JPH07297978A - Image transmitter - Google Patents

Abstract

PURPOSE:To make an image transmitter which is not provided with a page memory and to attain transmission time which is close to intermemory communication, in an image transmission means transmitting the data encoded by the system such as the arithmetic codes, which are adopted in a JBIG system. CONSTITUTION:The image data read by an original reading means 7 is encoded by an encoding means 3 such as a JBIG, etc., and the encoded data is stored in a code buffer 1. An arithmetic, control means 5 calculates the threshold of the data quantity within a code buffer 1 which is necessary at the time of starting communication from transmission speed and imparts the threshold to a threshold detection means 2. When the threshold detection means 2 detects that the code data of threshold amount is stored, an arithmetic control means 5 connects a line by a transmission means 8 and starts a transmission. At this time, because code data is already stored in the code buffer 1, the data waiting time in communication can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coded image transmitting apparatus such as an arithmetic code used in the JBIG system.

[0002]

2. Description of the Related Art Conventionally, in G3 facsimiles, etc., M
When transmitting data encoded by the H, MR, or MMR encoding method, the code generation speed is higher than the transmission speed on the line. Therefore, when transmitting an original, the original is read and encoded while being encoded in real time. The method of doing is common.

[0003]

However, in the case of performing the arithmetic coding adopted in the JBIG method, when the dominant symbols are continuous, there is a case where the code is not continuously generated for a certain period of time. If the generated code data from the rectifier is transmitted as it is, a waiting time occurs in the communication protocol, and it takes a very long communication time as compared with the case of having a code memory for one page.

Therefore, the present invention is an image transmitting apparatus for transmitting data encoded by an arithmetic code or the like adopted in the JBIG system, which does not have a page memory even when dominant symbols are continuous, and An object of the present invention is to provide an image transmitting device that can achieve a transmission time close to that of communication between memories.

[0005]

According to a first aspect of the present invention, there is provided an image transmitting apparatus for transmitting an arithmetically encoded image through a communication path, wherein the image is encoded by an arithmetic code for several lines. A code buffer for accumulating the encoded data, a threshold setting means for setting a threshold of the amount of code data in the code buffer required at the start of communication depending on the encoding rate and the transmission rate, and the encoding stored in the code buffer Threshold detection means for detecting that the data amount exceeds the threshold, control means for sending a transmission start signal by a signal from the threshold detection means, and a communication path is selected by the transmission start signal, the code data And a transmission means for transmitting.

The image transmitting apparatus according to claim 2 is the JBI.
In an image transmitting apparatus that transmits an image arithmetically encoded by the G method via a communication path, the output of a JBIG encoding unit that arithmetically encodes by the JBIG method is used to temporarily encode the encoded data of the image according to the transmission speed. Is stored in the code buffer, and after a predetermined storage amount is obtained, a communication path is connected and the code data is transmitted.

[0007]

According to the first aspect of the present invention, the threshold value of the code data amount in the code buffer required at the start of communication is set according to the coding rate and the transmission rate. Then, the coded data of the image coded by the arithmetic code for several lines is accumulated in the code buffer, and when it is detected that the amount of coded data stored in the code buffer exceeds the threshold value, the detection signal In response to the transmission start signal, the communication path is selected by the transmission start signal, and the code data is transmitted.

According to a second aspect of the present invention, the output of the JBIG encoding means for arithmetically encoding in the JBIG system is temporarily stored in the code buffer as the encoded data of the image in accordance with the transmission speed, and a predetermined storage amount is obtained. After that, the communication path is connected and the code data is transmitted.

[0009]

Embodiments of the image transmitting apparatus of the present invention will be described below.

FIG. 1 is a block diagram of an image transmitting apparatus using the JBIG encoding system according to an embodiment of the present invention, and FIG. 2 is a control program for an image transmitting apparatus using the JBIG encoding system according to the embodiment of the present invention. It is a flowchart of.

In FIG. 1, the operation control means 5 composed of a microcomputer controls the entire system and calculates the threshold value of the amount of generated codes at the start of transmission. The original reading means 7 reads the original one line at a time by sequentially scanning from the upper left end of the original.
It is a normal scanner. In the present embodiment, an example in which a scanner is connected as the document reading means 7 will be described.
When the present invention is carried out, any means for outputting an image may be used. The line buffer 6 can sequentially store the output of the document reading means 7 in line units, and can store image data for several lines. The JBIG encoding means 3 receives the encoding start signal from the arithmetic control means 5,
It is an encoder that generates encoded data by the JBIG encoding method.

The JBIG encoding means 3 comprises a code buffer 1
Each time one byte of encoded data encoded by the JBIG encoding method is generated, it is written and an address increment signal is sent to the address control means 4. Address control means 4
Is an address generating means for the JBIG encoding means 3 to write the encoded data into the code buffer 1.
The address is incremented for each address increment signal from the G encoding means 3. The threshold detection unit 2 detects the amount of encoded data generated in the code buffer 1 by constantly monitoring the address of the address control unit 4, and the arithmetic control unit 5 sets a threshold value of the accumulated amount of encoded data. When the threshold is exceeded, the arithmetic control means 5
The signal is output to.

Upon detection of the transmission start signal from the arithmetic and control unit 5, the transmitting unit 8 connects a communication line 9 of a telephone line, a wire such as an optical fiber, a wireless communication such as an optical communication, an electric wave, etc. , The encoded data is read from the code buffer 1 and transmitted.

Further, the structure of the main part will be described.

The JBIG encoding means 3 comprises an arithmetic control means 5
Is a coder that generates coded data by the JBIG coding method in response to a coding start signal from
Every time a byte is generated, coded data is written in the code buffer 1 and an address increment signal is sent to the address control means 4. The address control means 4 generates an address for the JBIG encoding means 3 to write the encoded data in the code buffer 1, and increments the address by an address increment signal from the JBIG encoding means 3.

Here, the encoded data output from the JBIG encoding means 3 is not generated at fixed time intervals, so in order to shorten the communication time, a fixed amount of codes is stored in the code buffer 1. It is necessary to start transmission after the encoded data is stored. That is, the JBIG encoding means 3
Even if the encoded data from is not output at regular intervals, for example, if 120 bytes of encoded data output is guaranteed in 1/10 seconds, it is calculated from the transmission rate and transmitted in 1/10 seconds. If the communication is started at the time when the encoded data of 1 is accumulated in the code buffer 1, the code generation rate is usually sufficient for the transmission time.
The encoding waiting time during communication will be deleted.

The calculation control means 5 calculates the threshold of the generated code amount for starting the transmission from the encoded data generation rate and the transmission rate of the JBIG encoding means 3, and as described above, 1 / Assuming that 120 bytes of encoded data output is guaranteed for 10 seconds, the amount of encoded data for transmission of 1/10 seconds is 120 bytes at the transmission rate of 9600 bps, and is 1/2 at the transmission rate of 4800 bps. Is 60 bytes, and the encoded data amount proportional to this transmission rate value is given to the threshold value detecting means 2 as a threshold value. In this embodiment, the transmission rate and the encoded data amount of the threshold value proportional to the transmission rate are stored as a map.
Therefore, if the transmission speed of the communication path 9 to which the transmission means 8 is connected or the reception speed of the receiving device side is determined, the encoded data amount of the threshold value is determined accordingly.

The threshold detecting means 2 detects the encoded data amount generated in the code buffer 1 by constantly monitoring the address of the address control means 4. Then, the generated encoded data amount is compared with the threshold value given from the arithmetic control means 5, and when the generated encoded data amount exceeds the threshold value, the threshold value detecting means 2 sends a detection signal to the arithmetic control means 5. To do. The arithmetic control means 5 sends a transmission start signal to the transmission means 8 in response to the detection signal of the threshold value detection means 2.

Next, the operation of the image transmitting apparatus using the JBIG encoding system of this embodiment will be described with respect to each block and the operation control means 5.

First, the sender sets an original to be sent on the original reading means 7, and this is detected by a sensor (not shown) (step S1), and a destination number, original density, and reading resolution are operated by an operation panel (not shown). Etc.,
When the start switch is pushed (step S2), the arithmetic and control unit 5 detects that the start switch is pushed,
A reading start signal is sent to the document reading means 7.

The document reading means 7 reads the document one line at a time from the upper left corner of the document by the sequential scanning method, and writes one line of image data in the line buffer 6 in response to a read start signal from the arithmetic control means 5. The line buffer 6 can sequentially store the output of the document reading means 7 line by line, and can store image data for several lines. When the document reading unit 7 finishes writing one line in the line buffer 6, the arithmetic control unit 5 detects whether the line buffer 6 is full, and if not, sends a reading start signal to the document reading unit 7 again, This operation is repeated until the line buffer 6 is full. If the image data of one line or more exists in the line buffer 6, the arithmetic control means 5 sends an encoding start signal to the JBIG encoding means 3 to start the encoding of the image data for each line. Then, the image data amount of the line buffer 6 is detected each time encoding is completed, and if the image data of one line or more is present, JBI is again detected.
A coding start signal is sent to the G coding means 3. This operation is repeated until the reading of the original is completed (steps S3 to S5).

The JBIG encoding means 3 comprises an arithmetic control means 5
The coded data is generated by the JBIG coding method in response to the coding start signal from, and the coded data is written in the code buffer 1 every time one byte of coded data is generated. Furthermore,
If there is image data of one line or more in the line buffer 6, the encoded signal is sent to the JBIG encoding means 3,
The image data for each line is encoded (steps S6 to S8).

During this time, the JBIG encoding means 3 sends an address increment signal to the address control means 4 every time the image data for each line is encoded, and the address control means 4 causes the JBIG encoding means 3 to perform a code buffer. The address for writing the encoded data to 1 is incremented. Therefore, the threshold value detecting means 2 can determine the amount of coded data accumulated in the code buffer 1 by looking at the address difference of the coded data stored in the code buffer 1. Since the encoded data generation rate and the transmission rate of the JBIG encoding means 3 are known, the threshold value determined by the encoded data generation rate and the transmission rate is set in the threshold value detection means 2 (step S9). And
The threshold value detection means 2 compares the set threshold value with the current encoded data amount stored in the code buffer 1 to determine whether the encoded data amount is equal to or larger than a predetermined threshold value (step S10). When the encoded data amount currently stored in the code buffer 1 is compared and it is determined that the encoded data amount is equal to or more than a predetermined threshold value, the arithmetic control unit 5 sends a transmission start signal to the transmission unit 8. Send out. In response to this, the transmitting means 8 receives the transmission start signal, connects the communication path 9 to the other party to communicate with, reads the encoded data from the code buffer 1, and transmits. In addition,
When it is determined that the amount of encoded data is equal to or larger than the predetermined threshold value, the arithmetic control means 5 sends a transmission start signal to the transmitting means 8, but the transmitting means 8 has already received the signal and transmitted. Occasionally, the transmission start signal will not be transmitted in duplicate (steps S11 and S).
12). Then, this operation is continued until the transmission of all encoded data is completed (step S13).

As described above, the image data read by the document reading means 7 is coded by the coding means 3 such as JBIG, and the coded data is stored in the code buffer 1. The calculation control means 5 calculates a threshold value of the amount of data in the code buffer required at the start of communication from the code conversion rate and the transmission rate, and gives it to the threshold value detection means 2. When the threshold detecting means 2 detects that the threshold amount of code data is accumulated, the arithmetic control means 5 connects the line by the transmitting means 8 and starts the transmission. At this time, since the code data is already stored in the code buffer 1, unnecessary time occupied by the communication path 9 due to waiting for the code data after the connection of the communication path 9 can be omitted.

That is, when the transmission means 8 which has received the transmission start signal connects the line to the other party to communicate and starts communication, a certain amount of code data is already stored in the code buffer 1. , It is possible to omit an extra communication time due to waiting for code data after the line is connected. Also, the code buffer 1
Can be transmitted without having to have a capacity as large as the image memory capacity for one document.

As described above, in the image transmitting apparatus of the above embodiment, the image transmitting apparatus for transmitting the arithmetically encoded image using the JBIG encoding method through the communication path 9 uses the arithmetic codes for several lines. A code buffer 1 for storing coded data of coded images, and the code buffer 1 required at the start of communication depending on the coding rate and the transmission rate.
Threshold value setting means for setting the threshold value of the code data amount in the step S9, threshold value detecting means 2 for detecting that the coded data amount stored in the code buffer 1 exceeds the threshold value, and the threshold value detection An arithmetic and control means 5 for transmitting a transmission start signal in response to a signal from the means 2 and a transmission means 8 for connecting a line by the transmission start signal and transmitting the code data are provided. It can be one example.

Therefore, the image such as the image data read by the document reading means 7 is encoded by JBIG or the like, and the encoded data is stored in the code buffer 1.
The arithmetic control unit 5 calculates a threshold value of the amount of data in the code buffer 1 required at the start of communication from the encoding speed and the transmission speed, and supplies it to the threshold value detecting unit 2. When the threshold detecting means 2 detects that the threshold amount of code data has been accumulated, the arithmetic control means 5 connects the communication path 9 by the transmitting means 8 and starts the transmission. At this time, since the code data is already stored in the code buffer 1, when the connection of the communication path is completed, the communication is promptly performed, and the time to wait for the data to be transmitted after the connection of the communication path is completed can be shortened. That is, since the communication path is connected after a certain amount of data to be transmitted is stored in the code buffer 1, the encoded code data waiting time can be omitted. Further, it is not necessary to have a large memory capacity such as an image memory for one original, and the means is simplified.

In the above embodiment, the threshold value setting means comprising step S9 sets the threshold value of the code data amount in the code buffer 1 required at the start of communication depending on the coding speed and the transmission speed. Is usually standardized, so that if the coding speed of the device is determined, the maximum memory capacity is determined. Therefore, the threshold value can be fixed to a specific value.

That is, the image transmitting apparatus for transmitting the arithmetically encoded image using the JBIG encoding method of the above embodiment via the communication channel 9 is the JBIG type arithmetic encoding JB.
The output of the IG encoding means 3 temporarily stores the encoded data of the image in the code buffer 1 according to the encoding rate and the transmission rate, and after a predetermined accumulation amount is obtained, the line is connected, and The code data may be transmitted, and this may be the embodiment of claim 2.

Therefore, the encoded data is accumulated in the code buffer 1, and when the threshold value of the data amount in the code buffer 1 required at the start of communication is reached, the arithmetic control means 5 connects the communication path 9 by the transmission means 8. , Start sending. At this time, since the code data is already stored in the code buffer 1, when the connection of the communication path 9 is completed, the communication is promptly performed, and the time to wait for the data to be transmitted after the connection of the communication path 9 is completed is shortened. it can. Therefore, since the communication path 9 is connected after a certain amount of data to be transmitted is stored in the code buffer 1, the waiting time for encoded code data can be omitted. Further, it is not necessary to have a large memory capacity such as an image memory for one original, and the means is simplified.

By the way, when the present invention is carried out, the communication path 9 output from the transmitting means 8 of the above embodiment is selected from telephone line, wire such as optical fiber, optical communication, and radio such as radio wave. You may.

Further, the threshold setting means comprising step S9 for setting the threshold of the code data amount in the code buffer 1 required at the start of communication according to the coding rate and the transmission rate of the above-mentioned embodiment is from the threshold detecting means 2. The operation control means 5 for sending a transmission start signal by a signal is provided with that function, but when the present invention is carried out, it is not limited to the threshold value detection means 2, but the address control means 4, threshold value detection. The arithmetic control unit 5 can also have the function of the unit 2.

[0033]

As described above, in the image transmitting apparatus of the first aspect, the threshold value of the code data amount in the code buffer required at the start of communication is set according to the coding rate and the transmission rate. Then, the encoded data of the image encoded by the arithmetic code for several lines is accumulated in the code buffer,
When it is detected that the amount of encoded data stored in the code buffer exceeds the threshold value, a transmission start signal is transmitted by the detection signal, a communication path is selected by the transmission start signal, and the code data is transmitted. To do.

Therefore, the encoded data is accumulated in the code buffer, and the arithmetic control means calculates the threshold value of the data amount in the code buffer required at the start of communication from the encoding rate and the transmission rate, and detects the threshold value. Give to the means. When the threshold detection means detects that the threshold amount of code data has been accumulated, the arithmetic control means connects the communication path by the transmission means and starts transmission. At this time, since the code data is already stored in the code buffer, when the connection of the communication path is completed, the communication is promptly performed, and the time to wait for the data to be transmitted after the connection of the communication path is completed can be shortened. Moreover, it is not necessary to have a large memory capacity such as an image memory for one original.

In the image transmitting apparatus according to the second aspect, the JB
The output of the JBIG encoding means for arithmetically encoding by the IG system is used to temporarily store the encoded data of the image in the code buffer according to the transmission speed, and after the predetermined storage amount is obtained, the communication path is connected. The code data is transmitted.

The encoded data is stored in the code buffer,
When the threshold of the amount of data in the code buffer required at the start of communication is reached, the communication path is connected and transmission is started. At this time, since the code data is already stored in the code buffer, when the connection of the communication path is completed, the communication is promptly performed, and the time to wait for the data to be transmitted after the connection of the communication path is completed can be shortened. Therefore, since the communication path is connected after a certain amount of data to be transmitted is stored in the code buffer, the encoded code data waiting time can be omitted.

[Brief description of drawings]

FIG. 1 is a block diagram of an image transmitting apparatus using a JBIG encoding method according to an embodiment of the present invention.

FIG. 2 is a flowchart of a control program of an image transmitting apparatus using the JBIG encoding method according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 code buffer 2 threshold value detection means 3 JBIG encoding means 4 address control means 5 arithmetic control means 6 line buffer 7 document reading means 8 transmission means 9 communication path

Claims (2)

[Claims] 1. An image transmitting apparatus for transmitting an arithmetically encoded image via a communication path, a code buffer for accumulating encoded data of an image encoded by arithmetic code for several lines, and an encoding speed. And threshold setting means for setting a threshold of the code data amount in the code buffer required at the start of communication according to the transmission speed, and threshold detection for detecting that the coded data amount stored in the code buffer exceeds the threshold. Means, a control means for transmitting a transmission start signal in response to a signal from the threshold detection means, and a transmission means for connecting a communication path by the transmission start signal and transmitting the code data. Image transmission device. 2. An image transmitting apparatus for transmitting an image, which is arithmetically encoded by the JBIG system, via a communication path, wherein the output of a JBIG encoding means, which is arithmetically encoded by the JBIG system, is coded according to the transmission speed. An image transmitting apparatus, wherein the coded data is temporarily stored in a code buffer, and after a predetermined amount of storage is obtained, a communication path is connected and the coded data is transmitted.