JPS61105172A - Line skip type facsimile equipment - Google Patents

Abstract

PURPOSE:To improves the transmission efficiency without omitting the amount of information, in regard to acsimile equipment in conformity with the recommendations of International Telegraph and Telephone Consultative Committee (CCITT), when same picture signal lines are continuous, by adding information on the number of the continuous same picture signal lines subsequent to the picture signal encoding bit. CONSTITUTION:When a continuous line number encoding request K is turned on, encoder 5 turns on the counted value transfer request M to the continuous line number counting circuit 6 and receives the counted value N. After delivering the counted value N, the continuous line number counting circuit 6 is initialized and starts the subsequent counting. The encoder 5 outputs N bits of '1' as special code in accordance with the counted value N and the code data Q in accordance with the code transfer clock R to a buffer memory 7. If the counted value N is '0' at that time, the encoder 5 does not output the special code and turns on the special code sending completion L and off the counted value transfer request M assuming that the coding is completed. Normally it is judged that the coding is completed when the special codes of the counted value N are completely sent.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to facsimile devices, and more particularly to facsimile devices that comply with the recommendations of the International Telegraph and Telephone Confederation (CCITT).

(Prior art and its problems) A binary white/black facsimile image signal obtained by binary quantizing image signal information and sequentially sampling it into pixels is encoded and transmitted. Furthermore, upon reception, a configuration is used in which encoded data transmitted is decoded to reproduce and record a nine-dimensional facsimile image signal. The encoding methods used at this time include the one-dimensional MH (modified Huffman) encoding method and the two-dimensional MR (modified read) encoding method shown in CCITT recommendation T4. -Depending on the run length of white/black pixels occurring in the facsimile image signal in the -dimensional MH encoding method.

This is a method of converting and transmitting a variable length code called an MH code.This variable length code uses a statistical method to calculate the run lengths that occur in the document.2 The run lengths that occur more frequently are determined by the shorter code bit number. Configured to assign. In addition, in the two-dimensional MR encoding method, the correlation between image signals between lines in the sub-scanning direction is utilized, and a code indicating the distance between pixel change points between two lines, called a mode code, is used in addition to the MH code for encoding processing. This is a method for transmitting data. By performing such encoding processing, general facsimile apparatuses suppress the redundancy of facsimile image signals and shorten transmission time.

However, in such encoding, a method is usually used in which the amount of information contained in the facsimile image signal is left intact so that the original facsimile image signal can be easily reproduced when decoded on the receiving side. . Therefore, if the facsimile image signal is complex, the number of encoded bits will be large, and if it is simple, the number of encoded bits will be small. This difference causes the transmission time to change. In addition, as a means to further improve transmission efficiency, there is a method of transmitting by appropriately switching the scanning line density depending on the image information density of the original image. This method can shorten transmission time by reducing the scanning line density when the original image is simple, but it also coarsely scans the two-character area, resulting in a loss of information and deteriorating image quality. There are drawbacks.

Documents generally consist of a white area and a text area.

Information is represented by character areas. Therefore, in order to improve transmission efficiency without losing the amount of information.

All you have to do is process the white area efficiently. However, this method has the drawback that it is effective only when one line of facsimile image signal is completely white, and that the transmission time cannot be shortened if the document has small margins. Also, for general facsimile machines, the minimum transmission time for one line is defined as 20m.
5ei line (CCITT recommendation) is the standard. The number of encoded bits transmitted during the minimum transmission time of one line is determined by the line speed and is generally called the minimum number of transmitted bits.

This minimum number of bits to be transmitted is the total number of bits of a special code called an EOL code indicating the beginning of one line, the number of encoded bits of the image signal of one line, and the number of fill bits. Here, the fill bit is added only when the sum of the number of encoded bits of one line and the number of EOL code bits is less than the minimum number of transmission bits, and consists of 1 bit of "°C".

Therefore, as long as the method described above is used, no matter how simple the document is, it will not be possible to transmit it faster than the time defined by the minimum transmission time for one line. In other words, even if redundancy is suppressed through encoding.

This is because if the number of encoded bits is less than the minimum number of transmission bits, Fill is inserted unconditionally, reducing transmission efficiency.

(Objective of the present invention) The object of the present invention is to focus on the correlation between the amount of information in the white area and character area of two images and the image in the sub-scanning direction, and to improve the transmission efficiency without losing the amount of information. The purpose of the present invention is to provide a line-skip type facsimile machine that can perform the following functions.

(Structure of the present invention) According to the present invention, if the reference numerals given in the drawings showing the structure of the embodiment of the present invention are adopted, the means for temporarily accumulating a series of image signals consisting of white/black binary image signals ( 1), means for detecting the presence or absence of a change in the image signal in the sub-scanning direction (3), means for counting the number of consecutive lines of the same image signal (6), and means for encoding the image signal line by line. The first encoder (
4), a second encoder (5) for outputting a special code indicating the number of consecutive identical picture signal lines, a transmission bit counting means (8) for ensuring the minimum transmission time of one line, and a line. A transmission section (Fig. 1) consisting of a speed matching buffer memory (7) and a speed matching buffer memory IJ (7L) for receiving encoded data from two lines A first decoder (101) for reproducing an image signal, and a second decoder (102) for decoding a special code indicating the number of consecutive lines of the same image signal.

A line-skip type facsimile apparatus is obtained, which includes a receiving section (FIG. 2) comprising a recording control means (103) capable of controlling recording of the same image signal a plurality of times.

(Example) Examples of the present invention will be described in detail below with reference to the drawings.

The figure is a block diagram of a line-skip facsimile machine that is an embodiment of the present invention, where ``■'' indicates a transmitting section, and ``■'' indicates a receiving section. First, the transmitter I will be explained. This transmitter includes a line memory section 1, a line memory write/read control circuit 2, a change detection circuit 3, an encoder 4, and an encoder 5.

A continuous line number counting circuit 6 and a buffer memory 7.

It consists of a transmission bit number counting circuit 8.

Before explaining the overall operation, the functions of each part will be explained first. The line memory unit 1 is a circuit for temporarily storing the white/black binary image signal A transferred from the 9-image signal reading unit line by line, and is a line memory for multiple lines so that writing/reading can be performed simultaneously. It functions as a buffer memory for speed matching between the Karanashi one-picture signal reading section, the encoder 4, and the change detection circuit 3.

The line memory write/read control circuit 2 includes a line memory section l.
Select the read line and write line.

Controls writing and reading. If writing is possible, turn on 1 line transfer request B to the image signal reading section.

Requests one line of image signal. The image signal reading section.

When the 1-line transfer request B is detected to be on, the 1-line transfer request C indicating the 1-line image signal section is turned on, and the image signal A is output at the same time.

Further, the image signal transfer control is performed line by line.

Further, the line memory write/read control circuit 2 writes the image signal A while C is on during one line transfer into the line memory section 1, and at the same time writes the image signal A of the previous writing line. It is output to the change detection circuit 3 in synchronization with the input timing. Furthermore, at this time, if there is image signal data that can be output to the encoder 4, the encoder 4 turns on the encoder readout enable J and requests data readout. At this time, if the encoder 4 outputs an image signal reading port and a query, a two-picture signal reading port and an encoded image signal H synchronized with the query are output from the line memory unit 1. The image signal transfer control with the encoder 4 is also performed line by line.

In addition, the line memory write/read control circuit 2 usually switches the write line memory every time writing of one line is completed, but when the no change signal G output from the change detection circuit 3 is on, the current write Since the image signal is the same as the previously written image signal, the writing line memory is operated to overwrite the image signal of the first line without switching even if writing of the image signal of one line is completed. By operating in this way, the two image signals are made to be equally constrained. It is assumed that normal operation is performed when the no-change signal G is off.

The change detection circuit 3 always compares the current write image signal A and the previous write image signal pixel by pixel while C is on during one line transfer,
During one line transfer, the no-change signal G is turned on or off depending on whether there is a change while C is on. The encoder 4 is a circuit for encoding the image signal line by line, and uses EOL code and MvMR code.

Sends Fill bit, etc. The encoder 5 is a circuit for transmitting special codes corresponding to the number of consecutive lines of the same image signal, and in this embodiment, it is assumed that the encoder 5 transmits a number of codes "1" corresponding to the number of consecutive lines. The continuous line number counting circuit 6 is a circuit for counting the number of continuous lines of the same image signal, and holds the counted value until the encoder 5 reads it out. Ba.

The file memory 7 is used for speed matching between the encoder side and the line side. The transmission bit counting circuit 8 is used to manage the minimum number of transmission bits for one line.

Next, the operation of the entire transmitting section will be explained. If encoding is to be started now, the line memory write/read control circuit 2 sets the write line memory in the line memory section 1 and turns on the 1 line transfer request B to the 2-picture signal reading section.

The image signal reading section turns on C during one line transfer in accordance with the one line transfer request B and outputs the image signal A.

Line memory write/read control circuit 2 includes line memory section 1
At the same time as the image signal A is written to , the previous write image signal A is outputted to the change detection circuit 3 in synchronization with the write timing. Also, the image signal output to the encoder 4 is as follows.

When the no-change signal G of the change detection circuit 3 is off, the previous written image signal is enabled to be read, and the encoded line read enable J is turned on. When the previous written image signal A and the current written image signal A are the same image signal, the output of the image signal to the encoder 4 is prohibited, and when the 9 image signals do not match, the image signal output is enabled. That's how it works. Line memory write/read control circuit 2 also. After performing the above operations, the write line memory and the read line memory are managed so as not to overlap.

The change detection circuit 3 compares the 1-picture signal A and the previous write picture signal from the line memory section 1 pixel by pixel while C is on during one line transfer, and writes the result to the line memory as a no-change signal G. The output signal is output to the input/read control circuit 2 and the continuous line number counting circuit 6. The continuous line number counting circuit 6 receives a no-change signal G.
Count the number of Cs during one line transfer while the encoder 5 is on.
It is held until it is read out. During this time, the line memory write/read control circuit 2 performs special processing as described above to skim the same image signal with equal constraints.

When the encoder 4 attempts to start encoding, it first sets the minimum number of transmission bits for one line in the transmission bit number counting circuit 8 using the transmission bit set signal T, and then outputs the encoded line from the line memory write/read control circuit 2. If readable J is on,
The EOL code is transferred to the code data O according to the lock P.
It is output to the buffer memory 7 as . Next, while reading the encoded image signal H using the image signal reading locke,
1α encoding while code r according to code transfer lock P
- Output to buffer memory 7 as data 0. Further, when the encoder 4 finishes encoding one line of the image signal, it turns on a continuous line number encoding request K to the encoder 5.

If the continuous line number encoding request K is turned on, the encoder 5
A count value transfer request M is turned on for the continuous line number counting circuit 6, and the count value N is received. The continuous line number counting circuit 6 is initialized when the count value N is passed to it and starts the next counting. According to this count value N, the encoder 5 outputs 1@1'' as the special code for N pieces, and according to the code transfer port R, the code data 5 is encoded as a special The encoder 5 turns on the code transmission completion and turns off the count value transfer request M. Normally, the encoder 5 determines that encoding has ended when the special codes for N count values have been transmitted.

When the continuous line number encoding request K is turned off, the special code transmission completion is turned off and preparations for secondary encoding are started.

When the special code transmission completion signal is turned on, the encoder 4 turns off the continuous line number encoding request K, checks the transmission completion signal S of the transmission bit number counting circuit 8, and if it is completed, starts encoding the next line and completes the encoding. If not, the Fill bit is output to the buffer memory 7 as code data O according to the code transfer port RIP until completion. The transmission bit number counting circuit 8 is a code transfer port after the transmission bit number set signal T is input.
RiP.

R is counted, and the encoder 4 outputs the resulting transmission completion signal S.
Output to. The buffer memory 7 performs speed matching between the encoding section and the line section and outputs the encoded data U according to the transfer timing V from the line. Thereafter, the transmission operation is performed by returning without this processing.

Next, the receiving section will be explained. The receiving section (2) is composed of a buffer memory 100, a decoder ioi, a decoder 102, and a recording control circuit 103.

The encoded data transferred from the line section is stored in the buffer memory 1 as encoded data a according to the code transfer port RId.
Temporarily stored in 00. The buffer memory 100 is for speed matching between the line section and the decoding section.

The temporarily stored encoded data is read out by decoders 101 and 102.

The decoder 101 sequentially reads and decodes the code data C according to the code reading lock d, and outputs it to the recording control circuit 103 while reproducing a binary image signal.

The decoding of the l line starts when the l line image signal transfer request from the recording control circuit 103 is on, and the image signal reproduced during this time is transferred to the reproduced image signal i according to the 2 excitation signal transfer port rij.
It is output to the recording control circuit 103 as a. Normally, the decoding process for one line starts with the detection of the EOL code, decodes the square code indicating the second image signal, first decodes the special code indicating the number of consecutive lines, and discards the Fi11 bit. It will be a return.

When the decoder 101 finishes decoding one line.

The special code decoding indicator f is turned on to instruct the decoder 102 to decode the special code. When the decoder 102 detects the special code decoding instruction f-on, the decoder 102 decodes the code data C while reading it from the buffer memory 100 using the code reading lock e. At this time, if there is no data '1'' indicating the special code, the code data C is discarded until EOL is detected, and after the discard is completed, the decoding end is notified to the decoder 101 by decoding end g.

When the decoder 101 receives the decoding end g, it turns off the special code decoding instruction f and starts decoding the next line. Furthermore, when there is data of 1'' indicating a special code, the number is counted and the end processing is then started.

The number of continuous lines detected by the decoder 102 is read by a continuous line number reading lock k from the recording control circuit 103.

The recording control circuit 103 receives the reproduced image signal for one line)
When finished, turn off the 1 line image signal transfer request,
The number of consecutive lines t is taken over.

The number of consecutive lines is taken over by outputting a continuous line number reading port, RI, when the special code decoding instruction is turned off. Thereafter, the recording control circuit 103 starts the recording operation of the reproduced image signal, but if the reproduced image signal of the next line can be received at this time, it turns on the 1-line image signal transfer request again.

The recording control circuit 103 operates as follows according to the image signal and the number of continuous lines. At the same time as outputting the reproduced image signal m, the recordable signal n is turned on.

The transfer of the reproduced image signal m for one line is completed and the recordable signal n is turned off. During this time, an image signal for one line is recorded. When recording of 1 line is completed, feed 2 sheets 9
Outputs one ie Lus 0. At this time, regarding the paper feed, the specified 1! It is assumed that the paper is fed by the density. When the recording of this 1 line is completed, the value of the number of consecutive lines t is checked, and the process is repeated by that value, and the process is repeated without the above-mentioned recording operation. If the recording control circuit 103 is configured to perform the recording operation of the reproduced image signal next time, the same operation can be repeated.

(Effects of the Present Invention) As described above, according to the present invention, continuous lines of the same image signal can be transmitted all at once, so there is an effect that the transmission time can be shortened without losing the amount of information.

[Brief explanation of drawings]

The figure is a block diagram showing the configuration of a line-skip facsimile machine that is an embodiment of the present invention.
is raining down on the receiver. 6 is a continuous line number counting circuit, 7 is a buffer memory, 8 is a transmission bit number counting circuit, 100 is a packer memory, 101 and 102 are decoders, and 103 is a recording control circuit, respectively. Gosamii Kotobuzu (n) 145';

Claims (1)

[Claims] 1. means for temporarily accumulating a series of image signals consisting of white/black binary image signals; means for detecting the presence or absence of a change in the image signal in the sub-scanning direction; means for counting the number of consecutive lines of the same image signal; The first step is to encode the image signal line by line.
a second encoder for outputting a special code indicating the number of consecutive lines of the same image signal, a transmission bit counting means for ensuring the minimum transmission time of one line, and a buffer for speed matching with the line. a transmitting section consisting of memory;
Buffer memory for speed matching to receive encoded data from the line, third decoder to decode the encoded data and reproduce the image signal, decodes a special code indicating the number of consecutive lines of the same image signal and a receiving section consisting of a recording control means that can control the recording of the same image signal multiple times, and when lines of the same image signal are continuous, the encoder of the image signal is 1. A line-skip facsimile device characterized in that information about the number of consecutive lines of the same image signal is added to and transmitted after the conversion bit.