JPH096311A - Outline font plotting device - Google Patents

Abstract

PURPOSE: To prevent the occurrence of a dropout at the time of painting out the inner section of an outline. CONSTITUTION: An edge data generating section 3 successively detects the intersection points of the vectors inputted from an input section 1 and an outline data generating section 2 and the half pixel lines in the horizontal direction, for example and quantizes the intersection point data by rounding processes such as a round off. The quantized intersection point data are called edge data. The obtained edge data are stored in a memory section 4. The storage is actually conducted by turning on the bits in the section 4 corresponding to the pixel position of the edge data. After the generation of horizontal direction edge data was completed, the intersection points of the vectors and the half pixel lines are successively detected in a similar manner and the edge data are stored in the section 4. An interpolation processing section 5 conducts the interpolation processes by turning on the bits which are turned off between the data in one of the horizontal or the vertical directions using the edge data stored in the section 4 as an input.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outline font drawing device for creating a bitmap image by filling the inside of the outline of character data in which only the outline is described by a vector.

[0002]

2. Description of the Related Art Conventionally, in a word processor, a printing device of a computer, or the like, there is a technique for filling the inside of the outline of an outline font with high speed and high quality. In this type of technique, generally, a pixel including the center is filled inside the contour. And, in the process, the following two rules are observed. (A) If the center of the pixel is inside the contour, the pixel is set as the visualization target pixel. (B) If two vectors forming an outline intersect a line connecting the centers of two adjacent pixels, one of the two adjacent pixels or both of the pixels are set as a visualization target. .

Further, in this type of technique, edge data corresponding to scan conversion in the horizontal direction is created from the vector data output by the contour data generator. At this time, the edge data is quantized and stored in the storage area as an integer value. Then, scan conversion is performed in the direction (horizontal direction) to which the edge data created thereby corresponds. As a result, a continuous portion of pixels to be filled (hereinafter, this continuous portion is referred to as a run) is output. Then, the output run is written in the storage area (reference: Supe
r ASCII Vol.2 \ # 8 August 1991 "Basic technology of DTP (5)" Yoshio Ohno: ASCII Corporation p.138, 139).

[0004]

However, the above-mentioned prior art has the following problems. That is, in the above-described technique of filling the inside of the outline of the outline font, in particular, when only the small dot bitmap font data is created, for example, only horizontal scan conversion is performed. Therefore, the inside of the outline shown in FIG. In the case of filling in, the portion that should originally be continuous may become discontinuous (hereinafter, this phenomenon is referred to as dropout), as shown in FIG. Therefore, it is difficult to create high quality bitmap font data.

Further, as shown in FIG. 11, when the inside of a contour that is thin to be filled and has a gentle inclination with respect to the scan line is to be filled, it must originally be continuous as shown in FIG. Dropouts sometimes occurred in some parts. Therefore, it is difficult to create high quality bitmap font data.

[0006]

The outline font drawing apparatus of the present invention is characterized by the following points in order to solve the above-mentioned problems. (1) 1. An input unit is provided for inputting information necessary for developing an outline font including a character code and enlargement ratio. 2. A contour data generation unit that generates contour data represented by a vector connecting a start point and an end point from the information input by the input unit and the outline font data is provided.

3. An edge data generation unit is provided which detects, as edge data, the respective intersections of the contour data generated by the contour data generation unit and the scan lines in the first direction and the second direction perpendicular thereto. . 4. The edge data generation unit includes a storage unit that stores each edge data detected. 5. Take out the edge data stored in the storage unit,
An interpolation processing unit that performs interpolation processing and stores the edge data after the interpolation processing again in the originally extracted storage area is provided.

(2) 1. A first direction edge data generator for inputting outline data and generating edge data in the first direction is provided. 2. A scan conversion unit that performs scan conversion of the edge data generated by the first direction edge data generation unit is provided. 3. A second-direction edge data generation unit that generates edge data in a second direction perpendicular to the scan conversion direction by the scan conversion unit is provided. 4. A second direction edge data interpolating unit that interpolates the edge data generated by the second direction edge data generating unit is provided.

(3) In (2), the second direction edge data generating section is characterized in that the edge data is generated only for the outline of either the rising transition or the falling transition.

[0010]

[Action]

(1) The edge data generation unit sequentially detects the intersections of the vectors input from the input unit and the contour data generation unit and the horizontal half-pixel lines, and quantizes the intersection data by rounding rounding, for example. . Quantized intersection data is called edge data. Then, the obtained edge data is stored in the storage area. The edge data is actually stored by turning on a bit in the storage area corresponding to the pixel position of the edge data.
At this time, if the bit is already turned on, no operation is performed on the bit. When the horizontal edge data generation is completed, the vector and
The intersections with the vertical half pixel lines are sequentially detected, and the edge data is stored in the storage area. The interpolation processing unit receives the edge data stored in the storage area as an input, and in one of the horizontal direction and the vertical direction,
Interpolation is performed by turning on the off bits between edge data. However, if there is no interpolation section, no processing is performed.

(2) The horizontal edge data generator receives the outline data, generates horizontal edge data, and stores it in the first storage area. At the same time, the vertical edge data generation unit inputs the same outline data, generates vertical edge data, and stores it in the second storage area. That is, the horizontal edge data generation unit
The intersections of the outlines and the scan lines in the horizontal direction are sequentially detected, and quantization is performed by rounding processing, for example, rounding. In this case, with the horizontal edge data, edge data is generated for both outlines of rising transitions and falling transitions in the vertical direction. Then, the generated edge data is stored in the first storage area. Actually, the bit in the first storage area corresponding to the position of the edge data is turned on. On the other hand, the vertical edge data generation unit
The intersection between the outline and the scan line in the vertical direction is sequentially detected, and quantization is performed by rounding processing. The scan conversion unit inputs the horizontal edge data and fills in between the pair of edge data. At this time, in order to match the edge data with the actual position of the pixel, the left edge data of the pair of edge data is turned on, but the right edge data is turned off to perform the scan conversion. . Then, the result is output to the third storage area.

(3) In (2), for the edge data in the vertical direction, the edge data is generated only for the outline of the falling transition in the horizontal direction. As a result, the overhead due to the interpolation processing can be reduced.

[0013]

Embodiments of the present invention will now be described in detail with reference to the drawings. (First Embodiment) FIG. 1 is a block diagram of the outline font drawing apparatus according to the first embodiment of the present invention. The illustrated apparatus includes an input unit 1, a contour data generation unit 2, an edge data generation unit 3, a storage unit 4, and an interpolation processing unit 5. The input unit 1 extracts information necessary to form a character and inputs it to the contour data generation unit 2. The contour data generation unit 2 is based on the information of the characters to be displayed which is input from the input unit 1.
The outline font data is appropriately accessed to perform processing such as enlargement / reduction of the outline of the character and linear approximation of the curved section. Then, the vector data forming the contour of the character is output.

The edge data generation unit 3 receives the vector data represented by the coordinates of the start point and the end point and creates edge data in the horizontal direction (first direction), and the storage unit 4
To be stored. At the same time, edge data in the vertical direction is created and stored in the storage unit 4. The interpolation processing unit 5 receives the edge data stored by the edge data generation unit 3 as input, creates bitmap font data of a character to be displayed, which is a final output, and stores it again in the storage unit 4. The storage unit 4 is composed of a RAM or the like, and temporarily stores edge data, and at the same time, stores bit map font data of a character to be displayed which is a final output. The storage unit 4 is a storage area corresponding to 1 bit per pixel.

Next, the details of the edge data generation unit 3 that receives the vector data output from the contour data generation unit 2 and creates edge data will be described with reference to FIGS. 2, 3, and 4. The edge data generation unit 3 uses v shown in FIG.
Edge vectors are created by sequentially inputting vectors 1 to v4. A specific example will be described below. The edge data generation unit 3 sequentially detects the intersections of the vector v1 in FIG. 2 and the horizontal half pixel lines, and quantizes the intersection data by rounding and rounding. That is, in the case of horizontal scanning, a rounded-off value is used as edge data for a vector having a positive vertical direction. Further, for a vector in the negative direction, a value obtained by subtracting "1" from the rounded value is used as edge data. On the other hand, in the case of scanning in the vertical direction, the value obtained by subtracting “1” from the rounded-off value is used as the edge data for the vector in the positive direction in the horizontal direction. Then, for the vector in the negative direction, the rounded-off value is used as the edge data.

Next, the edge data thus obtained is stored in the storage unit 4. The edge data is actually stored by turning on the bit in the storage unit 4 corresponding to the pixel position of the edge data. Here, ON means "1" and OFF means "0". At this time, if the bit is already turned on, no operation is performed on the bit. When the generation of the horizontal edge data is completed, the vector v in FIG.
The intersections of 1 and the vertical half-pixel line are sequentially detected, and the edge data is stored in the storage unit 4. In FIG. 3, points indicated by lowercase alphabets are vector v
The point of intersection of 1 and the horizontal half-pixel line, which is indicated by a capital letter, is the vector v1.
And the vertical half-pixel line.

FIG. 4 shows a state in which the edge data in the vector v1 is stored in the storage unit 4 corresponding to 1 bit per pixel. For example, the storage area [5 in FIG.
2] indicates both the edge data at the intersection point b detected by the horizontal scanning and the edge data at the intersection point F detected by the vertical scanning in FIG. The above-described processing is similarly performed for the vectors v2 to v4. FIG. 5 shows a state in which edge data is created and stored for all the vectors v1 to v4.

The interpolation processing unit 5 receives the edge data stored in the storage unit 4 shown in FIG. 5 as an input, and in either one of the horizontal direction and the vertical direction (in this embodiment, selects the horizontal direction), the edge. Interpolation is performed by turning on bits that are off between data. However, if there is no interpolation section, no processing is performed. In the case of this embodiment, since there is no interpolation section, the contents of the storage unit 4 shown in FIG. 5 in which the edge data is stored become the bitmap font data of the character to be displayed which is the final output. FIG. 9 shows how the bitmap font data is visualized. On the other hand, the state of the storage unit 4 when the interpolation process is required is shown in FIG.
Shown in Then, FIG. 7 shows the state of the bitmap font data of the display character that is finally output by performing the interpolation process using the edge data stored in the storage unit 4 as an input.

As described above, in the conventional horizontal scan conversion alone, as shown in FIG. 8, a portion that should originally be continuous becomes discontinuous when a bitmap image is created. Although high quality bitmap font data could not be obtained, the present invention enables efficient interpolation processing. That is, according to the present invention, since the edge data generation unit 3 generates horizontal / vertical direction edge data, it is possible to obtain high-quality bitmap font data without dropout, as shown in FIG. In addition, the edge data generation unit 3
Since the edge data in the horizontal direction and the edge data in the vertical direction are stored in the common storage unit 4, the memory consumption can be reduced.

In the interpolation processing section 5, the horizontal,
Alternatively, since only interpolation processing in one vertical direction is performed, time loss due to scanning in both horizontal and vertical directions can be reduced, and the bitmap font data of the character to be displayed, which is the final output, is again stored in the storage unit 4 storing the edge data. Since it is stored, further reduction in memory consumption can be realized.

(Second Embodiment) Next, a second embodiment of the present invention will be described. FIG. 10 is a block diagram of the outline font drawing apparatus according to the second embodiment of the present invention. The illustrated apparatus is a horizontal direction (first direction) edge data generation unit 1
1, a scan conversion unit 12, a vertical direction (second direction) edge data generation unit 13, a vertical direction (second direction) edge data interpolation unit 14, and the like. The horizontal edge data generation unit 11 receives the outline data 15 and generates horizontal edge data. Then, the generated edge data is stored in the first storage area 16.

The scan conversion unit 12 includes the first storage area 1
Input the horizontal edge data stored in 6,
Perform scan conversion. Then, the final bitmap image is output to the third storage area 18. The vertical edge data generation unit 13 uses the outline data 15
Is input and vertical edge data is generated. Then, the generated edge data is stored in the second storage area 17. The vertical edge data interpolation unit 14 receives the vertical edge data stored in the second storage area 17, and stores the edge data in the third storage area 18.

Next, the operation of the above-mentioned device will be described using the example of FIG. The horizontal edge data generation unit 11
The outline data shown in FIG. 11 is input to generate horizontal edge data. Then, the edge data is stored in the first storage area 16. At the same time, the vertical edge data generation unit 13 inputs the outline data shown in FIG. 11 and generates vertical edge data. Then, the edge data is stored in the second storage area 17. A specific example of this process will be described below.

The horizontal edge data generator 11 is shown in FIG.
The intersections of the outline shown in 1 and the scan lines in the horizontal direction are sequentially detected, and quantization is performed by rounding processing of rounding. With horizontal edge data, edge data is generated for both outlines of rising transitions and falling transitions in the vertical direction (see FIG. 14). Then, the generated edge data is stored in the first storage area 16. As means for storing the edge data, there are various methods such as a linear list method, a bitmap method for expressing 1 pixel by 1 bit, and an array method for expressing 1 pixel by 1 byte. This will be explained using the map method. Actually, the bit in the first storage area 16 corresponding to the position of the edge data is turned on. Here, ON indicates “1” and OFF indicates “0”. FIG. 15 shows a state in which the horizontal edge data thus generated is stored in the first storage area 16 using the bitmap method.

The vertical edge data generator 13 is shown in FIG.
The intersection between the outline shown in 1 and the scan line in the vertical direction is sequentially detected, and quantization is performed by rounding processing. For the vertical edge data, the edge data is generated only for the outline of the falling transition in the horizontal direction (see FIG. 17). FIG. 18 shows a state in which the generated vertical edge data is stored in the second storage area 17. The scan conversion unit 12 receives horizontal edge data and fills in between the pair of edge data. This time,
In order to match the edge data with the actual position of the pixel, the left edge data of the pair of edge data is turned on, but the right edge data is turned off to perform the scan conversion. Then, the third storage area 18
Output the result to. FIG. 16 shows a bitmap image generated as a result of performing scan conversion on all horizontal edge data.

The vertical edge data interpolating unit 14 inputs the vertical edge data and outputs the edge data to the third storage area 18 as a bit map image.
Since the edge data in the vertical direction is aligned with the actual position of the pixel at the time of generation, the edge data can be directly interpolated as a bitmap image. In this embodiment, the second storage area and the third storage area
Interpolation of the vertical edge data can be realized by performing an OR operation on the storage area. FIG. 19 shows a bitmap image in which interpolation of vertical edge data has been completed.

As described above, the portion where the dropout occurs in the horizontal scan conversion can be limited to the portion where the two outlines forming a pair intersect the line connecting the centers of two vertically adjacent pixels. Therefore, by generating and interpolating vertical edge data as in the present invention, as shown in FIG. 19, high-quality bitmap font data without dropout can be obtained. Further, since the vertical edge data is overlapped at the portion where dropout occurs, it is only necessary to generate edge data for an outline of either a rising transition or a falling transition in the horizontal direction as in the present invention. , Can keep high quality.

As described above, according to the present embodiment, the time overhead of the vertical edge data generation and interpolation can be reduced for the horizontal scan conversion, and the processing can be performed at high speed. Further, when the means for storing the edge data is in the bitmap format, a logical operation can be used to generate the bitmap image, and the processing can be performed at higher speed. Further, the storage area for the edge data and the storage area for the bitmap image can be shared, and the memory consumption can be reduced.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made. For example, with regard to quantization, rounding processing may be performed by rounding down or rounding up, in addition to rounding processing by rounding.

Further, in the above-described embodiment, the case where the scan conversion in the horizontal direction is performed and the edge data in the vertical direction is interpolated has been described, but the present invention is not limited to the case where the roles of the horizontal direction and the vertical direction are exchanged. Effective for processing in all directions. That is, when scan conversion is performed in a certain direction, the present invention can be realized by generating and interpolating edge data in a direction perpendicular to the scan direction. Further, in the above-described embodiment, a very simple character filling process is used as an example in order to facilitate the description and to explain that the horizontal scan conversion is not sufficient. . Therefore, in the embodiment, the target bitmap image can be obtained only by scan conversion of the vertical edge data. However, in reality, it is necessary to perform a filling process of various characters having a complicated shape, and the present invention exerts a further effect when filling a complicated character of such a shape. You can Further, the effect is not limited to the outline font, and it is also possible to exert an effect on the filling of various figures output by a page description language or the like.

[0031]

As described above, according to the outline font drawing apparatus of the present invention, edge data is generated in the first direction and the second direction perpendicular to the first direction, and interpolation processing is performed in either one of the directions. Since this is done, it has the following effects. That is, it is possible to prevent dropout when filling the inside of the outline of the outline font, especially when creating small dot bitmap font data. For this reason,
It is possible to easily create high quality bitmap font data. Further, even when a portion to be filled is thin and the inside of the contour having a gentle inclination with respect to the scan line is filled, it is possible to prevent dropout from occurring in a portion that should originally be continuous. This facilitates creation of high quality bitmap font data.

[Brief description of drawings]

FIG. 1 is a first outline font drawing apparatus according to the present invention.
FIG. 4 is a block diagram of an embodiment of FIG.

FIG. 2 is an explanatory diagram of an example of vector data.

FIG. 3 is an explanatory diagram of an example of intersection data in horizontal and vertical directions.

FIG. 4 is an explanatory diagram of stored contents (1) in a storage unit.

FIG. 5 is an explanatory diagram of stored contents (No. 2) in the storage unit.

FIG. 6 is an explanatory diagram of stored contents (No. 3) in the storage unit.

FIG. 7 is an explanatory diagram of stored contents (No. 4) in the storage unit.

FIG. 8 is an explanatory diagram of a result of filling outline data (No. 1).

FIG. 9 is an explanatory diagram of a result (part 2) of filling outline data.

FIG. 10 is a block diagram of a second embodiment of the outline font drawing apparatus of the present invention.

FIG. 11 is an explanatory diagram of an example of a narrow outline.

FIG. 12 is an explanatory diagram of a narrow outline filling example (No. 1).

FIG. 13 is an explanatory diagram of a narrow outline filling example (No. 2).

FIG. 14 is an explanatory diagram of a result (part 1) of generating edge data.

FIG. 15 is an explanatory diagram of a state example (1) of bits in a storage area.

FIG. 16 is an explanatory diagram of a state example (part 2) of bits in a storage area.

FIG. 17 is an explanatory diagram of a result (2) of generation of edge data.

FIG. 18 is an explanatory diagram of an example (part 3) of states of bits in a storage area.

FIG. 19 is an explanatory diagram of a state example (4) of bits in a storage area.

[Explanation of symbols]

 1 Input Section 2 Contour Data Generation Section 3 Edge Data Generation Section 4 Storage Section 5 Interpolation Processing Section 11 Horizontal Edge Data Generation Section 12 Scan Conversion Section 13 Vertical Edge Data Generation Section 14 Vertical Edge Data Interpolation Section

Claims (3)

[Claims] 1. An input unit for inputting information necessary for developing an outline font including a character code and an enlargement ratio, and a vector connecting a start point and an end point from the information input by the input unit and the outline font data. A contour data generation unit that generates contour data, and contour data generated by the contour data generation unit,
An edge data generation unit that detects, as edge data, each intersection of a first direction and a scan line in a second direction perpendicular to the first direction, and a storage unit that stores each edge data detected by the edge data generation unit. And an interpolation processing unit that extracts the edge data stored in the storage unit, performs interpolation processing, and stores the edge data after the interpolation processing again in the storage region that was originally extracted. Outline font drawing device. 2. A first direction edge data generation unit for inputting outline data and generating edge data in a first direction, and a scan for performing scan conversion of the edge data generated by the first direction edge data generation unit. A conversion unit, a second direction edge data generation unit that generates edge data in a second direction perpendicular to the scan conversion direction by the scan conversion unit, and edge data generated by the second direction edge data generation unit And a second-direction edge data interpolating unit that performs the interpolation processing of 1. 3. The outline font drawing device according to claim 2, wherein the second direction edge data generation unit generates edge data only for an outline of either a rising transition or a falling transition.