JPH0732458B2 - Code converter - Google Patents

Description

The present invention relates to a code converter suitable for a facsimile apparatus for image transmission. In particular, it is used for a mass storage device for storing image information and a facsimile apparatus with a storage / broadcast means having a plurality of communication line ports.

〔Overview〕

The present invention provides a code converter suitable for a facsimile apparatus for image communication, in which a plurality of line memories and a selector for selectively selecting the output thereof are provided between a pair of encoders and decoders, and code conversion is performed for each scanning line. By adopting a configuration in which the image information to be processed is switched to perform time-division processing, the use efficiency of the encoder and the memory is high, the memory capacity is not wasted, and the facsimile apparatus has a pair of codecs for each communication port line. It is an unnecessary and economical device.

[Conventional technology]

FIG. 2 is a block diagram of a facsimile apparatus including a conventional code converter. In FIG. 2, an encoder 4 is connected to the scanner unit 3 and is an encoder for compressing the amount of image information stored in the disk device 5. Codec (CODEC) 2
Reference numerals 1 and 22 input data compressed by the encoding system of this device from the disk device 5, decompresses the data, compresses it to the encoding system of the partner terminal and gives it to the communication control unit 12, and This is a coder / decoder that receives data compressed by the encoding method that it has from the communication controller 12, decompresses it, compresses it by the encoding method that this device has, and gives it to the disk device 5.

Conventionally, a facsimile apparatus does not know the characteristics of a communication partner terminal at the time of scanning and reading an original, and therefore, this encoding is performed by the encoder 4 using an encoding method predetermined by the apparatus. The information was compressed and stored in the disk device 5.

On the other hand, there are various types of terminals as communication counterpart terminals, and some of them cannot be transmitted / received by the encoding method stored in the disk device 5. In such a case, at the time of transmission / reception, it is necessary to perform code conversion according to the coding method of the partner terminal. Therefore, the communication control units 12 ₁ , 12 ₂
The two codecs 21 and 22 are installed to face each other between the disk drive 5 and the disk device 5, and code conversion is performed here.

[Problems to be solved by the invention]

As a memory for this purpose, a first-in first-out memory was used, but since the amount of information for one scan of the facsimile apparatus is large,
Had to use a fairly large amount of memory.

Further, in such a conventional facsimile apparatus, since a pair of codecs are installed for each communication port line, one
There is a drawback in that it is difficult to have a large number of ports due to economical restrictions due to an expensive communication port.

The present invention solves the above-mentioned drawbacks, and an object of the present invention is to provide an economical code converter which has a simple memory configuration and does not require a pair of codecs for each communication port line.

[Means for solving problems]

The present invention relates to a code converter including a decoder for expanding compressed image information and an encoder for compressing an output of the decoder, and a plurality of units for sequentially storing the output of the decoder for each scanning line. Line memory and a selector that selects and outputs a line memory in which information immediately before the image information that is being expanded by the decoder is stored in the plurality of line memories, and the encoder is It further comprises means for compressing the output of the decoder using the output of the selector as a reference line.

[Action]

The compressed image information is expanded by the decoder. The outputs of the decoder are sequentially stored in a plurality of line memories for each scanning line, and the outputs of the plurality of line memories are selected by a selector and output. The encoder compresses the output of the decoder while referring to the output of the selector as a reference line. When compressing, a plurality of line memories are sequentially switched and used, and a plurality of image information are time-divisionally processed for each scanning line. By the above operation, since a new reference line is always given to the encoder, a pair of encoders is not required for each communication port line, which is economical.

Further, since two memories for one scanning line are prepared and used by switching them, there is no waste in the configuration.

〔Example〕

Embodiments of the present invention will be described with reference to the drawings. First
1 is a block diagram of a facsimile apparatus including a code converter according to an embodiment of the present invention. In FIG. 1, the facsimile device includes a common bus 100, a central processing unit 1 that is connected to the common bus 100 to control the entire device, and a RAM (RAM) that is connected to the common bus 100 and temporarily stores compressed data. When,
Connected to the common bus 100, a scanner unit 3 that scans a document, and an encoder 4 that is connected to the common bus 100 and that compresses the output of the scanner unit 3 by the encoding method of this device and outputs the compressed data to the common bus 100. , A disk device 5 for storing data compressed by an encoding method of this device, and a common bus 10
A decoder 6 connected to 0 for expanding data stored in the disk device 5 and a printer 7 for printing out the output of the decoder 6 are provided.

Further, the facsimile machine is connected to the common bus 100,
If the other terminal has a different encoding method, the disk device 5
Decompressor 8 which inputs compressed data from compressed data or compressed received data via ram 2 for each scanning line, and expands it, and stores the data of one scanning line at the output of decoder 8 Line memories 10 ₁ and 10 ₂ and line memories 10 ₁ and 10 ₂
A selector 11 for selecting and outputting the data stored in
Connected to the common bus 100, the output of the decoder 11 is used as a reference line to compress the output of the decoder 8 according to the encoding method of the partner terminal and output to the common bus 100, or the encoding method of this device. An encoder 9 for storing in the disk device 5 via the common bus 100.

Further, the facsimile apparatus is connected to the common bus 100, and if the encoding method of the partner terminal is the same as the encoding method of this apparatus, the facsimile apparatus inputs the data via the compressed data common bus 100. And send it to the other terminal,
Receives compressed data and sends a common bus to the disk device 5.
If the encoding method of the other terminal is different, the compressed data is input from the encoder 9 via the common bus 100, transmitted to the other terminal, and the compressed data is received. The communication control units 12 ₁ and 12 ₂ are provided to the ram 2 via the common bus 100.

The operation of the code converter having such a configuration will be described.
In FIG. 1, the transmission original is scanned by the scanner unit 3, and the read image signal is input to the encoder 4. The encoder 4 compresses and encodes the image signal from the scanner unit 3 and sends it to the common bus 100. The compressed data sent to the common bus 100 is stored in the RAM 2 under the control of the central processing unit 1. This data is further transferred from the ram 2 to the disk device 5. The image information of the transmission document is stored in the disk device 5 in document units, and then transmitted via the communication control unit 12 ₁ and the communication control unit 12 ₂ . However, when the encoding method of the other terminal and the encoding method of the compressed data stored in the disk device 5 (that is, the encoding method of the encoder 4) are different at the time of transmission, the compressed data of the disk device 5 Cannot be transmitted as it is, and it is necessary to decode it once and then encode it by the encoding method of the partner terminal. Furthermore, since the communication by the communication control unit 12 ₁ and the communication by the communication control unit 12 ₂ are performed independently, two different image information may be transmitted at the same time. The operation in this case will be described below.

The image information X transmitted by the communication control unit 12 ₁ is read from the disk device 5 by a predetermined amount according to the progress of the transmission and the RAM 2
Is transferred to a predetermined area x of Image information Y transmitted by the communication control unit 12 ₂ is also transferred similarly to the other predetermined area y in the ram 2. The image information X is transferred to the RAM 2 by the decoder 8.
One scanning line (from the line sync code to the next line sync code) is read from the area x of. The decoder 8 decompresses the data for one scanning line and outputs the original image signal for the one scanning to the line memory 10 ₁ and the encoder 9. Encoder 9 compresses the image signal from the decoder 8 with reference to the image signals from the line memory 11 set to pass the output of the selector 11 of the line memory 10 ₁ as a reference line. At the same time, the output image signal of the decoder 8 is written in the line memory 10 ₁ . The compressed image information is written from the encoder 9 into the buffer memory in the communication control unit 12 ₁ .

When the coding conversion of the data of one scanning line of the image information X is completed in this way, the decoder 8 next reads the data of the image information Y of one scanning line from the area y of the ram 2 and expands it. Encoder 9 compresses the image signal from the decoder 8 an image signal from the line memory 10 ₂ is switched to pass the output selector 11 of the line memory 10 ₂ as the reference line. Simultaneously, the output picture signal of the decoder 8 is written to the line memory 10 _2. Image information compressed is written from the encoder 9 to the buffer memory of the communication control unit 12 _2. Hereinafter, similarly, the image information X and the image information Y are alternately encoded and converted one scanning line at a time by using the line memory 10 ₁ and the line memory 10 ₂ , respectively, and are converted into the communication control unit 12 ₁ and the communication control unit 12 ₂ . Transfer each.

The communication control unit 12 ₁ and the communication control unit 12 ₂ transmit the respective image information written in the buffer according to the communication control procedure.

Further, the image information transmitted from the terminal is directly stored in the disk device 5 when the encoding method is the same as the encoding method of this device. If the encoding system is different from the encoding system of this device, the RAM 2, the decoder 8, the line memory 10, the selector 11 and the encoder 9 are used to encode with the encoding system of this device, and the disc device 5 Is stored.

In the above embodiments, the case where the number of the communication control units 12 is two has been described, but even if there are three or more communication ports, the same can be realized by increasing the number of line memories 10.

〔The invention's effect〕

As described above, according to the present invention, a plurality of line memories and a selector that selectively selects the output thereof are provided between a pair of a decoder and an encoder, and image information to be code-converted is switched for each scanning line. By performing time-division processing by means of time-division processing, the utilization efficiency of the encoder is improved, and since the memory for one scanning line is switched and used, the utilization efficiency is high and there is an excellent effect that the memory capacity is not wasted. Further, there is an advantage that a pair of codecs provided for each communication port becomes unnecessary and an economical device can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram of a facsimile apparatus including a code converter according to an embodiment of the present invention. FIG. 2 is a block diagram of a facsimile apparatus including a conventional code converter. 1 ... Central processing unit, 2 ... Ram, 3 ... Scanner unit,
4,9 ...... encoder, 5 ...... disk device, 6, 8 ...... decoder, 7 ...... printer, 10 _1, 10 ₂ ...... line memory, 11
...... Selector, 12 ₁ , 12 ₂ ...... Communication control section, 21 ₁ , 21 ₂ , 22
₁ , 22 ₂ …… Codec, 100 …… Common bus.

Claims (1)

[Claims] 1. A decoder (8) for decompressing compressed image information.
And a code converter (9) for compressing the output of this decoder, comprising: a plurality of line memories (10) for sequentially storing the output of the decoder for each scanning line; A selector (11) for selecting and outputting a line memory in which information immediately before the image information expanded by the decoder is stored in the line memory, and the encoder outputs the output of the selector. A code converter comprising means for compressing the output of the decoder as a reference line.