JPH0683950A - Smoothing interpolation system for facsimile equipment or printer - Google Patents

Abstract

PURPOSE:To perform smooth interpolation by solving lack of continuity of a character or a figure when original pixels are doubled as they are in 100-to-200 dpi enlargement line density conversion. CONSTITUTION:This system has a (m)-line, (n)-column window memory part which stores binarized data to be processed, and a center point is set at a reference pixel (p); and data of four pixels in two lines and two columns are processed by a logical arithmetic part 2 from the reference pixel (p) and its peripheral pixels to a reference pixel point and outputted to an arithmetic output part 3. When the reference pixel P is set at all points on an original image, an image which is doubled in a main scanning and a subscanning direction is obtained. Therefore, the logic of the logical arithmetic part 2 of this system is altered to easily obtain an image whose outline is smooth.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can be used in facsimile machines and printers, and in particular, in smoothing interpolation which can be used in linear density conversion when recording in a printer having a fine linear density or in doubling a recorded image. Regarding the scheme.

[0002]

2. Description of the Related Art As shown in FIG. 3, a smoothing data interpolation method in a conventional facsimile apparatus or printer has a main scanning interpolation section 7 and a sub-scanning interpolation section 8, and the interpolated data is output by a printer output section 9. It is designed to output. Next, the operation will be described.

When the linear density of data to be recorded by the printer is 200 dpi and the resolution of the printer is 400 dpi, the main scanning interpolation section 7 doubles the linear density in the main scanning direction when printing out. Sub-scanning interpolation unit 8
Doubles the line density in the sub-scanning direction with 400 dp data
Print out after setting the linear density to i. Next, the main scanning interpolation method will be described.

In the main scanning interpolation method, as shown in FIGS. 4A and 4B, FIG. 4A is an original image and FIG. 4B is an interpolated image. The images a to h in FIG. 4A are doubled in the main scanning direction and interpolated into A0 to H0 and A1 to H1. The interpolation logic at this time is shown in Equation 1.

## EQU1 ## A0 = a A1 = f (a, b, e, f) B0 = b B1 = f (b, c, f, g) where f () is a logical operation function.

As described above, the original images are interpolated for A0 to H0, and A1 to H1 are obtained from the four surrounding pixels by a logical expression. Next, the sub-scanning interpolation method will be described.

In the sub-scanning interpolation method, as shown in FIGS. 5A and 5B, FIG. 5A shows an original image (image before sub-scanning interpolation) and FIG. 5B shows an image after interpolation. Is. Pixels a to h in FIG. 5A are doubled in the sub-scanning direction to generate pixels A0 to H0,
Interpolated into A1 to H1. Equation 2 shows the interpolation logic.

## EQU00002 ## A0 = a A1 = f (a, b, e, f) B0 = b B1 = f (b, c, f, g) C0 = c C1 = f (c, d, g, h) , F () are logical operation functions.

As described above, in A0 to H0, the original image is A
1 to H1 are obtained from four surrounding pixels by a logical expression.

[0008]

However, in the above conventional smoothing interpolation method, in order to further interpolate the data after the main scanning interpolation in the sub-scanning direction, the interpolated data is obtained by further interpolation. The resulting image is likely to be worse than the original image.

Further, there is a drawback in that the obtained image is crushed and the resolution is lowered depending on how to take the logic.

The present invention has been made in view of the above-mentioned conventional circumstances, and therefore, the object of the present invention is to provide a novel smoothing for a facsimile or printer which can solve the above-mentioned drawbacks inherent in the prior art. It is to provide an interpolation method.

[0011]

In order to achieve the above object, a smoothing interpolation method in a facsimile and a printer according to the present invention stores an input image signal in a window memory unit of m lines and n columns, and a reference pixel. Section, the logical operation section performs logical operation from the reference pixel and its surrounding pixels to simultaneously interpolate four pixels in two lines and two columns simultaneously in main scanning and sub-scanning, and the interpolated pixels are sent to the printer section. It has a function to output.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail with reference to the accompanying drawings with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

Referring to FIG. 1, binary data of 0 and 1 accumulated in the window memory unit 1 of m lines and n columns has a central pixel as a reference pixel, and this reference pixel is p.
In the reference pixel portion, like the logic output unit 3, 4 pixels of 2 lines and 2 columns of X0 to X3 and 4 pixels of the reference pixel p of m lines and n columns are arranged.
And the surrounding pixels to obtain the respective values by the functions defined in the logical operation unit 2. The data of the logical operation unit 3 thus obtained is printed by the printout unit 4.

The logical operation method will be described with reference to FIG. 2 by taking the window memory unit 1 with 3 lines and 3 columns as an example.

FIG. 2A shows the original image, and FIG. 2B shows the image after interpolation. The interpolated images X0 to X3 are obtained by logical operation from a to i of the original image according to the equation (3).

X0 = f ₀ (a, b, c, d, e, f, g, h, i) X1 = f ₁ (a, b, c, d, e, f, g, h, i) X2 = f ₂ (a, b, c, d, e, f, g, h, i) X3 = f ₃ (a, b, c, d, e, f, g, h, i) where f ₀ ~ F ₃ are different logical operation functions.

If a logical operation function is defined as shown in Equation 3 and Equation 4, an image in which the original image is doubled in the main and sub directions can be obtained.

X0 = f ₀ (a, b, c, d, e, f, g, h, i) = e X1 = f ₁ (a, b, c, d, e, f, g, h, i) = e X2 = f ₂ (a, b, c, d, e, f, g, h, i) = e X3 = f ₃ (a, b, c, d, e, f, g, h, i) = e By changing this arithmetic expression to various expressions, it is possible to easily change the property of the image to be obtained. As described above, the processing for one reference pixel can be performed.

If the window of m lines and n columns is moved by one pixel in the main scanning direction and also by one line in the sub-scanning direction, all pixels of the original image become reference pixels, and
A sub-doubled image is obtained. At this time, there are pixel points where the surrounding pixels of the reference pixel are not on the original image. In this case, if the pixel points that are not on the original image are fixed to either white or black, the original method will be used. All pixel points on the image can be smoothed and interpolated.

[0019]

As described above, according to the present invention,
In order to simultaneously interpolate the input binarized data in the main scanning and sub-scanning directions, line density conversion, smoothing the contours of characters and the like at the time of double magnification, thickening the line width, It is possible to efficiently perform conversion processing of the original image such as thinning the line width.

According to the present invention, the arithmetic expression of the logical operation unit is also obtained from the original image, so that the arithmetic expression can be simply constructed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a logical system of the present invention, (a)
Is a window showing the original image, and (b) is a window showing the image after interpolation.

FIG. 3 is a block diagram for explaining a conventional method.

FIG. 4 is a schematic diagram illustrating conventional main scanning interpolation,
(A) is a window showing an original image, and (b) is a window showing an image after interpolation.

5A and 5B are schematic diagrams illustrating a conventional sub-scanning interpolation method. FIG. 5A is a window showing an original image, and FIG. 5B is a window showing an image after interpolation.

[Explanation of symbols]

 1 ... m line n column window memory unit 2 ... logical operation unit 3 ... calculation output unit 4 ... printout unit 5 ... window of 3 lines 3 columns of original image 6 ... window after interpolation 7 ... main scanning interpolation unit 8 ... sub Scan interpolation unit 9 ... Printer output unit 10 ... Main scan interpolation original image window 11 ... Main scan interpolation window 12 ... Sub scan interpolation original image window 13 ... Sub scan interpolation window

Claims (1)

[Claims] 1. m lines of printout data when binary density data is converted to double the linear density in both main scanning and sub-scanning, or when the image is doubled in the main scanning and sub-scanning directions. It has a window memory unit of n columns, and uses the center point of the window memory unit as a reference pixel, and interpolates the data for 4 pixels of 2 lines and 2 columns from the reference pixel and surrounding data to a reference pixel point by a logical operation. By doing
A smoothing interpolation method for facsimiles and printers, which is characterized in that main scanning and sub-scanning are doubled at the same time.