JPS63280574A - Conversion system for binary picture - Google Patents

Abstract

PURPOSE:To obtain a picture without distortion due to conversion by dividing a matrix picture being the result of magnified picture information before the conversion with a desired magnification and applying binary discrimination to each element so as to output a converted picture. CONSTITUTION:A conversion ratio calculation means 111 calculates the conversion ratio of a picture and a picture magnifying means 121 expands the picture information by a desired magnification in response to the conversion ratio to output a matrix picture. A picture information split means 131 divides the matrix picture by a desired division number and a picture element deciding means 141 applies binary discrimination to each divided element to output the conversion picture. After the matrix picture expanding the picture information before conversion is split, the binary discrimination of each divided element is applied, then the picture without distortion due to the conversion is obtained.

Description

[Detailed Description of the Invention] [Summary] This is a binary image conversion method in which a matrix image obtained by enlarging pre-conversion image information at a desired magnification is divided, a binary judgment is made for each element, and conversion is performed. By outputting the image, it is possible to obtain an image without distortion due to conversion.

[Industrial application field]

The present invention relates to a binary image conversion method, and more particularly, to a binary image conversion method for enlarging or reducing a read image in a facsimile machine, for example.

[Prior Art] For example, a known facsimile device can transmit image information of a document such as text and photographs to a long distance using a communication line. At present, image communication can be carried out via public telephone lines, so such facsimile devices have been widely used in the era of office automation.

Generally, when transmitting image data read from a document by a sending facsimile machine to another facsimile machine,
If the size of the original scanned on the sending side differs from the recording paper size output on the receiving side, or when the pixel density read on the sending side differs from the pixel density output on the receiving side, the image information of the scanned original It becomes necessary to expand or reduce the number of constituent pixels.

For example, the original to be read on the sending side and the recording paper output on the receiving side are both A4 size, and the image information density on the sending side is 2.
If the image information density on the receiving side is 240 dpi, it is necessary to enlarge the read image information at a ratio of 200:240=5:6.

FIG. 5 shows an explanation of a conventional example when enlarging image information of a read document. (b) is a part of the scanned image (
5 pixels x 5 pixels), and (b) shows the image information (6 pixels x 6 pixels) when the image information shown in (a) is expanded.
pixel).

In the figure, the shaded areas correspond to black pixels, which correspond to image information "1" in the facsimile machine.Other areas correspond to white pixels, which correspond to image information "0". ing.

Conventionally, in order to expand the image information of 5 pixels to the image information of 6 pixels, the image information of a certain line was focused on, and the same 1 line as the image information was expanded.
Image information for each line was added.

On the other hand, when reducing the image information of 6 pixels to the image information of 5 pixels, some of the image information is deleted.

[Problem that the invention seeks to solve]

By the way, in the conventional method described above, pixels are added or deleted every few pixels depending on the pixel ratio of the original image and the converted image, so the resulting converted image is
There was a problem that the original image was distorted.

The present invention was created in view of the above points, and an object of the present invention is to provide a binary image conversion method that makes it possible to obtain an image free from distortion due to conversion.

[Means for solving problems]

FIG. 1 is a principle block diagram of the binary image conversion method of the present invention.

In the figure, conversion ratio calculation means 111 calculates the conversion ratio before and after image conversion.

The image information enlarging means 121 receives the image information of the image before conversion, and outputs a matrix image obtained by enlarging the image information at a desired magnification according to the conversion ratio calculated by the conversion ratio calculating means 111.

The image information dividing means 131 divides the matrix image output from the image information enlarging means 121 into a desired number of divisions.

The pixel determining means 141 performs binary judgment on each element of the matrix image divided by the image information dividing means 131,
Get the transformed image.

Therefore, the system as a whole is configured to perform binary determination after dividing the matrix image obtained by expanding the introduced image information.

[For production]

The conversion ratio calculating means 111 calculates the conversion ratio of the image, and the image information enlarging means 121 enlarges the image information at a desired magnification according to the conversion ratio and outputs a matrix image.

The image information dividing means 131 divides the matrix image into a desired number of divisions, and the pixel determining means 141 performs binary determination on each divided element and outputs a converted image.

In the present invention, after dividing a matrix image obtained by enlarging the pre-conversion image information, binary determination is performed on each divided element, thereby making it possible to obtain an image free from distortion caused by conversion.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 shows the configuration of a binary image conversion method in an embodiment of the present invention.

(2) Correspondence between the embodiment and FIG. 1 Here, the correspondence between the embodiment of the present invention and FIG. 1 will be shown.

The conversion ratio calculation means 111 corresponds to the image processing section 211.

The image information enlarging means 121 corresponds to the image converting section 221° conversion matrix storage section 253.

The image information dividing unit 131 corresponds to the image converting unit 221° conversion matrix storage unit 253.

The pixel determining means 141 corresponds to the image converting section 221.

Examples of the present invention will be described below assuming that the correspondence relationship as described above exists.

In FIG. 2, the facsimile device 200 includes a reading unit 263 that reads image information of a transmitted original, a recording unit 265 that prints image information of a received original, and a compressor for compressing transmitted data. and image processing unit 2 for restoring received data.
11, a memory 251 for storing transmitted and received data, a modem 275 for modulating and demodulating data, a network control device 273 for controlling external lines, and a network control device 273 for transmitting and receiving instruction signals and data. modem 275
, a main control section 210 that performs overall control, and an operation panel 261 through which an operator manually inputs instructions and data.

The memory 251 also includes a conversion matrix storage section 253 that stores work data for obtaining a conversion section from the received image information. The image processing section 211 includes an image conversion section 22 that performs control for enlarging/reducing the received image information.
Contains 1.

Main control unit 21O1 line control unit 2711 image processing unit 211
．． Memories 251 are connected by a bus.

Instructions and data from the operation panel 261 are sent to the main control unit 210.
is input. The image data read by the reading section 263 is input to the image processing section 211.

Received data from the image processing section 211 is input to the recording section 265.

The transmission data is sent to the line controller 271. It is output from the network control device 273 via the modem 275. The received data is received by the network controller 273 and input to the line controller 271 via the modem 275.

The line control unit 271 and network control device 273 are connected and input and output control signals to and from each other.

Facsimile machine 200 and facsimile machine 290 are connected via an external public line. The configuration of facsimile machine 290 is the same as that of facsimile machine 200, and the description thereof will be omitted.

(2) Operation of the Embodiment FIG. 3 shows the operation of the binary image conversion method in the embodiment.

Moreover, FIG. 4 shows image information in the embodiment.

(a) is the image information of a part of the original image (5 pixels x 5 pixels), (b) is the image information that is six times the number of pixels of the image information shown in (a), and (c) is the image information of a part of the original image (5 pixels x 5 pixels). The image information after conversion is shown.

Now, consider a case where the facsimile device 200 receives image information of a document sent from the facsimile device 290 and expands the number of pixels of 200 dpi to the number of pixels of 240 dpi in both the horizontal and vertical directions within the facsimile device 200. It is assumed that the image information received by the facsimile device 200 has already been stored in the memory 251.

Hereinafter, reference will be made to FIGS. 2 to 4.

First, the image conversion unit 221 converts the facsimile device 290
The horizontal and vertical ratios for enlarging/reducing the number of constituent pixels of the original document received from are calculated (step 311). The number of constituent pixels of the received image is 200 dpi, and the number of constituent pixels of the image to be output from the facsimile device 200 is 2.
Since it is 40dpi, 200dpi: 240d
pi-5: becomes 6.

Therefore, if the horizontal expansion ratio is X, :X, then :X
, =5:6. Similarly, the vertical enlargement ratio is Yo:Y
t, then Yo:Yt=5:6.

Next, the image conversion unit 221 reads the received image information stored in the memory 251 and divides the image information according to the value XO+Y0 of the enlargement ratio for the original image determined in step 311 (step 312). The result is stored in the conversion matrix storage section 253.

The horizontal direction of the image information stored in the memory 251 is
(=5), the image information is divided into 1 block of 5 pixels x 5 pixels by dividing the image into pixels of y and (=s) in the vertical direction. FIG. 4(A) shows image information of 5 pixels×5 pixels extracted as a certain block.

Next, the image conversion unit 221 converts each pixel of the blocks divided in step 312 to the value X+ for the converted image of the enlargement ratio.
, Yt (step 313), and the result is stored in the conversion matrix storage section 253. X,=6.
Since Yl = 6, a matrix image is obtained in which each pixel is expanded to 6×6 pixels.

Next, the image conversion unit 221 divides the matrix image according to the enlargement ratio values X, (=6) and Y, (=6) for the converted image (step 314).

The matrix image is divided into six parts both vertically and horizontally, and the results are stored in the conversion matrix storage section 253. Figure 4 (b) shows (
An explanation of the image information obtained by dividing the matrix image obtained from one block shown in b) in step 314 will be shown below.

Next, the image conversion unit 221 performs a binary determination for each element divided in step 314 (step 315). Do the following.

When the number of white pixels and black pixels is the same, it is determined that the pixel is a black pixel.

The image conversion unit 221 performs the binary determination in step 315 on all divided elements in the block, and obtains image information of 6 pixels x 6 pixels after enlargement (step 316).
Figure (c) shows the results of binary determination for each divided element of the matrix image shown in (b). In the figure,
Each division element of image information shown in (b) (6 pixels x 6 pixels)
corresponds to one pixel shown in (c). In this way, in step 316, pixel information of 6 pixels x 6 pixels is obtained from the 5 pixel x 5 pixel pixel information of the expanded light divided in step 312. The obtained image information is stored in the memory 251.

Next, the image conversion unit 221 determines whether the binary determination in step 316 has been completed for all blocks (
step 317). If there remain blocks for which the binary determination has not been completed, a negative determination is made, and the processing from step 313 onward is repeated for the blocks for which the binary determination has not been completed.

When binary judgment is completed for all blocks, step 3
An affirmative determination is made in step 17, and the process ends.

First, the image conversion unit 221 converts the image information of the expanded light into 5 pixels×
Divide into blocks of 5 pixels, and divide each pixel in the block into 6
Enlarge to 6 pixels x 6 pixels. Next, the vertical pixels and horizontal pixels of the enlarged pixel block are divided into six, and a binary determination is performed for each divided element. In this way, pixel information of 5 pixels x 5 pixels can be converted to pixel information of 6 pixels x 6 pixels.

Therefore, an image without distortion due to enlargement can be obtained.

Although the above-described embodiment of the present invention considers increasing the number of pixels, the same applies to reducing the number of pixels. We have considered the case where image information received by the facsimile machine 2200 and stored in the memory 251 is enlarged, but the reading unit 26
The same applies to the case where the image information read in step 3 is enlarged and then transmitted to the facsimile device 290.

In addition, in the embodiment, a binary decision was made by majority vote, but since a normal document for facsimile communication has a large proportion of white pixels, a binary decision was made taking into account the ratio of white pixels to black pixels.
By performing value judgment, it becomes possible to perform more natural scaling.

The present invention can be applied to equipment that performs digital processing of image data.

Furthermore, in ``correspondence between examples and FIG. 1'',
Although the correspondence between FIG. 1 and the present invention has been described, those skilled in the art will easily imagine that the present invention is not limited to this and that there are various modifications.

〔Effect of the invention〕

As described above, according to the present invention, a converted image can be obtained by dividing a matrix image obtained by enlarging the pre-conversion image information at a desired magnification and performing binary judgment for each element. It is extremely useful.

[Brief Description of the Drawings] Fig. 1 is a principle block diagram of the binary image conversion method of the present invention, Fig. 2 is a block diagram of an embodiment to which the binary image conversion method of the present invention is applied, and Fig. 3 FIG. 4 is an explanatory diagram of the operation of one embodiment of the present invention, FIG. 4 is an explanatory diagram of image information of one embodiment of the present invention, and FIG. 5 is an explanatory diagram of a conventional example. In the figure, 111 is a conversion ratio calculating means, 121 is an image information enlarging means, 131 is an image information dividing means, 141 is a pixel determining means, 200, 290 is a facsimile device, 210 is a main control section, 211 is an image processing section, 221 251 is a memory, 253 is a conversion matrix storage unit, 261 is an operation panel, 263 is a reading unit, 265 is a recording unit, 271 is a line control unit, 273 is a network control device, and 275 is a modem. The scraps of the present invention! Block diagram No. 1 Construction drawing Supporting strength of the support force I Lβ Month diagram No. 3 (A) ) Figure 5

Claims (1)

[Claims] Conversion ratio calculation means (1
11), the image information of the image before conversion is introduced, and the conversion ratio calculation means (1
Image information enlarging means (1) outputs a matrix image obtained by enlarging the image information at a desired magnification according to the conversion ratio calculated in step 11)
21), image information dividing means (131) for dividing the matrix image output from the image information expanding means (121) into a desired number of divisions, and for each element of the matrix image divided by the image information dividing means (131). pixel determination means (141) for performing a binary determination to obtain a converted image; and a pixel determining means (141) for performing a binary determination to obtain a converted image, and is characterized in that it is configured to perform a binary determination after dividing a matrix image obtained by enlarging the image information. Binary image conversion method.