KR20070020696A - A character font display method - Google Patents

Abstract

The present invention relates to a method of displaying a character font, each step is

Enlarging the character font to be displayed on the screen by a set multiple;

Generating a bitmap image of the enlarged character font;

Rotating the character font of the bitmap image by a predetermined angle;

Moving the rotated text font to reference coordinates on a screen;

Setting a pixel area of the text font shifted to the reference coordinate;

Calculating transparency in the pixel after setting the pixel area of the character font;

Calculating a corresponding pixel value to be output on the screen using the calculated transparency; And

And displaying the pixel of the character font on a screen.

Aliasing, anti-aliasing, font, magnification, rotation, transparency, pixels

Description

{A character font display method}

1 is a diagram for explaining a general aliasing font and antialiasing font.

2 is a flowchart illustrating a method of displaying a character font according to the present invention.

3 is a process of forming a bitmap image of a character font according to the present invention;

4 is moved to the reference coordinates after the rotation of the character font according to the present invention.

5 is a pixel area setting diagram of a character font according to the present invention;

Fig. 6 is a drawing for calculating the transparency of a set pixel area of a character font according to the present invention.

<Description of Drawing>

10 character font 15 pixels

20 pixel map

The present invention relates to a character font display method, and more particularly, to a character font display method for displaying a high quality anti-aliased character font on a screen with a small amount of calculation.

Conventionally, in displaying a character font, a bitmap font, i.e., a method of displaying a location of a point to be taken on a screen in a bit string, and a vector font, i.e., a character to be displayed on a screen, are formed of a polygon The method is represented as a set and then displayed.

However, in displaying a character on the screen using the bitmap font and the vector font as described above, aliasing is likely to occur on the font boundary of the displayed character, and a large amount of computation is required when processing the image to reduce it. This is necessary.

The present invention has been made to solve the problems of the prior art, an object of the present invention is a character font display for achieving anti-aliasing of the character font displayed on the screen with little computation and without the addition of hardware To provide a way.

Character font display method according to the present invention for achieving the above object,

Enlarging the character font to be displayed on the screen by a set multiple;

Generating a bitmap image of the enlarged character font;

Rotating the character font of the bitmap image by a predetermined angle;

Moving the rotated text font to reference coordinates on a screen;

Setting a pixel area of the text font shifted to the reference coordinate;

Calculating transparency in the pixel after setting the pixel area of the character font;

Calculating a corresponding pixel value to be output on the screen using the calculated transparency; And

And displaying the pixel of the character font on a screen.

Prior to the description of the embodiment according to the present invention, the terms used in the present invention are summarized as follows.

<Term description>

Bitmap font: A bitmap font is a data display method that expresses a character as a set of dots. Since the bitmap font is displayed quickly because it does not undergo a complicated operation, it is widely used for screen display. However, since the bitmap font is distorted when enlarged or reduced in size, character data must be prepared for each size (dot number) in preparation for size change. Therefore, there is a problem that the amount of data increases.

-Vector font: A vector font is a method of displaying a character after storing it as a vector of directions (direction and length), and has a feature of obtaining a character that is arbitrarily adjusted according to enlargement and reduction. .

Aliasing: refers to a phenomenon in which irregular dividing lines are generated between pixels of a font (see FIG. 1A).

Anti-aliasing: refers to a screen processing technique for naturally and smoothly expressing an image of a screen so that an aliasing phenomenon does not occur (see FIG. 1 (b)).

Alpha value (α): A transparency control factor of a bitmap image.

Hereinafter, with reference to the drawings will be described a preferred embodiment according to the present invention.

A method of displaying a character font according to the present embodiment will be described with reference to FIG.

As shown in FIG. 2, first, the character font is enlarged by a set multiple for anti-aliasing of the character font to be displayed on the screen [S10], and then a bitmap image of the enlarged character font is generated [S20]. As shown in FIG. 3, in the present embodiment, the horizontal and vertical sizes of the character font 10 are enlarged twice, respectively, but the present invention is not limited thereto and the enlargement multiple may be arbitrarily set by those skilled in the art.

After the conversion to the bitmap image in step S20, the character font of the bitmap image is rotated by a predetermined angle and then the rotated character font is moved to the reference coordinates on the screen [S30, S40]. As shown in FIG. 4, in rotating the character font by the set angle, the rotation angle setting can be arbitrarily set by a person skilled in the art, and the rotated character font is moved to the reference coordinates Dx and Dy.

In the above, the movement of the rotated character font to the reference coordinate is carried out by the following equation (1).

,

,

In the above description, Px and Py are character font coordinates displayed on the screen.

          Dx, Dy is the font reference coordinate on the screen

          Fx, Fy means coordinates in the character font.

Returning to the flowchart of FIG. 2 again, the character font after the rotated character font is moved to the reference coordinates (Dx, Dy) is represented by (Px, Py) and (Fx, Fy) as shown in FIG. 5.

That is, as shown in Fig. 5, the character font after being moved to the reference coordinates (Dx, Dy) is the coordinates (Px, Py) on the screen and coordinates (Fx) in the character font, respectively, as in (a) and (b). , Can be expressed as (Fy). On the other hand, in order to obtain information about one pixel (Px, Py) of the character font, as shown in (c) of Figure 5, the peripheral pixels, that is, (Px, P _{y +1} ), (Px, P _{y -1} ), (P _{x + 1} , Py) and (P _x-1 , Py) will be apparent to those skilled in the art.

If so, the transparency (α value) of the character font is calculated by the following procedure.

First, after selecting a pixel area for calculating the transparency of the character font [S50], the transparency is calculated at the selected pixel, and the calculation method is calculated as in Equation 2 below [S60].

A = T / S, 0 ≤ A ≤ 1

In the above, A is transparency (α)

          S is the total number of pixels in the (Px, Py) region

          T is the number of '0's in the S region

For example, as shown in FIG. 6, for example, referring to a method of calculating transparency in a corresponding pixel of a portion of 'a' of a character font 10, the total number of pixels present in the font is' 4 'and the number of' 0's present in the pixel region is '2', so the alpha value α, which is the transparency A, becomes 0.5.

In this way, the corresponding pixel value to be output on the screen is calculated by applying the calculated transparency [S70], which is performed through Equation 3 below. For reference, Equation 3 below is a formula for calculating the pixel value by using the transparency (α value) apparent to those skilled in the art.

New Pixel Value = [Old Pixel Value * (1-α)] + [RGB color value of corresponding pixel font * α]

In the above, α means transparency.

As shown in Equation 3, by displaying the corresponding pixel value calculated by applying the transparency (α) on the screen, the display of the anti-aliased character font is made [S80].

As described above, in the present invention, the display of the high quality anti-aliased text font can be achieved by applying the enlargement of the text font, calculating the transparency of the enlarged text font, and calculating the pixel value of the corresponding font.

In interpreting the technical scope of the present invention, it should not be construed as being limited to the embodiments described above, and the technical scope of the present invention should be determined by reasonable interpretation of the matters described in the claims.

According to the character font display method of the present invention, since the character font is enlarged twice or more and then displayed on the screen by applying transparency (α value), a high quality anti-aliased character font can be displayed, and the character Even when the font is rotated, the font shape is preserved as it is.

Claims (3)

Enlarging the character font to be displayed on the screen by a set multiple; Generating a bitmap image of the enlarged character font; Rotating the character font of the bitmap image by a predetermined angle; Moving the rotated text font to reference coordinates on a screen; Setting a pixel area of the text font shifted to the reference coordinate; Calculating transparency in the pixel after setting the pixel area of the character font; Calculating a corresponding pixel value to be output on the screen using the calculated transparency; And And displaying the corresponding pixel of the character font on a screen. The method of claim 1, Character font display method, characterized in that the movement to the reference coordinate after the rotation of the character font is made through the following formula.

In the above description, Px and Py are character font coordinates displayed on the screen.           Dx, Dy is the font reference coordinate on the screen           Fx, Fy is the coordinate in the character font The method of claim 1, The transparency is a character font display method characterized in that it is calculated through the formula below. A = T / S, 0 ≤ A ≤ 1 In the above, A is transparency (α)           S is the total number of pixels of the font in the (Px, Py) region           T is the number of '0's in the S region

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