JPH0747339B2 - Data converter - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data conversion device for converting outline data representing the outline of a character such as a character or a symbol into bit data, and more particularly to improvement of a conversion method. Is.

2. Description of the Related Art When processing data related to characters such as characters and symbols using a computer and displaying it in some form such as printing or display, it is common to form bit data for each pixel, which is the minimum processing unit. Has been done. At this time, if bit data is created in advance for all the characters to be processed and stored in the memory, a very large capacity memory is required. Therefore, as described in Japanese Patent Publication No. 53-41017, the characters are It is desirable that the outline data representing the contour is stored and converted into bit data by a data conversion device at the time of display.

In this data conversion device, a plurality of scanning lines that are parallel to one of the X and Y2 axes are assumed on the coordinate plane that defines the outline data, and pixels that include the intersections of each scanning line and the outline of the character. After all bit data corresponding to (contour pixels) are set to bit data representing the presence of a character constituting line (hereinafter referred to as character display bit data), pixels surrounded by these contour pixels (referred to as internal pixels). ) Is set to all the bit data corresponding to character display bit data.

However, in this data conversion device, the setting of the character display bit data is performed in two steps, that is, the setting step for the contour pixel and the setting step for the internal pixel. Has been Moreover, the character display bit data is set for each internal pixel sequentially for each internal pixel. That is, for each of a large number of bits corresponding to pixels arranged on one scanning line, it is sequentially determined whether or not the data of the bit is character display bit data, and each bit is displayed until the first character display bit data appears. The data of is kept as it is, which is the data indicating the absence of the character composing line, and all the data of each bit from the appearance of the first character display bit data to the appearance of the next character display bit data is the character display bit data. Will be changed to. When the second character display bit data appears, the subsequent bit data remains the data representing the absence of the character component line, and if the third character display bit data appears, the subsequent bit data. Is changed to character display bit data. In this way, if it is determined whether or not the data of each bit is character display bit data sequentially and the bit data is set for all pixels, it takes time to perform the process, and the bit data can be set quickly. I can't do it.

Therefore, an object of the invention of claim 1 is to provide a data conversion device capable of quickly converting outline data into bit data.

In addition to the problem of the invention of claim 1, it is an object of the invention to provide a data conversion device that can accurately convert outline data of a character including a thin character constituting line into bit data. It was done.

Further, an object of the invention of claim 3 is to provide a data conversion device capable of more rapidly setting bit data of pixels when a large number of pixels exist between two paired coordinates. It was done.

Means for Solving the Problems The invention of claim 1 is, as shown in FIG. 1 for solving the above problems, (a) a contour line of a character assumed on a coordinate plane defining outline data. And (b) intersection point coordinate calculation means for obtaining the coordinates of intersection points with a plurality of mutually parallel scanning lines at pixel positions, and (b) coordinate values of the intersection points obtained by the intersection point coordinate calculation means for each scanning line. In the order of the size of the two, the two coordinates adjacent to each other are taken out, and each of them is paired and stored, and (c) each of the pairs of coordinates stored by the intersection coordinate storage means. Bit data corresponding to all the pixels between the coordinates is configured to include bit data setting means for collectively setting the data representing the existence of the character constituting line.

Here, "obtaining the coordinates of the intersection of the character contour line and the scanning line at the pixel position" means obtaining the coordinates of the intersection itself if the intersection represents a pixel position (for example, the center of the pixel). Otherwise, to obtain the coordinates of the point that represents the position of the pixel closest to the intersection. In this case, as the pixel closest to the intersection, it is common to use the pixel closest to the intersection among the pixels inside the contour of the character configuration line as in the embodiment described later. Of the outer pixels, the pixel closest to the intersection,
Alternatively, it is also possible to adopt the pixel that is literally closest to the intersection regardless of whether it is inside or outside the contour line. In any case, the expression "all pixels between the coordinates of each pair" includes both the case of including the pixel itself corresponding to the coordinates of each pair and the case of not including the pixel itself.

Further, in the data conversion device according to the second aspect of the present invention, when the intersection coordinate storage means has a small width on one scanning line of the character configuration line, the intersection coordinate calculation means determines only one intersection coordinate. Is stored in a pair.

In the data converter according to the invention of claim 3, the intersection coordinate calculation means, the intersection coordinate storage means and the bit data setting means are constituted by a computer,
The bit data setting means is provided with a group unit setting means for setting bit data in bit data group units when there is one or more groups of bit data which can be processed in parallel by a computer between two paired coordinates. It is supposed to be

In the data conversion device according to the invention of claim 1, the character display bit data is first set for the contour pixels as in the conventional device, and then the internal pixel is set based on the character display bit data. Is not set for the character display bit data, but the bit data is set directly on the basis of the coordinates of each pair of intersections of the contour line of the character and the scanning line. The bit data corresponding to all the pixels between these coordinates are set as the character display bit data at once. As for the coordinates of the intersections obtained by the intersection coordinate calculating means, when arranged in order of size, two adjacent ones are taken out and stored as a pair. Therefore, two coordinates forming each pair are stored. Since the character constituting line always exists between them, the bit data corresponding to the character constituting line can be surely obtained even if the bit data is set to the character display bit data all at once.

Thus, according to the first aspect of the invention, the bit data is set in one step, and it is necessary to determine for each pixel whether or not the bit data corresponding to the pixel is character display bit data. Therefore, the outline data can be converted into bit data easily and quickly.

Further, in the invention of claim 2, the effect that the outline data is accurately converted into the character display bit data can be obtained. When the ends of the character forming line are sharp and partially thin, or when the entire character forming line is thin, the intersection of the contour line of the character forming line and the scanning line forms one character. Sometimes two lines should be obtained, but only one line is obtained. In such a case, in the conventional data conversion device, the contour line of another character constituting line and the scanning line are separated from one intersection point. The bit data corresponding to the pixels up to the intersection of will be the character display bit data, and bit data representing a character having a shape different from that represented by the outline data will be set. Therefore, conventionally, it has been necessary to create outline data carefully so that such a situation does not occur.

On the other hand, according to the data conversion device of the second aspect, even if only one coordinate at the intersection of the contour line and the scanning line is obtained, the same coordinate is stored as a pair, and thus the pair is stored. The two coordinates are always obtained for the same character component line, and the bit data corresponding to the pixels between different character component lines are not mistakenly set as the character display bit data. The shape represented by will be displayed correctly.

In the invention of claim 3, the bit data setting means has one or more groups of bit data which can be processed in parallel by a computer constituting the bit data setting means or the like between the paired coordinates. Is equipped with a group unit setting means for setting bit data in units of bit data groups. Therefore, in comparison with the case where each bit data in the bit data group is individually set,
Bit data can be set quickly.

Embodiment Hereinafter, a case where the present invention is applied to a device for converting outline data into bit data in a laser printer will be described in detail with reference to the drawings, taking the case where the present invention is applied.

FIG. 2 is a diagram mainly showing a portion related to data conversion in the control circuit of the laser printer. The microcomputer unit 10, which is the main body of this control circuit, includes a CPU 12, a character ROM 14, a program ROM 16, a text memory 18, a working memory 20, an intersection coordinate memory 22, and a bit data memory 24.
Is equipped with. The CPU 12 and the like are connected by a bus 28, and an input device 30 and a printing unit 32 are connected to the bus 28. The input device 30 inputs necessary data to the microcomputer unit 10, and the printing unit 32 is a unit for performing printing by a laser printing method based on a command from the microcomputer unit 10. The resolution of this laser printer is 300 Dot / Inch.

The CPU 12 includes a data reading unit 3 as shown conceptually in FIG.
6, an intersection coordinate calculation unit 38 for obtaining the coordinates of the intersection between the outline of the character and the x-direction defining line x, a data setting unit 40 for setting bit data, and the like are provided. Text memory 18
Is for storing character data consisting of code data input from the input device 30, and the working memory 20
Stores the data necessary for executing the program. The intersection coordinate memory 22 stores the coordinate values obtained by the intersection coordinate calculation unit 38,
In 24, bit data obtained by the setting of the data setting unit 40 is stored.

The character ROM 14 stores outline data of characters such as alphabets and other characters and symbols. As shown in FIG. 5, the coordinate planes that determine the outline of the character are 1000 (vertical (Y-axis) and horizontal (X-axis)).
It has a size of × 1000, and uppercase letters of the alphabet are drawn between Y and Y coordinate values 200 to 1000, and lowercase letters are also drawn between 0 and 200. Regarding the X-axis direction, the center of the coordinate plane and the center of the character are made to coincide. When the outline of the character is designed on such a coordinate plane, the character composition line 44 that constitutes the character is formed.
Has a width and is surrounded by a contour line 46. The outline data is created for each line element that connects a point with a circle in the figure of the contour line 46 as shown by taking “H” as an example, and the type of the line element and each point at both ends are created. Includes coordinates, etc. The coordinates of each of these points are sequentially stored along a fixed direction (indicated by an arrow in the drawing) defined on the contour line 46, and are stored first of the two points at both ends of each line element. The point is the start point, and the point stored later is the end point. The outline data includes straight line data and each coordinate of the start point and end point when the line element is a straight line, and includes curve data, a function formula of the curve and each coordinate of the start point, end point, and auxiliary point when the line element is a circular arc. In the case of, it includes the arc data and the coordinates of the start point, the end point, and the center point of the circle. The character ROM 14 also includes the number N of line elements for each character.
Is remembered.

In this laser printer, conversion of outline data to bit data is performed by the pixel screen 50 shown in FIG.
Is performed using. Pixel screen 50 is computational for converting outline data to bit data, but is illustrated here as being real for ease of understanding. Further, the pixel here is a minimum print unit when printing is performed by a laser, and the pixel screen 50 is orthogonal to each other in one plane and is parallel to the X-axis direction and the Y-axis direction. , Pixels are defined by a plurality of pixel section lines p provided at equal intervals. In this embodiment, the pixels are square, and beat data indicating whether or not to print is created for each pixel. In addition, x that passes through the center point of each pixel (hereinafter referred to as the pixel center point) and is parallel to the X-axis direction and the Y-axis direction, respectively.
A direction defining line x and a y direction defining line y are set, and the position of each pixel is represented by the coordinates of the pixel center point. Note that the pixel may have a rectangular shape or another shape.

Although the pixel screen 50 is supposed to correspond to the printing surface of the printing paper, one character is taken out and shown in FIG. 6 for easy understanding. Therefore,
The scale values actually attached to the x-direction defining line x and the y-direction defining line y in the whole pixel screen 50 are integers appropriate to the scale values attached to the x-direction defining line and the y-direction defining line in FIG. However, here, only one character will be considered.

The conversion of outline data into bit data is performed on the assumption that the outline of the character is superimposed on the pixel screen 50, and in the present embodiment, dots are formed at each pixel in the outline of the character. , The bit data of the pixel is set to 1. All or part of one pixel is included in the contour, but the specific conversion to bit data will be described in detail later.

In addition, this laser printer has 4.8 points for characters,
Printing can be performed in any size such as 10 points, 12 points, 20 points, 24 points, 30 points, etc., and the coordinate values of the contour formed on the 1000 × 1000 coordinate plane are converted according to the printing size. If the character of B point is represented by C × C pixels, a coordinate plane in which one side of one pixel is 1 is assumed on the pixel screen 50, and the contour is determined on the 1000 × 1000 coordinate plane. By multiplying the coordinate value of C / 1000 by, the coordinate value on the assumed coordinate plane on the pixel screen 50 can be obtained. Here one character is 20 × 20
The case where printing is performed at 4.8 points represented by pixels will be described. From 0 attached to the pixel screen 50 of FIG.
The numbers up to 20 are the coordinate values in this case. When overlaying the outline of the character on the pixel screen 50,
The coordinate value of the reference point of each character on the pixel screen 50 is also determined based on the print position data, and the coordinate value of the obtained reference point and the converted coordinate value are used for superposition.

The program ROM 16 further stores various programs necessary for printing, including the program for bit data conversion shown in the flowchart of FIG. The conversion of outline data into bit data will be described below by taking the letter “H” as an example.
Although the printing is not essential for understanding the present invention, a detailed description thereof will be omitted, but in the present laser printer, printing is performed page by page. Data of one page of the document data stored in the text memory 18 is read, outline data of characters constituting the data is converted into bit data, and printing is performed.

First, after the outline data, the number of line elements, and the print size of the character processed in step S1 (hereinafter abbreviated as S1; the same applies to other steps) are read out, and then the outline 46 of the character is read in S2. And the x-direction defining line x, the x-coordinate of the intersection is obtained for each line element forming the contour line 46. The rules for obtaining the x coordinate will be described below with reference to FIGS.

When the line element is a straight line that intersects both the x-direction defining line x and the y-direction defining line y, as shown in FIG. 7, a plurality of x-direction defining lines are provided from the start point to the end point of the line element. x and x
Although it intersects at the position indicated by the mark, the x coordinate of the intersection point is the x point of the actual intersection point of the x direction defining line x and the line element.
Not the coordinates but the center point of the pixel closest to the actual intersection inside the character component line defined by the line element (the shaded area in the figure) (the point marked with a circle in the figure) The x coordinate of) is taken as the intersection. x direction standard line x
When the actual intersection between the line element and the line element coincides with the center point of the pixel, the x coordinate of the intersection is directly taken as the intersection between the x-direction defining line x and the line element.

In addition, when the line element is parallel to the x-direction defining line x as shown in FIG. 8 and the inclination angle of the line element with respect to the x-direction defining line x is small, short, and adjacent to each other, as shown in FIG. If it is located between the two x-direction defining lines x, the intersection is processed as no intersection. Further, as shown in FIG. 10, when inclined line elements are connected to both ends of a line element located on the x-direction defining line x, there is no intersection for the line elements on the x-direction defining line x. For the points at both ends of the two slanted line elements, the coordinates of the intersection are determined only for the points on the outer side (the left side in the figure), and there is no intersection for the points on the inner side. Furthermore,
As shown in FIG. 11, two slanted line elements intersect, and in the vicinity of the intersection of these line elements, there is only one pixel center on one x-direction defining line x. When the constituent line is partially thin, the x coordinate of the center of the same pixel for each of the two inclined line elements is the x coordinate of the intersection. Therefore, even when the ends of these two slanted line elements exactly coincide with each other on the x-direction defining line x, the same x coordinate is obtained as the x coordinate of two intersections.

Further, as shown in FIG. 12, when the two contour line elements are parallel to the y-direction defining line y and the interval is narrow and the pixel center point is not included between them, Intersection x
Find the coordinates. Of the two contour line elements, the coordinates of the intersection point of the one with the smaller x coordinate value and the x-direction defining line x are the coordinates of the pixel center point on the side where the character component line exists from those actual intersection points. At the same time, the same coordinate is set as the x coordinate of the intersection for the other contour line element. When the pixel center point is included between the two contour line elements, the x coordinate of the pixel center point is obtained as the x coordinate of the two intersections.

The outline of the letter "H" according to these rules
If the intersection of each line element that constitutes 46 and each x-direction defining line x is obtained, the intersection is the position marked with a black circle as shown in FIG. In the case of the present embodiment, there are 20 x-direction defining lines x for each character, and the x-coordinate of each intersection is stored corresponding to the y-coordinate representing the position of each x-direction defining line x. The coordinates of the intersection are stored in the intersection coordinate memory 22 in S3, and the number of intersections is stored at the head of the storage area for each x-direction defining line x. In FIG. 14, the number of intersections obtained for "H" and a part of the x coordinate values are shown in a table for each x direction defining line x. Then, after n is incremented by 1 in S4, it is determined whether or not n is N or more in S5, that is, whether or not the calculation of the x coordinate of the intersection point is completed for all the line elements forming the contour line 46. Done. If not finished yet, the determination result is NO, and the x coordinate of the intersection is calculated for the next line element. When the processing is completed, the determination result is YES, and n is cleared in S6.

Next, in S7, the x-coordinate values of the intersections stored in S3 are rearranged in ascending order for each x-direction defining line x, and two smaller values are extracted and paired. The x-coordinate of the intersection is calculated for each line element, and the value of the x-coordinate is calculated in S3 and stored in the memory 22 in order. This is because it is not always stored in order of size. In the present laser printer, the character line is thin, and only one coordinate of the intersection is included between the two contour line elements that define the character line, or the contour line is included even if no coordinate is included. Since the same x-coordinate is stored for each prime, two x-coordinates of intersections are obtained regardless of which part of the character configuration line is taken. Therefore, when the x-coordinates are rearranged in ascending order to form a pair of two, a character composing line always exists between the paired coordinate values, and the bit data corresponding to the pixel between the coordinate values. Can be set to 1 all at once. In addition, in the present embodiment, bit data is set also for a pixel whose intersection is the pixel center point.

After the coordinate values are rearranged in this way, bit data is set in S8. Bit data setting is 1
It is done collectively in bytes. The microcomputer unit 10 is capable of processing 1-byte data in parallel, and since 1-pixel data is represented by 1-bit, 8-pixel bit data is set all at once. Here, the paired coordinate values are (5, 18), and the description will be made with reference to FIG. The coordinate value (5,18) represents the actual pixel position on the pixel screen 50.

First, the number of pixels whose bit data should be set to 1 is obtained. That is, on one x-direction defining line x, after subtracting the coordinate value 5 of the start point from the coordinate value 18 of the end point of the line segment defined by the two coordinate values (5,18) paired,
Add one. Next, the coordinate value of the starting point is subtracted from the coordinate value that is larger than the coordinate value of the starting point and is a 1-byte division. The coordinate value of a bit that serves as a partition between mutually adjacent bytes is the coordinate value that serves as a partition. The pixel number (this number matches the coordinate value) is given from 0, and the pixel number of the partition is a multiple of 8. Therefore,
8 to 5 is subtracted, and the subtracted value 3 is the number of pixels having a coordinate value larger than that of the starting point pixel among the pixels included in the group in which pixels of 0 to 7 are set as one unit. Therefore, the bit data corresponding to these three pixels are collectively set to 1.

Next, it is calculated how many groups have 8 units as one unit in the remaining pixels for which 1 bit data is to be set. After subtracting the smallest coordinate value of the divisions from the coordinate value of the end point, 1 is added, and the value obtained thereby is divided by 8. After subtracting 8 from 18, add 1 and divide this by 8 to get 1 remainder 3. Therefore, there is one group with 8 pixels as one unit, and after the bit data is set to 1 for these 8 pixels collectively, the bit data is set to 1 for the remaining 3 pixels collectively.
When the setting of bit data is completed for each of the coordinate values stored for each x-direction defining line x as described above,
Program execution returns to the main routine.

As described above, according to this laser printer, it is possible to collectively set the bit data corresponding to the pixel in which the character configuration line exists, and the bit data set corresponding to the pixel for each pixel as in the conventional case. It is not necessary to set the bit data while determining whether the bit is 0 or 1, and since the bit data is set collectively in 1-byte units, a comparison is made when setting 1 bit at a time. The processing speed is fast, and data conversion can be performed extremely quickly.

In addition, the coordinates of the intersection of the thin character constituent lines are 2
Since the characters are calculated one by one, it is not necessary to take special consideration so as to obtain two intersection coordinates when designing the character, and the effect of facilitating the design can be obtained.

As is clear from the above description, in this embodiment,
The x direction defining line x constitutes a scanning line, and S of the program ROM 16
The portion storing 2 and the portion executing S2 of the CPU 12, that is, the intersection coordinate calculating unit 38 constitutes the intersection coordinate calculating means, and the portion storing S7 of the intersection coordinate memory 22 and the program ROM 16 and executing S7 of the CPU 12 are executed. The portion and the portion constitute the intersection point coordinate storage means, and the portion for storing S8 of the program ROM 16 and the portion for executing S8 of the CPU 12, that is, the data setting portion 40 constitute the bit data setting means. Then, of the part that executes S8, the part that collectively processes the bit data of each byte constitutes the group unit setting means.

Although the x-direction defining line x is the scanning line in the above embodiment, other straight lines such as the y-direction defining line y may be used as the scanning line.

Further, in the above-described embodiment, two intersections with the scanning line are obtained for each thin character-constituting line, so that the effect of facilitating the character design can be obtained. If it is designed to be calculated one by one, it is possible to omit the function of calculating two identical coordinates for thin character component lines.

Furthermore, outline data is expressed only by coordinates,
You may comprise by another means. When expressed only by coordinates,
For a character that is composed of multiple straight lines, outline data is composed of coordinate data groups for each line element of the contour, and for characters that include a curve, coordinate data of the multiple points required to define the curve. Configure outline data to include groups.

Furthermore, the present invention can be applied to printers other than laser printers, and in addition to printers, the present invention is generally applied to devices that need to convert outline data of characters such as characters and symbols into bit data. can do.

In addition, although not exemplified, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a block diagram conceptually showing the structure of the data conversion apparatus according to the present invention. FIG. 2 is a block diagram showing a control circuit of a laser printer provided with a data converter according to an embodiment of the present invention. FIG. 3 is a diagram conceptually showing a CPU constituting the above control circuit. FIG. 4 is a flow chart showing a data conversion program of the programs stored in the program ROM of the control circuit. Fifth
The figure is a diagram showing the contour of the character H converted by the data conversion device. FIG. 6 is a diagram showing the above-mentioned letter H by being superimposed on the pixel screen. 7, 8, 9 and 10
FIG. 11, FIG. 11 and FIG. 12 are diagrams for explaining how to obtain the coordinates of the intersections of the line elements and the scanning lines that form the outline of the character converted by the data conversion device. First
FIG. 13 is a diagram showing the position of the intersection determined for the character H on the pixel screen, and FIG. 14 is the x of the intersection.
It is a figure which shows the coordinate value in the table for every x direction prescription line x. First
FIG. 15 is a diagram for explaining the setting of bit data performed based on the coordinates of the intersections. 10: Microcomputer part 44: Character composition line, 46: Contour line 50: Pixel screen, x: x direction standard line y: y direction standard line

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Claims (3)

[Claims] 1. A data conversion device for converting outline data representing a contour of a character such as a character or a symbol into bit data for each pixel, wherein the character contour line is assumed on a coordinate plane defining the outline data. And the intersection point coordinate calculation means for obtaining the coordinates of the intersection points with a plurality of scanning lines parallel to each other at the position of the pixel, and the coordinates of the intersection points obtained by the intersection point coordinate calculation means are the size of the coordinate value for each scanning line. In the case of arranging in the order of two, two coordinates adjacent to each other are taken out, and the coordinates are stored in pairs, and all the pixels between the coordinates of each pair stored by the intersection coordinate storage means. A bitter data setting means for setting the bit data corresponding to the above to the data representing the existence of the character constituent lines which constitute the character all at once. Converter. 2. If only one intersection point coordinate is obtained by the intersection point coordinate calculating means because the intersection point coordinate storage means has a small width on one scanning line of the character constituting line, one of the intersection points is calculated. 2. The data conversion device according to claim 1, wherein two coordinates are stored as a pair. 3. The intersection point coordinate calculation means, the intersection point coordinate storage means and the bit data setting means are constituted by a computer, and the bit data setting means performs parallel processing by the computer between the two paired coordinates. 3. The data conversion device according to claim 1, further comprising group unit setting means for setting bit data in units of bit data groups when there is one or more possible groups of bit data.