JPH06350833A - Facsimile equipment - Google Patents

Abstract

PURPOSE:To generate satisfactory picture data whose picture quality is faithful to an original picture without deteriorating the picture quality as much as possible when picture data equivalent to a normal mode is generated from picture data of a fine mode, for example. CONSTITUTION:At the time of converting picture data of a prescribed read mode into picture data of a read mode whose read pitch is larger, picture data G9-G12 with the number of rows less than that of picture elements in a matrix MX are generated based on the black/white distribution situation of the plural picture elements G0-G11 over an auxiliary scanning direction and a main scanning direction in the matrix MX in the unit of the prescribed matrix MX with the plural columns and plural rows of the respective picture elements of picture data at the prescribed read mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile machine.

[0002]

2. Description of the Related Art As is well known, a facsimile apparatus has a fine mode, a super fine mode, etc. as a reading mode of a document image in addition to a normal mode. However, depending on the model of the facsimile apparatus, a document feeding motor feeds a document. There is one in which the scanning is performed only in the fine mode in which the pitch is fixed and the scanning of the original image is performed. When carrying out normal mode facsimile communication in such a facsimile apparatus, it is necessary to convert image data read and scanned in the fine mode into normal mode image data. Therefore, conventionally, as such a conversion method, a process of thinning out image data obtained by reading and scanning in the fine mode for each line is performed. Further, as another means, there has been adopted a process of synthesizing image data of 3 lines in fine mode to create image data of 1 line by using a method called so-called 3 line synthesizing.

[0003]

However, in the former means described above, the thin mode image data is thinned in the main scanning direction in order to thin out the fine mode image data at every line interval. In that case, there is a problem that fine lines are missing in the reproduced image, and the image quality of the reproduced image is considerably deteriorated. On the other hand, in the latter means of the related art, the black and white of the pixels of one line is determined based on the black and white data of a plurality of pixels of three lines, and thus the phenomenon of thin line loss as in the former case does not easily occur. However, the latter three-line synthesizing means determines black and white of one pixel from three pixels in the same column across three lines, and the correlation between adjacent pixels in the sub-scanning direction. However, the black-and-white correlation between pixels adjacent in the main scanning direction is not considered at all. Therefore, even with such a three-line synthesizing means, the image quality is still inferior to the actual original image, and there is still room for improvement in this respect.

The present invention has been proposed in view of the above points. For example, when image data corresponding to the normal mode is created from image data in the fine mode, image data in a predetermined mode has a larger reading pitch than that. It is an object of the present invention to provide a facsimile apparatus capable of creating image data faithful to a document image without degrading the image quality as much as possible when converting the image data in the scanning mode.

[0005]

A facsimile apparatus according to the present invention, which has been proposed to achieve the above object, converts image data in a predetermined reading mode into image data in a reading mode having a larger reading pitch. In this case, in a predetermined matrix unit of a plurality of columns and a plurality of rows of each pixel of the image data in the predetermined reading mode, the matrix is formed based on the black and white distribution state of the pixels in both the sub-scanning direction and the main scanning direction in the matrix. It is configured to create image data having a smaller number of rows than the number of rows of pixels inside.

[0006]

In the facsimile apparatus according to the present invention having the above-mentioned structure, the image data in the predetermined reading mode is reduced to the image data having a smaller number of lines (the number of lines) to increase the reading pitch. Can be converted as image data in the reading mode. Thus, in the conversion processing of such image data, each pixel of the new image data is based on the black-and-white distribution situation of a plurality of pixels distributed in a predetermined matrix in both the sub-scanning direction and the main scanning direction. The black-and-white judgment processing is performed. Therefore, it is possible to bring the image data closer to the actual original image and to improve the image quality, as compared with the case where the image data is reduced based on the relation of the image data only in the sub-scanning direction.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a facsimile apparatus F according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an example of the hardware configuration of a facsimile apparatus F according to the present invention. This facsimile device F is a CCD for reading and scanning an image of a document 2 projected from a light source 1.
Reading sensor 3 such as a sensor, and this reading scanning sensor 3
2 for black-and-white binarization processing of the image signal (pixel signal) output from the A / D converter 9 and converted into a digital signal by the A / D converter 9.
The digitization processing circuit 4 is provided. This binarization processing circuit 4
A sub-line sampler 6, a hard codec 7, a printer 8 and the like are connected to the change-over switch 5 connected in the subsequent stage, and configured to transfer the black and white binarized image data to any one of them. There is.

Of the above, the subline sampler 6 is
It has the following functions to convert the image data read and scanned in the fine mode (7.71 / mm) into the image data corresponding to the normal mode (3.851 / mm). That is, the sub-line sampler 6 is used in the binarization processing circuit 4 as shown in FIG.
1, n2 ..) and a plurality of rows (m1, m2 ..) of image data are processed, for example, a matrix MX of 3 columns (n1 to n3) × 4 rows (m2 to m5) In this matrix MX, a total of nine pixels G0 to G8 are reduced in the sub-scanning direction and newly combined to create four pixels G9 to G12. Specifically, for example, if the target pixel whose black and white is to be determined at the present time is G12, and the creation processing of the other pixels G9 to G11, that is, the black and white determination processing has already been completed, this subline sampler 6 Then, the target pixel G1
2 black and white are newly created pixels G9 to G11 and other pixels G0 to G8 input from the binarization processing circuit 4 in total 1
It is determined based on the black and white distribution state of two pixels.

As the above determination method, a method using the equation shown in the equation 1 is adopted.

[Equation 1] As an example of the weighting factor wi of this equation, for example, the weighting factors w0 to w11 of each pixel as shown in FIG. 4 are adopted.
As the weighting factor wi, a value empirically obtained by experiments or the like is adopted, but in general, the pixel of interest G12
The closer to the pixel, the larger the value. Also, the peripheral pixel value P
As i, a black-and-white value of each of the pixels G0 to G11, that is, 0 in the case of white and 1 in the case of black is adopted.
Next, in the sub-line sampler 6, the value f obtained by the formula 1 is compared with a predetermined threshold value Th, and if the relation of f ≧ Th is satisfied, the pixel of interest G12 is black,
If the relationship of f <Th is satisfied, the target pixel G12 is determined to be white.

As described above, in the subline sampler 6,
When deciding the black and white of the pixel of interest G12, the pixel G0 obtained by the actual reading scan in one matrix MX.
To G11 image data and the previously created new pixel G9
The distribution of the total of 12 pixels from G11 in both the main scanning direction and the sub scanning direction is taken into consideration. In addition, the sub-line sampler 6 has one matrix MX.
When the black-and-white determination of the four pixels G9 to G12 in the pixel is completed, the matrix MX is shifted by one pixel to perform the same process as before, and a new pixel (G
Image data of pixels corresponding to 9 to G12) are sequentially created,
With respect to the image data of all lines input from the binarization processing circuit 4 side, it is configured to execute the creation processing of a new pixel in the matrix MX unit. Therefore,
Although the sub-line sampler 6 has the same number of columns as the image data obtained by the binarization processing circuit 4, it outputs image data with the number of rows (the number of lines) reduced to 1/2. Become.

FIG. 2 is an explanatory diagram showing an example of the hardware structure of the main part of the sub-line sampler 6. The sub-line sampler 6 has a register 20 to which the image data binarized in black and white is inputted from the binarization processing circuit 4, and a total of 12 pixels which store the image data of 12 pixels G0 to G11 shown in FIG. D flip-flop circuits D-FF0 to 1
1, a register 22 for storing each newly obtained image data of the pixels G9 to G11, and a ROM table 23
And so on. The latest image data in the matrix MX shown in FIG. 3, that is, the image data of the pixels G6, G3, and G0 is the D flip-flop circuits D-FF6 and D-FF.
3 and D-FF0 are respectively D-inputted, and each image data of the pixels G9 to G11 previously obtained is registered in the register 22.
From the D flip-flop circuits D-FF 9 to 11 are input. Furthermore, the other pixels G
Regarding 1, G2, G4, G5, G7, and G8, D flip-flop circuits D-FF0, D-FF1, and D-FF
3, the data output from the D-FF4, the D-FF6, and the D-FF7 are D-input. This is because it is not necessary to input new image data for all nine pixels G0 to G8 by shifting the matrix MX column by column along the main scanning direction.

In such a configuration, the sampling clock SCLK is input to each circuit, so that a total of 12
The image data of the pixels G0 to G11 are output from the D flip-flop circuits D-FF0 to D11. Then, the ROM table 23 outputs the data corresponding to these image data, that is, the same data as the data obtained by performing the calculation of the equation 1 and the comparison / determination process between the numerical value f obtained by this calculation and the threshold Th. . Therefore, this ROM23
From the image data of the target pixel G12
Output as 0 and black = 1.

In FIG. 2, reference numeral 24 is a means for switching and inputting predetermined substitute data to the D flip-flop circuit D-FF when edge processing of image data is performed. When processing the edge of the image data of each line, for example, when the matrix MX shown in FIG. 3 is located further to the left than the state shown in FIG. 3, a total of 12 peripheral pixels of the target pixel G12 is determined. Although the distribution situation cannot be taken into consideration, the above-mentioned means 24 is for inputting predetermined image data for edge processing instead of actual image data in such a case.

In FIG. 1, in addition to the above, in the facsimile apparatus F, a CPU 10 for executing operation control and signal processing control of each unit, a ROM 11 and a RAM 12 functioning as a system memory, an image memory 13, and a modem 14a. And line control unit 14b connected to line L
The facsimile communication control unit 14 and the like are also provided.

Next, the operation of the facsimile apparatus F having the above structure will be described. First, when the image of the original 2 is read and scanned by the reading sensor 3 at the fine mode pitch, it may be desired to transmit the image in the normal mode to the external facsimile machine. In such a case, such fine mode image data may be binarized and then input to the sub-line sampler 6 to create image data in which the number of lines is reduced to 1/2. As a result, image data obtained by reducing the image A of the document 2 as shown in FIG. 5A to 1/2 along the sub-scanning direction as shown in FIG. 5B is obtained. Incidentally, it is not reduced in the main scanning direction. Thus, in the reduction and conversion of the image data by the sub-line sampler 6, as described in FIG. 3, there is a total of 12 units in the unit of a fixed matrix MX that is wide in the main scanning direction as well as in the sub scanning direction. The target pixel G12 based on the black-and-white distribution status of the individual pixels GO to G11.
Has decided on black and white. Therefore, according to such processing,
In addition to the difficulty of missing fine lines in the sub-scanning direction, it is possible to create image data with good image quality in the main-scanning direction in consideration of the black and white situation.

The image data created and converted as described above is transferred to the hard codec 7 to encode / compress MR, MH, etc., and then the facsimile communication control unit 14 sends the image data to an external facsimile apparatus. And send it as is. When the receiving side facsimile apparatus prints out the received image data, the image data on the same line is repeatedly printed on the recording paper K twice at fine pitch intervals as shown in FIG. 5C, for example. It is only necessary to output the image, which makes it possible to obtain an image with good image quality.

In the above embodiment, the relationship between the fine mode and the normal mode has been described as an example, but the present invention is not limited to this. It goes without saying that the present invention can also be applied to the case of converting image data in the relationship between the fine mode and the super fine mode, for example.

[0018]

As can be understood from the above description, according to the facsimile apparatus of the present invention, when the image data in the predetermined mode is converted into the image data in the reading scan mode having a larger reading pitch than that, Since the black-and-white determination processing of each pixel of new image data is performed based on the black-and-white distribution status of a plurality of pixels distributed in a predetermined matrix in both the sub-scanning direction and the main-scanning direction to reduce the image data. To
Compared to the conventional method in which image data lines are simply thinned out or image data is reduced based on the relationship of image data only in the sub-scanning direction, image data that is faithful to the original image is created and the image quality of the reproduced image is improved. The effect that it can raise is acquired.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a facsimile apparatus according to the present invention.

FIG. 2 is an explanatory diagram showing a configuration of a main part of a subline sampler that constitutes a facsimile apparatus according to the present invention.

FIG. 3 is an explanatory diagram of a case where image data reduction and conversion processing is executed by the facsimile apparatus according to the present invention.

FIG. 4 is an explanatory diagram showing an example of weighting factors used when executing reduction and conversion processing of image data in the facsimile apparatus according to the present invention.

FIG. 5 is a diagram showing an example of a reduction processing state of image data and a reproduced image thereof.

[Explanation of symbols]

 1 light source 2 original 3 reading sensor 4 binarization processing circuit 6 sub-line sampler 7 hard codec 8 printer 10 CPU 14 facsimile communication control unit 20, 22 register 23 ROM table F facsimile machine

Claims (1)

[Claims] 1. When converting image data in a predetermined reading mode into image data in a reading mode having a larger reading pitch than that, a plurality of columns and a plurality of rows of pixels of the image data in the predetermined reading mode are predetermined. In this matrix unit, image data having a number of rows smaller than the number of rows of pixels in the matrix is created based on the black-and-white distribution state of pixels in both the sub-scanning direction and the main scanning direction in the matrix. Fax machine.