JPH03186895A - Method for forming outline font - Google Patents

Abstract

PURPOSE:To reduce a change between the aspect ratio of the whole picture element width of picture elements included in an original bit map font and the aspect ratio of a bit map font formed from an outline font after expanding the vertical/horizontal ratio of the original bit map font by vectorizing the outline of the expanded bit map font to form the outline font. CONSTITUTION:A bit map font constituted of mXn picture elements is expanded to (2m+1)X(2n+1) picture elements and the outline of the expanded bit map font is vectorized to form the outline font. Thereby, the aspect ratio of the line width of the formed outline font is approximately the same as that of the picture element width of the original bit map font. Since the aspect ratio of the picture element width of the bit map font obtained by magnifying the outline font is approximately equal to that of the original bit map font, a change in the appearance can be reduced, and even in the case of expressing an oblique line as an outline font, the pattern can be prevented from being divided by the outline font.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for generating outline font data from bitmap font data in electronic devices such as personal computers and word processors that have bitmap fonts but do not have outline fonts. Regarding.

[Conventional technology]

If bitmap font data is enlarged as it is, the edges will become rough and the appearance of the characters will be spoiled, so outline font data may be generated from it so that the edges become smooth lines. Conventional methods for generating outline font data include those described in Japanese Patent Publication No. 63-10433 or Japanese Patent Application Laid-Open No. 64-91176.

The method described in Japanese Patent Publication No. 63-10433 is a method that traces the outline of a bitmap font as it is, and the method described in Japanese Patent Application Laid-Open No. 64-91176 is a method that traces bitmap font data by an integral number of 2 or more. This method generates outline font data by enlarging the outline and converting it into hectors.

[Problem to be solved by the invention]

FIG. 4 shows an example of a partial pattern of a bitmap font of 6×6 pixels in the vertical and horizontal directions, where black circles indicate pixels belonging to the font pattern, and other parts indicate pixels belonging to the background pattern. In the former method, when the outline of a 1-pixel wide pattern is converted into a hector using bitmap coordinates as shown in Figure 4, the generated vector data is expressed as a set of coordinate values (], 2) - (4). , 2)-(1, 2), and the line width in the vector data (outline font pig) becomes O. Here, line width refers to the difference between the maximum and minimum values of the X coordinate (or Y coordinate) of a vertical line (or horizontal line) in hector data (outline font data).

Furthermore, when generating an outline font from a bitmap font, ideally the coordinates of the boundary between the font pattern and the background should be extracted.

However, since the P1-Map font is determined for pixels, coordinates cannot be defined at pixel boundaries. Therefore, the coordinates of the outline are actually obtained by extracting the pixels of the font pattern on the border. Therefore, the line width of the outline font data and the pixel width of the line of the bitmap font data differ by one. That is, if the line width of the outline font data is χ and the pixel width of the bitmap font data is Y, then X=Y-1.

When the vector data (outline font data) generated by the former method is expanded twice, it becomes (2, 4) - (8
, 4)-(2, 4), and the line width in the vector data remains O even after expansion.

In this way, in the former method disclosed in Japanese Patent Publication No. 63-10433, when outline font data is generated from bitmap font data having a partial pattern of 1 pixel width, after scaling the generated outline font, , even if you convert it to bitmap font data and display/print it, the line shown in the bitmap font will be 1 pixel wide regardless of the enlarged size, resulting in characters whose design is significantly different from the original bitmap font. will be generated.

In addition, in the latter method, the outline font is generated after multiplying the bitmap font data by an integer, so even if an outline font is generated from a bitmap font with a width of 1 pixel, the line width of the outline font will not become 0. do not have. However, even with this method, there is a drawback that when the character size is changed based on an outline font generated from a bitmap font, the aspect ratio of the pixel width of the original bitmap font is not accurately reproduced. For example, as shown in FIG.
Consider expanding a pixel-width bitmap font to twice its size and then vectorizing its outline to generate an outline font.

FIG. 6 shows the bitmap font of FIG. 5 enlarged twice. When this is vectorized in the vertical and horizontal 4 connected directions using pixels belonging to the font pattern as outlines, the generated vector data is as shown in Figure 6.
-(7,2)-(74)-(9,4)-(9,5)-
(79)(4,9)-(4,5)-(2,51(2,4
)(4,4)-(4,2), and the horizontal line width of the generated vector data is 5-4=1, and the vertical line width is 74-3. When this vector data is enlarged ten times and converted into bitmap font data, the horizontal pixel width of the enlarged bitmap font data becomes 1 xlO+1 = II pixels, and the vertical pixel width becomes 3XIO+I - 31 pixels. The above operations double the bitmap font data and multiply the outline font data by 10, so the original font is enlarged 20 times. However, if you multiply the original font data by 20, the horizontal pixel width will be I x 20.
=20 pixels, and the vertical pixel width is 2×20=40 pixels. That is, if an outline font is generated and then enlarged, the pixel width will have an aspect ratio that is significantly different from the pixel width aspect ratio of the original bitmap font. Furthermore, if the line segment pattern of 1 pixel width arranged in a 45-degree direction as shown in FIG. 7 is expanded three times using the method described in JP-A-64-91176, the pattern shown in FIG. 8 will be obtained. A pattern is obtained. When this is vectorized in the vertical and horizontal 4 connected directions, the generated data is (12, 3) - (1
4,3) -(14,5)(12,5) -(12,3
), (9,6)-(11,6)(11B)-(9,8)
-(9,6), (6°9)-(8,9)-(8,11)
-(6,11)(6,9),(3,12)-(5,1
2) - (5, 14) (3, 14) - (3, 12), which has the drawback that the pattern, which should originally be a continuous diagonal line, is divided by vectorization.

Japanese Patent Publication No. 63-10433 and Japanese Unexamined Patent Application Publication No. 63-1983 mentioned above
49] The disadvantage of the method described in Publication No. 176 is that in the case of high-resolution bitmap fonts exceeding 48 pixels x 48 pixels, the pixel width of the bit pattern that makes up the font is sufficiently wide, so it is difficult to see it. 48 pixels x 48
When converting a bitmap font of medium or low resolution, which is less than a pixel, to an outline, the above-mentioned drawback becomes noticeable because the pixel width is thin.

On the other hand, since such bitmap fonts are designed for composing main text, they are generally designed to have narrow pixel widths. Therefore, even if you simply enlarge the font, the aspect ratio of the pixel width to the font size will change, the pixel width will be narrow compared to the font size, and the characters will become weak and unsuitable for headings, etc. There were drawbacks.

The present invention was developed in view of the above circumstances, and after enlarging a bitmap font to 2 m + 1 pixel in height x 20 + 1 pixel in width, the outline is vectorized to generate an outline font. When scaling is performed, such as enlarging or reducing, there is little change in the aspect ratio of the pixel width of the original bitmap font from the aspect ratio of the bitmap font generated from the enlarged outline font, and the diagonal direction Even when a bitmap font with a pattern of To provide an outline font generation method capable of generating outline fonts.

[Means for solving the problem] A first outline font generation method according to the present invention includes:
In an outline font generation method in which an outline font is generated by enlarging a bitmap font composed of vertical and horizontal pixels (m and n are integers) and vectorizing the outline of the enlarged bitmap font, the bitmap font is Length and width (2m+1) X (2r++1
) pixel to a bitmap font and vectorize the outline of the enlarged bitmap font to generate an outline font. The outline font generation method for generating a font is characterized in that pixels of the outline of the bitmap font or pixels of the background adjacent thereto are specified at the time of selection, and the specified pixels are vectorized to generate the outline font.

[Effect]

In the present invention, when obtaining outline font data from bitmap font data consisting of m vertical pixels x horizontal n pixels, the coordinates of the bitmap font data (when i and N are pixels belonging to the bitmap font pattern, It is mapped to the coordinates (2i+1, 23+1), and the coordinates of the eight neighboring pixels of the mapped pixel are expanded to 21 pixels vertically x 2n+1 pixels horizontally as pixels that belong to the newly generated bitmap font pattern. , convert the outline into vectors to obtain outline font data.

As a result, the aspect ratio of the line width of the generated outline font is equal to the aspect ratio of the pixel width of the original bitmap font data. However, when you scale it, the aspect ratio does not change much. In addition, in order to control the line width of the generated outline font data, when vectorizing the outline, it is possible to selectively specify whether pixels belonging to the font pattern or pixels in the background adjacent to it are to be vectorized. .

〔Example〕

Hereinafter, the present invention will be explained based on drawings showing embodiments thereof.

FIG. 1 is a block diagram showing a schematic configuration of a font generation device used to implement the outline phone) generation method (hereinafter referred to as the method of the present invention) according to the present invention. The configuration of the font generation device will be explained along with its general operation based on FIG.

In the figure, 1 is the CPU, and the CI) U 1 is the RO
The following processing is executed according to the program stored in M2. The CPU 1 selects the font R based on the bitmap font characters specified on the keyboard 5, the size of the characters to be output, and their line widths.
Read the bitmap font data of the specified character from OM 3 and use the method of the present invention to create (2m+I
2nX ] ) and write it into RAM 4. Also C
The PU 1 traces the outline of the font pattern enlarged on the RAM 4 by specifying the line width from pixels belonging to the font pattern or pixels belonging to the background part, vectorizes it, generates an outline font, and generates the generated outline. Write font data to IlAM 4.

At this time, contour tracking can be done using, for example, the book written by Takeshi Angoin and Masayuki Nakajima.
"Computer Image Processing", Sanpo Publishing, 1979, P. 6
Known methods such as those described in Nos. 7 to 69 can be used.

In addition, the CPU 1 multiplies the outline font data written in the RAM 4 by a coefficient to convert it to the output size specified on the keyboard 5 and re-enter the output size. A.M.
Write in 4. If the contours of the outline font data generated here become rough and detract from the aesthetic appearance of the characters, a known smoothing algorithm can be applied to smooth the contours. By applying a known contour filling algorithm to the data generated in this way, CPI+
1 indicates that the characters specified on the keyboard 5 are displayed or printed on the CIIT 6 or the printer in the specified size and line width.

Next, the outline font generation procedure of the method of the present invention will be explained. Here, an example of generating an outline font from a bitmap font shown in FIG. 5 will be explained. The pixel at the coordinates (i, j) in the font pattern of a bitmap font with a width of 2 pixels horizontally and a width of 1 pixel vertically within 6 x 6 pixels (not shown in Figure 5) is expressed as the coordinates (2i+ 1, 2j-1-
1). Then, the 8 neighboring pixels of the mapped pixel, namely the coordinates (2i, 2j), (2i+1, 2
j), (2i + 2, 2j) (2i, 2j +
1 ), (2++ 2.2j-1-1), (2i, 2
j+2), (2i+1, 2j+2), (2i+ 2
, 2j+2) as pixels belonging to the newly generated font pattern, and enlarges the bitmap font of the specified character to 2m+1 pixels in height and 20+1 pixels in width. FIG. 2 is a diagram showing a bitmap font enlarged by the method of the present invention. Pixels in the outline of the bitmap font shown in FIG. 6 or in the background adjacent thereto are tracked and vectorized using a known method. .

At this time, when the pixels of the outline are traced in the vertical and horizontal 4 connected directions and converted into 2 vectors, the generated outline font data is (4, 2) - (8, 2) - (8, 4) (10
,4) −(10,6) −(8,6) −(810)
-(4,10) -(4,6) -(2,6)(2,4
) - (4, 4) - (4, 2), the vertical line width of the hector data is 6 - 4 = 2, and the horizontal line width is 8 - 4 wings 4. After expanding this data by a factor of 10, Foley, J, D, +
Van Ilam, A.
also of Interactive Compute
or Graphics, Addison-Wes
leyPubshing Company, 198
2. When the bitmap font data is converted into bitmap font data using the known method described in P.P., 457-460, the vertical pixel width of the enlarged bitmap font data is 2 x 10 + 1 =
21 pixels, and the horizontal pixel width is 4XIO-1-1=41 pixels. Even if the original bitmap font is multiplied by 20, the horizontal pixel width is 20 pixels and the vertical pixel width is 40 pixels, so according to the method of the present invention, even if the outline font is generated and then enlarged, the original via) map font The aspect ratio of pixel width can be preserved very well.

In addition, by specifying the line width from the keyboard 5, pixels in the background adjacent to the outline are specified, traced and converted into hectors, the generated outline font data is (3
,1)-(9,1)-(93)-(Il,3)-(1,
1,7)-(9,7)(911)-(3,11)-
(3,7) −(1,7)(L 3)−(3,3)−
(3,1), and the vertical line width of the hector deck is 7-3=
4. The horizontal line width is 9-3=6, making it a strong outline font with thick line width suitable for large enlargements.
This is suitable for emphasized characters such as headings. If this is enlarged 10 times and converted into a bitmap font using a known method, the vertical pixel width after enlargement will be 4X10+1-41 pixels, the horizontal pixel width will be 6 XIO+ 1 = 61 pixels, and the vertical pixel width will be smaller than the horizontal pixel width. The characters are emphasized and strong.

FIG. 3 is a diagram showing a bitmap font when a line segment pattern of 1 pixel width arranged in the 45° direction as shown in FIG. By making the eight neighboring pixels of pixel (2i+1, 2j+1) a newly generated font pattern, a bitmap font as shown in FIG. 3 can be obtained. When this is converted into a hector by contour tracing in 4 connected directions, (82) - (10, 2) - (10, 4) - (8, 4) (
8,6)-(6,6)-(6,8)-(/1(4,10
) −(2,10) −(2,8) −(48) −(4,
6) - (6, 6) - (6, 4) (8, 4) - (8, 2)
Therefore, the pattern is not broken by hectorization.

〔effect〕

As explained above, in the present invention, prior to converting into an outline, a bitmap font consisting of m×n pixels is enlarged to (2m+1)×(2n+1) pixels, and the enlarged bitmap font outline is converted into a hector. By generating an outline font, the aspect ratio of the line width of the generated outline font becomes the aspect ratio of the pixel width of the original bitmap font, and even if the outline font is scaled, The aspect ratio of the bitmap font pixel width and 8
) 5 The aspect ratio of the original bitmap font becomes approximately the same, and there are fewer changes in appearance. Furthermore, even when diagonal lines are converted into an outline font, the pattern is not divided by the outline font.

In addition, when converting to line fonts, by selectively specifying the outline of the bitmap font or the pixels in the background adjacent to it, excellent effects can be achieved, such as obtaining strong characters with thick line widths when enlarged. .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a font generation device used to implement the method of the present invention, and FIGS. 2 and 3 are enlargements of the partial patterns shown in FIGS. 5 and 7, respectively, using the method of the present invention. Figure 4 shows the bitmap font when
．． 5.7 is a diagram showing a partial pattern of a bitmap font, and FIGS. 6 and 8 are diagrams showing a bitmap font when the partial patterns shown in FIGS. 4 and 7 are respectively enlarged using the conventional method. It is. 6 I...CPU...ROM 3...Font ROM 4...RAM Patent

Claims (1)

[Claims] 1. Outline font generation that enlarges a bitmap font composed of m×n pixels (m and n are integers) and vectorizes the outline of the enlarged bitmap font to generate an outline font. In the method, the bitmap font is arranged vertically and horizontally (2m+1)×(2n
+1) An outline font generation method characterized by enlarging a pixel bitmap font and generating an outline font by vectorizing the outline of the enlarged bitmap font. 2. In an outline font generation method in which an outline font is generated by vectorizing the outline of a bitmap font, a pixel of the outline of the bitmap font or a pixel of the background adjacent to it is specified at the time of selection, and the specified pixel is vectorized. An outline font generation method characterized in that an outline font is generated using the following steps.