JPH0256874B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Description of the field to which the invention pertains The present invention relates to a dot character output processing device, particularly a dot image output device such as a facsimile machine that enlarges characters, etc. composed of dot characters vertically and horizontally. The present invention relates to a dot character output processing device that provides a high quality screen when outputting to a computer.

(2) Description of conventional technology When outputting a document expressed in character code form to a dot image output device such as a facsimile, a code/pattern (C/P) conversion process is used to convert the character code into a character pattern. Is required.
The dot characters used in the C/P conversion process are 16×16,
There are various types such as 18 x 16, 24 x 24, 32 x 32, etc., but when using these dot characters to output to a dot image output device such as a facsimile, it is necessary to create characters of the desired size with a good balance between vertical and horizontal directions. In order to obtain this, the number of vertical and horizontal pixels (referred to as enlargement ratio) that correspond to one dot of the dot character is adjusted. For example, 18 x 16 dot characters are approximately 4 mm square and vertical.
When outputting to a facsimile with a resolution of 3.85 lines/mm and 8 pixels/mm horizontally, each dot of an 18×16 dot character is enlarged by 1 times vertically and 2 times horizontally. In addition, the same 18 x 16 dot characters are vertically printed with dimensions of approximately 8 mm square.
When outputting to a facsimile with a resolution of 7.7 lines/mm and 8 pixels/mm horizontally, each dot of an 18×16 dot character is enlarged four times both vertically and horizontally. However, if the dot matrix size of the dot character is small, or if the magnification ratio is large even if the matrix size is large, the diagonal lines included in the dot character will appear blurred or the steps will become noticeable, resulting in poor character quality. It was hot. Figure 1 shows an example of 18x16 dot characters, and Figure 2 shows an example of 18x16 dot characters.
The character patterns are shown when the dots are enlarged four times both vertically and horizontally, but in both cases the diagonal lines appear faded and the diagonal lines are uneven, and the quality of the characters is not necessarily good.

(3) Purpose of the invention In order to eliminate these drawbacks, the present invention refers to the surrounding dots for each dot of a dot character,
By replacing each dot with a replacement pixel pattern according to the enlargement rate according to the logical conditions of the surrounding dots, interpolation processing that involves the addition or removal of black pixels is performed simultaneously with the enlargement process. The purpose is to improve the quality of output characters by smoothing diagonal lines.

(4) Explanation of the structure and operation of the invention Although the present invention is not limited thereto,
As shown in the figure, the 18 x 16 dot characters in Figure 1 are
The processing apparatus according to the present invention will be explained by taking as an example smoothing processing of a character pattern enlarged four times horizontally.

Figures 3a and 3b are diagrams showing examples of diagonal lines to be smoothed included in the dot characters in Figure 1;
2 corresponds to the dot unit of the dot character (the size varies depending on the enlargement ratio), and 2 corresponds to the pixel unit of the facsimile output character. Also the third
As shown in Figure c, dots 3 to 6 indicate the attributes of pixels in the pixel pattern replaced from the dots, 3 is a white pixel, 4 is a black pixel in a pixel pattern simply enlarged from a black dot, and 5 is a black pixel in a pixel pattern simply enlarged. A black pixel in a pixel pattern for interpolation (referred to as an interpolation pixel pattern) replaced from a white dot. 6 indicates a black pixel in an interpolation pixel pattern replaced from a black dot.

In the present invention, interpolation processing is performed with respect to diagonal lines included in dot characters, focusing on two types of parts that degrade character quality. That is, as shown in FIG. 3a, the diagonal line can be divided into two parts, the upper side and the lower side of the diagonal line, and in the present invention, as shown in FIG. For the dots below the diagonal lines, the black dots corresponding to the corners of the diagonal lines are replaced with an interpolation pixel pattern corresponding to the magnification ratio in which part of the pixels are made black as an interpolation process. Processing above the diagonal line is interpolation by adding black pixels, and processing below the diagonal line is interpolation by removing black pixels. On the other hand, when interpolation processing is not performed, the processed dots are replaced with simply enlarged pixel patterns (referred to as simple enlarged pixel patterns). In the following description, the interpolation pixel pattern and the simple enlarged pixel pattern will be collectively referred to as a replacement pixel pattern.

Next, interpolation logic conditions for determining whether or not to perform interpolation processing, and, if performed, how to interpolate, will be described. Figure 4 explains the reference range for establishing interpolation logic conditions, and a
~n, Z are each dot character 1 dot 1 (p
xq pixels), and Z specifically represents a dot to be processed. In the present invention, the 3.times.5 dots (an, Z) of the dot character are referred to, and if the interpolation logic conditions are met, the center dot Z is replaced with an interpolation pixel pattern. If the interpolation logic conditions are not met, the pixel pattern is replaced with a simple enlarged pixel pattern. The black pixel positions (interpolated positions) in the interpolated pixel pattern are located at the four corners of the processing dot Z, and these positions are based on the logic of the dots e, g, j, and h, that is, with the processing dot Z as the center. This can be determined using logic by referring to 3 x 3 character dots, but if interpolation processing (1) may round corners that should be right angles, or (2) may crush white dots, interpolation processing may be performed. Therefore, the reference range is expanded to 3×5 character dots and a logical condition is provided. This interpolation condition can be flexibly set according to the characteristics of the character pattern by considering (1) and (2) above. Figures 5a and 5b show examples of interpolation logic conditions corresponding to 3x5 reference dots. In the case shown in Figure 5a, the interpolation positions are one at the upper left and two at the upper left/lower left. This is a case in point. Regarding the representation of each dot, as shown in Figure 5b, 7 is a white dot (p x p pixels), 8 is a black dot, and 9 is a dot character that can be either white or black (don't care dot). show.
10 shows a case where a white dot is replaced with an interpolated pixel pattern as an interpolation process, and 11 shows a case where a black dot is replaced with an interpolated pixel pattern for explanation of interpolation positions. For example, when replacing the illustrated dot 1a with the dot 1b, when any of the patterns h, l, m, n shown in FIG. 5 appears in the reference range illustrated in FIG. Replace it with a character dot in the shape of dot 1b. However, this replacement is not performed when the illustrated pattern p appears. The same applies to other cases. Interpolation logic conditions for other interpolation positions can be obtained by making the conditions shown in FIG. 5 symmetrical upward/downward or left/right depending on the interpolation position.

Next, a replacement pixel pattern and its output will be explained. In the present invention, enlargement and interpolation processing is performed by replacing each dot of a dot character with a pixel pattern according to the enlargement rate, such as enlarging each dot of 4 x 4 pixels to 8 x 8 pixels.
For this process, a replacement pixel pattern corresponding to the maximum enlargement ratio according to the purpose is prepared in advance. The replacement pixel pattern consists of several interpolation pixel patterns in which some pixels are black, and an enlarged pixel pattern in which black or white dots are simply enlarged. One of the patterns is selected. Then, by sampling the selected pixel pattern according to a separately given enlargement rate, a pixel pattern to be replaced with the processed dot is output. FIG. 6 is an example of a replacement pixel pattern, which is used when interpolating the upper left corner of a processing dot. The replacement pixel pattern shown in FIG. 6 can be used up to a magnification of 8. In addition, the arrows in Figure 6 indicate the positions where the sample is taken.
Reference numeral 15 indicates sample positions in the vertical direction, and 16 to 19 indicate sample positions in the horizontal direction, each with an enlargement factor equal to the number of arrows. That is, for example, one character dot is 4
To obtain 4× pixels, extract the pixels corresponding to the intersections between the arrow positions 13 and 17, and the upper left corner will be black.
A pattern for 4 pixels is obtained. Therefore, by appropriately selecting the content or sample position of the replacement pixel pattern in this way, effective interpolation can be achieved regardless of whether the magnification is small or large, or if the magnification is different vertically/horizontally. can.

This figure shows an example in which the character pattern shown in FIG. 7 is processed using the interpolation processing conditions shown in FIG. 5, the interpolation pixel pattern shown in FIG. 6, and the sample positions shown at 13 and 17.

Next, embodiments according to the present invention will be described. 8th
The figure is a block diagram showing an embodiment, in which 20 is a buffer memory for storing dot characters, 21 to 22 are line memories for storing one line of dot characters, and 2 is a buffer memory for storing dot characters.
3 to 25 are shift registers corresponding to the reference dots in FIG. 4, 26 is a clock input terminal, 27 is an input terminal for enlargement ratio, 28 is a ROM for storing interpolation pixel patterns, and 29 is the output of shift registers 23 to 25. 30 is a ROM 28 that corresponds to the address selected by the output of the ROM 29.
A sample control circuit 31 samples the data according to the magnification input from the terminal 27.
This is a buffer memory that stores the output of the ROM28. The operation of the block diagram shown in FIG. 8, which is composed of these components, will be explained below.

First, a clock is applied to the terminal 26, and then a clock is applied to the terminal 27.
If you give vertical/horizontal enlargement ratio to , buffer memory 2
The pattern of dot characters from 0 is stored in line memories 21 and 22, shift registers 23 and 23 in dot units.
Transferred to 25. The ROM 29 reads the outputs of the shift registers 23 to 25 as address inputs every input clock, and outputs the address information of the pattern ROM 28 to the sample control circuit 30. Next, the sample control circuit 30 reads the contents of the ROM 28 corresponding to the address selected by the ROM 29.
The data are sequentially read out while being sampled at appropriate timings according to the vertical/horizontal enlargement ratio input from the terminal 27 and output to the buffer memory 31.

As described above, one dot of the dot character stored in the buffer memory 20 is read for each input clock, enlargement and interpolation processing are performed according to the vertical/horizontal enlargement ratio, and the corresponding processing dot is Outputs the pixel pattern that should be replaced. .
In principle, the present invention does not care about the type of dot characters (font, dot matrix size) or the type of dot image output device, so it cannot be applied to the case of outputting the 18 x 16 dot characters used in the above explanation to a facsimile. It is not limited.

(5) Explanation of Effects As explained above, according to the present invention, when outputting dot patterns such as characters composed of dot matrix to a dot image output device such as a facsimile, it is possible to achieve desired vertical/horizontal balance. For any enlargement ratio specified to obtain a character size of It has the advantage of being able to perform high-speed processing through sequential processing due to its hardware configuration. In addition, the present invention provides various types of dot characters (fonts,
This method has the advantage that it does not depend on the dot matrix size) or the type of dot image output device.

[Brief explanation of drawings]

Figure 1 is a diagram showing an 18x16 dot character, Figure 2 is a diagram showing a character pattern in which the dot character in Figure 1 is enlarged four times both vertically and horizontally, and Figure 3a is a diagram of the character pattern in Figure 1. An example of a diagonal line included in a dot character, FIG. 3B is an explanatory diagram showing the interpolation processing result for FIG. 3A, FIG. 3C is an explanatory diagram explaining the types of each character dot,
FIG. 4 is an explanatory diagram showing 3×5 reference dots necessary for the processing of the present invention, FIGS. 5 a and b are explanatory diagrams showing examples of interpolation pixel logic conditions necessary for the processing of the present invention,
FIG. 6 shows an example of a replacement pixel pattern necessary for the processing of the present invention, FIG. 7 shows an example of the processing according to the invention, and FIG. 8 shows a block diagram of an embodiment of the invention. In the figure, a to n, Z...Character dots in the reference dots, 1...Character dots, 2...Pixel units, 3...
...Black and white pixels, 4...Black pixels in the simple enlarged pixel pattern to be replaced with black dots, 5...Black pixels in the interpolation pixel pattern to be replaced with white dots, 6...Black pixels in the interpolation pixel pattern to be replaced with black dots, 7...
...White letter dot, 8...Black letter dot, 9...
Don't care character dots, 12-15...Horizontal sample position, 16-19...Vertical sample position, 20
...Buffer memory, 21, 22...Line memory, 23-25...Shift register, 26...Clock input terminal, 27...Enlargement rate input terminal, 28
... Replacement pixel pattern ROM, 29 ... Replacement pixel pattern address selection ROM, 30 ... Sample control circuit, 31 ... Buffer memory.

Claims (1)

[Scope of Claims] 1. In a dot character output processing device that converts a dot pattern composed of a dot matrix into a pixel pattern compatible with an output device,
and p from the dot pattern read out by the first means.
a second means for extracting a partial pattern for ×q dots; a third means for storing in advance a plurality of types of pixel patterns for performing enlargement and interpolation processing, each with a pixel pattern having the maximum enlargement rate; a fourth means for selecting one of the plurality of types of replacement pixel patterns stored by the third means from the logical condition of the reference dot extracted by the second means; and a fifth means for inputting a vertical/horizontal enlargement ratio. selecting one of the replacement pixel patterns having the pixel pattern with the maximum magnification rate by the fourth means, and sampling the replacement pixel pattern according to the magnification rate input by the fifth means; and a sixth means for outputting the reference range corresponding to the p×q partial pattern by the first means, while sequentially moving the reference range corresponding to the p×q partial pattern one dot at a time, and outputting the dot corresponding to the center dot of the reference range. By outputting the replacement pixel pattern for
A dot character output processing device characterized by performing vertical/horizontal enlargement processing of a dot character and interpolation processing involving addition or removal of black pixels simultaneously.