JPS5881382A - Compressive encoding system of facsimile equipment - Google Patents

Abstract

PURPOSE:To perform efficient encoding compression for various originals by assigning an MH code having less bits between a white and a black MH code corresponding to a white and a black run-length number of a picture signal. CONSTITUTION:Binary picture signals from respective lines led out of a reading circuit are stored temporarily in a picture signal buffer memory 1 and read out successively, and a change point detecting circuit 2 detects a pause between a white and a black signal. Then, their white and black run-length numbers are counted successively by an addess counter 3 to apply address signals to an MH code ROM4. Without discrimination between the white run length and black run length, the MH code ROM4 outputs the same MH code corresponding to the run-length number and the code is stored in a buffer memory 5. Then, a microprocessor 6 performs control so that a white MH code follows a line synchronizing code without fail.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an FEs encoding method for a facsimile machine,
Particularly, the object of the present invention is to realize more efficient compression encoding in a facsimile machine that uses MH codes.

In recent years, CO engineering TT G11j Eve facsimile machines are designed to compress and encode one signal using MH code before transmitting it.

The white run length of one signal was coded into a white MH code, and the black run length was coded into a black MH code.

By the way, the above ME code takes into consideration the Hi degree of each white and black full length, and assigns an MH code with a small number of bits to a high frequency full length, and assigns an MH code with a large number of bits to a high frequency full length. It is now in good condition. Therefore, for full-length numbers 1 to 4, the white MH code has a larger number of t bits than the black MEI code, and for full-length numbers 5 and 6, the white ME code and black MH code have the same number of bits. For run lengths of 0 and 7 or more, the black MB code has a larger number of bits.

However, some manuscripts have white characters appearing intermittently on a black background, and some have a striped t in black and white that repeats every dot. Therefore, the conventional MH encoding described above cannot be said to be efficient for such documents.

Therefore, according to the present invention, each of the white and black run lengths of the #i-signal is always encoded into a 10,000 MH code having a smaller number of bits among the white and black 1illH codes.

The details of the present invention will be explained below with reference to the drawings.

FIG. 1 shows a schematic configuration of a transmitting side device of a facsimile machine employing the present invention. In the same figure, the reading circuit (
The binary image signals of each fin derived from the fins (not shown) are stored in 1 image signal buffer 1 memory IJ (1) K-1 and then sequentially read out, and then sent to the change point detection circuit (2) for white and black signals. delimiter is detected. Then, the run length numbers of the white signal and the black signal are sequentially counted by the address counter (3). Each count result of this counter (3) is the next MH code R
The present invention is characterized in that it is applied as an address signal of OM (41).
Il! In the ROM (4), there is a full length l! Black MH codes corresponding to each of the numbers 1 to 6 are stored in advance, and white MH codes corresponding to each of the full length numbers 0 and 7 or more are stored in advance with each full length number as an address. has been done. Therefore, when the address counter (4) counts the number of full lengths that an image signal consists of, the same MH code corresponding to that number of full lengths will be displayed regardless of whether it is a white full length or a black full length.
The MH code read from OM(4) is stored in the code buffer 51.

On the other hand, Microb Cl-1! The fuser (6) causes each of the circuits mentioned above to perform the above-described operations, but at this time, it is controlled in a first-order manner. In other words, the queen processor (6) is 1 twin l
Prior to the encoding of i(!r), a line synchronization code (EOL
), and control is performed so that the next MH code after this synchronization code is always the MH code corresponding to the white run length. Therefore, if the first fin length of the image signal of a line consisting of 1 is black 7, the microprocessor (6) is fin synchronized? After creating 1 (EOI, ), first,
The MH code of White 0 is read from the ROM (41), and then the MH code of White 7 is read from the 1st ROM (4) by the above-mentioned operation.
Pressure control is performed so that reading is performed from the beginning. Therefore, in this case, the code string signal stored in the code buffer (5) is cooo
o.

0000001 00110101 1111...
・KOL White 0 White 7...] Then, K like this and the above buffer 1 memory (5)
The t code string signals stored in the t code string signal are sequentially read out, modulated, and sent out to the line. In the same figure, the code string signal derived from the demodulation circuit (not shown) is stored in the code buff 7 memory (7) and the %EOL
A line synchronization code (EOL) is detected in the detection circuit (8). Then, the synchronization code detection output is shifted by 7 lip props (9) for black and white discrimination, and the microprocessor ○O decodes from the MH code corresponding to the white full length based on the output of this 7 lip 70 fude. I decide to start.

Therefore, now the aforementioned code string signal (0000EOL
White 0 White 7...-]'s first M
When the H code (00110101) is introduced into the shift register □, the microphone o 7' at sender (to) transfers the full length number 0 corresponding to the MH code to the MH decoding ROM.
It is read from Q3, but since it is the full length number rjO, it is not preset on the counter side. In addition, 1st RO
Ma2JK stores in advance the number of run lengths corresponding to each MW code as an address.

When the white 0 decoding is completed in this way.

The micro 1g processor (to) inverts the fri1b/70fp (9) and takes in its output, thereby knowing that it is now decoding the black run length. When the primary MH code (1111) is introduced into the shift register ■, the microprocessor αoh reads out the run length number 7 corresponding to that ME code from the ROM (2), and presets this run length number in the counter 03. .

Next, when the full length 1!7 is preshifted to the i period counter (to), this time it is a case of black run length decoding, so the microprocessor αO counts down the counter (to) by the reset value. As a result, seven pieces 111 are sequentially stored in both signal buffer memories α♦ as white symbols. At the same time, when the microprocessor - 〇〇 has finished presetting the will allocation counter (to), it inverts the 7 rif de and 7 cy knob (9) again, so that the next step is to decode the white full length number. Know.

Therefore, when the next full length number is preset to counter 0 in the same manner as described above, the microprocessor
(IH) Next, a number of 10'' corresponding to the preset number of full lengths is sequentially stored in both signal buffer memories α4 as black signals.

Thereafter, in the same manner, both the white and black signals for one fin are alternately stored in the buff 7 memory α◆. When the image signal for 1 Myin is stored in this memory α♦, it is read out and the f8 recording operation is performed.

4. As explained above, according to the inventive μ formula, whether it is a white run length or a black run length of a binary image signal, the white and black MH corresponding to the run length number are determined. Since encoding is performed using the MH code with the smaller number of bits among the codes, efficient encoding compression can be performed on various manuscripts, and the conventional GI[@yoV% Speeding up is possible.

Furthermore, since there is no need to provide encoding and decoding ROMs for white and black, there is an advantage that the memory capacity can be reduced (%).

[Brief explanation of the drawing]

The drawings schematically show the configuration of a facsimile machine employing the present invention, and FIG. Figure 2 shows the receiving side device in g4IW&.

Claims (1)

[Claims] (1) In a facsimile machine that transmits a signal by MH encoding so that the beginning of each line starts with a line synchronization code followed by a code corresponding to white information, the white and A compression encoding method for a facsimile machine, characterized in that a black full-length is assigned a ten-thousand MH code having a smaller number of bits among white and black ME codes corresponding to the number of full-lengths.