JP3070770B2 - Image coding device for parallel processing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encoding apparatus for encoding an image signal in a facsimile or an electronic file by a variable-length encoding method, and more particularly, to efficiently performing a plurality of types of encoding processing. The present invention relates to an encoding device suitable for

[0002]

2. Description of the Related Art Conventionally, in an image processing apparatus such as a facsimile or an electronic file device, an image signal is encoded using an encoding device for the purpose of efficient transmission and recording of image information. .

A conventional technique for efficiently performing such an image signal encoding process is disclosed in, for example,
As described in JP-A-237868, a plurality of output buffers for temporarily storing code data obtained by compressing and converting an image signal are used, and a plurality of encoding processing units are used. Are operated in parallel to perform encoding processing at high speed.

However, for example, in a facsimile, there is a case where it is desired to simultaneously encode different unrelated image information processing. In other words, transmission, reception, storage of transmission originals in memory, output of various reports, and copying, etc., are performed independently at the same time as much as possible within two or more as much as possible in terms of system resource allocation. This is an operation form called multi-access executed, and has recently become popular for the purpose of improving the serviceability of the apparatus.

[0005] For example, if a user wants to prioritize the reception of a document to be transmitted by a user using a facsimile that transmits image information stored in a memory to a memory during the memory transmission, a multi-access mode that enables the user to do so is Therefore, it is necessary to store the transmission original in the memory at the time of memory transmission.

In the memory transmission operation, transmission original image information stored in the memory in a compression-encoded state is fetched from the memory, temporarily decoded, and re-encoded by an encoding method that can be received by a transmission destination facsimile. , Which is an operation mode for transmission after that. In addition, the transmission document memory storage operation is a process in which a transmission document is read by a scanner and the image information is stored in a memory. Usually, in order to increase the number of documents that can be stored, the image information is compressed and encoded. After being accumulated. As described above, in this multi-access mode, two types of encoding processes are performed simultaneously.

[0007] In a conventional coding apparatus which is based on a single coding process, two coding apparatuses are required to respond to such multi-access. However, one of them is not always used and is very uneconomical.

[0008]

Problems to be Solved by the Invention JP-A-62-2378
No. 68, which performs the conventional encoding process in parallel, is a series of units of image information processing, for example, a parallel encoding process of image information for one page. Image information processing, for example, encoding of a plurality of pages is not performed sequentially for each page. For this reason, when performing parallel encoding between pages required in the multi-access mode, the number of encoding devices required is equal to the number of parallel processes.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to execute a plurality of independent encoding processes in a time-division manner for each process so that one unit can execute a plurality of encoding processes in parallel. It is an object of the present invention to provide an efficient image coding apparatus which enables the image coding.

[0010]

In order to achieve the above object, an image encoding apparatus according to the present invention comprises the following steps.
Each <br/> picture information to be of a plurality of types of coding processing of inputting Te Toggles, meet the image encoding apparatus for <br/> coding by switching the coding method corresponding to each of a plurality Each type of sign
-Division processing to switch the time-division processing in line units
A control unit and an encoding process switched by the time division process control unit.
Image information encoded in the format corresponding to the bus width of the system bus.
Variable-length characters when serial-to-parallel conversion
Save the odd code generated by encoding in the encoding method,
The following image information encoded by the encoding method is stored.
Serial / parallel conversion is performed after the end of the odd code.
A plurality of serial / parallel conversion registers to be transmitted ;
A multiplexer for selecting any one of the outputs of the plurality of serial / parallel conversion registers ;
Input switching control and each of the input switching
To a plurality of serial-to-parallel conversion register image information
Timing of the output destination of the assignment and the multiplexer of selecting operation
And having a control unit for performing a ring control.
Also, (2) each encoding process of three or more types is performed by each encoding process.
Time-division processing system that switches by time-division on a line-by-line basis
Control unit and the encoding process switched by this time division process control unit.
Image information encoded in
Serial-parallel conversion and transmission of multiple serial
The parallel conversion register and each serial / parallel conversion register
Multiplexer to select any one of the outputs of the register
And input switching control of each image information and this input switching
Of each encoding process by the time-division process control unit corresponding to
Switching operation, multiple serial / parallel of each image information
Assignment of output destination to conversion register and multiplication
A control unit for controlling each timing of the lexer selecting operation;
It is characterized by having. Also, (3) above (1) also
Or the image encoding device according to any one of (2).
On the line unit of each image information based on the instruction from the user.
Setting section for setting the input switching timing
And each timing by the control unit based on this setting
It is characterized by performing control.

[0011]

According to the present invention, a plurality of serial / parallel conversion registers are provided, and a plurality of types of time-divisional encoding processing are performed in line units via the respective serial / parallel conversion registers. Then, the output selection from the serial / parallel conversion register is switched in accordance with the switching timing of the encoding process, and plural types of encoding processes are performed in parallel. As described above, in order to perform a plurality of types of encoding processing in a time-division manner on a line-by-line basis, at the time of switching between the plurality of types of encoding processing, a serial interface corresponding to the bus width of the system bus of the code by the serial / parallel conversion register is used.
Odd words occur in parallel conversion. However, in each of the plurality of serial / parallel conversion registers,
This odd word is saved, and when control returns to the self-encoding process again, the code can be packed following the end of the odd word. Further, the switching timing of a plurality of types of encoding processing and the assignment to each of the serial / parallel conversion registers are set based on an instruction input from a user. This allows the user to freely switch the encoding process. In this way, a plurality of encoding processes can be freely operated in parallel with one encoding device.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a configuration according to the present invention of an image coding apparatus according to the present invention.

The image encoding apparatus according to the present embodiment is provided in a facsimile, and has an input unit 1 for controlling input of binarized original image information from a host system bus, and an input unit 1 for converting the binarized information. A parallel-to-serial converter (described as a parallel-to-parallel converter in the figure) 2 for converting to serial data; a change point detector 3 for detecting a change point of white and black binarization from the serial data; And a run-length mode signal detector 4 for detecting a run-length at the time of one-dimensional encoding and a mode signal at the time of two-dimensional encoding, and an input based on the detected run-length and mode signal. A code generator 5 for extracting codes and code length information corresponding to the extracted signals, a shift register 6 for sequentially discharging the codes extracted by the code generator 5, and a host system for storing the codes. Two serial-parallel conversion shift registers (serial-parallel conversion in the figure) that output serial-parallel conversion according to the width of the bus and store odd words of coded image information that occur when switching the process to be encoded A shift register), a multiplexer 9 for selecting an output from one of the serial / parallel conversion shift registers 7 and 8 and sending it to the host system bus, and an encoding process according to the present invention. It has a time-division processing control unit 10 and a time-division setting unit 11 for controlling the division processing operation, and operates the entire apparatus including the operation according to the present invention based on an instruction from a user input via a host system bus. And a control unit 12 for controlling

[0015] For example, as a variable-length coding method of image information in facsimile, MH (Mo) defined by an international standard with the intention of ensuring communication and compatibility.
modified Huffmann) or MR (Mo
Difficult Relative Element A
address design) method and M
Encoding methods such as an MR (Modified MR) method are widely used, and the present embodiment is also based on encoding using these methods.

With such a configuration, the image encoding apparatus according to the present embodiment performs a plurality of encoding processes required in the multi-access mode in a time-division manner and in parallel, thereby solving the problems of the prior art. be able to. Hereinafter, the control unit 12
The processing operation of each processing unit according to the present invention based on the above control will be described.

First, the input unit 1 fetches a plurality of black-and-white binary image information to be coded, which are alternately sent from the host system bus in line units. Output. The parallel / serial converter 2 converts the input binary information into serial data and sends the serial data to the change point detector 3. The change point detection unit 3
From this serial data, a change point of binarization of white and black is detected.

When the change point is detected by the change point detecting section 3, the run-length mode signal detecting section 4 at that time determines the run-length in the one-dimensional coding mode and the run-length in the two-dimensional coding mode. A mode signal indicating the relative positional relationship between the nearest change point on the reference line and the noticed change point on the encoding line is determined, and the result signal is sent to the code generator 5. That is, the one-dimensional encoding mode (M
(This occurs in the H coding method and the MR coding method.)
, A color signal indicating black and white and a run length, and in a two-dimensional encoding mode (generated in the MR encoding system and the MMR encoding system), a mode signal is transmitted to the code generation unit 5, respectively. Sent.

The code generator 5 converts a code corresponding to the input signal into a ROM (Read O
A search is performed from a code table stored in an nly memory (read only memory) or the like, and the searched coded image information is loaded in parallel into the shift register 6 in the next stage. still,
The shift register 6 needs to have a width of 13 bits or more, which is the maximum code length. Also, the code generator 5
At the same time as the parallel loading to the shift register 6, the code length information retrieved from the code table is sent to the time division control unit 10. Based on the code length information, the time-division processing control unit 10 adjusts the timing so as to suppress the next code generation by the code generation unit 5 until the searched code is discharged from the shift register 6 to the next stage. I do.

Next, the coded image information serially output from the shift register 6 must be divided according to the parallel width of the bus before being sent to the host system bus (parallel bus) and subjected to serial / parallel conversion. Must. However, in the present embodiment, it is necessary to pay attention to the problem that occurs at this time because the encoding process is switched. That is, when the encoding process is switched, it is easy to perform it for each line in raster scanning. However, even if the encoding process is switched in any unit, any encoding method is a variable-length encoding method. For this reason, the last coded image information word in one encoding process is not always filled with a code. When such a word is transferred, it cannot be decoded on the receiving side. To solve such problems, serial
Parallel conversion shift registers 7 and 8 are provided. That is, the serial / parallel conversion shift registers 7 and 8
When the encoding process is switched again and the control returns to the original encoding process, such an odd word is stored so that the code is packed again at the end thereof. Then, the multiplexer 9 selects an output from one of the serial / parallel conversion shift registers 7 and 8, and sends out the coded image information to the host system bus.

A time-division setting unit 11 switches the encoding process switching timing of the time-division processing control unit 10 and a serial / parallel conversion register based on an instruction signal from a facsimile user input via a host system bus. 7 and 8 are assigned to the respective encoding processes. Then, based on the setting, the time-division processing control unit 10 selects the output destination of the coded image information from the shift register 6 (one of the serial / parallel conversion shift registers 7 and 8) for each encoding process. , The selection of the multiplexer 9 (the selection of one of the serial / parallel conversion shift registers 7 and 8) is performed in accordance with the processing of the encoding target input through the input unit 1.

As described above, the image encoding apparatus according to the present embodiment comprises a time-division processing control section 10, a time-division setting section 11, two serial / parallel conversion shift registers 7,
By providing the multiplexer 8 and the multiplexer 9, two different encoding processes can be performed in parallel. Further, the user can easily switch the encoding process by designating which serial / parallel conversion register is to be used. For example, during transmission to the memory, the transmission original is stored. In this case, the encoding process for reading the original can be performed with priority.

In this embodiment, the description has been made on the premise that a coding method such as an MH coding method, an MR coding method, and an MMR coding method in facsimile is used. However, the present invention can be applied to an image processing system other than a facsimile as long as the variable length coding method is used. In the present embodiment, the two types of encoding processes are described as operating in parallel at the same time. However, in order to operate more encoding processes at the same time, the serial / parallel conversion registers are set to the number of encoding processes. Just prepare.

[0024]

According to the present invention, it is possible to perform a plurality of independent encoding processes in a time-division manner for each process, and to perform a plurality of encoding processes in parallel by one unit. An image processing system such as a facsimile can be configured more economically.

[0025]

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of a configuration according to the present invention of an image encoding device to which the present invention has been applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input part 2 Parallel-serial conversion part 3 Change point detection part 4 Run-length mode signal detection part 45 Code generation part 6 Shift register 7, 8 Serial-parallel conversion shift register 9 Multiplexer 10 Time division processing control part 11 Time division Setting unit 12 Control unit

Claims (3)

(57) [Claims] 1. A plurality of types that are switched and input in line units
Each image information to be encoded process of the kind, pairs respectively
Met image coding apparatus for coding by switching to the encoding scheme response, by time division each encoding processing of a plurality of types on a line-by-line basis
Time-division processing control means for switching, and encoding by the encoding processing switched by the time-division processing control means.
Serialized image information according to the bus width of the system bus.
-When sending data after performing parallel conversion, use the variable-length encoding method.
Save the odd code generated by encoding
Image information encoded by the encoding method
A plurality of serial-to-parallel conversion means that produce feed and serial-parallel conversion following the end of the over-de, and an output selecting means for selecting one of the output of the plurality of serial-parallel conversion means, The input switching control of each image information and the input switching
And wherein the this <br/> and a control unit for performing corresponding to the timing control of the selection operation of the output destination of the allocation and the output selection means to the plurality of serial-parallel conversion means of each image information Image encoding device. 2. Three types of switching and inputting in line units
Each image information to be subjected to each of the above encoding processes is
Code to switch to the encoding method corresponding to
Device, Each of the above three or more types of encoding processing is
Time-division processing control means to switch over time-division in units
When, Encoding by the encoding process switched by the time-division processing control means
Serialized image information according to the bus width of the system bus.
・ Multiple serial / parallel converters for parallel conversion and transmission
Conversion means; Any of the outputs of the plurality of serial / parallel conversion means
Output selection means for selecting one of The input switching control of each image information and the input switching
Each of the above encodings by the corresponding time division processing control means
Processing switching operation, the above multiple Real
.Assignment of output destination to parallel conversion means and upper
Control each timing of the selection operation of the output selection means
An image encoding device, comprising: a control unit. 3. The method according to claim 1 or 2,
An image encoding device according to Based on the instructions from the user, in line units of the above image information
Setting procedure for setting the input switching timing
Having a step, Based on the setting in the division setting means, the control means
Image code characterized by performing each of the above timing controls
Encryption device.