low level of technical difficulty due to the characteristics of the encoding system and the ease of controlling a plurality of B channels, which can also be said to be an advantage.

[0046]

[Other Embodiments] In the embodiments described above, the ISD
Although the case of communication using 2B+D channels of the N basic interface has been described, it is also possible to perform parallel transmission of one document using 3 channels of the ISDN temporary group interface.

[0047]

As described above, according to the present invention, hierarchically encoded image encoded data can be transmitted over a plurality of ISDN B channels, and the apparent communication time can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of an embodiment according to the present invention;

FIG. 2 is a diagram showing an example of the storage format of layered encoded data stored in the HD in this embodiment;

FIG. 3 is a diagram showing an example of a transmission control procedure in ISDN in this embodiment,

FIG. 4 is a diagram showing an example of the contents of a D channel call setup protocol data unit in this embodiment;

FIG. 5 is a flowchart showing an example of a data transmission processing sequence of the transmitting side device of the present embodiment;

FIG. 6 is a flowchart showing an example of a data reception processing sequence of the receiving side device of the present embodiment.

[Explanation of symbols]

1 CPU, 2 ROM, 3 RA
M, 4 input/output device controller, 5
Image input scanner, 6 Printer, 7
Image memory, 8 encoding/decoding section, 9 hard disk input/output controller, 10 HD10, 11
CCU, 12 ISDN line, 13
System bus, 14 image data bus

Claims (4)

[Claims] 1. Encoding means for sequentially encoding image data from low resolution to high resolution using a hierarchical encoding method, and storage means for individually accumulating encoded data at each bit rate encoded by the encoding means. and transmitting means for transmitting the encoded data stored in the storage means to another device using a connecting ISDN line, and the transmitting means transmits encoded data of each bit rate or grouped encoded data. Connect ISDN to send one image data for use
A transmission device characterized by simultaneously using a plurality of B channels. 2. The image transmission apparatus according to claim 1, further comprising transmitting image data of one document over a plurality of B channels to the communication partner device using user-to-user information of the communication protocol data unit of the D channel. 1. A transmission device characterized by comprising a notification means for notifying that . 3. In the image transmission device according to claim 2, if all of the requested B channel calls with the communication partner device cannot be established, one document is coded according to the number of established B channels. 1. A transmission device comprising switching means for switching to transmit digitized data. 4. The image transmission device according to claim 2, further receiving an incoming call from a communication partner device and decoding the encoded data received separately from a plurality of B channels as image data of one document. A transmission device comprising a decoding means for decoding.