JPH0777969A - Font rasterising device and method thereof - Google Patents

Abstract

PURPOSE:To output a character which uses optical illusion technology and is good in readability. CONSTITUTION:A storage part 13 is stored with reference outline information consisting of border position information 11a, outline character information 11b, and a deletable flag 11c extracted by an extraction part 12 and a conversion part 15 converts the information into outline information of optional size. Further, a stroke correction part 16 corrects the border position information converted by the conversion part 15. At this time, a deletion flag detection part 16a refers to deletable flags and detects deletable strokes, and a deletion judgement part 16b judges whether each stroke is less than a specific threshold value. A correcting process which deletes the strokes which are deletable and less than the specific threshold value is performed. Further, an outline character information correction part 17 corrects the outline character information converted by the conversion part 15 according to the correction and a development part 14 develops raster data based on the corrected outline character information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a font rasterizing apparatus and method for forming a raster character image of arbitrary size from reference outline information.

[0002]

2. Description of the Related Art In recent years, in the field of desk publishing and the like, when outputting a raster character image, instead of a dot font, the shape of a character represented by several points indicated by coordinates and an outline or outline connecting them The outline font, which is the font that defines, has come to be used.

In order to output a raster character image of a character by using this outline font, coordinate position information of some dots serving as a base point is held as a part of the outline information, and this base point is used when outputting the character. A line (outline) that passes through the character is calculated, the inside of the outline is filled, and the resulting raster character image is output.

In the background in which the outline font has come to be used, the outline font basically needs to hold only the coordinate data of the base point, so that a fine font having a large number of dots is stored. This is because the required storage capacity is much smaller than that of the dot font. Also, when outputting characters of different sizes, the basic outline font is enlarged / reduced by calculation, so that it is not necessary to have a font for each character size like a dot font. Further, in the outline font, characters can be transformed relatively freely. That is, by using outline character information in outline fonts, compared to the case of using raster character data in dot fonts, characters of arbitrary size and modified / modified characters can be stored in a high quality with a low storage data amount. This is because the character can be obtained.

As a related technique for outputting high quality characters by using the outline information, Japanese Patent Laid-Open No.
There is a character processing device described in Japanese Patent Publication No. 006164.
This character processing device uses outline information when the width of each stroke represented by the outline becomes uneven when enlarging / reducing processing, or when the balance between strokes becomes unbalanced. A correction technique is disclosed. As a result, it is possible to output a high-quality raster character image that makes use of the characteristics of characters, for example, the characteristics peculiar to Kanji characters.

[0006] Japanese Patent Application No. 3-292407 describes a drawing device for efficiently performing rasterization processing when drawing a character from outline information. This is to perform various processes regarding how to expand the outline on the bitmap plane, make appropriate decisions based on the form of dot misalignment, and use this result to select and perform the appropriate process. Is.

Further, in Japanese Patent Laid-Open No. 2-219094, extra points (control points) are used when a raster character image is generated by using particularly reduced outline character data (including vector font character data). In order to solve the problems that the characters are crushed or the width of the line is varied within the characters, and the processing time is long due to the large number of points, the point data to be deleted may be deleted depending on the reduction ratio. An identifier indicating a reduction ratio to be deleted is added in advance, and when the reduced character is generated, the point data to be deleted is identified by the identifier of each point data according to the reduction ratio, and the point data is deleted. Describes a vector font character reduction method for generating reduced characters according to point data.

On the other hand, of the raster character data in the dot font, the human illusion is applied to the raster characters of the size of 10 dots or 12 dots, and the strokes in the characters are artificially omitted to improve readability. The technique of improving, that is, the optical illusion technique is used.

For example, FIG. 17 is a diagram showing 10-dot × 10-dot “negative” raster character data.
7, the "element", which is the central element of the character "negative", is 4
When expressed by the horizontal stroke of a book, the element "eye" is crushed, and the legibility of the character "negative" becomes worse. Therefore, the horizontal stroke of the element "eye" is artificially made into three horizontal strokes. Is expressed as. By using the illusion technique in which the element "eye" of the character "negative" is "day", the readability of the character "negative" can be improved even with a low-resolution output device.

[0010]

As described above, conventionally, the raster character data in the case where the resolution for one character is low such as 10 dots × 10 dots is improved in the readability of the character by using the illusion technique. .

However, in a font rasterizing device using outline information capable of obtaining a character of any size and a modified / modified character with a low storage data amount and high quality, a character using the above-mentioned illusion technique is output. I couldn't.

For this reason, even if the font rasterizing apparatus uses outline information, the output character may be crushed if the resolution per character is low, and the character having good readability may be output. could not.

Therefore, the present invention eliminates such a problem, and when the resolution per character is low, a font rasterizing apparatus and method capable of outputting a legible character as a character using the illusion technique. The purpose is to provide.

[0014]

SUMMARY OF THE INVENTION The present invention relates to a stroke for forming a character of an arbitrary size from the reference outline information in a font rasterizing device for generating raster data of a character of an arbitrary size based on the reference outline information. Calculating means for calculating stroke information; first judging means for judging whether each stroke of the strokes indicated by the calculated stroke information is a predetermined omissible stroke in the reference outline information; Second judgment means for judging whether or not each stroke line width of the stroke indicated by the calculated stroke information is below a predetermined threshold value, judgment by the first judgment means and the second judgment means With reference to the result, exclude strokes that can be omitted and whose stroke line width is less than or equal to a predetermined threshold value. Characterized by comprising a drawing means for drawing the characters of any size having a stroke which is the calculated.

[0015]

According to the present invention, when the raster data of a character of an arbitrary size is generated based on the reference outline information, the calculating means calculates the stroke information regarding the stroke forming the character of the arbitrary size from the reference outline information. The first determining means determines whether or not each stroke of the strokes indicated by the calculated stroke information is a predetermined omissible stroke in the reference outline information, and the second determining means determines the stroke. The drawing means determines whether or not each stroke line width of the stroke indicated by the calculated stroke information is less than or equal to a predetermined threshold value, and the drawing means determines that the stroke line width can be omitted and has a predetermined stroke line width. Characters of arbitrary size having the calculated strokes are drawn by excluding strokes that are less than or equal to a threshold value.

Therefore, it is possible to output a legible character even when the character is drawn on the bitmap having a low resolution due to the reduction.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a font rasterizing device which is an embodiment of the present invention.

In FIG. 1, the font rasterizing apparatus uses outline character information 11b, vertical / horizontal stroke boundary position information 11a extracted manually or automatically from the outline character information 11b, and boundary position information 11a. Correspondingly, the external storage unit 11 that stores outline information including a erasable flag 11c indicating that this stroke can be erased,
An extraction unit 12 that extracts boundary position information 11a, outline character information 11b, and a deletable flag 11c for an arbitrary character from the external storage unit 11, and a storage unit 13 that temporarily stores the extracted or corrected outline information. , The outline information stored in the storage unit 13 is enlarged / reduced to a specified arbitrary size,
Alternatively, the conversion unit 15 that performs conversion such as arbitrary rotation processing, the stroke correction unit 16 that corrects the boundary position information of the outline information that is converted by the conversion unit 15, and the boundary position information that is corrected by the stroke correction unit 16 An outline character information correction unit 17 that corrects the outline character information based on the original, an expansion unit 14 that raster-expands the corrected outline character information on a bitmap, and the above-described extraction unit 12, storage unit 13, expansion unit 14, Converter 15,
Stroke correction unit 16, outline character information correction unit 1
7 is connected to each other, and is composed of a control unit 18 that controls each processing.

Further, the stroke correction unit 16 includes a storage unit 1.
The width of the stroke with reference to the deletion flag detection unit 16a that detects whether the stroke can be deleted by referring to the deletion possible flag 11c stored in No. 3 and the boundary position information converted by the conversion unit 15. And a deletion determination unit 16b that determines whether or not is less than or equal to a predetermined threshold value. When the stroke detected by the deletion flag detection unit 16a has a stroke width equal to or smaller than a predetermined threshold value by the deletion determination unit 16b, the stroke is deleted.

Here, the stroke is a stroke of a character defined by the outline generated by the outline character information, and the boundary position information is coordinate information indicating the boundary position of the stroke on the outline coordinates. . The stroke and boundary position information will be described later in detail with reference to the drawings.

FIG. 2 is a block diagram showing the functional arrangement of a printer system incorporating the font rasterizing device shown in FIG.

In FIG. 2, a data input unit 21 receives input data 23 printed or displayed by an output device 22 such as a printer or CRT, and supplies it as data 28 to a data interpretation execution control unit 27.

The font processing unit 26 manages and retrieves font data. Then, if there is raster character data 29 for the requested character, it is supplied to the data interpretation execution control unit 27. When the data 29 designates outline characters, the font processing unit 26 performs enlargement / reduction processing of outline information, transformation processing, or the like.
After further expansion processing, the data interpretation execution control unit 27
Supply to. A font file 31 is connected to the font processing unit 26, and the font processing unit 26 extracts font data 32 from the font file 31. Here, the external storage unit 11 of FIG. 1 corresponds to the font file 31, and the other constituent elements of FIG. 1 correspond to the font processing unit 26.

The image processing section 25 processes the data interpreted by the data interpretation execution processing section 27 and develops it on the image memory 33. The expanded data 34 is supplied to the data output unit 24 via the image processing unit 25 and the data interpretation execution processing unit 27, and is output as output data 36 to the output device 22 connected to the data output unit 24. . In this case, what is stored in the image memory 33 includes the character data expanded by the font processing 26 in addition to the image data expanded by the image processing unit 25.

FIG. 3 is a diagram showing a circuit configuration of the printer system of FIG. That is, FIG. 3 shows an actual hardware configuration.

In FIG. 3, the CPU 41 is connected to the following parts via a bus 42.

(1) RAM 43: This is a random access memory and is used as a memory area for temporarily storing character data and a work area for transforming / developing character data of outline information. It is used to temporarily store a program for controlling the operation, or temporarily store various data processed for the execution of the program. Further, the RAM 43 has an image memory area and also serves as the image memory 33 shown in FIG.

(2) Magnetic disk device 44: This is an external storage device that stores programs for controlling the printer system and font files, and also stores data for saving as necessary. .

(3) Communication control unit 45: This is connected to an external telephone communication network, a local area network or the like via a cable 46. Then, data for printing is input from an information source such as a host computer connected to these. This data is, for example, data described in a page description language or the like.

(4) Keyboard 47: This is a device to which a mouse 48 as a pointing device can be connected and which inputs various data for operating the printer system. Data for printing can also be directly input from the keyboard 47.

(5) CRT control unit 49: graphic
It is connected to a CRT 51 as a display, and controls to visually display various data.

(6) Printer control unit 52: Functions as the data output unit 24 shown in FIG. 2 and controls the printing of the laser printer 53.

Next, an outline of the operation of the printer system including the font rasterizing device will be described with reference to the flowchart.

FIG. 4 is an operation flowchart of the printer system.

In FIG. 4, first, input data for printing is read (step 101). This input data is in the command format, and the CPU 41 causes the data interpretation execution control unit 27 to interpret the command. As described above, this command is written in the page description language.

Then, it is judged whether or not this command is a command for font processing (step 10).
2) If the command is for font processing, the font processing unit 26 performs font processing (step 10).
3). Then, the process proceeds to step 107. On the other hand, if the command is not a font processing command in step 102, it is further determined whether or not the command is an image processing command (step 104). If the command is an image processing command, the image processing unit Image processing is performed at 25 (step 105), and the process proceeds to step 107. If the command is not for image processing in step 104, the data interpretation execution control unit 27 performs other command processing such as a language processing system in the data interpretation execution control unit 27 (step 106), and proceeds to step 107. To do.

In step 107, the data interpretation execution control unit 27 determines whether or not the input data is finished,
If not completed, the process proceeds to step 102 and the above-described processing is repeated. On the other hand, when the input data is completed, the image contents expanded in the image memory area in the RAM 43 are transferred to the laser printer 53, and the laser printer 53 prints.

Next, the font processing in step 103 will be described.

First, FIG. 5 is a diagram showing the structure of a font file required for font processing.

In FIG. 5, one font file is one font file, and the file is composed of a raster character information section 61 and an outline character information section 62.

The raster character information section 61 includes raster character information 63 and character width information 64.

The outline character information section 62 has outline character information 65, character width information 66, stroke boundary position information 67, and a stroke erasable flag 68.

Here, the input character information is defined for either or both of the raster character information section 61 and the outline character information section 62, and the raster character information section 61 uses the character size and character code. The outline character information section 62 can search for a character in the character information by the character code.

FIG. 6 is a flowchart showing the font processing procedure of the font processing unit 26.

In FIG. 6, first, the raster character information section 61 in the font file is searched for the character size and character code of the character information requested (step 20).
1). Then, from the search result, the raster character information section 6
It is judged whether or not the character size and the character code of the requested character information are present in 1 (step 202). When the character information of the requested character size and character code exists in the raster character information section 61, all the requested information such as the raster character information 63 and the character width information 64 is transferred from the raster character information section 61 to the RAM 43. Transfer to (step 20
3) Then, this process ends.

On the other hand, if the requested character information does not exist in the raster character information section 61 in step 202, the outline character information section 62 is searched for the character information of the requested character code (step). 20
4). If the character information requested from the search result does not exist, error processing is performed (step 20).
6) Then, this process ends. On the other hand, when the requested character information exists in step 206, the process further proceeds to step 207.

At step 207, the outline character information 65, the character width information 66, the stroke boundary position information 67, the stroke deletable flag 68, etc. of the requested character information existing in the outline character information portion 62 are set to R.
Transfer to AM43.

Then, the conversion unit 15 performs enlarging / reducing processing to uniformly set the outline character information 65, the character width information 66, and the stroke boundary position information 67 temporarily stored in the RAM 43 to the required size (step 208). . Of course, not only the enlargement / reduction processing but also the processing such as deformation is performed.

Further, the stroke correction section 16 performs the correction processing of the stroke boundary position information which has been enlarged / reduced in step 208 (step 209). In this correction process, the stroke information in the outline information uniformly converted by the conversion unit 15 is emphasized for correction, and the value of the stroke boundary position information is set to a value suitable for bitmap expansion. to correct. That is,
Perform rounding processing by integerization. Then, when the deletion flag detection unit 16a detects a deletable stroke and the width of the detected stroke is equal to or smaller than a predetermined threshold value, a correction process for deleting the stroke is performed.
The correction for deleting such strokes often occurs in the case of reduction conversion.

Next, when the correction of the stroke boundary position information by the stroke correction unit 16 is completed, the outline character information correction unit 17 makes a final correction processing of the outline character information based on the corrected stroke boundary position information. (Step 210). This correction processing is to correct the positions other than the stroke boundary position to appropriate values based on the stroke boundary position information corrected in step 209. That is, based on the correction value of the stroke boundary position that has been preferentially processed and the value of the stroke boundary position before this correction, the continuous conversion relation of other positions including this value is obtained, and based on this continuous conversion relation. hand,
All outline character information is corrected. As a result, the corrected stroke maintains its corrected value, and the outline character information of the other portions is corrected to an appropriate value by the above-described continuous conversion relationship corresponding to the corrected stroke.

The outline character information thus corrected and temporarily stored in the RAM 43 is raster-expanded by a predetermined method by the expansion unit 14 to form a raster character (step 211). This ends the font processing.

Next, the font processing in steps 208 to 211 will be described based on a concrete example.

FIG. 7 is a diagram showing the structure of the reference outline character information portion of the character "eye", and FIG. 8 shows the outline of the reference outline information of the character "eye" on the outline drawing coordinates. It is a figure.

In FIG. 7, the reference outline information of the character "eye" is displayed in the pointer storage area 71 as the first step.
In this storage area 71, a pointer P1 indicating the storage address of the outline character information 74, a pointer P2 indicating the storage address of the vertical stroke boundary position information 75, and a horizontal stroke boundary position information 76 are sequentially stored from the start address A1. Pointer P3 indicating the storage address of the vertical stroke deletable flag 77, pointer P4 indicating the storage address of the horizontal stroke deletable flag 78, pointer P5 indicating the storage address of the horizontal stroke deletable flag 78, and pointer P6 indicating the storage address of the character width information 79. Is stored.

The outline character information 74 indicated by the pointer P1 stores the outline line type 72 and the control point 73 as a pair. And outline line type "0"
Means the start point of the outline to be closed, and the control point paired with this point indicates the coordinates on the outline drawing coordinates. Further, the outline line type “1” means that the outline is a straight line, and indicates that the coordinates up to this are straight lines. Other outline line types such as circles and higher-order curves are prepared in advance, but they are not used for the reference outline character information of the character “eye”.

For example, the first of the outline character information 74
The 0th outline line type is "0", the control point corresponding to this is (20, 57), and this control point corresponds to the control point SP1 in FIG. The next second outline line type stored is "1", and the control point corresponding to this is (20, 8).
A straight line is drawn from 7) to coordinates (20, 8). That is, a part of the outline of the vertical stroke is drawn. Here, the straight line between the drawn control points is called a segment, and the closed outline is drawn as a set of this segment. Similarly, the next third outline line type stored is "1", and the control point corresponding to this is (84, 8).
A straight line segment is drawn from the third control point coordinate (20, 8) to the third control point coordinate (84, 8). Similarly, a straight line segment is drawn from the coordinates (84, 8) to the coordinates (84, 57) by the outline line type “1” and the fourth outline character information of the control point coordinates (84, 57). From the coordinate (84,57) to the coordinate (20,57) according to the outline line type "1" and the fifth outline character information of the control point coordinate (20,57).
A straight line segment is drawn up to. Thus, the outline CL1 to be closed is drawn.

Similarly, the outline CL2 is defined by the sixth to tenth outline character information.
, The outline CL3 is drawn by the eleventh to fifteenth outline character information, and the outline CL4 is drawn by the sixteenth to twentieth outline character information.

Next, the stroke boundary position information 75, 76 indicated by the pointers P2, P3 will be described. This stroke boundary position information indicates the stroke boundary position on the outline drawing coordinate with respect to the stroke forming the "eye". The boundary is shown as a set of [outside, inside] of this outline drawing area.

For example, vertical stroke boundary position information 75
Is the boundary position of two vertical strokes of the character "eye" by [20,28] by the first and second pairs and [84,76] by the third and fourth pairs. Will be shown. Further, the horizontal stroke boundary position information 76 is [8,1] based on the first and second pairs.
5], [22, 2 according to the third and fourth pairs
9], [43, 3 according to the fifth and sixth pairs]
6] and by the seventh and eighth pairs [57,
50] indicates the boundary position of the four strokes next to the character “eye” (see FIG. 8).

Next, the stroke erasable flags 77 and 78 indicated by the pointers P4 and P5 will be described. The vertical and horizontal stroke erasable flags 77 and 78 will be described.
Is the vertical and horizontal stroke boundary position information 7 described above.
It is stored corresponding to each set of boundary positions of 5 and 76. When the flag is "1", it indicates that the corresponding stroke can be deleted, and when the flag is "0", it corresponds. It indicates that the stroke to be deleted cannot be deleted. In this case, since the horizontal stroke erasable flag is "1", it indicates that the stroke indicated by the pair [22, 29] of the horizontal stroke boundary position information 76 corresponding to this flag can be deleted. There is.

Further, the character width information 79 indicated by the pointer P6
Indicates the size of the area in which the character is drawn. In this case, the character width information 79 is "100". Therefore, the outline drawing coordinate plane shown in FIG. 8 is a 100 × 100 drawing area in the first quadrant in which both the X axis and the Y axis are positive.

It should be noted that X1, Y of the control point (X1, Y1)
Reference numeral 1 denotes the X coordinate and the Y coordinate on the outline drawing coordinates, respectively. Further, it goes without saying that this outline drawing coordinate plane is a virtual one in processing and is not actually drawn.

Next, the conversion unit 15 in step 208.
The enlarging / reducing process will be described. Note that, here, a case will be described in which the reference outline information is reduced to 1/10.

FIG. 9 is a diagram showing a result of the outline information reduced to 1/10. In FIG. 9, the conversion unit 15 controls the control point information 73 of the outline character information 74 of the reference outline information shown in FIG. 7, the vertical and horizontal stroke boundary position information 75 and 76, and the vertical and horizontal stroke erasable flags. 77, 78, and the character width information 79 are uniformly set to 1/10, the control point information 73a of the outline character information 74a, the vertical and horizontal stroke boundary position information 75a, 76a, and the vertical and horizontal stroke erasable flags. 77a, 78a, and character width information 7
9a is reduced and converted.

Next, the correction process of the stroke boundary position information reduced and converted by the conversion unit 15 will be described. This process corresponds to step 209.

FIG. 10 is a diagram showing a process of correcting stroke boundary position information.

First, the stroke boundary position information on the outside of the stroke boundary position information uniformly reduced and converted by the conversion unit 15 shown in FIG. That is, integer processing is performed. As a result, the vertical and horizontal stroke boundary position information 75b and 76b shown in FIG.
Is corrected as follows. Next, calculate the distance between the outer and inner stroke boundary positions that form a pair, round this calculation result, and add this rounded value to the already rounded outer stroke boundary position value. Then, correction is performed using this value as the inner stroke boundary position information. The result is as shown in FIG.

That is, the inner stroke boundary position is calculated as shown in the following equation.

(Inner stroke boundary position) = (Integralized outer stroke boundary position) + FIX (Distance from outer stroke boundary position to inner stroke boundary position) Here, FIX () is an integer. This is the function to do. Also,
The distance from the outer stroke boundary position to the inner stroke boundary position is substantially the stroke line width.

For example, taking the third and fourth stroke boundary position information 76a in FIG. 10A as an example,
The third value is the outer stroke boundary position information “2.
2 ”, the fourth value is the inner stroke boundary position information“ 2.9 ”. First, the outer stroke boundary position information“ 2.2 ”is converted into an integer, and as shown in FIG. Becomes "2.0". Next, the outer stroke boundary position information “2.2” and the inner stroke boundary position information “2.
9 "and the distance" 0.7 "is calculated, and this distance" 0.
"7" is converted into an integer to give a distance of "1.0". Then, the corrected distance "1.0" is added to the outer stroke boundary position information "2.0" which has been already integer-corrected, and as shown in FIG. The position information “3.0” is requested.

Next, the deletion flag detector 16a searches the stroke deletable flags 77 and 78 to detect the stroke having the flag "1". In this case, it is detected that the second flag of the horizontal stroke deletable flag 78 is "1". Furthermore, the deletion determination unit 16b
Determines whether the stroke width corresponding to the stroke for which this flag is "1" is less than or equal to a predetermined threshold value "1". If the stroke width is less than "1", The correction unit 16 sets the stroke boundary position information inside the stroke corresponding to this flag to the same value as the stroke boundary position information outside. Therefore, the fourth value of the horizontal stroke boundary position information is corrected to the same value “2.0” as the third value “2.0”, as shown in FIG. As a result, when the stroke deletable flag is "1" and the stroke width is equal to or smaller than the threshold value "1", the stroke width indicated by the stroke boundary position information becomes "0". It will be deleted.

Here, FIG. 11 is a diagram showing an outline imaged by the correction of stroke boundary position information. FIG. 11A shows an outline imaged from the stroke boundary position information of FIG. 10A, and shows a state in which the reference outline information is uniformly reduced. On the other hand, FIG.
An outline imaged from the stroke boundary position information in (d) is shown, which shows that one horizontal stroke is deleted. Note that FIG. 11 is merely an image diagram. This is because the outline character information has not been corrected yet, and is simply the stroke boundary position information correction for correcting the outline character information.

Now, returning to FIG. 10, in FIG. 10 (e), the stroke correction section 16 sorts vertical and horizontal stroke boundary position information. This sort process rearranges the values of the stroke boundary position information in ascending order. This sort is performed in order to obtain the above-mentioned continuous conversion relationship. The result of this sort processing is as shown in FIG. 10E, and the values are sorted in ascending order.

Next, the stroke correction section 16 performs a process for obtaining a continuous conversion relationship based on the sorted boundary position information 75f and 76f. That is, based on the stroke boundary position information before and after the correction, the following values are obtained for each of the stroke boundary position information by the following equation. That is, (increment of polygonal line) = (change amount of stroke boundary position after correction) / (change amount of stroke boundary position before correction) (Y intercept) = (stroke boundary position after correction) − (stroke before correction) Boundary position) x (increment of polygonal line) is calculated.

FIG. 12 is a diagram showing the results of the polygonal line increments and Y intercepts for obtaining the continuous conversion relationship. In FIG. 12, for example, the first value of the polygonal line increment 75g and the Y intercept 75h is obtained as follows. First, the increment of the polygonal line is (the increment of the polygonal line) = (3.0-2.0) / (2.8-2.0) = 1.25, and the Y-intercept is (Y-intercept) = 2.0-1.0 × 1.25 = -0.5. In this way, all line increments and Y
Find the intercept. However, when the following information does not exist, for example, the increment of the fourth polygonal line and the Y intercept of the vertical stroke boundary position information set the polygonal line increment to “1”, and the polygonal line increment “1” to Y Find the intercept. That is, (increment of polygonal line) = 1.0 (Y intercept) = 8.0−8.4 × 1.0 = −0.4. Further, the polygonal line increment 76g and the Y-intercept 76h of the horizontal stroke boundary position information are similarly obtained.

The increment of the broken line thus obtained and the meaning of the Y-intercept will be described.

FIG. 13 is a diagram showing a continuous conversion relationship before and after correction of control points. In FIG. 13, FIG.
The continuous conversion relationship before and after the correction of the X coordinate value of the control point is shown, and FIG. 13B shows the continuous conversion relationship before and after the correction of the Y coordinate value of the control point.

In FIG. 13A, the horizontal axis shows the X coordinate position data of the control point before correction, and the vertical axis shows the X coordinate value position data of the control point after correction. FIG. 13 (a)
The conversion points P1 to P4 in (1) and (2) indicate the conversion points before and after the correction of the stroke boundary position information, and the above-mentioned polygonal line increment and Y intercept were obtained in order to determine the straight line passing through these conversion points P1 to P4. Is. For example, the straight line between the conversion points P1 and P2 is the polygonal line increment 75g and Y shown in the upper column of FIG.
Increment of the first polygonal line in the intercept 75h "1.2
5 ”and the Y intercept“ −0.5 ”. Therefore, by obtaining such a continuous conversion relationship, the control point information existing between conversion points is also arranged at an appropriate position in relation to the stroke boundary position. For example, when the X coordinate of the control point is “5.2” before correction, the corrected X coordinate is “5.0” due to the linear relationship between the conversion point P2 and the conversion point P3.

This is because the polygonal line increment is "0.83",
Since the Y-intercept is “0.68”, the corrected X coordinate is determined as 0.83 × 5.2 + 0.68 = 5.0.

The conversion relationship between the conversion point P1 and the origin is indicated by a straight line connecting the conversion point P1 and the origin.
As for the values of 4 or more, as described above, a continuous conversion relationship is represented by a straight line passing through the conversion point P4 and having a polygonal line increment of "1". Of course, it may be a straight line connecting the point (10, 10) and the point P4.

It should be noted that instead of a straight line between the conversion points, a characteristic curve such as a high-order curve passing through the conversion points may be used as a continuous conversion relationship.

In addition, FIG. 13B shows the Y coordinate position data of the control points before correction on the horizontal axis, and the Y coordinate position data of the control points after correction on the vertical axis. Similarly to the above), the continuous conversion relationship by the polygonal line increment 76g and the Y intercept 76h obtained based on the relationship before and after the correction of the lateral stroke boundary position information is shown. As a result, the value of the Y coordinate data of the control point is converted appropriately, and an unnatural outline is drawn.

FIG. 14 is a diagram showing final correction data of outline character information.

In step 210, the outline character information correction unit 17 corrects the final correction data of the outline character information to the control point information 73b. In this correction processing, the outline character information converted by the conversion unit 15 is corrected and converted based on the continuous conversion relationship of the X coordinate and the Y coordinate of the control point shown in FIG.

In the case of FIG. 14, only the control points related to the stroke boundary position information are shown. However, even when there is a control point not related to the stroke boundary position information, the X of the control points is calculated based on the above-mentioned continuous conversion relationship. The coordinate value and the Y coordinate value are converted and corrected.

This is for correcting the partial outline information such as "" added to "large" of the character "dog" and the position of the control point existing between the boundary positions to an appropriate position.

As a result, the outline on the outline drawing coordinates of the finally corrected outline information is as shown in FIG. As shown in FIG. 15, due to the reduction, a predetermined horizontal stroke of the character “eye” is deleted, so that a legible character can be generated.

The setting of the threshold value of the stroke width in the deletion judging section 16b can be arbitrarily changed.

Finally, in step 211, raster characters are generated based on the corrected outline character information.

The raster character expansion processing of the outline character information is performed by using a scan conversion algorithm such as an edge flag algorithm that does not fill a portion having a width of "0".

FIG. 16 is a diagram showing an example of processing for expanding outline character information into raster characters. FIG.
In (a), outline drawing coordinates and bitmap drawing coordinates are superimposed, and a bit is drawn at each intersection of bitmaps, for example, at an intersection PB. Here, "1 dot" of bitmap drawing coordinates corresponds to "1" of outline drawing coordinates. Then, as shown in FIG. 16A, a horizontal stroke segment is extracted based on the outline character information, and dots are arranged in this horizontal segment. Further, the scanning is performed from the bottom to the top in the vertical direction, the bits lined up in the X-axis direction are taken out, the exclusive OR with the bit immediately above is taken out, and the process of writing the dot again is performed, whereby the filling is performed. As a result, a raster character as shown in FIG. 16 (b) is generated.

In the present embodiment, the extraction unit 12 extracts the predetermined basic stroke boundary position information 11a and calculates the corrected outline character information of an arbitrary size based on this stroke boundary position information. However, the stroke boundary position information is automatically extracted only from the outline character information 11b itself, and the corrected outline character information of an arbitrary size is calculated based on the automatically extracted stroke boundary position information. Good.
In this case, the calculation time for automatic extraction is required, but conversely, since it is not necessary to store the stroke boundary position information 11a in the external storage unit 11, the storage capacity can be reduced.

In this way, in this embodiment, even if the resolution is reduced and the resolution is low, by deleting the predetermined strokes, it is possible to output high-quality characters with good readability.

[0095]

As described in detail above, according to the present invention, when raster data of a character of an arbitrary size is generated based on the reference outline information, strokes forming the character of the arbitrary size from the reference outline information are generated. Stroke information regarding the calculated stroke information is determined, it is determined whether each stroke of the stroke indicated by the calculated stroke information is a predetermined omissible stroke in the reference outline information, and the stroke indicated by the calculated stroke information is calculated. It is determined whether each stroke line width is less than or equal to a predetermined threshold value, and as a result of the determination, strokes that can be omitted and whose stroke line width is less than or equal to a predetermined threshold value are excluded. An arbitrary size character having the calculated stroke is drawn.

Therefore, even when a character is drawn on a bitmap having a low resolution due to the reduction, the outline character information is corrected to faithfully reproduce the stroke width of the character and delete the predetermined stroke. Therefore, it is possible to output high-quality characters with good readability.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a font rasterizing device that is an embodiment of the present invention.

FIG. 2 is a diagram showing a functional configuration of a printer system incorporating the font rasterizing device of FIG.

3 is a diagram showing a circuit configuration of the printer system of FIG.

FIG. 4 is an operation flowchart of the printer system.

FIG. 5 is a diagram showing a configuration of a font file necessary for font processing.

FIG. 6 is a flowchart showing a font processing procedure of a font processing unit 26.

FIG. 7 is a diagram showing a configuration of a reference outline character information part of a character of “eye”.

FIG. 8 is a diagram showing an outline of reference outline information of a character “eye” on outline drawing coordinates.

FIG. 9 is a diagram showing a result of outline information reduced and converted to 1/10.

FIG. 10 is a diagram showing a process of correcting stroke boundary position information.

FIG. 11 is a diagram showing an outline imaged by correcting stroke boundary position information.

FIG. 12 is a diagram showing a result of a polygonal line increment and a Y-intercept for obtaining a continuous conversion relationship.

FIG. 13 is a diagram showing a continuous conversion relationship before and after correction of control points.

FIG. 14 is a diagram showing final correction data of outline character information.

FIG. 15 is a diagram showing an outline on outline drawing coordinates by the finally corrected outline information.

FIG. 16 is a diagram showing an example of rasterization processing from outline character information to raster characters.

FIG. 17 is a diagram showing 10-dot × 10-dot “negative” raster character data using the optical illusion technique.

[Explanation of symbols]

11 External Storage Device 11a Boundary Position Information 11b Outline Character Information 11c Deletable Flag 12 Extraction Section 13 Storage Section 14 Expansion Section 15 Conversion Section 16 Stroke Correction Section 16a Deletion Flag Detection Section 16b Deletion Judgment Section 17 Outline Character Information Correction Section 18 Control Section

Claims (2)

[Claims] 1. A font rasterizing device for generating raster data of characters of arbitrary size based on reference outline information, and calculation means for calculating stroke information regarding strokes forming the characters of arbitrary size from the reference outline information. A first determination means for determining whether each stroke of the strokes indicated by the calculated stroke information is a predetermined omissible stroke in the reference outline information, and a stroke indicated by the calculated stroke information The second judgment means for judging whether or not each stroke line width is less than or equal to a predetermined threshold value, and the judgment results by the first judgment means and the second judgment means are omitted. Strokes that are calculated and exclude strokes whose stroke line width is less than or equal to a predetermined threshold Font rasterization apparatus being characterized in that; and a drawing means for drawing any size of a character having a stroke. 2. A font rasterization method for generating raster data of a character of an arbitrary size based on reference outline information, wherein stroke information regarding a stroke forming the character of the arbitrary size is calculated from the reference outline information, It is determined whether each stroke of the stroke indicated by the stroke information is a predetermined omissible stroke in the reference outline information, and each stroke line width of the stroke indicated by the calculated stroke information is a predetermined stroke. It is determined whether it is less than or equal to a threshold value, and as a result of the above determination, an arbitrary size that has the calculated stroke excluding strokes that can be omitted and whose stroke line width is less than or equal to a predetermined threshold value. A font rasterization method characterized by drawing the characters of.