JPS6072486A - System for forming facsimile transmission code - Google Patents

Abstract

PURPOSE:To use a table ROM for coding and decoding a two-dimension code by providing a fixed memory table separating and storing data into a number of polarity consecutive from the head, remaining bit number excluding coded data of the polarity and the remaining data excluding the polarity data respectively. CONSTITUTION:A data other than ''0'' from a data buffer 3, a data bit number other than ''0'' from a bit counter 4 and a consecutive ''0'' number of the head from a ''0'' number counter 5 in the transmission data are inputted to a ''0'' insertion circuit 6, from which the data is transmitted as a transmission data of 8-bit white run length. On the other hand, an input reception data is stored once in a reception buffer 8 and when the head consecutive ''0'' number is detected by a ''0'' number detection counter 9, the first 8-bit area in 16 bits in a table ROM2 is searched based on 8-bit including the remaining data to output the restored data. The table ROM is used in common by storing separately the data in the fixed memory table and using the data for coding and decoding in this way.

Description

Detailed Description of the Invention (1) Technical Field of the Invention The present invention relates to a facsimile transmission code which uses a fixed memory table in common for encoding and decoding two-dimensional codes used in facsimile, thereby reducing memory capacity. This is related to the creation method.

(2) Conventional technology and problems Conventionally, 00j was used as an international standard for facsimile communication systems.
G3 format (digital) according to TT recommendation is applied, but
The compression and decompression codes and decoding methods are -dimensional MH (Modified Huffman) method and two-dimensional M
The R (modified read) method is used. Among these, the MR method expresses the relative relationship between image signals over two lines using the following nine types of codes. These bit lengths are up to 7 bits long for each type.

■o; Same sign above and below (“1”) VR (1), VL (1): Sign change for the 1st bit on the right (left) side〃(2),〃(2); #2nd bit〃//
(3), //(3): # 3rd bit 〃P (pass)
; No change of 4 bits or more H (horizontal code); In the case of run-length display, this MR method has a fixed memory table to encode the transmitted data and decode the received data. Outside run length data is stored. The gin length data is defined by the MH (Modified Huffman) method, where termination codes (64 x 2 black and white) and makeup codes (40 x 2 (black and white)) are stored in a 2-byte area along with their bit numbers, for example, in a 512-byte table. ROM is used. Furthermore, since the transmission data encoding circuit and the reception data decoding circuit have independent circuit systems, separate table ROMs with the same contents are provided for encoding and decoding. The inventor of the present invention considered the idea of using a common table ROM for encoding and decoding to reduce the memory capacity by half in order to take advantage of the LSI implementation.

(3) Purpose of the Invention The purpose of the present invention is to provide a facsimile transmission code creation method that uses a common table ROM for encoding and decoding two-dimensional codes used in facsimile.

(4) Structure of the Invention In order to achieve the above-mentioned object, the facsimile transmission code creation method of the present invention extracts the encoded data of an image signal by excluding the number of one consecutive polarity from the beginning and the encoded data of the polarity. The facsimile machine has a fixed memory table that decomposes and stores the number of remaining bits and the remaining data excluding the polarity data, and stores the data indicating the number of bits read from the table and the remaining data. This method is characterized by creating a transmission code.

(5) Implementation of the invention FIG. 1 is an explanatory diagram of the configuration of an embodiment of the present invention.

In the figure, the table ROM2 has M
Nine types of R codes and 208 syn-length signals are stored.

These signals are shown as "white run length 4" in the M2 diagram, for example.
Starting from the 8-bit data ■ with the code "ooi oi oal" of "0", the remaining data ■6 excluding the consecutive 0'' at the beginning of the white run length data ■ is placed in the first 8-bit area of the 16-bit area. Put the bit in the upper position and fill the lower two bits with 0''. The next 4 bits in the 8-bit area represent the number of consecutive 0's at the beginning of the white length data.
The next 4 bits are continuous "□II, no. f-11tD
Ytsu,. 1 yo □, 1.0 1st. Then, the white run length data (■) is counted by the counter 1, and the counted number is stored in the table ROM 2 as an address.
The 16-bit data consisting of ① and ② is accessed sequentially.

Then, store the data ■ other than consecutive "0" in the data buffer 3 other than @0, put the number of data bits ■ into the bit counter 4 other than 0", count it, and count the number of continuous 0°' at the beginning ■ is entered into the "0" number counter 5 and counted.

□ The transmission data is the data from the data buffer 3 other than 0'' and the data from the bit counter 4 other than ``On''. The number of zeros and the leading consecutive 0° number from the 0" number counter 5 are input to the "0" insertion circuit 6, and the remaining 6 bits of data other than 0" are extracted.
bit is added and sent as 8-bit white 2-length transmission data.

On the other hand, the input reception data is temporarily held in the reception buffer 8,
At the point where the 0" fine detection counter 9 detects the first consecutive 10" number, based on the 8 bits containing the remaining data:
First 8 bits out of 16 bits in table ROM 2: When the area is searched and the first 6 bits match, the second
In the example shown in the figure, when □ reaches the "white gin length 40", it matches the contents of the data buffer 3 other than "〇-", and at this time: 4 bits of the 0" slight detection counter 9 and the number "0" Match the 4 bits of the counter 5 with the match detection circuit 7, and also check the power of the bit counter 4 other than "0" at the time of the day.
Put the 4 bits of the runt line into the coincidence detection circuit 7 and enable the 6 bits of data other than 0'' from the buffer 8.
A match is detected between this data and the contents of the restorer 3 containing data other than "0", and restored data is output. 1. In this way, data can be stored in fixed memory tables in a shared manner by being used for encoding and decoding. -,.

Jl [# Ll j 51C177/&-fl! J28
At 3°, the encoded data is read from the beginning with successive symbols “
The number of 0'', the remaining bits excluding 0, the number, and 0.
Fixed memory that is separated and stored in the remaining data after excluding
9f-7''k and 301 constant mediori 7°'' can be shared to supply required data to the encoder circuit and the decoder circuit.

In this way, one table R゛OM is used for encoding and decoding.
9. This is advantageous in the case of LSI implementation, etc., since it is possible to share the memory and reduce the amount of memory by half.

[Brief explanation of the drawing]

Fig. 1 is a configuration explanatory diagram of an embodiment of the present invention, and Fig. 2 is a functional explanatory diagram of main parts of the embodiment. In the figure, 1 is a counter, 2 is a table ROM, and 3 is data other than 0". buffer, 4 is a bit counter other than °°0', 5 is a "0" number counter, 6 is a 0" insertion circuit, 7 is a match detection circuit, 8 is a reception buffer, 9 is a "0°" number detection counter Patent applicant Fujitsu Ltd. Sub-agent Patent attorney 1) Yoshishige Saka

Claims (1)

[Claims] Decomposes the encoded data of the image signal into the number of consecutive polarities from the beginning, the number of remaining bits after excluding the encoded data of the polarity, and the residual data after excluding the polarity data, and stores each of them. 1. A method for creating a facsimile transmission code, comprising a fixed memory table, and creating a facsimile transmission code using data indicating the number of bits read from the table and residual data.