JPH07221963A - Facsimile communication system - Google Patents

Abstract

PURPOSE:To improve the communication efficiency by adding a frame related to picture data after succeeding pages whose transmission is not finished to a block within a range of the maximum number of frames when the transmission is decided to be finished with the number of frames less than the maximum number of frames. CONSTITUTION:A CPU 2a discriminates whether or not 256 HDLC frames are finished as to image data of a transmission object file designated by the operation of a key entry device 9. When HDLC processing by one page is finished in the stage that the 256 HDLC frames are not finished, no block end processing is implemented so long as the mode is not revised and the HDLC frame processing is continued, then facsimile coding data by plural pages are fetched on one block. Thus, it is possible to send image data of the plural pages in one block, resulting that the communication efficiently is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an error correction function (ECM
Mode: Error Correction Mode)
The present invention relates to a facsimile communication method for performing communication control using the.

[0002]

2. Description of the Related Art Conventionally, in a facsimile communication system in which communication control is performed using an error correction function (ECM mode), a partial page transmission system is adopted in consideration of effective use of lines and memories. In this partial page transmission method, one page of facsimile information (encoded data) can be transmitted up to 2
The 56 frames are divided into blocks each of which is transmitted.

In this case, the number of frames of a partial page (block) is 256 frames except for the final partial page, but the final partial page is usually less than 256 frames. In the ECM mode, the communication control procedure is performed in units of 1 block.

[0004]

However, in the conventional method, since the block division is performed for each page, image data having a small amount of information such that the image data for one page does not reach 256 frames is processed in plural pages. In the case of transmission, the communication control procedure in the ECM mode is performed for each block that is less than 256 frames, and the number of times the communication control procedure is performed is larger than the transmission amount of image data, resulting in a longer communication time. The efficiency of communication was reduced.

Further, when image data of a large number of pages is received, flow control (maximum 60 seconds) and command retransmission may occur due to the ability of data processing and recording speed. In this case, communication efficiency is further reduced. It was

The present invention has been made to solve the above problems, and an object thereof is to improve communication efficiency in a facsimile communication system in which communication control is performed using an error correction function (ECM mode). is there.

[0007]

In order to achieve the above object, the first invention is to frame facsimile-encoded image data together with error correction data into an HDLC format and preset a maximum number of frames in one block. Determining means for determining whether or not the framing of the image data for one page is completed with a number of frames less than the maximum number of frames in the one block in the facsimile communication method for executing the communication control procedure for each block. When the determination unit determines that the framing of the image data for one page is completed with the number of frames less than the maximum number of frames in the one block, the block is not yet included in the maximum number of frames. And an adding unit for adding a frame related to the image data on and after the next page of transmission.

In order to achieve the above object, in the second invention, the judging means in the first invention counts the number of frames involved in framing in the process of sequentially framing the image data of each page. Counting means,
A detection unit for detecting the end of the image data of the page whose frame number is counted by the counting unit, and the count unit detects the end of the image data of one page by the detection unit. When the count value does not reach the maximum number of frames in the one block, it is configured to determine that the framing of the image data for one page is completed with the number of frames less than the maximum number of frames in the one block. ing.

In order to achieve the above object, in the third invention, the additional means in the first or second invention is
Even when the determination unit determines that the framing of the image data for one page is completed with the number of frames less than the maximum number of frames in the one block, the image data of the page for which the framing is completed. When the modes such as the resolution of the image data of the other page that have not been transmitted and the like are different, the processing of adding one frame is avoided and the completion processing of one block is performed.

[0010]

According to the addition means of the first aspect of the invention, when the judgment means judges that the framing of the image data for one page is completed by the number of frames less than the maximum number of frames in one block, the maximum frame By adding a frame relating to the image data of the next page and subsequent pages that have not been transmitted to the block within the range of the number, the image data of a plurality of pages can be converted into one.
One block (partial page) is taken in to reduce the number of blocks, thereby reducing the number of times the communication control procedure is executed and improving communication efficiency.

The judging means according to the second aspect of the invention comprises a counting means for counting the number of frames involved in framing the image data of each page in the process of being sequentially framed, and the counting means counting the number of frames. A detection means for detecting the end of the image data of the existing page, and when the detection means detects the end of the image data of one page, the count value by the counting means is within the one block. When the maximum number of frames is not reached, it is determined that the framing of the image data for one page is completed with the number of frames less than the maximum number of frames in the one block. Then, the adding means operates in the same manner as the first invention based on the determination result.

In the third invention, in the adding means in the first or second invention, the determining means completes the framing of the image data for one page with the number of frames less than the maximum number of frames in the one block. Even if it is determined that the frame addition processing is performed, if the image data of the page for which the framing is completed and the image data of other pages that have not been transmitted have different modes such as resolution, the frame addition process is avoided. By performing the completion processing for one block, it is possible to prevent image data having different modes such as resolutions from being mixed in one block (partial page), and to enable the receiving side to perform appropriate output according to the mode. . Also in the third invention, when the modes such as the resolution are the same, the adding means operates similarly to the first invention to perform the frame adding process.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a facsimile apparatus to which a facsimile communication system according to an embodiment of the present invention is applied.

In FIG. 1, reference numeral 1 is a CG (character generator) circuit, which generates a character pattern to be printed on a report, a page header or the like. A system control unit 2 has a CPU 2a, a ROM 2b, and a RAM 2c, and C
The PU 2a controls the operation of the entire apparatus according to various programs preset in the ROM 2b, such as programs corresponding to the flowcharts of FIGS. 3 to 7 described later.
At this time, the CPU 2a uses the RAM 2c as a work area.

A gamma conversion circuit 3 performs mutual conversion between the CMYK color image and the RGB color image. A color / monochrome conversion circuit 4 performs mutual conversion between a color image and a monochrome image. A pixel density conversion circuit 5 converts the paper size and resolution. Reference numeral 6 denotes a frame memory, and image data encoded by facsimile is expanded for each block. Reference numeral 7 denotes a communication control unit, which controls calling / calling to / from a partner terminal and transmission / reception of image data according to a protocol of a binary code control procedure defined in ITU Recommendation T30 under the control of the CPU 2a.

Reference numeral 8 denotes an I / O control unit, which is a key input device,
It controls input / output devices such as a display device, a scanner device, and a printer device. Reference numeral 9 denotes a key input device, which has a numeral key, a mode setting key, a start button, a stop button, etc., and is used to instruct the facsimile apparatus to perform various operations. The numeric keys are used to input a dial number and to specify a file number of a file in which image data to be communicated is stored.
Reference numeral 10 denotes a display device having an operation display panel 10a composed of a color LCD, which is memory full,
Displays out of paper, ink, communication status, etc.

A scanner device 11 reads a document image according to a mode (paper size, character / photograph, resolution, color / monochrome, etc.) designated by a mode setting key.
A printer device 12 prints image data on paper. Reference numeral 13 denotes a DMA (Direct Memory Access) control circuit, which transfers image data between memories without passing through the CPU 2a.

An image encoding / decoding circuit 14 facsimile-encodes and compresses color and monochrome image data and the like, and decodes and expands the compressed image data and the like. 15 is SCSI (Small Compu
ter System Interface),
It controls the interface with the hard disk. 1
6 is a non-volatile memory such as a hard disk, which is a CPU
Image data and the like are saved in a file format under the control of 2a. An image bus 17 is used to transfer image data and the like. A system bus 18 is used for transferring a system control signal or the like from the CPU 2a.

Communication control in this facsimile apparatus is as follows.
Basically, it conforms to ITU's T4 and T30 recommendations, but differs from ITU's T4 and T30 recommendations in the following two points. That is, (a) Image data format in ECM (error correction mode) defined by the T4 recommendation. (B) Q signal processing and fax message reception processing during ECM specified in the T30 recommendation.

FIG. 2 is a diagram showing a frame format of image data at the time of ECM in this embodiment.
The difference from the T4 recommendation is that one block (1
In the present embodiment, one block (one partial page) is used, while the facsimile encoding 1 or less present in the partial page) is used.
There is no limitation on the facsimile encoded data existing in the above. The facsimile encoded data is data for one physical image page described by the Huffman code defined in the ITU T4 and T6 recommendations.

In FIG. 2, FCD is facsimile encoded data, RTC is a signal indicating the end of facsimile encoded data, RCP is a signal indicating the end of one block, FCS is a frame check (error correction) sequence, and F is F. A flag field indicating the start and end of each frame, A is an address field, C is a control field, and F is a field.
CF is a facsimile control field, and FIF is a facsimile information field. The framing based on the format of FIG. 2 is performed according to the flowchart of FIG.
It is performed under the control of the PU 2a.

That is, the CPU 2a uses the key input device 9
The image data of the file to be transmitted specified by the operation of is HDLC (High
hlevel Data Link Control)
The frame is formed and expanded in the frame memory 6 (step S1), and it is determined whether or not the HDLC frame formation for 256 frames is completed (step S2). as a result,
If the 256-frame HDLC frame conversion is completed, the process proceeds to step S6, and the 256-frame HDLC frame is completed.
If the framing is not completed, HDL for one page
It is determined whether or not the C framing is completed (step S
3).

As a result, if the HDLC framing for one page is not completed, the process returns to step S1 and (2
Perform HDLC framing (for 56 octets). On the other hand, if the HDLC framing for one page is completed, it is determined whether or not the page is the last page (step S4). As a result, if it is the final page, the process proceeds to step S6. On the other hand, if it is not the final page, it is determined whether or not the mode of paper size, character / photo, resolution, color / monochrome, etc. has been changed on the next page (step S5), and if the mode has not been changed,
Returning to step S1, if the mode has been changed, the process proceeds to step S6.

In step S6, three RCP frames are added as one block completion processing. Then, it is determined whether or not the final page is HDLC framed (step S7). If the final page is not HDLC framed, the process returns to step S1. If the final page is HDLC framed, This framing process ends.

As described above, the HDLC for 256 frames
HDL for one page when the framing is not completed
When the C framing is completed, the block completion processing is not performed unless the mode is changed, and the HDLC framing is continued, so that the facsimile coded data of a plurality of pages is captured in one block (partial page). I am trying to do it. Thereby, it becomes possible to transmit image data of a plurality of pages in one block. As a result,
It is possible to reduce the number of blocks as a whole and to reduce the number of times of executing the communication control procedure performed for each block, thereby improving the communication efficiency.

When the mode is changed between pages, the number of HDLC frames for one page is 256.
The reason why the block completion processing is performed even when the number of frames is less than one is because it is presumed that the facsimile-encoded image data does not include mode information such as resolution in the present embodiment. This is to prevent image data having different modes such as resolutions from being mixed in (partial page), and to allow the receiving side to perform appropriate output according to the mode.

Therefore, when the facsimile-encoded image data includes mode information such as resolution, even if the mode is changed between pages, 1
When the number of HDLC frames for a page is less than 256, block completion processing may not be performed, and image data having different modes such as resolution may be mixed in one block (partial page). In this case, the communication efficiency can be further improved as compared with the case where the block completion process is performed by changing the mode between pages.

Next, the transmission control in this embodiment will be described with reference to FIG.
A description will be given according to the flowchart of FIG.

The CPU 2a waits until a transmission command is input by operating the key input device 9 (step S4 in FIG. 4).
1) When a transmission command is input, a predetermined pre-procedure is executed (step S42). Then, it is determined whether or not the error correction method according to the present invention (hereinafter, referred to as extended ECM communication) and the destination terminal device are compatible with respect to paper size, character / photo, resolution, color / monochrome ( If there is no compatibility in step S43), normal transmission processing is performed (step S44), a predetermined post-procedure is executed (step S46), and the transmission control ends.
On the other hand, if there is compatibility, the extended EC shown in FIG.
The M transmission process is executed (step S45), a predetermined post-procedure is executed (step S46), and the transmission control ends.

In the extended ECM transmission process, as shown in FIG. 5, first, the HDLC framed image data is transmitted by the communication control unit 7 (step S401). Then, it is determined whether or not the transmission of the image data for one block is completed (step S402), and if the transmission of the image data for one block is not completed, the process returns to step S401.

On the other hand, if the transmission of the image data for one block is completed, it is judged whether or not the transmission of the image data of the final original (page) is completed (step S403), and the image data of the final original (page) is obtained. Has been sent, PP
The communication control unit 7 is instructed to send S / EOP (end of procedure) (step S404), and step S46 of FIG.
Return to.

On the other hand, if the transmission of the image data of the final document (page) has not been completed, it is determined whether or not the mode of the resolution or the like has been changed in the next block (step S405). As a result, if the mode has been changed, the communication control unit 7 is instructed to send PPS EOM (end of message) (step S406) and waits for a response (step S407). Then, when a response is received, the content of the response is PP including the error frame number.
It is determined whether it is R (partial page request) or MCF (message confirmation) (step S408).

As a result, if the response content is MCF (message confirmation), the procedure returns to step S42 in FIG. 4 to perform the pre-procedure. On the other hand, the response content is PPR (partial page request)
If so, a retransmission frame is set (step S41
2) Return to step S401, and instruct the communication control unit 7 to transmit the retransmission frame.

When it is determined in step S405 that the mode has not been changed, the communication control unit 7 is instructed to transmit the PPS / MPS (multi-page signal) (step S409), and the response is waited ( Step S4
10). When the response is received, it is determined whether the response content is PPR (partial page request) or MCF (message confirmation) (step S41).
1). In step S409, the PPS / NULL specified in the ITU T30 recommendation is not transmitted, but the PPS / NULL is transmitted.
MPS is being sent, but PPS / NULL as recommended
May be sent. That is, if there is no mode change,
Whether to send PPS / NULL or PPS / MPS has no meaning in this extended ECM transmission. In the conventional ECM transmission, it is necessary to indicate the block delimiter with the PPS / NULL or PPS / MPS command, and also to indicate the delimiter of the facsimile encoded data (physical one page). ,
In extended ECM transmission, PPS / MPS (or PPS / N
This is because the (ULL) command simply indicates a block delimiter.

In step S411, the response content is PPR.
If it is determined to be a (partial page request), a retransmission frame is set (step S412), and step S4
Returning to step 401, the retransmission frame is transmitted by the communication control unit 7. On the other hand, when the response content is determined to be MCF (message confirmation), the next block is set (step S413), the process returns to step S401, and the block is transmitted by the communication control unit 7. In this extended ECM transmission method, PPS / MPS (or PPS / MPS) is used.
The page counter set in the FIF (facsimile information field) of the command (NULL may be used) has no meaning, and only the block counter is used. That is, by checking the block counter,
Check if the image data is sufficient. On the other hand, the facsimile encoded data (physical page number) is PPS.E.
The page counter set in the FIF of the OM or PPS / EOP command is used for verification.

Next, the reception control in this embodiment will be described with reference to FIG.
Description will be given according to the flowchart of FIG. 7.

The CPU 2a waits for the image data to be received (step S61 in FIG. 6), and when the image data is received, executes a predetermined pre-procedure (step S62).
Then, it is determined whether or not the extended ECM transmission function and the transmission source terminal are compatible with respect to paper size, characters / photographs, resolution, color / monochrome (step S
63) If there is no compatibility, normal reception processing is performed (step S64), a predetermined post-procedure is executed (step S66), and the transmission control ends. On the other hand, if there is compatibility, the extended ECM reception process shown in FIG. 7 is executed (step S65), a predetermined post-procedure is executed (step S66), and the reception control ends.

In the extended ECM receiving process, as shown in FIG. 7, first, the HDLC framed image data is received via the communication control unit 7 (step S601). Then, it is determined whether the image data for one block has been received (step S602), and if the image data for one block has not been received, the process returns to step S601.

On the other hand, when the image data for one block has been received, it is next determined whether or not PPS / MPS (multi-page signal) has been received (step S603).
If you do not receive these, further PPS / EOM
It is determined whether or not (end of message) is received (step S604), and if these are not received, it is further determined whether or not PPS / EOP (end of procedure) is received (step S605). As a result, this PPS / EO
If P (procedure end) is not received, step S6
When it is received, the process returns to step S66 of FIG.

In step S604, the PPS / EOM
When it is determined that (end of message) is received, F
Whether or not there is a communication error is determined based on CS (frame check sequence) (step S606). As a result, if there is no communication error, MCF (message confirmation)
Is sent to the transmission source (step S607), and the process returns to step S62 in FIG. On the other hand, if there is a communication error, PPR
(Partial page request) is sent to the sender (step S6
09), and returns to step S601.

When it is determined in step S603 that the PPS (partial page signal) and the MPS (multipage signal) have been received, it is determined whether or not there is a communication error based on the FCS (frame check sequence) (step S608). ). As a result, if there is no communication error, MCF
(Message confirmation) is sent to the transmission source via the communication control unit 7 (step S610), the process returns to step S601, and if there is a communication error, a PPR (partial page request) is transmitted via the communication control unit 7 to the transmission source. To send (step S
609) and the process returns to step S601.

As described above, since the communication control in this facsimile apparatus is basically performed in accordance with the ITU's T4 and T30 recommendations, software is required for the facsimile apparatus based on the ITU T4 and T30 recommendations. It can be realized without any increase in cost, with only a slight change.

The present invention is not limited to the above embodiment, and the maximum number of frames in one block is 25, for example.
Instead of using 6 frames, the maximum number of frames may be set arbitrarily, for example, the maximum number of frames in one block may be 64, as defined in the ITU Recommendations T4 and T30. Further, the facsimile encoded data can be described by a code other than the Huffman code. When the mode is changed between pages of the facsimile encoded data by providing a field for registering the mode (resolution, document width, etc.) of the encoded image data in the facsimile encoded data. However, it is also possible to transmit coded data of different modes in a mixed manner in the same block.

[0044]

As described above, according to the present invention,
Communication efficiency can be improved in a facsimile communication system in which communication control is performed using an error correction function (ECM mode).

More specifically, according to the first invention, the image data for one page is framed by the judging means.
When it is determined that the process is completed with the number of frames less than the maximum number of frames in the block, the adding unit adds a frame related to the image data of the next page or later that has not been transmitted to the block within the range of the maximum number of frames. It is possible to capture image data of a plurality of pages in one block (partial page) and reduce the number of blocks, thereby reducing the number of times the communication control procedure is executed and improving communication efficiency.

According to the second aspect of the invention, when the count value by the counting means does not reach the maximum number of frames in one block at the time when the end of the image data of one page is detected by the detecting means, the determining means Determines that the framing of the image data for one page has been completed with a number of frames smaller than the maximum number of frames in one block, and the adding means operates based on this determination result in the same manner as in the first aspect of the invention. Thereby, it becomes possible to improve communication efficiency.

According to the third invention, the adding means is
Even when the determination unit determines that the framing of the image data for one page is completed with the number of frames less than the maximum number of frames in one block, the image data of the page for which the framing is completed and untransmitted When the mode such as the resolution is different from the image data of the other page, the mode such as the resolution is set in one block (partial page) by avoiding the frame addition process and performing the completion process of one block. Avoid mixing different image data,
Allow the receiving side to perform appropriate output according to the mode.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a frame format of image data in ECM (error correction mode).

FIG. 3 is a flowchart showing a frame processing (block processing) of image data.

FIG. 4 is a flowchart showing transmission control.

5 is a flowchart showing an extended ECM transmission process in step S45 of FIG.

FIG. 6 is a flowchart showing reception control.

FIG. 7 is a flowchart showing an extended ECM receiving process in step S65 of FIG.

[Explanation of symbols]

 2 ... System control unit 2a ... CPU 2b ... ROM 2c ... RAM 6 ... Frame memory 7 ... Communication control unit 9 ... Key input device 11 ... Scanner device 14 ... Image encoding / decoding circuit 16 ... Hard disk

Claims (3)

[Claims] 1. A facsimile communication method in which facsimile-encoded image data is framed together with error correction data into an HDLC format and a maximum number of frames in one block is preset and a communication control procedure is executed for each block. Determination means for determining whether or not framing of the image data for one page is completed with a frame number smaller than the maximum number of frames in the one block, and framing of the image data for one page by the determining means. When it is determined that the process has been completed with the number of frames less than the maximum number of frames in the one block, an adding unit that adds a frame relating to the image data of the next page and subsequent pages that have not been transmitted to the block within the range of the maximum number of frames. And a facsimile communication method characterized by being provided. 2. The determining means counts the number of frames relating to framing in the process of sequentially framing the image data of each page, and the page whose number of frames is counted by the counting means. Detecting means for detecting the end of the image data, and when the detecting means detects the end of the image data of one page, the count value by the counting means becomes the maximum number of frames in the one block. When not reached, 1
2. The facsimile communication system according to claim 1, wherein it is determined that the framing of the image data for one page has been completed with the number of frames less than the maximum number of frames in the one block. 3. The addition means is 1 by the determination means.
Even when it is determined that the framing of the image data for a page is completed with the number of frames less than the maximum number of frames in the one block, the image data of the page for which the framing is completed and other untransmitted 3. The facsimile communication system according to claim 1 or 2, wherein when the mode such as the resolution of the page image data is different from the image data of the page, the addition process of the frame is avoided and the completion process of one block is performed.