JP2561931B2 - Dot character pattern vectorization method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to vectorization of a character pattern formed as a dot pattern, and particularly to vectorization suitable for automatic processing by a processor, and the vector character pattern obtained by this is It can be stored in a storage device such as a ROM or a floppy disk and used for displaying or printing characters as a character font for word processors, personal computers or digital fax machines.

[Prior art]

When expanding a dot character pattern composed of dot patterns, for example, a dot character pattern composed of 24x24 dots to a dot character pattern composed of 48x48 dots, one dot is expanded to four dots. In addition, when reducing a 24 × 24 dot character pattern to a 16 × 16 dot character pattern, one dot is deleted from three dots in the vertical and horizontal directions to display or print. However, the enlarged or reduced dot character pattern is not preferable for practical use because the shape of the character is greatly broken.

On the other hand, when enlarging the vectorized dot pattern n times in length and n ² times in area, the X-axis and Y-axis values of the coordinates of the start point are each multiplied by n, and each line is For the value indicating minutes, it is sufficient to multiply the length by n times while keeping the direction as it is. To reduce the length to 1 / n, similarly, set the X-axis and Y-axis values of the start point coordinates to 1 / n. It is sufficient that the length of the line segment and the length of the line segment are 1 / n, and the rotation of the character pattern can be easily performed by converting the line direction and the line length by calculation.

Also, instead of giving the line direction and line length as above,
By giving the coordinates of the direction change point at which the direction of the line segment changes and converting the coordinates, the same processing as above can be performed.

In applications such as desktop publishing where there is a strong demand for enlargement / reduction or rotation of characters, it is desirable to retain it as the above vector data that is easy to perform arithmetic processing for enlarging / reducing / rotating character patterns. Creating such a vector character pattern requires significantly more work than creating a character pattern using a dot pattern, and automation of vectorization processing is also difficult.

〔Purpose〕

The present invention has a wide range of enlargement / reduction,
It is an object of the present invention to obtain a vectorization method for a dot character pattern in which the quality of the character pattern due to the reduction is small and the vectorization process is easy to automate.

〔Constitution〕

FIG. 1 is for explaining the principle of the vectorization method of the dot character pattern according to the present invention, and illustrates the case of vectorizing the dot character pattern of “heart” composed of 24 × 24 dots. .

The figure (a) is a dot character pattern consisting of 24 x 24 dots, and RO that stores a large number of dot character patterns
It is selected and read from M or a storage device by a character code or the like.

The contour of such a dot character pattern can be
When the contour line is taken by the well-known eight-direction contouring by the direction and four directions of 45 ° diagonal lines, four independent contour lines m ₁ , m ₂ , m ₃ , m ₄ as shown by solid lines in the figure are obtained. can get. FIG. 6B shows only this contour line.

As is known, this contour line is tracked, for example, in the clockwise direction, and the coordinates of the bending points at which the contour line bends are sequentially stored, or the start point of the loop drawn by the contour line is used as a reference. Vectorization is performed by sequentially storing the direction and distance from the edge to the next break point.

When this vectorization is performed, this character pattern is developed on a pattern memory having a storage capacity of, for example, dots for one character, in this example, horizontal 24 × vertical 24 = 576 dots. The contour line is traced from the first black dot encountered by performing the raster scan as shown by the thin line only on the upper part from the point of the upper left corner (0,0) as shown in.

In the contour line shown in FIG. 1 (b), the dot at the upper left end of the contour line m ₃ is first obtained by this raster scan.
Since d ₃ is encountered, this contour line is traced clockwise starting from this dot d ₃ and vectorization is performed on this contour line m ₃ by a known method.

In the present invention, the contour line that has been vectorized, in this example, the contour line m ₃ is erased from the pattern memory and only the contour lines m ₁ , m ₂ , m ₄ are removed as shown in FIG. 1 (c). Are left on this pattern memory.

Since encounters the dot d ₂ at the upper left of the contour line m ₂ by performing the same manner raster scanning and the aforementioned performs vectorization of contour lines m _2, the contour line m ₂ If this vectorized ends Is erased and only the contour lines m ₁ and m ₄ are left on the pattern memory as shown in FIG.

In this way, when the vectorization of the remaining contour lines m ₁ and m ₄ is completed, all the contour lines are erased from this pattern memory, so the raster scan above is performed after the vectorization of the contour line m ₄ is completed. However, the dot indicating black is not encountered, and it can be mechanically recognized that the vectorization for this character pattern is completed.

Therefore, when vectorizing a mechanized dot character pattern, it is not necessary to separately provide a means for detecting the end of vectorization, and the vectorization device and processing can be simplified.

Next, an embodiment of vectorization of the dot character pattern of "Naga" according to the present invention will be specifically described with reference to FIG.
Note that, for convenience of illustration, only the portion of the "naga" toward the upper left is shown.

First, as shown in FIG. 2A, for example, 48 × 48 selected by a character code or the like from a dot character pattern storage device such as a ROM storing a dot character pattern.
The dot pattern of the character "Naga" consisting of dots is loaded into the dot map memory having a dot storage capacity of 48 × 48 corresponding to the storage area for the dot pattern for one character.

In the next step, the present applicant loaded this dot map memory in order to apply the vectorization method disclosed in the invention entitled "Vectorization Method of Dot Character Pattern" filed on the same day as the patent application. The dot character pattern "Naga" is expanded to a 96 x 96 dot pattern that is twice as large in both vertical and horizontal directions by expansion processing using the well-known raster kernel subroutine (RASUTER KERNEL SUBROUTINE), and the first pattern memory such as video RAM (VRAM). In the area, for example, storage area X = 0-95, Y = 0-95
Load as shown in Figure (b).

Next, when raster-scanning this storage area is encountered and a "1" indicating a black dot is encountered, the contour is traced clockwise from this point, for example, to perform known four-way contouring, and as shown in FIG. 2 (c). Extract the contour line as shown in the above VRAM
Second storage area X = 128−192, Y = which is another storage area of
Write to 0-95.

Note that, when this contour line is extracted, if all the pixels adjacent to the pixel in the eight directions around the pixel are white or black dots in the dot character pattern, it is not the contour but the adjacency in the eight directions. A pixel in which white and black dots are mixed in each pixel is set as a point on the contour, and a point on such contour is stored in the corresponding storage element of the storage area to generate a contour line in this storage area. .

If the pixels adjacent in the eight directions around a certain pixel p are q ₁ to q ₈ as shown in FIG. 3, the above logic is expressed as follows.

IF p = 1 AND q ₁ ＋ q ₂ ＋ q ₃ ＋ q ₄ ＋ q ₅ ＋ q ₆ ＋ q ₇ ＋ q ₈ <8 THEN EDGE The second logic to improve the processing speed is IF p ＝ 0 THEN NON-EDGE IF q ₂ ＋ q _{4 + q 5 + q 7 <} 4 THEN EDGE ELSE IF q 1 + q 3 + q 6 + q 8 < may be 4 THEN EDGE ELSE NON-EDGE. Note that 1 is a value indicating black and 0 is a value indicating white,
The third IF statement of the above second logic is for extracting the corner pixels of the key shape as contour points. If this IF statement is not present, a diagonal line with an inclination of 45 ° is used. Will be included.

A process for extracting the contour line of the dot portion on the upper part of the "permanent" shown by I in FIG. 2 (c) from the dot pattern on the upper part of the "permanent" shown in FIG. To be more specific, first, by scanning the first storage area of the VRAM storing this dot pattern by raster scanning, "1" indicating a black dot is first detected at the point shown as 1 in the figure. Therefore, the coordinates (X ₁ , Y ₁ ) of the point a are stored, the contour line is then tracked clockwise, and the coordinates of each break point are sequentially stored in the memory.
The direction of the line connecting each break and the next break is the direction code T
It is stored together with the length C of the line as (4 directions of right, bottom, left, and top, which are 1, 2, 5, and 6 in accordance with the subscript in FIG.

The direction code T and the line length C for the 1 to 26 break points in the upper dot portion of the above "Naga" are as follows.

T _(1-26) = (1,2,1,2,1,2,1,2,1,2,1,2,5,2,5,6,5,6,5,
6,5,6,5,6,5,6) C _(1-26) = (3,2,4,2,4,2,2,2,2,2,2,1,2,2, 5,2,2,4,2,
2,2,2,2,2,2,1) In the next fourth step, the dot character pattern is vectorized by the contour lines generated in the second storage area as described above. In the vectorization in the example, 1 for consecutive line segments with the same slope.
It is represented as one vector. However, when the lengths of the vertical and horizontal vectors are 1 dot or more in terms of the number of dots before expansion, for example, when the size is doubled, it becomes 2
If the number of dots is greater than or equal to the dot, it means that the vertical line and the horizontal line cross each other, and therefore cannot be represented as one vector.

This logic uses the above direction code T and line length C, for example, IF T _(i) = T _{(i + 2)} AND C _(i) = C _{(i + 2)} AND T _{(i + 1)} = T _{(i + 3)} A
ND T _{(i + 1)} = T _{(i + 3)} THEN REJECT ELSE SELECT is performed, and ten fold points (1, with a circle on the contour line shown by the dotted line in Fig. 2 (d) (1, 2,6,12,13,15,16,18,20,2
Only the coordinates of 6) are selected and stored in the storage device, and the coordinates of the other broken points indicated by x are discarded and the vectorization ends. The ten folding points are the coordinates of the direction change points of the contour line of the reproduced dot character pattern formed by connecting the folding points.

According to the present invention, the contour line written in the second storage area of the VRAM is configured to be erased when the vectorization of the contour line as described above is completed. When the vectorization for the point portion is completed, only the contour line for the remaining "water" shape excluding this point portion is left as the contour line in the second storage area of the VRAM.

Therefore, when raster scanning is performed on the second storage area after the vectorization and deletion of the upper point portion of the above "Naga" is completed, the convex portion left side of the contour line indicated by II in FIG. When the dot z of the above is first encountered, the vectorization processing similar to that described for the contour I above is performed from this dot, and the vectorization processing similar to the above for other independent contours is completed. For example, the second area of the pattern memory is cleared, and since dots indicating black are not encountered even if raster scanning is performed, it can be identified that the vectorization process for the dot character pattern is completed.

The vector character pattern generated as described above can be used in a device such as a word processor or a personal computer by transferring it from the storage device in which it is stored to a storage medium such as a ROM or a floppy disk.

In the above description, it is assumed that the dot character pattern is stored in the pattern memory while holding its shape for convenience of description, but it is possible to perform the above-described processing in the processing device that performs vectorization. For example, it is obvious that it is not necessary to maintain the shape of the character pattern, and it is not necessary to expand the dot character pattern on the pattern memory.

FIG. 3 is a diagram showing an embodiment of the configuration of the vectorizing device according to the present invention, and when a vectorization processing request is made to the patterning processing CPU via the interface, this CPU
Reads the character pattern from the pattern ROM that stores the dot character pattern, the read character pattern is subjected to the vectorization process according to the present invention as described above on the bitmap memory, and the coordinates of the obtained break point are Stored in vector coordinate RAM.

In addition, reading the coordinates from this vector coordinate RAM
Pattern processing CP by transfer request from interface
Sent to this interface under the control of U.

〔effect〕

According to the present invention, it is possible to achieve a special effect that it becomes easy to automatically vectorize a dot pattern by a processing device such as a processor.

[Brief description of drawings]

 FIG. 1 is a diagram for explaining the principle of the present invention, FIG. 2 is a diagram for specifically explaining an embodiment of the present invention, FIG. 3 is a diagram for explaining extraction of contour points, and FIG. FIG. 3 is a diagram showing an embodiment of a vectorization device.

Claims (1)

(57) [Claims] In a vectorization method of a dot character pattern, a raster scan is performed on a storage area of a pattern memory in which a contour of a dot character pattern is loaded, and the contour is sequentially traced from the first black point encountered. A vectorization method for a dot character pattern, characterized in that the contour line is erased when the tracking of one contour line is completed.