JPS63257382A - Picture communication equipment - Google Patents

Abstract

PURPOSE:To apply density conversion without giving an evil influence upon each input/output processing by applying picture element density conversion in the subscanning direction or main scanning direction separately at the picture data input/output to/from a picture input section and output section or at picture data input/output to/from the picture memory. CONSTITUTION:Since the picture element density is adjusted by the control of a video clock with respect to the main scanning direction, the picture density conversion in the main scanning direction does not give effect onto the processing speed. Thus, the density conversion with respect to the main scanning direction is applied in the input/output relating to a picture read section 1 and a picture recording section 2, and the density conversion relating to the subscanning direction is applied via the picture memory 12 by using the picture read section 1 and the picture recording section 2 to apply picture input/output and the density conversion in the subscanning direction is applied electronically in the input/output of the picture memory 12. Thus, the picture element density conversion is applied without lowering the picture input/output speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image communication device, and particularly to an image communication device that inputs and outputs image data at different pixel densities in the main scanning and sub-scanning directions of an image.

[Prior Art] Currently, facsimile machines use the G3 system, which inputs and outputs image signals using an analog line such as a subscriber line.
method is the mainstream. Furthermore, the G4 system, which inputs and outputs image signals via digital lines, is also becoming popular.

The G3 method and the G4 method use different encoding methods for redundancy suppression, and also have different standard pixel densities. Therefore, when configuring a device that uses both the G3 and G4 systems, or when relaying image data between both systems, it is necessary to convert the pixel density in addition to converting the encoding system.

Particularly in a facsimile machine having one image reading head ≠ end and image recording section, it is uneconomical to provide different reading sections and recording sections depending on the system, so it is inevitably necessary to convert the pixel density.

[Problem to be Solved by the Invention 1] In order to form image data with different pixel densities in the image reading unit, switching the video cropper such as a COD line processor in the main scanning direction, and changing the document transport in the sub-scanning direction. A method is used in which the same part of the document is read twice by stopping the motor at regular intervals. When pixel density conversion is performed in the reading unit with such a configuration, the document is temporarily stopped, which deteriorates the image quality. Alternatively, there is a problem that the processing speed decreases.

Also, when performing pixel density conversion on the recording device side, it is necessary to change the video crotter νJ and stop the motor for transporting the recording medium at regular intervals. (2) Density conversion is performed by a method such as extracting one line of image data. In this case as well, there are similar problems in that the image deteriorates and the processing speed decreases.

Furthermore, in the above-mentioned method, both the image reading section and the image recording section are used with their original resolution reduced, which is very uneconomical.

[Means for Solving the Problems] In order to solve the above problems, the present invention stores image data in an image memory at different pixel densities in the main scanning and sub-scanning directions for five images. The image communication device that transmits and receives images through processing includes an image input section and an image output section that have a constant pixel density, an image memory that stores image data, means for transmitting and receiving image data, and transmitting and receiving images. In this case, pixel density control means divides and performs pixel density conversion in the main scanning direction or sub-scanning direction between the image memory and the transmitting/receiving means and between the image memory and the image input section or image output section. The established configuration was adopted.

[Operation] According to the above configuration, pixel density conversion in the main scanning or sub-scanning direction is performed by dividing and converting image data when inputting and outputting image data to the image input section and output section, or when inputting and outputting image data to the image memory. , density conversion can be performed without causing any adverse effects on each input/output process.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

FIG. 1 shows an example of an image communication device adopting the present invention.
This figure shows the structure of a facsimile device that can perform image communication in G3 and G64 formats.

In the figure, what is indicated by the reference numeral 1 is an image reading section configured using an image sensor such as a COD line sensor. When reading a document, main scanning is performed by controlling the video clock of the image sensor, and sub-scanning is performed by moving the image sensor and the document relative to each other.

Further, the reference numeral 2 designates an image recording section that performs recording using a desired donmatrix method, such as a thermal printer. In the case of a thermal printer, the recording head has a length that is equal to the width of the recording medium, and the main scanning of the recording is performed from the control of the video clock without making the recording head scan, and by the relative movement of the recording head and the recording medium. Perform recording sub-scanning.

It is assumed that the image reading unit 1 and the image recording unit 2 have a standard resolution in the G3 system, that is, 16 pel in the main scanning direction and 15.4 pel in the sub-scanning direction.

When the image reading section 1 and the image recording section 2 as described above are provided as an image input section and pixel density conversion is performed to (from) the 04 method, conventionally, line duplication processing or line extraction in the sub-scanning direction is performed. In order to process
Processing speed decreases. However, in the main scanning direction, the pixel density can be adjusted by controlling the video clock.

Pixel density conversion in the main scanning direction does not affect processing speed.

In this embodiment, in consideration of this point, density conversion in the main scanning direction is performed during input/output for the image reading section 1 and image recording section 2, and density conversion in the sub-scanning direction is performed in the image reading section 1 and image recording section 2. Accordingly, image input/output is performed via the image memory, and density conversion in the sub-scanning direction is electronically performed during input/output to the image memory.

With such a configuration, pixel density conversion can be performed without reducing image input/output speed.

The configuration for the above processing will be described in detail below.

The image reading unit l extracts the image signal Vl using the vertical synchronization signal VSyncl, water cycle signal HSync1. Controlled by a video clock Vclk for synchronizing pixel reading. A bar above the sign of a signal in the figure indicates that the signal is negative logic active, but this bar will be omitted in the following text.

The image signal v1 outputted from the image reading unit 1 is inputted via a D flip-flop 7 to an encoder 9 that uses a run-length code such as the MH method, and is encoded.
and stored in the image memory 12. Signal control by the D flip-flop 7 and synchronization of the two-code processing by the encoder 9 are performed by circuit elements 3 to 6 and vertical synchronization signals VSync1. Horizontal synchronization signal H
Controlled by Syncl.

Cell 3 is a counter that counts 50 positive edges of the video clock Vclk, and when counting is completed, it outputs a carry CR to the OR gate 4 and the OR gate 6 via the input terminal 5. OR gate 4 is horizontal synchronization signal HS
The logical sum with yncl is used as a negative logic active signal, and the initial value of the counter 3 is preset.

The other input terminal of the OR gate 6 has a video clock V
C1k is input, and the output of the OR gate 6 changes in synchronization with the video clock VCIk.

The output signal of OR gate 6 is the new video clock VC
It is input to the D flip-flop 7 and encoder 9 as Ikll.

The counter 3, the OR gates 4 and 6, and the inverter 5 are used to perform density conversion of image data output from the image reading section 1 in the main scanning direction.

The encoder 9 encodes the image data output from the D flip-flop 7 using a predetermined encoding method based on the vertical synchronizing signal VSyncl, the horizontal synchronizing signal H5yncL, and the video clock VC1kll.

The encoded image data is stored in the image memory 12, and at this time the data is input via the data bus VB. Read/write address and input/output direction are interface signals! Controlled by ii/f.

On the other hand, when the image signal V2 is recorded by the one-image recording section 2, the five-image recording section 2 is synchronized by the vertical synchronization signal VSync2 and the horizontal synchronization signal H3ync2. Here, the horizontal synchronizing signal Hsync2 is returned from the image recording unit 2 side as the recording operation progresses. The 0 image value v2 is input to the image recording unit 2 via the D flip-flop 8.

The image data recorded by the image recording section 2 is stored in an image memory 12 in advance by being read by an image reading section l or received via one line, and is sent to an encoder 9 and a decoder 10 of the same type. After decoding (decoding) the data, the data is input to the image recording section 2. The decoding process of the decoder IO and the output operation of the D flip-flop 8 are synchronized by the video clock VC1k2 generated by the oscillator 11.

Each of the above parts consists of a microprocessor, etc.
Controlled by PU13. A control program for the CPU 13 is stored in the ROM 13a.

The CCU 14 performs encoding, decoding, modulation and demodulation of image signals according to the 04 system using the MMR system, line control, analysis and generation of procedural signals, and has a configuration similar to that of a known system. Image data to be transmitted and received is input and output between the CCU 14 and the line N.

Although not shown here, there is also a CCU that performs G3 transmission and reception, and the image data read by the image reading unit l by this CCU is transferred to the image memory 12.
The received image data is also recorded without density conversion.

Next, an explanation will be given of the operation when transmitting and receiving images in the G4 system using the image reading section 1 and the image recording section 2 having the pixel density of the 03 system in the above configuration.

As mentioned above, each image reading section 1 and image recording section 2 have 63
Since the resolution conforms to the standard, it is necessary to convert the pixel density from G3 to 04 when transmitting one image, and from G4 to 63 when receiving an image.

Therefore, when reading one image and sending it, there are 16 images in the main scanning direction.
-1 from pel (G3) to 15.7 pel (G4),
9% density conversion, and 15.4pe 1 in the sub-scanning direction
+1.9% from (G3) to 15.7pet (G4)
density conversion is required.

Conversely, when receiving and recording one image, it takes 15.7pe in the main scanning direction.
+1.9% density conversion from l (G4) to 16 pel (G3), and 15.7 pel (G
A density conversion of -1.9% from 3) to 15.4 pel (G4) is required.

Of this density conversion, conversion in the main scanning direction is performed during input/output between the image reading section 1, image recording section 2, and image memory 12, and conversion in the sub-scanning direction is performed between the image memory 12 and the CCU.
This is done during input/output between 14 and 14.

First, image reading? The case of transmitting the image read by A1 will be described in detail.

FIG. 2 shows the timing of each signal in FIG. 1.

Here, general signal timing when reading one image is shown.

In FIG. 2, the vertical synchronizing signal VSync is used to synchronize the beginning of the document, and this signal controls the start of reading 34 images of one page.

The horizontal synchronizing signal HSync synchronizes image reading line by line, and the video clock VC1k synchronizes image reading of one dot.

That is, image data is read out one dot at a time from the line sensor in synchronization with the video clock VC1k, and document feeding is performed every line in synchronization with the horizontal synchronization signal HSync to form the video signal V1.

The video signal v1 is input to the encoder 9, encoded to form one image data Vd, and stored in the one image memory 12.

FIG. 3 shows the main scanning density conversion performed by circuits 3 to 6 during image reading. Figure 3 1
The stage shows the video clock VC1kl, and the counter 3 counts this positive edge. When the count value of the counter 3 reaches 50, the counter 3 outputs a negative logic carry CR as shown in the middle row. As a result, the pulse of the video clock VC1kll outputted via the OR gate 6 disappears by l clocks as shown in the lower part of FIG. 3, so that the image data input to the D flip-flop 7 at this time is
A dot is removed.

Further, the count value 50 is again preset in the counter 3 via the OR gate 4 by the output of the carry CR. This initialization of the counter 3 is also performed every line in synchronization with the horizontal synchronizing signal HSync.

In this way, density conversion in the main scanning direction of the video signal input to the encoder 9 is performed by electronic processing of extracting one dot out of every 50 dots.

The encoder 9 encodes the input image data,
Since predetermined EOL (end-of-line) data is required at the end of one line, the EOL data is output in synchronization with the horizontal synchronization signal H5ync, as shown in Figure 4, and encoded data with EOL added. is stored in the image memory 12. When storing image data, the image data is stored in the image memory 12 in byte units for termination codes and make-up codes.
will be written to.

Density conversion in the sub-scanning direction is performed when reading data from the image memory 12. FIG. 5 shows the control procedure of the CPU 13 when transmitting the image data stored in the image memory 12 through density conversion in the main scanning direction as described above.

First, the CPU 13 takes out one byte of image data from the image memory 12 in step S1 of FIG. 5, and inputs it to the CCU l4 in step S2.

In step S3, the same data is written to the internal memory, and in step S4, it is determined whether the data processed in steps 5l-S3 is EOL.

If it is not EOL, the process returns to step S1 to continue processing the image data of that line.

If EOL is detected in step S4, step S5
Then, a software counter that counts the number of EOLs, that is, the number of processed lines, is incremented by one.

In step S5, it is determined whether or not the EOL counter has counted 50 lines. If 50 lines have not been transmitted, the process moves to step S7, and if it has, the process moves to step S8.

In step S7, the data stored in the internal memory is cleared for each line processed, and the process returns to step S1 to process the next line.

In step S8, one line of image data currently stored in the internal memory is used as the next line information.
Input to CU 14. And measure 50 lines E
Clear the OL counter in step S9 and proceed to step S1
Return to

When transmitting one image as described above.

Density conversion in the sub-scanning direction, in which the same line data is inserted every 50 lines, can be performed when reading data from the image memory 12.

On the other hand, density conversion when the received image data is recorded by the image recording section 2 is performed as follows. In this case, when writing the received image data to the image memory 12, pixel density conversion in the sub-scanning direction is performed, and the image memory 12
Also, when outputting to the image recording section 2, pixel density conversion in the main scanning direction is performed.

FIG. 6 shows the processing procedure of the CPU 13 when receiving an image.

In step 321 of FIG.
Receive from 14 and input 1 byte of data.

Next, in step S2, the state of the flag that controls line data extraction is determined, and if the flag is off, the process moves to step S23, and if it is on, the process moves to step S28.

In step S23, the image data input from the CCU 14 is written into the image memory 12, and in step S24,
Determine whether EOL is detected. If EOL is detected, the process moves to step S25, but if EOL is not detected, the process returns to step S21 to continue processing that image line.

In step S25, the EOL is used to count the number of lines mentioned above.
The counter is incremented by 1, and it is determined in step S26 whether or not it has reached 50. If 50 lines have not been processed, the process returns to step S2.1 and proceeds to process the next line.

When 50 lines have been counted, the line extraction flag is turned on and the process returns to step S21. This prevents writing of one line to the image memory 12 in step S23.

On the other hand, in step S28, EOL is detected and EO
If L is detected, the line extraction flag is turned off in step S29. This prohibits writing of data up to the end of one line.

As described above, when the image recording section 2 records the data stored in the image memory 12 with a pixel density of 15.7 pels, the image data is first read out from the image memory 12 and then decoded by the decoder 10. do.

At this time, 16pe where the oscillator 11 outputs image data
+ video clock VCl k2, and in synchronization with this video clock, the D flip-flop 8
By performing output control using , it is possible to perform pixel density conversion in the main scanning direction.

The above description assumes that the image reading section and the image recording section have a resolution of 63 system, but even if they have the resolution of another image communication system such as G4 system, pixel density conversion to a different image communication system can be performed using the same process. can be done.

[Effects of the Invention] As is clear from the above, according to the present invention, image communication is performed in which image data is transmitted and received at different pixel densities in the main scanning and sub-scanning directions of an image through image data storage processing in an image memory. The apparatus includes an image input section and an image output section having a constant pixel density, an image memory for storing image data, means for transmitting and receiving image data, and when transmitting or receiving images, the image memory and the transmitting and receiving means. Since the configuration includes a pixel density control means that performs pixel density conversion in the main scanning direction or sub-scanning direction separately between the image memory and the image input section or the image output section. By performing pixel density conversion in the main scanning or sub-scanning direction separately when inputting and outputting image data to and from the image input section and output section, or when inputting and outputting image data to and from the image memory, no harm is caused to each input and output process. You can perform density conversion as follows,
An excellent image communication device capable of high-speed image input/output processing can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an image communication device adopting the present invention, FIGS. 2 to 4 are timing charts showing the operation of the device in FIG. 1, and FIGS. 5 and 6, respectively. 2 are flowcharts showing image transmission and reception operations by the apparatus shown in FIG. 1, respectively. 1... Image reading section 2... Image recording section 3...
・Counter 4.6...Or gate 5...
inverter

Claims (1)

[Claims] In an image communication device that transmits and receives image data at different pixel densities in the main scanning and sub-scanning directions of an image through image data storage processing in an image memory, an image input section and an image output section each having a constant pixel density; When an image memory for storing image data and a means for transmitting/receiving image data are provided, and image data is to be transmitted or received, there is a space between the image memory and the transmitting/receiving means, and between the image memory and the image input section or the image output section. 1. An image communication device comprising a pixel density control means for dividing and performing pixel density conversion in the main scanning direction or the sub-scanning direction.