JPH09127930A - Character output device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a character output device for converting an outline data into an image data followed outputting in which the reduction in readability accompanying the contraction of characters can be prevented or suppressed. SOLUTION: A character output device is provided with the following essential requirements within a CPU 5. (1) A density setting means scans the outline of a character in a determined direction in picture element coordinate, and sets the picture elements within an area (outline area) judged to be present on the inside of the outline on the scanning line to a first density, and other picture elements to a second density. (2) A density correcting means sets, when two outline areas make contact to each other or are partially superposed, one or a plurality of picture elements situated in the vicinity of the terminal on the contacting side or superposing side of at least one of these areas to a third density intermediate between the first and second densities.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character output device for displaying or printing out characters, symbols, figures, etc. (hereinafter collectively referred to as characters).

[0002]

2. Description of the Related Art Conventionally, as a character output device such as a printer or a display, a method of storing the shape of a character as outline data representing its outline and converting the outline data into image data of pixels and outputting the image data Things are widespread. Specifically, the coordinate system that defines the pixels of the output device (pixel coordinates)
On the other hand, by overlapping the above outline and scanning the outline in a predetermined direction, the pixels existing inside the outline are distinguished from the pixels existing outside, and the pixels determined to be present inside the outline are turned on. By doing so, image data of the character is generated (hereinafter, the process of converting outline data into image data by such a method is referred to as scan conversion process). Here, when enlarging or reducing the character, the outline of the reference size is enlarged or reduced to the specified size and then overlapped with the pixel coordinates, and then the scan conversion process is performed to specify the specified outline. Image data corresponding to the size is generated.

[0003]

Discrimination between the inside area and the outside area of the outline in the above-mentioned scan conversion processing is performed by digital processing in units of pixels. That is, if the outlines that make up the outline pass inside the pixel,
For example, based on whether the center of the pixel is inside or outside the outline, the entire pixel is processed so as to belong to either the inside or outside of the outline. Therefore, when the area is digitized in this way, an error corresponding to the pixel width inevitably occurs near the outline.

Here, in the case of a character composed of a plurality of linear regions, such as a character, if the line width is sufficiently larger than the spread of one pixel, the error due to the digitization is almost ignored. can do. However, when the character is reduced in size and the line width is reduced, the influence of the above error is gradually increased, and the readability of the character is deteriorated, for example, as shown in FIG. There's a problem.

SUMMARY OF THE INVENTION An object of the present invention is to prevent or suppress deterioration of readability due to character reduction in a character output device for converting outline data into image data and outputting the image data. It is to provide a device capable of doing.

[0006]

According to the present invention, it is assumed that an outline based on outline data defining a contour shape of a character is superposed on a coordinate system (pixel coordinates) defining pixels of an output device. When the positional relationship between the pixel coordinates and the outline satisfies a certain standard, the pixels determined to be inside the outline are set to the first density, and the other pixels are set to the first density different from the first density. The present invention relates to a character output device that converts outline data into image data defining pixel information by setting the second density and outputs a character image based on the image data, and has the following requirements. It is characterized by being configured. Density setting means: scans the outline in a predetermined direction in pixel coordinates, and sets the pixels in a region (outline region) determined to exist inside the outline on the scanning line to the first density. . Density correction means: When two outline regions are formed in contact with each other or partially overlap each other on a scanning line, at least one of the outline regions is near the end of the contact or overlap side. Density correction processing is performed in which the density of one or more pixels located is a third density intermediate between the first density and the second density.

In the character output device configured as described above, two outline areas which should be originally separated and discriminated from each other on the scanning line are in contact with each other or partially due to the digitization error or the like. , The pixels located in the vicinity of the end on the contacting or overlapping side of at least one of the outline areas are overlapped with each other by the density correcting means. Since the density is the intermediate third density, it is difficult for the characters to be crushed due to the continuation of the adjacent outline areas. As a result, it is possible to prevent or suppress the deterioration of readability due to the reduction of the character,
As a result, small-sized characters can be output beautifully.

Next, it is possible to provide correction prohibiting means for prohibiting the density correction processing of the specific pixel by the density correcting means. The correction prohibiting means can prohibit the density correction processing in the outline area when the formation length of the outline area along the scanning line is equal to or less than a predetermined value. For example, when the outline area has a length of only one pixel, the outline area may disappear or become unclear when the density correction processing is performed. However, by prohibiting the density correction processing, the above-mentioned problem can be avoided. More specifically, the correction inhibiting unit has one of two outline regions formed in contact with each other or partially overlapping each other on the scanning line, and has a smaller formation length than the other. Further, when the formation length is equal to or smaller than a predetermined value, the density correction processing in the one outline area can be prohibited.

The third concentration can be set in any of a plurality of stages. As a result, the density correction process can be performed more finely. In this case, the density correction means sets the density of the pixel to be subjected to the density correction processing on the scanning line in any one of the plurality of stages according to the combination of the formation lengths along the scanning line of the two outline regions. Can be configured to.
By doing this, for example, in the case of linear areas formed close to each other in the character image, the density of the pixel to be corrected is adjusted according to the combination of the line widths, so the readability of both areas is further enhanced. be able to.

Next, it is possible to set two or more scanning directions that intersect each other, and it is possible to perform outline scanning and identification of correction pixels for each of these scanning directions. As a result, the conversion accuracy of the image data from the outline data, that is, the resolution of the character image can be improved as compared with the case where scanning is performed in only one direction. In this case, the density correction means can be configured to include the following requirements. Third density setting means: at least one of the outline regions is formed when two outline regions are formed in contact with each other or partially overlap each other on the scan line every time scanning with one scanning line is completed. On the other hand, the processing of setting the density of one or a plurality of pixels located near the end on the side of contact or overlapping to the third density is performed for each scanning direction. Final density determining means: For each pixel, the third density setting means determines the final set density of each pixel based on the combination of densities set for each scanning direction. According to the above configuration, when the set densities for the same pixel are different depending on the scanning direction, the final density determination unit determines the final set density for each pixel according to the combination of the densities for each scanning direction. Correction processing becomes possible.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a configuration example of a character output device of the present invention. That is, the character output device 1 includes an I / O port 4, a CPU 5, a ROM 6 and a RAM connected to the I / O port 4.
7, a computer main body 2 including a disk storage device 8 and the like, and a printer 3 connected to the computer main body 2 through the I / O port 4. Also,
An input unit 9 such as a keyboard and a display control unit 10 are connected to the I / O port 4, and the display control unit 10 has a CR.
A monitor 11 such as a T or a liquid crystal display is connected. The CPU 5 is the main body of the density setting means, the density correcting means and the correction inhibiting means.

An output control program storage unit 6a is formed in the ROM 6 of the computer main body 2, and an output control program for controlling a character output process described below in this embodiment is stored therein. Furthermore, RO
The density determination table storage unit 6b for storing the density determination table is stored in M6, and its role will be described later. On the other hand, the RAM 7 has a work memory 7
a, text memory 7b, X scan intersection memory 7c,
A Y scan intersection memory 7d and the like are formed. The work memory 7a is used when the CPU 5 executes a program.
Used to temporarily store the required data. In addition, the text memory 7b stores the code and size of the character input from the input unit 9 and the character modification information such as the rotation and italic of the character or the superscript / subscript. Other roles of the memory will be described later.

On the other hand, the disk storage device 8 is composed of a hard disk device, a magneto-optical disk device or the like, and a character storage portion 8a and an image memory 8b are formed therein. In the character storage unit 8a, character data corresponding to a large number of characters such as characters and symbols of various typefaces in a one-to-one correspondence is stored so as to be randomly read in units of one character. The character data includes outline data that gives the contour shape of each character, and character attribute data such as character width. The character data storage unit 8a can be formed in the ROM 6 as the same 6c.

FIG. 2 shows an example of outline data. That is, as shown in FIG. 1A, reference coordinates 15 are set in the computer main body 2, and the outline data of each character is obtained by vectorizing each constituent line of the outline (outline) 16 on the reference coordinates 15. It is described as a combination of the vector data when displayed. A specific example is shown in FIG. The data is composed of a flag indicating the processing content and a coordinate value that gives the position of the pointer at the time when the processing corresponding to the flag is completed. Where 1
Indicates the X coordinate, the numerical value 2 indicates the Y coordinate, the flag “S” indicates the process of moving the pointer to the drawing start point, and the flag “L”.
Indicates a process of moving the pointer from the immediately preceding coordinate to the coordinate corresponding to the flag and drawing each constituent line of the outline 16 based on the trajectory of the pointer.
And in the case of the outline 16 shown in (a),
It is composed of 12 line segments starting from the coordinate value of (58, 25) and returning to the coordinates again, and each constituent line forms a vector defined by the coordinate values of the starting point and the end point. Can be seen. In addition, the above-described constituent line may be formed in a linear shape, or may be formed in a curve such as a Bezier curve, a B-spline curve, or an arc.

As shown in FIG. 3A, the outline of the character based on the outline data thus constructed is superimposed on the pixel coordinates 20 as it is or after being appropriately enlarged or reduced (scaling). Then, the pixel P existing in the outline 16 'on the pixel coordinate 20 is set to the first density, for example, black by the scan conversion processing described later, and the outline 1
By setting the pixels (not shown) existing outside 6'to the second density, for example, white, the image data corresponding to the character image as shown in FIG. It will be described and generated as an aggregate. Here, each pixel is capable of gradation output with a third density (for example, gray) intermediate between the first and second densities.

Returning to FIG. 1, the image memory 8b contains
Image data of a character generated based on the character data is stored. The image memory 8b may be formed in the RAM 7 as the same 7e.

The printer 3 also includes a print output unit 13 that prints out an image of a character based on the image data. The print output unit 13 is composed of, for example, an electrophotographic printing device using a laser light source, an inkjet printing device, or the like. In addition, between the print output unit 13 and the I / O port 4, the computer main body 2
It is possible to provide a printer buffer memory 12 for temporarily storing image data and the like sent from the side.

The flow of processing in the character output device 1 will be described below with reference to a flowchart. First, FIG.
In S1, the character code and size data (hereinafter, collectively referred to as text data) is input using the input unit 9. These input data are stored in the text memory 7b (FIG. 1) of the RAM 7 as a text file. It should be noted that the text file created in advance may be stored in the disk storage device 8 or the like, and may be read out and used as appropriate. Next, in S2 and S3, the outline data corresponding to the character code included in the text data is sequentially read from the character storage unit 8a, and the outline of the character based on the outline data is scaled based on the size data described above. The pixel coordinates 20 (FIG. 3) are overlaid.

Subsequently, in S4 and S5, scan conversion processing is performed on the overlapped outlines. The scan conversion process is individually executed in two directions (that is, the X direction and the Y direction) orthogonal to each other. FIG. 5 shows the flow of the X-direction scan conversion process (S4). First, in S21, the Y coordinate of the scan line (scan line) is initialized, and then S23.
In X, a scanning line in the X direction corresponding to the first Y coordinate value is generated, and as shown in FIG. 7, all intersections between the scanning line Ym and the outline 16 'are calculated. That is, the process of determining whether or not a predetermined reference point (for example, the center of a pixel) set in a pixel is inside the outline is determined by performing processing for pixels arranged on the scan line from one side to the other side. The first pixel row (outline area) determined to have the above reference point inside the outline (start point; B1, B2)
Etc.) and the last one (end point; E1, E2, etc.) of each reference point is calculated as the coordinate value of each intersection. The calculated coordinate values of the intersections are stored in the X scan intersection memory 7c of the RAM 7 as an X scan intersection list as shown in FIG. Subsequently, in S25, a predetermined pixel on the scan line is set to black to perform a filling process, and in S26, the Y coordinate value of the scan line is updated and the process returns to S22, and the same process is repeated. Be done. The process ends when the scans corresponding to all the Y coordinate values are completed.

FIG. 6 is a flow chart showing details of the filling processing in S25. First, in S27, the X coordinates of the starting point and the ending point for each outline area stored in the intersection list are paired, and the pairs of coordinates are sorted based on the X coordinate value of the starting point. Next, in S28, the pointer is set to the first sorted start point, and the pixels from the start point to the end point paired with the start point are made black (that is, the first outline area is filled). Subsequently, the process proceeds to S37, the pointer is moved to the start point of the next outline area, and the process returns from S29 to S30 to similarly perform the filling processing of the outline area.

Next, in S32, it is determined whether the pixel corresponding to the start point of the current outline area and the pixel corresponding to the end point of the immediately previous outline area are adjacent to each other or overlap each other. If Yes, as shown in FIG. 15, two outline areas u1
And u2 are connected to each other, which means that the displayed character is crushed, and the process proceeds to the density correction process of S33 and thereafter. First, in S33, it is determined whether there are three or more pixels between the start point of the immediately previous outline area and the end point of the current outline area. If Yes, the process proceeds to S34, and it is determined whether or not there are two or more pixels between the start point and the end point of the current outline area.

If Yes in S34, the process proceeds to S36, as shown in FIG.
As shown in 1 (a), for example, the pixel P corresponding to the starting point on the region u2 side is changed to gray (that is, corrected to gray). As shown in FIG. 11B, the area u1
The pixel P corresponding to the end point on the side may be gray, or the pixel P corresponding to both the start point of the area u2 and the end point of the area u1 may be gray, as shown in FIG. is there.

On the other hand, the case of No in S34 means that the length of the region u2 in the scan line direction is one pixel width or less, as shown in FIG. 12, and in this case S35.
The pixel P corresponding to the end point of the area u1 is changed to gray in step. On the other hand, if No in S33, that is, the area u1
When the number of pixels existing from the start point of the area to the end point of the area u2 is 2 or less, for example, as shown in FIG.
This means that the lengths of the two outline areas u1 and u2 in the scan line direction are both less than or equal to one pixel width. In this case, S34 to S36 are skipped, and the pixel density correction processing is not performed. However, as shown in FIG. 13A, by distinguishing one of the two outline regions of one pixel width which are in contact with each other from gray, the visibility may be improved, and in this case, the density correction processing is performed. It is possible to adopt a mode in which

When the pixel correction registration processing is completed in this way
Proceed to S37, and move the pointer to the start point of the next outline area. Then, the process returns to S29 and the following processes are repeated. If the processing has been completed for all outline areas in S29, the filling processing is completed. The details of the X-direction scan conversion processing (S4) are as described above, but the content of the Y-direction scan conversion processing (S5) performed subsequently is exactly the same as the X-scan conversion processing except for the scanning direction. Therefore, the description will be omitted.

Next, in S6, the images of the characters respectively obtained in the X-direction and Y-direction scan conversion processing are combined to obtain the final image data of the characters (see FIG. 10). Here, when performing image composition, the pixel density set in the X-direction scan conversion and Y
If the densities of the pixels set in the directional scan conversion are different from each other, the final set density is determined by referring to the density determination table stored in the ROM 6. FIG. 9 shows an example of the density determination table. In (a), for example, pixels that are gray in at least one of the X-direction and Y-direction scan conversions are uniformly set to the final gray. ing.

Further, in (b), there is shown an example in which the finally set density is set to any one of a plurality of levels depending on the type of combination including gray. In the present embodiment, the gray density can be set to any one of three levels of gray 1 to gray 3 (for example, the larger the number, the higher the density). In this case, in the scan conversion processing for each direction, the density correction is uniformly performed with the same density (for example, gray 2), and when the images are combined, one of white, black, and gray 1 to 3 is selected depending on the combination of the set densities. The density of each pixel is finally set.
10A and 10B are respectively shown in FIG. 9A.
9A and 9B are schematic views showing an example of image synthesis based on the tables of FIGS.

Further, as shown in FIGS. 13A to 13C, a combination of lengths of the two outline regions u1 and u2 in the scanning direction (for example, a combination of character line widths).
Depending on the above, the density of the pixel can be set to any one of two or more. For example, as the average width of the two outline regions u1 and u2 formed by sandwiching the pixel to be changed to gray becomes smaller, the gray density can be increased, and in the illustrated example,
(A) is set to gray 3, (b) is set to gray 2, and (c) is set to gray 1.

The image data obtained as described above by the image synthesis is stored in the image memory 8b (FIG. 1). Then, in S7, a character image is printed from the printer 3 based on the image data.
The output is completed and the whole process is completed. In addition, when the image data generated by the above processing is left in the image memory 8b and the character of the same type and size is output next time, the image memory 8b
If you use the image data stored in
It is not necessary to repeat the image data generation process including the scan conversion process and the density correction process (S2 to S6 in FIG. 4: hereinafter referred to as expansion process) each time, and the processing efficiency can be improved.

The pixel density correction processing may be performed by once setting the density of the designated pixel to black (first density) and then changing it to gray (third density). It does not matter if the third concentration is directly set instead of the first concentration. Further, in the above-described embodiment, the pixel density correction processing is executed for each scan line each time, but the pixels set to gray in at least one of the scan conversion processing in each direction are uniformly used. In the case of outputting in gray of the same density, the pixels to be corrected are registered in the RAM 7 etc., and after all scan conversion processing is completed, the density change from black to gray is collectively performed based on the registered contents. You may do it.

The image of the character based on the image data can be displayed / outputted on the monitor 11, for example, in addition to being printed / outputted on the printer 3. In this case, character data different from that for printing may be used for monitor output.

In the above-described embodiment, the character image development process is mainly performed on the computer main body side, but it may be performed on the printer side. FIG. 14 shows an example of the apparatus configuration in that case. In this configuration, the printer 3 includes a printer control unit 30 including a computer or the like. The printer control unit 30 includes an I / O port 31 and a C connected to the I / O port 31.
The output control program is provided in the output control program storage unit 34a in the ROM 34, the density determination table is stored in the same density determination table storage unit 34b, and the character data is stored in the same character storage unit 34c. Remembered Also, RAM
The work memory 33a, the X scan intersection memory 33b, the Y scan intersection memory 33c, the image memory 33d, and the like are formed in the 33. That is, the text data stored in the text memory 7b or the like on the computer main body 2 side is transferred to the printer control unit 30, and the CPU 32 executes the expansion processing according to the same flow as that described above based on the text data.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration example of a character output device of the present invention.

FIG. 2 is an explanatory diagram showing an example of outline data.

FIG. 3 is an explanatory diagram showing an outline after scaling and an output example of a character image based on the outline.

4 is a flowchart showing the overall flow of processing in the character output device of FIG.

FIG. 5 is a flowchart showing details of the X-direction scan conversion processing.

FIG. 6 is a flowchart showing details of a filling process in the scan conversion process.

FIG. 7 is an explanatory diagram of intersection point calculation processing between an outline and a scan line.

FIG. 8 is an explanatory diagram showing an example of an X-scan intersection list.

FIG. 9 is an explanatory diagram showing an example of a density determination table.

FIG. 10 is a schematic diagram showing an outline of pixel correction processing based on a density determination table.

FIG. 11 is a schematic diagram showing a specific example of pixel correction.

FIG. 12 is a schematic diagram showing another specific example.

FIG. 13 is a schematic diagram showing an example in which the density of a pixel is set to one of a plurality of levels depending on the combination of the lengths of outline areas.

FIG. 14 is a block diagram showing another configuration example of the character output device of the present invention.

FIG. 15 is a schematic diagram illustrating how a character is crushed by forming outline regions in contact with each other.

[Explanation of Codes] 1 character output device 5 CPU (density setting means, density correction means, correction prohibition means) 16 outline u1, u2 outline area P pixels

Claims (6)

[Claims] 1. An outline based on outline data defining a contour shape of a character is assumed to be superimposed on a coordinate system (hereinafter, referred to as pixel coordinate) defining pixels of an output device, and the position of the pixel coordinate and the outline. Pixels that are determined to be inside the outline when the relationship satisfies a certain criterion are set to the first density, and the other pixels are set to the second density different from the first density. According to the character output device for converting the outline data into image data defining the information of the pixel and outputting the image of the character based on the image data, in the pixel coordinates, the outline is in a predetermined direction. And scan on that scan line,
Density setting means for setting the pixel in the area determined to exist inside the outline (hereinafter, referred to as outline area) to the first density, and the two outline areas are in contact with each other on the scanning line. Alternatively, when a part of them is formed so as to overlap with each other, the density of one or a plurality of pixels located in the vicinity of the end on the side where they are in contact or overlap with at least one of the outline areas is defined as the first density. And a density correction unit that performs density correction processing to obtain a third density intermediate between the second density and the second density. 2. A correction prohibiting means for prohibiting the density correction process in the outline area when the formation length of the outline area along the scanning line is equal to or less than a predetermined value. 1. The character output device according to 1. 3. The correction prohibiting means has one of the two outline regions formed in contact with each other on the scanning line or partially overlapped with each other, and one of the two outline regions has a length greater than that of the other. The character output device according to claim 2, wherein the density correction processing is prohibited in the one outline area when the formation length is small and the formation length is equal to or less than a predetermined value. 4. The third density can be set to any one of a plurality of levels, and the density correction means sets the two outline regions for a pixel on the scanning line for which the density correction processing is to be performed. 4. The character output device according to claim 1, wherein the density is set to any one of the plurality of stages in accordance with the combination of the respective formation lengths along the scanning line. 5. The scanning direction is set to two or more intersecting each other, and the outline scanning and the density correction processing are performed for each scanning direction.
The character output device according to any one of 1. 6. The density correction unit, when the scanning with one scanning line is completed, when the two outline regions are formed in contact with each other on the scanning line or partially overlap each other, A process of setting the density of one or a plurality of pixels located in the vicinity of the end on the side of contact or overlapping with at least one of the outline areas to the third density;
Based on a combination of the third density setting means for each scanning direction and the density set for each pixel by the third density setting means for each pixel, a final set density of each pixel is set. The character output device according to claim 5, further comprising: final density determination means for determining.