JPH0792957A - High-quality character output device - Google Patents

Abstract

PURPOSE:To alter specific scaling for a character, to generate dot data having small distortion, and to output a character of high quality by providing scaling correction data as to a specific character size wherein each character deteriorates in print quality when outline character data are converted into dot data. CONSTITUTION:Character size information on respective characters and scaling correction information corresponding to sizes are stored corresponding to each other and when a desired character is outputted with a character size for which scaling correction is defined (S93), the scaling correction information is used (S95 and S96) to apply scaling different from scaling corresponding to the specified character size (S97), thereby converting the outline data after a processing (S98) for the correction scaling into dot data.

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 which stores character data as outline data composed of contour lines and creates and outputs high quality dot data from the outline data.

[0002]

2. Description of the Related Art Conventionally, as a method of generating characters such as characters and symbols, outline data of characters and symbols (hereinafter, referred to as
There is an outline method using the outline data). This method reads out outline data of a character from the storage unit according to the character code, scales it to an arbitrary character size, and then converts it into dot data. The converted data was output from an output device such as a laser printer. . In this method, the character shape data is composed of one or more outline data, and the outline data is given as a closed curve composed of a combination of straight line elements and curved line elements. After scaling this outline data to a specified arbitrary character size, overlay it on a pixel screen that has pixels in multiple rows x multiple columns corresponding to the dot data of the output device, and the relationship with the outline data satisfies a certain standard. The dot data was created and output by turning on the pixel.

[0003]

However, when the outline data as described above is converted into dot data by the conventional method, the dot data has a constant size and a constant size due to the characteristics of the output device such as a printer or a display. Since it can only be placed in the position of, a quantization error occurs,
The shape of the outline data and the shape of the converted dot data were different. Then, when trying to output a small character especially when the resolution of the output device is low, the dot size forming the character becomes small and the quantization error becomes large, so the shape of the dot data is distorted and the character quality is There was a problem of decline. Figure 2
When outputting a bilaterally symmetric “T” character with a character size as shown in FIG. 5, the corresponding dot data is
Depending on the positional relationship with the pixel screen, the left and right sides may have a very unbalanced dot shape as shown in FIG. 6, which may deteriorate the quality of the characters to be output. Note that the fill method in this example is an example in which the dot is turned on if the center coordinates of the output dot positions are inside the scaled outline, but similar problems occur with other fill methods. Occur.

The present invention has been made to solve the above-described problems, and when converting outline data to dot data, distortion of the shape of dot data is corrected by correcting the scaling process as necessary. It is an object of the present invention to provide a high quality character output device capable of reducing the number of characters and outputting a character of higher quality.

[0005]

To achieve this object, a high quality character output device of the present invention stores the shape of a character outline as outline data composed of straight line elements and curved line elements, A device that searches outline data according to the specified character code, scales the searched outline data to a size according to the specified character size, converts it to dot data, and outputs it. Correction data storage means for storing information and correction information for correcting scaling processing in that size in association with each other, and when a desired character and character size are designated, the correction data storage means The presence / absence of correction and, if correction is specified, the correction amount are extracted, and the scale of outline data is calculated based on that. And a scaling correction means for changing the grayed process.

[0006]

In the high quality character output device of the present invention having the above-mentioned structure, after the character code and the output size are inputted, the character size information and the correction information in the size are stored in correspondence with each other. Based on the means, it is determined whether or not the scaling process is corrected when an arbitrary character is output in an arbitrary size. When the scaling process is corrected, the correction amount is extracted, and the correction amount is calculated based on the correction amount. The scaling value of the character is changed to, the outline data of the character is converted to the coordinate system of the pixel screen based on the changed scaling value, and further converted to dot data for output.

[0007]

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 block diagram showing a portion of a control circuit of a laser printer to which the present invention is applied, which mainly generates dot data from outline data. The microcomputer unit 10 that is the main body of this control circuit includes a CPU 14, a character ROM 17, and a program ROM.
16, text memory 110, working memory 15,
Dot data memory 18, scaling correction data RO
And M19. And these CPU1
4 and the like are connected to each other via the system bus 13. Further, an input device 11 and a printing unit 12 are connected to the microcomputer unit 10 via a system bus 13.

The input device 11 inputs a character code, a character size, and character modification information such as italics and rotation supplied from the outside.

The program ROM 16 stores programs for executing various controls described later in this embodiment.

The text memory 110 is the input device 1
The character code, the character size, the character modification information such as italics and rotations input from 1 are stored.

The character ROM 17 stores character shape data and character data such as the character width of the character, and this character data can be read out character by character. The character width is the information indicating the distance from the start point of the current character to the start point of the next character when the next character is continuously output without any special position specification for the character to be output. This is information that is also called a character feed amount. The shape data of each character is outline data that is a set of closed curves composed of the coordinate values of the straight line element and the curved line element of the character. The storage format of the outline data will be described later in detail.

In the scaling correction data ROM 19,
Scaling correction data for scaling correction processing described later is stored. The scaling correction data will be described in detail later.

The CPU 14 performs the processing for realizing the present embodiment in accordance with the program given by the program ROM 16.

The working memory 15 temporarily stores data required when the CPU 14 executes a program.

The dot data memory 18 stores the dot data converted from the outline data.

The printing unit 12 is a device for printing the dot image data read from the dot data memory 18 by the electrophotographic method.

The format of the outline data stored in the character ROM 17 will be described below. In the present embodiment, the case where the curve element of the outline data is represented by only a cubic Bezier curve (hereinafter simply referred to as curve) will be described. The outline data, for example, for the character shape shown in FIG. 2, is stored as a combination of a type flag as shown in FIG. 3 and coordinate value data accompanying it. Here, in the type flag, "S" indicating the start point of one closed curve of the outline data, "L" indicating the end point of the straight line, "B1" indicating the first control point of the curve, and the second point of the curve.
There are “B2” indicating the control point, “B” indicating the end point of the curve, “*” indicating the end of one closed curve, and “!” Indicating the end of the outline data. Coordinate data is "*" and "!"
There is one set of x and y for each type of flag other than. The starting points of the straight line and the curve are fictitious points called current points at that time. The current point moves to the start point of the closed curve, and to the end point of the straight line or curve.

Next, details of the data stored in the scaling correction data ROM 19 will be described. In the present embodiment, the scaling correction data corresponds to the outline data of each character and is stored for each character. An example of scaling correction data for one character will be described with reference to FIG. The scaling correction data is composed of a horizontal dot size range, which is the maximum and minimum pair of horizontal dot sizes of characters, and a correction flag corresponding to the range. The “lateral dot size after correction scaling” in FIG. 4A is a value obtained by calculation and is not stored in the scaling correction data ROM 19. The horizontal dot size of a character is a calculated value that indicates how many dots the character width of the character becomes after scaling, and is treated as a numerical value with a decimal point. The correction flag is "U"
Or “D”, “U” is an instruction to round up the horizontal dot size, and “D” is an instruction to round down.
A region in which the horizontal dot size range is not defined or a horizontal dot size range without a correction flag is interpreted as no correction.

In the case of the scaling correction data shown in FIG. 4A, the horizontal dot size before correction and the horizontal dot size after correction have the relationship shown in FIG. 4B. Note that the scaling correction is finally applied only to the scaling of the outline of the character shape, and the dot size of the character width used when determining the start point of the next character is the value before or after the correction regardless of the correction. The value of is used.

Next, the outline of the conversion processing from outline to dot data according to the present embodiment will be described with reference to the flowchart of FIG.

First, in step S81, the character code of the character to be output is input, and then in step S82, the character size to be output is input. In step S83, the outline data corresponding to the character code of the character and the character width data are fetched from the character ROM 17. Step S8
In 4, the character scaling process and the coordinate conversion according to the designation such as rotation and inversion are performed. Here, the outline is converted into coordinate values corresponding to a pixel screen in which the size of one dot is 1. This step will be detailed later.
In step 85, the outline data finally obtained is filled in by the raster scan method and converted into dot data. The raster scan method is a known technique and is not a main part of the present invention, so a detailed description thereof will be omitted.

Next, details of the scaling processing in step S84 will be described with reference to FIG.

First, using the given scaling value as it is, the number of dots of the character width is calculated in step S91. If this value is explained in the case of FIG. 5, for example,
The character width is the portion represented by W and is 7.25 dots. The grid indicated by 51 represents a pixel screen. In step S92, it is determined whether a special coordinate conversion process such as rotation or inversion is necessary. If a special coordinate conversion process is performed, an unexpected result may occur in the scaling correction process of the present embodiment, so the correction process is not performed and the process jumps to step S98.

In step S93, the scaling correction data ROM 19 is searched, and the correction flag corresponding to the character width calculated in step S91 is read. If the correction data is the data shown in FIG. 4A, the dot data range corresponding to the value of 7.25 dots is searched and the correction flag “U” is obtained. At this time, if there is no dot data range corresponding to the given character width, or if there is a dot data range but no correction flag, no correction is made and the process jumps to step S98. The correction flag obtained in step S93 is determined in step S94. If the correction flag is "U", the rounding up correction is performed and the process proceeds to step S95.
If the correction flag is "D", it is determined that the correction is rounding down, and the process proceeds to step S96.

In step S95, the dot size of the character width is rounded up. If the character width is 7.25 dots,
Use 8 dots. Conversely, in step S96, the character width is truncated. If the character width is 7.25 dots, set it to 7 dots. Next, in step S97, a scaling value is calculated such that the character width before scaling becomes a rounded up or truncated character width, and the current horizontal scale value is changed so that the scaling value becomes a new horizontal scale value. .

In step S98, the outline data of the character is subjected to coordinate conversion processing based on the vertical scale value and the corrected horizontal scale value, and outline data for performing the filling processing is generated. In this embodiment, in the case of normal portrait output, the horizontal scale represents scaling in the x coordinate direction, and the vertical scale represents scale in the y coordinate direction. However, in the case of land scale output, the opposite is true.

As a result, considering the case where the character data of "T" shown in FIG. 5 is corrected by the correction data shown in FIG. 4A, the character width W of FIG. 5 is 7.25 dots. And the correction flag corresponding to 7.25 dots is "U".
Therefore, the corrected character width is 8 dots. If the characters in FIG. 5 are scaled using horizontal scaling such that the character width is 8 dots, the result shown in FIG. 7 is obtained.
The character "T" has a shape that extends slightly laterally in FIG. 7, but the dot pattern as a result of painting is balanced on the left and right, making the shape of the character "T" easier to see. The problem that the shape extends in the lateral direction,
This is the degree of quantization error at the time of dot formation and does not pose a practical problem.

In the present embodiment, only horizontal scaling is corrected with respect to character scaling correction, but vertical scaling correction or vertical and horizontal correction may be used. Further, in the present embodiment, the correction is instructed by designating whether the dot size of the character width is rounded up or rounded down, but a method of separately storing a correction value or a method of using another flag may be used. . Further, the correction data is not stored for each character, but a method of having the correction data for a character set including a plurality of characters may be used.

[0030]

As is apparent from the above description, in the high quality character output device of the present invention, the character size in which the character quality is particularly deteriorated is corrected by performing the scaling correction if necessary. It is possible to obtain a high-quality character dot pattern in which the symmetry and the like are further maintained.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a high quality character output device that is an embodiment of the present invention.

FIG. 2 is a diagram for explaining outline data of characters.

FIG. 3 is a diagram showing a method of storing character outline data.

FIG. 4 is a diagram for explaining a configuration of scaling correction data of the high quality character output device, (a) shows an embodiment of a storage system of scaling correction data, and (b) shows (a).
It is a graph explaining the content of.

FIG. 5 is a diagram for explaining a character scaling process.

FIG. 6 is a diagram showing a result of a conventional method corresponding to the example of FIG.

FIG. 7 is a diagram showing a result of scaling correction in the high quality character output device corresponding to the example of FIG.

FIG. 8 is a flowchart showing an outline of character dot data conversion processing by the high quality character output device.

FIG. 9 is a flowchart showing an operation of scaling correction processing by the high quality character output device.

[Explanation of symbols]

 14 CPU 17 Character ROM 18 Dot Data Memory 19 Scaling Correction Data ROM 51 Pixel Screen

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G06T 3/40 11/20

Claims (3)

[Claims] 1. The outline shape of a character is stored as outline data composed of straight line elements and curved line elements, outline data is searched in accordance with a specified character code, and the searched outline data is specified in a specified character size. In a character output device that performs scaling processing to a size according to the above and then converts it into dot data and outputs it, the character size information of the character and the correction information for correcting the scaling processing in that size are stored in association with each other. The correction data storage means, the desired character and the character size are designated, the presence / absence of the correction and the correction amount, if the correction is designated, are retrieved from the correction data storage means, and based on that, And a scaling correction means for changing the scaling processing of the outline data. Quality character output device. 2. The character size information of the correction data storage means can be stored independently for each character,
The high-quality character output device according to claim 1, wherein the character width is a value obtained by scaling the character width of the target character. 3. The correction information of the correction data storage means,
This flag indicates rounding up or rounding down the length of the specified part in the dot unit system when the target character is scaled without correction, and the flag indicates the length of the specified part in the dot unit system after the scaling process. The high-quality character output device according to claim 1, wherein the scaling correction unit obtains a scaling value that matches the rounded up or rounded down length.