JPH06274151A - Hinting processing method - Google Patents

Abstract

PURPOSE:To easily enlarge or reduce an outline font while holding its symmetry by moving the outline points which constitutes the outline font so that a control point after the enlargement or reduction moves to a specific position. CONSTITUTION:Outline data are read out of a font file 1 and a control point is inputted from a control point information input part 6 and added to the outline font. The control point is, for example, the intersection of the axis of vertical symmetry and the axis of horizontal symmetry of a figure which is vertically and horizontally symmetrical. Then the control point is moved to the center or border of a pixel after enlargement or reduction and all the outline points constituting the outline font are moved according to the quantity of the movement to generate bit map data 5. Consequently, the symmetry of the outline font is maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hinting method for symmetrical figures, especially line-symmetrical and point-symmetrical figures.

[0002]

2. Description of the Related Art FIG. 15 is a processing configuration diagram of a conventional outline font. The outline data read from the font file 1 is expanded as a contour line in the expansion unit 2 and scaled as needed, and the hinting processing unit 3 performs line width correction or the like on the outline data according to the hinting information. Hinting is applied, and the rasterizer 4 performs a filling process to expand the contour into bitmap data 5.

Regarding the above-mentioned technology, NIKK
EI BYTE / JUNE 1992pp158-165
(Reference 1), same FEBRRUARY 1992 pp11
2-123 (reference 2).

In the following description, it is assumed that the pixel is a unit square with the grid point at the lower left corner, and therefore the center of the pixel is (m + 0.5, n + 0.5), where m and n are integers. . Of course, the grid point may be assumed to be the pixel center.

The problem of the prior art will be described using an example in which a character "H" designed in a space of 256 × 256 pixels is reduced to 16 × 16 pixels. The outline data read from the font file 1 is shown in FIG.
It is developed on the memory as a contour line as shown in. When the outline data is reduced to 16 × 16 pixels, the data shown in FIG. 17 is obtained.

Here, if a filling rule is adopted for the filling processing, that is, a pixel having a pixel center on or inside a contour line is inverted, the left vertical stem becomes 2 pixels and the right vertical stem. Becomes 1 pixel.

Further, when the x and y coordinates of each point are rounded off, FIG. 18 is obtained, and in this case as well, the thickness of the vertical stem is different. On the other hand, when rounding up or down is used instead of rounding, the stem on the right side becomes thicker and the stem on the left side becomes thinner. Such a problem that the line width varies is also pointed out on page 163 of the above-mentioned document 1. A technique for solving this is a technique called hinting. For example, Japanese Patent Laid-Open No. 3-1
61793 gazette, the same 3-163596, the same 3-225.
394.

[0008]

However, all of the techniques described in the above publications are for correcting the line width of the straight line portion, and do not consider the symmetry of the figure. That is, FIG. 11 shows an example of the input contour line data (circular figure). When such a "circle" is scaled, bitmap data (pixels in which each hatched square is one dot) as shown in FIG. 12 is generated according to the positional relationship between the contour line and the dots. The output graphic is asymmetric even though the input graphic is symmetrical.

FIG. 13 shows an example of two input figures (inequality signs). FIG. 14 is a diagram in which these two input figures are scaled. The left and right figures retain their symmetry, but if two figures that form a pair are arranged side by side, the symmetry is lost and hinting fails.

An object of the present invention is to provide a hinting processing method for performing scaling while maintaining the symmetry of outline fonts.

Another object of the present invention is to beautifully hint a symmetrical graphic by performing the hinting processing on the symmetrical graphic in any order without considering the context of the conventional hinting processing method. To provide a way to do.

[0012]

In order to achieve the above object, the invention according to claim 1 develops outline font data on a memory, corrects a contour line according to hinting information, and fills the inside of the contour line. In the hinting processing method for generating bitmap data, the outline font data includes control point information, and the outline points forming the outline are moved so that the scaled control points move to a predetermined position. However, it is characterized in that bit map data having symmetry is generated.

According to a second aspect of the invention, the predetermined position is the center of the pixel or the boundary of the pixel.

According to another aspect of the invention, the control point is
It is characterized in that it is set for each character or for each element that constitutes the character.

In the invention according to claim 4, the control point is
It is characterized in that it is set for each contour line.

According to a fifth aspect of the present invention, after the contour point is moved, a predetermined hinting process is applied to the contour point to generate symmetric bit map data.

The invention according to claim 6 is characterized in that the contour point is subjected to a predetermined hinting process before and after the movement of the contour point to generate bit map data having symmetry. .

According to a seventh aspect of the present invention, before the movement of the contour point, a predetermined hinting process is applied to the contour point to generate bitmap data in which symmetry is maintained.

[0019]

[Operation] A control point is given to outline data.
As this control point, for example, the intersection of the vertically symmetrical axis and the horizontally symmetrical axis of a figure that is vertically and horizontally symmetrical is the control point. After scaling, the control point is moved to the pixel center or the pixel boundary, and all the contour points that form the outline font are moved according to this movement amount, whereby bitmap data is generated. This preserves the symmetry of the outline font.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention. In FIG. 1, the font file 1, the expansion unit 2, the hinting processing unit 3, the rasterizer 4, and the bitmap data 5 are the same as those of the conventional one described above, and in the present invention, a control point information input unit 6 is newly provided. Has been.
The outline data is read from the font file 1, and the control points are expanded from the control point information input unit 6 to the expansion unit 2.
And the control points are added to the outline data.

FIG. 2 shows an example of a figure in which control points P are added to outline data. As such a control point, an intersection of a vertically symmetrical axis and a horizontally symmetrical axis of a figure which is vertically and horizontally symmetrical is used as the control point. Alternatively, the center of symmetry of the point symmetric figure is used as the control point.

The figure shown in FIG. 2 has n contour points (0 to 0).
n-1). FIG. 3 shows an example in which FIG. 2 is scaled. FIG. 4 is a processing flowchart for moving the contour points in the expansion unit 2.

This embodiment will be described with reference to FIG. 4. After scaling, the x-coordinate (Px) of the control point P is rounded to obtain X '.
Then, the y-coordinate (Py) of the control point P is rounded to Y '(step 101). The difference between the x coordinate (Px) of the control point P and X ′ is Dx, and the difference between the y coordinate (Py) of the control point P and Y ′ is Dy (step 102). Control point P
Of the control point P is moved to Y '(step 103). n is set to 0 (step 10
4) Subtract Dx from the x coordinate (nx) of the contour point n and subtract Dy from the y coordinate (ny) of the contour point n (step 10).
5). The number n is incremented by 1 (step 106), the process ends when n reaches the total number of contour points, and otherwise returns to step 105 (step 107).

Here, the rounding process includes a process of moving the control point P to a specific reference position such as a pixel center or a pixel boundary, as well as rounding and truncation.
You can select the one that fits your situation, such as rounding up. Further, in this embodiment, an example in which all the contour points of a character are shifted by the same amount has been shown, but the present invention is not limited to this, and for example, the deviation may be proportionally distributed to the whole. That is,
It suffices to adjust the reference position of the character without greatly disturbing its shape.

FIG. 5 shows a figure hinted after moving the contour points. This figure is, as is clear from FIG.
Its symmetry is retained.

FIG. 6 is a processing flow chart when the upper half of the inequality sign and the lower half of the equal sign are processed separately, for example, the sign ".ltoreq.". p is set to 0 (step 201), and p is the number of constituent elements of the character (symbol “≦”).
Is composed of an inequality sign and an equal sign, the number of constituent elements is 2.), the processing is ended, and otherwise, the following steps are executed (step 202).
The above-described processing of FIG. 4 is performed on the p-th element (step 203). Increase p by 1 (Step 20
4) and returns to step 202.

The present invention is, for example, in addition to the above embodiment,
It can also be applied to a figure in which a plurality of contour lines (each "." Is composed of one contour line) constitutes each element, such as "..". The processing flowchart in this case is almost the same as that shown in FIG. 6, and the constituent elements are replaced with contour lines. Furthermore, for example, "..."
Alternatively, it can be applied to a figure such as “∴” that needs to satisfy both the symmetry of the entire character and the symmetry of each part at the same time.

In addition to the above-described embodiment, the control point may be a specific point on the axis of symmetry of the vertically symmetrical figure, such as points p1 and p2 in FIG. is there. As shown in FIG. 8, the figure of FIG. 7 is hinted while the symmetry of the left and right figures is maintained. Further, in the present embodiment, in addition to the above-mentioned one, if it is a line symmetric figure, one point on the axis of symmetry for each constituent element or contour line of the character,
The control point can be used, and in the case of a point symmetric figure, the center of symmetry can be used as the control point.

In the above-described embodiment, the symmetrical figure is moved to an appropriate position before the conventional hinting is performed, and then the conventional hinting process is performed to beautifully hint the symmetrical figure. However, the above-described movement of the symmetric figure is not limited to before the conventional hinting, and may be after the conventional hinting or during the hinting.

That is, FIG. 9 shows a part of the configuration of another embodiment. First, the hinting processing section 31 performs a conventional hinting process to shape the contour line, and then the decompression section 21 performs the contouring. Move the point to the proper position.

FIG. 10 shows a partial configuration of still another embodiment. First, in the first hinting processing section 32, a part of the conventional hinting processing, for example, initialization of internal data and line width matching are performed. After performing the processing, the contour point is moved to an appropriate position in the expansion unit 22 described above, and finally, in the conventional hinting procedure, a portion that has not been performed (for example, the width of the arc, the margin The second hinting processing unit 33 executes a process of aligning the width).

[0032]

As described above, according to the first and second aspects of the present invention, the outline points forming the outline are moved so that the control points after scaling move to a predetermined position. , It is possible to easily scale while maintaining the symmetry of the outline font.

According to the third and fourth aspects of the present invention, the control points are set for the entire character, the constituent elements of the character, and the contour line, so that the symmetry can be easily established for each of the elements that make up the outline font. You can change the magnification while holding it.

According to the fifth, sixth and seventh aspects of the present invention, the symmetrical pattern can be beautifully hinted without considering the competitive relationship of the processing procedure with the conventional hinting processing.

[Brief description of drawings]

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

FIG. 2 shows an example of a graphic to which control points are added.

FIG. 3 shows an example of scaling of FIG.

FIG. 4 is a processing flowchart for moving a contour point according to the present embodiment.

FIG. 5 shows a figure hinted after moving a contour point.

FIG. 6 is a processing flowchart for moving a contour point according to another embodiment.

FIG. 7 is a diagram of an inequality sign with control points set.

FIG. 8 shows a hinted graphic (inequality sign).

FIG. 9 shows a partial configuration of another embodiment of the present invention.

FIG. 10 shows a partial configuration of still another embodiment of the present invention.

FIG. 11 shows an example of input contour line data (circular figure).

FIG. 12 shows an example of a circular figure for which hinting has failed.

FIG. 13 shows an example of an input graphic (inequality sign).

FIG. 14: Graphic that hinting failed (inequality sign)
For example:

FIG. 15 is a processing configuration diagram of a conventional outline font.

FIG. 16 is expanded outline data.

FIG. 17 is scaled outline data.

FIG. 18 is rounded-out outline data.

[Explanation of symbols]

 1 Font File 2 Development Section 3 Hinting Processing Section 4 Rasterizer 5 Bitmap Data 6 Control Point Information Input Section

Claims (7)

[Claims] 1. The outline font data is expanded on a memory, and the outline is corrected according to the hinting information,
In a hinting processing method for generating bitmap data by filling the inside of a contour line, the outline font data includes control point information, and an outline is constructed so that the scaled control points move to a predetermined position. A hinting processing method, characterized in that the contour points to be moved are moved to generate bitmap data in which symmetry is maintained. 2. The hinting processing method according to claim 1, wherein the predetermined position is a pixel center or a pixel boundary. 3. The control point is set for each character or for each element forming the character.
Hinting treatment method described. 4. The hinting processing method according to claim 1, wherein the control point is set for each contour line. 5. The hinting processing method according to claim 1, wherein after the contour points have been moved, a predetermined hinting process is applied to the contour points to generate bitmap data in which symmetry is maintained. . 6. The Hinge according to claim 1, wherein the contour point is subjected to a predetermined hinting process before and after the movement of the contour point to generate bitmap data in which symmetry is maintained. Processing method. 7. The hinting process according to claim 1, wherein a predetermined hinting process is applied to the contour point before the movement of the contour point to generate bitmap data in which symmetry is maintained. Method.