JPH01282961A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To execute the transmission and reception of picture data without damaging necessary information by selectively operating first and second converting means to convert the picture element density of transmitting picture data and receiving picture data. CONSTITUTION:A first picture element density converting part 51 is provided to convert the picture element density of the transmitting picture data from a picture reading part 50 and a second picture element density converting part 59 is provided to convert the picture element density of the receiving picture data. Changing-over switches 10 and 11 are controlled in correspondence to respective switching signals 16 and 17 from a control part 12 and an operating part 13 instructs the switching of the changing-over switches 10 and 11 to the control part 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a facsimile device for both G3/G4, and in particular has an image recording section or an image reading section having a predetermined pixel density for G3 or G4, The present invention relates to a facsimile device that performs pixel density conversion of a received image or a transmitted image.

[Prior Art] In recent years, standardization of facsimile machines has been progressing according to CCITT recommendations, and there are currently standards from Group 1 to Group 4 (hereinafter referred to as G1 to G4), each of which has different communication procedures and codes. The system employs methods such as Of these standards, facsimile machines compatible with 01 to G3 are analog devices mainly intended for public telephone networks, and facsimile machines compatible with G4 are digital devices intended for digital communication networks. Therefore, the communication image processing method is different, and in G3 compatible devices, the image signal is MH (
Modified Huffman) encoding is standard, while MMR (Extended Modified Read) encoding is standard in G4. Furthermore, the pixel density of the communication image is also different, with G3 having 8 pixels/mm in the main scanning direction and 3.0 pixels/mm in the sub-scanning direction.
G4 is a unit of millimeter system like m for 85 pixels.
The standard is inch system, such as 200 pixels/inch for both main and sub-scanning.

At present, analog lines (
The G3 standard, which uses public telephone lines), is the mainstream, but as the amount of communication information increases, the G4 standard, which uses digital lines, is the mainstream.
Standard facsimile machines are making inroads. G like this
With the shift from G3 to G4 standard equipment, facsimile machines compatible with G3 and G4, which are compatible with both G3 and G4 standards, have become popular.

FIG. 5 is a block diagram showing the configuration of such a facsimile machine that can be used for both G3 and G4. 50 is an image reading unit that optically reads a document and converts it into an electrical signal, 51 is a pixel density conversion unit, and The pixel density of the image signal is converted and output to the encoder 52. The encoder 52 compresses the pixel-converted read image data and stores it in the image memory 53.

In this way, when the communication destination facsimile device is a G4 device, the encoder/decoder 54 performs MMR encoding and the 04 communication section 55 transmits it to the communication line, and when communicating to a G3 device, the encoder/decoder performs MMR encoding. The G3 communication controller 57 encodes the received data into an MH code and transmits the code using the G3 communication controller 57.

Conversely, image data of the 04 standard can be sent to the 04 communication control unit 55.
When received, the encoder/decoder 54 decodes the MMR code and stores it in the image memory 53, and when the G3 communication controller 57 receives 03 standard image data, the encoder/decoder 56
The image is decoded and stored in the image memory 53. A decoder 58 decompresses the image data in the image memory 53 and decodes it into image data.The image data decoded by the decoder 58 is converted into a pixel density by a pixel conversion unit 59 and becomes an image for a thermal printer or the like. It is recorded by the recording section 6o.

[Problems to be Solved by the Invention] However, as described above, there is a difference in pixel density of image data between the G3 standard and the 04 standard. For example, if we assume that the pixel density of each of the image reading section 50 and the image recording section 60 in FIG. 200 pixels/inch) is the image recording section 60
Since the recording pixel density is equal to the recording pixel density in , the image reproduced by the recording section 6o matches the original original image. However, since the pixel density of G3 standard received image data received via an analog line is different from the pixel density of the image recording unit 6o, the image reproduced in the recording unit 60 has a different length and width from the original original image. It becomes a scaled version.

In other words, the pixel density in the millimeter system (G3 standard) corresponding to the image data in the inch system (G4 standard, 200x200 pixels/inch) is 8x7.7 pixels/mm, but the pixel density is 200x7.7 pixels/mm.
Converting 200 pixels/inch to mm is approximately 7.87X
Since the number of pixels is 7.87 pixels/mm, the millimeter image recorded by the image recording unit 6o becomes an image that is short in the vertical direction and lengthened in the horizontal direction.

This is shown in FIG. 6A, where 65 shows the original original image, and 66 shows the image reproduced in the millimeter system (G3) after reading the original 65 in the inch system (G4) described above. In order to eliminate such problems, pixel density conversion is performed in pixel conversion sections 51 and 59. This means, for example, that the pixel density of 8 x 7.7 pixels/mm in the G3 standard is 20 x 7.7 pixels/mm in the 04 standard.
When converting to a pixel density of 0x200 pixels/inch, 1 pixel is thinned out every 64 pixels in the main scanning direction, and 1 pixel column that is the same as the previous column is added to each pixel column in the sub-scanning direction. It is outputting.

In this way, the output image will be the same size as the original document image size, but the image quality will deteriorate because processing such as pixel data thinning and interpolation is performed during the pixel density conversion process. There is a problem. This is shown in Figure 6B, where 65 shows the same original document image as in Figure 6A.
67 undergoes pixel density conversion and is reproduced/played by the image recording section 60.
The recorded output document is shown.

In order to solve these problems, it is possible to adopt an image recording unit equipped with a printer that can automatically convert the pixel density and record, but this poses the problem of increasing product cost and is generally not Considering that the printer installed in the facsimile machine has a fixed pixel density,
It is absolutely necessary to convert the pixel density using software etc. and output it to the image recording unit, but if pixel conversion is always performed, as mentioned above, the image quality will deteriorate, for example, the size of the received image will fluctuate. Even in the case of images where image deterioration is more of a problem than image deterioration, there is always a problem that deterioration of reproduced images occurs.

The present invention has been made in view of the above-mentioned conventional examples, and for example, when there is no problem even if the size of the image fluctuates, but you do not want the image quality to deteriorate, or when you do not care if the image quality of the reproduced image deteriorates, It is an object of the present invention to provide a facsimile device that allows a user to select whether or not to perform pixel density conversion of image data in cases where different sizes of images are undesirable.

[Means for Solving the Problems] In order to achieve the above object, a facsimile apparatus of the present invention has the following configuration. That is, the facsimile apparatus is capable of transmitting an image and forming an image of a received image by converting the pixel density of received image data or transmitted image data, and the facsimile apparatus includes a first converting means for converting the pixel density of the transmitted image data; , a second conversion means for converting the pixel density of the received image data, and a selection means for selecting whether to cause each of the first and second conversion means to perform conversion processing.

[Operation] In the above configuration, pixel density conversion processing is executed by each of the first conversion means that converts the pixel density of the transmitted image data and the second conversion means that converts the pixel density of the received image data. It operates so that it can be selected by the selection means whether or not to do so.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Description of facsimile machine (Fig. 1)] Fig. 1 is a block diagram showing a schematic configuration of a facsimile machine according to an embodiment.
Parts common to the conventional facsimile machine in FIG. 5 are indicated by the same symbols.

Here, we will focus on the differences from the conventional example mentioned above.
Reference numerals 10 and 11 denote changeover switches, which operate to switch the connection to terminal a or terminal A in response to changeover signals 16 and 17 from the control section 12, respectively. The control unit 12 includes a CPU such as a microcomputer that controls the entire device, a ROM that stores CPU control programs and various data, and a RAM that is used as a work area for the CPU. 13 is the control unit 12
It is an operation unit that instructs switching of the changeover switches 1o and 11, and is equipped with an alternate key 14.15. When the key 14 is turned on, the switch 1O is set to the a side, and when the key 14 is turned off, the switch 1o is set to the b side. connected to. Similarly, when the key 15 is on, the switch 11 is connected to the a side, and when the key 15 is off, the switch 11 is connected to the b side.

[Operation Description (FIGS. 1 to 3)] FIG. 2 is a flowchart showing the transmission process in the facsimile machine of the embodiment, and FIG. 3 is a flowchart showing the reception process in the facsimile machine of the same embodiment.

In FIG. 2, a transmitted document is read by the image reading unit 50 in step S1, and if the switch 1o is connected to the a side, pixel density conversion is performed by the pixel density conversion unit 51 in step S3, and encoding processing is performed in step S4. However, if the switch 10 is connected to the b side, the process proceeds directly to encoding processing without performing pixel density conversion. In this way, data is compressed by the encoder 52 in step S4 and stored in the image memory 53 in step S5.

In step S6, M is selected depending on whether the transmission mode is G3 or 04.
H or MMR encoding is performed, and in step S7, the corresponding communication control unit (55 or 57) transmits the image data to the line.

In FIG. 3, when image data of G3 or G4 is received in step S10, the received image data is decoded by the corresponding encoder/decoder (54 or 56) in step S2, and stored in the image memory 53 in step S12. do. Step S1
3 reads the image data from the image memory 53 and decodes it (
If the switch 11 is connected to the a side in step S14, the pixel density conversion unit 59 performs pixel density conversion in step S15. Then, in step 816, the image recording section 60 forms an image of the image data subjected to pixel density conversion.

Further, if the switch 11 is connected to the b side, the process advances to step S16, and image formation is performed without performing pixel density conversion in the image recording section 6o such as a thermal printer.

[Description of key manual processing (FIG. 4)] FIG. 4 is a flowchart showing key manual processing from the operation section 13 in the control section 12 of the facsimile machine of the embodiment. This control program is stored in the ROM of the control section 12. Stored.

In step S20, a key signal of the operation unit 13 is inputted,
In step S21, it is checked whether the key 14 is turned on.

If the key 14 is on, the process proceeds to step S22, where the switching signal 16 is output and the switch 10 is connected to the a terminal side.

On the other hand, if the key 14 is off, the process advances to step S23;
The switching signal 16 connects the switch 10 to the b side.

Similarly, the state of the key 15 is checked in step S24, and if the key 15 is on, the process advances to step S25.
The switch 11 is connected to the a terminal side by the switching signal 17,
If the key 15 is off, the process advances to step S26 and the switch 11 is connected to the b terminal side.

In this way, if the key 14 is on, the image reading unit 5
The pixel density of the image signal read with 0 is converted and the key 1
If 5 is on, the pixel density of the received image signal will be converted.

To explain an example of this pixel density conversion, the image reading unit 50
Consider a case where the pixel density read by the image reading unit 50 is 8×7.7 pixels/mm, and the document image read by the image reading unit 50 is transmitted at 04. At this time, the operator presses key 1 on the operation unit 13.
When you press 4, the pixel density conversion unit 51 interpolates the same 1 pixel every 63 pixels, deletes 1 pixel column every 45 pixels in the sub-scanning direction, and converts the pixel density to 200X in the 64 method.
It corresponds to 200 pixels/inch.

For example, when the received image is 03 standard image data and the recording density of the image recording section 60 is 200 x 200 pixels/inch, the pixel density conversion section 59 converts the pixel density by turning on the switch 15. be exposed. This deletes one pixel for every 64 pixels in the main scanning direction of the image data, and adds one pixel column that is the same as the previous column for every 45 pixel columns in the sub-scanning direction. The image formed will be the same size as the received original.

In any of the above-described pixel density conversions, pixels are thinned out or added non-uniformly, resulting in deterioration in image quality even if the image sizes match.

Therefore, even if the sizes of the images are different, if you do not want to perform such pixel density conversion, you can turn off both or one of keys 14 and 15 to prevent pixel density conversion from being performed. .

Figure 7 shows a G3 standard facsimile machine 70 relaying a 04 standard facsimile machine 71 to a G3 standard facsimile machine 72.
facsimile machine 7.
If pixel density conversion is performed between 0 and 71, and pixel density conversion is also performed between facsimile devices 71 and 72, the transmitted image will deteriorate as shown at 75-77. In such a case, since the pixel densities of the machine 70 and the facsimile device 72 are the same, if the keys 14 and 15 of the operation unit 13 of each facsimile device are turned off, pixel density conversion will not be performed midway. Therefore, image data can be transmitted without deteriorating image quality.

In addition, not only in the case of such relays, but also when transmitting detailed originals such as photographs or information, by turning off keys 14 and 15 and transmitting and receiving without converting the pixel density,
Able to send detailed information accurately.

As described above, according to this embodiment, it is possible to select whether or not to perform pixel density conversion on transmitted and received images, thereby making it possible to transmit and receive image data without losing necessary information. This allows for example manuscripts such as photographic manuscripts in which even the smallest details are important, or manuscript image data such as designs in which the details of the information are not so important but accuracy in image size is required. This has the advantage that it is possible to select whether or not to perform pixel conversion in response to each request.

Further, in this embodiment, since the part for issuing conversion instructions is composed of simple switches and operation keys, the cost can be lower than adding a pixel conversion function to the printer or image reading section of the image recording section.

[Effects of the Invention] As explained above, according to the present invention, there is an effect that it is possible to select whether or not to perform pixel conversion of transmitted and received images.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of a facsimile machine according to an embodiment; FIG. 2 is a flowchart showing transmission processing in the facsimile machine according to the embodiment; FIG. 3 is a flowchart showing reception processing in the facsimile machine according to the embodiment; Figure 4 is a flowchart showing the key manual processing in the control unit, Figure 5 is a block diagram showing the schematic configuration of a conventional facsimile machine, and Figure 6A is the original document and its output without pixel density conversion. FIG. 6B is a diagram showing an original document and an example of an output document output by performing pixel density conversion on the original document, and FIG. 7 is a diagram showing an example of an original document when facsimile image data is relayed and transmitted. FIG. 3 is a diagram showing image deterioration due to pixel density conversion performed in each facsimile device. In the figure, 10.11...Selector switch, 12...Control unit, 13...Operation unit, 14.15...Key, 16.
17...Switching signal, 5o...Image reading section, 51.5
9... Pixel density conversion section, 52... Encoding section, 53.
... Image memory, 54.56 ... Encoding/decoding section, 5
5...G4 communication control unit, 57...G3 communication control unit,
58...Decoding section, 60... Image recording section, 61...
-Digital line, 62...Public telephone line (analog line). Patent Applicant: Canon Co., Ltd. Figure 4 Original tsubo, Otaka Output layer, Ohei Figure 6A redundant) Output layer, Kozue Figure 6B Figure 7

Claims (1)

[Claims] A facsimile device capable of converting the pixel density of received image data or transmitted image data to perform image transmission and image formation of the received image, the facsimile device comprising: a first converting means for converting the pixel density of the transmitted image data; A facsimile apparatus comprising: second converting means for converting pixel density of image data; and selecting means for selecting whether to cause each of the first and second converting means to perform conversion processing.