JP3114289B2 - Character pattern generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character pattern generator for obtaining a dot pattern from data representing the outline of a character.

[0002]

2. Description of the Related Art In recent years, with the spread of desktop electronic publishing, high-resolution laser beam printers, and the like, an outline font type character pattern that can always output a high-quality dot pattern character regardless of the size of the character with a small memory capacity has been generated. Equipment has come to be used.

[0003] Such an outline font type character pattern generator is disclosed in, for example, Japanese Patent Application Laid-Open No. Sho 50-14230, in which coordinate information for reproducing the outline of a character is stored, and these control points are stored. By performing a predetermined process on the character dot pattern.

FIG. 4 shows the configuration of a conventional character pattern generator. In FIG. 4, 1 is a memory storing data representing the outline of a character, 2 is a linear conversion circuit, 3 is a correction processing circuit,
5 is a dot pattern conversion circuit, 6 is a dot pattern storage memory, and 9 and 10 are work memories. The operation of the conventional character pattern generator will be described below.

The linear conversion circuit 2 performs a linear conversion on a control point of a straight line or a curve, which is the outline data of the character input from the memory 1, and stores coordinate data representing the outline of the converted character in the work memory 9. Output.

The correction processing circuit 3 causes the final output character to be distorted or the line to be broken due to the calculation accuracy of the linear conversion or the quantization error of the output coordinate value, and the balance of the entire character pattern is lost. Correction processing is performed to correct. Data unique to each character called hint information is additionally used for correction processing and is linearly converted in the linear conversion circuit 2. Note that the hint information and its processing are not directly related to the present invention, and thus detailed description is omitted.

Here, the correction processing will be described. In FIG. 5, the dot grid of the display device is shown by a solid line, and the outline of the character "3" after the linear conversion is shown by a broken line (white circles represent control points). The outline of the character 'three' at this stage has a value below the dot grid unit, ie, below the decimal point. FIG. 6 shows a character pattern obtained by simply rounding the value representing this outline and rounding it to a dot grid. As can be seen from FIG. 6, the width of the horizontal bar above the character "3" is two dots, while the remaining two horizontal bars are one dot, and the balance of the characters is poor. Therefore, in order to eliminate such inconvenience, the following correction processing is performed.

FIG. 8 is a flowchart showing a process for correcting the horizontal bar above the character "3". As shown in FIG. 7, the coordinates of the four control points representing the horizontal bar on the character '3' after linear conversion are (x1, y1), (x2, y1), (x1,
y2), (x2, y2). Also, let y2 be a reference Y coordinate. That is, in the horizontal bar above the character "3", the lower boundary is the reference. This information shall be held for each rectangle.

In step 1, two Y coordinates y1
And then round after determining the difference between y2. In this case, (y1-y
2) is approximately 1, so in this case the rounded result is 1
Becomes

In step 2, the values of y1 and y2 are rounded, and the difference is calculated. y1 and y2 are rounded up and down, respectively, and the difference is 2. Since the results of step 1 and step 2 are different, step 3 is followed by step 4. If the result is the same, the result of rounding in step 2 is adopted for the rectangle currently being processed.

In step 4, the result of step 2 is changed so that the two Y coordinates are rounded in the same direction. In this case, since the reference y2 is rounded downward, a value obtained by truncating the decimal point of y1 is set as the upper boundary. Thus, the corrected character dot pattern shown in FIG. 4 is obtained.

The output of the correction processing circuit 3 is output from the work memory 10
Is stored in

The dot pattern conversion circuit inputs coordinate data of a control point representing a contour subjected to correction processing from the work memory 10, converts the coordinate data into a character dot pattern, and stores this in the dot pattern storage memory 6.

[0014]

However, in a conventional outline font type character pattern generating apparatus, the time required for the entire conversion process for the correction process is long, and the proportion of the entire conversion time exceeds 50% in some cases. Sometimes.

The present inventor has analyzed the size of characters handled by the character pattern generator. When the character size to be converted is relatively small, the calculation accuracy in the conversion process and the quantization error of the output coordinate values are relatively low. Therefore, the balance of the output character pattern is greatly lost. Conversely, when the character size is relatively large, the error becomes relatively small, so that the balance of the output character pattern is small, and the character quality is not visually affected.

In view of the above, the present invention takes into consideration a certain amount of allowance, does not perform correction processing when converting large-size characters, and performs correction processing when converting small-size characters. It is an object to convert a character outline information into a dot pattern at high speed without visually affecting quality.

[0017]

In order to solve the above problems, an image data processing apparatus according to the present invention calculates coordinate data indicating a character outline corresponding to a character size from character outline data, and quantizes the coordinate data. A character pattern generating apparatus for generating a character pattern that has been converted to dot development, wherein the first quantizing means for quantizing the coordinate data by a predetermined method, and a line width between the quantized coordinate data, Second quantizing means for quantizing at least one piece of coordinate data by a method different from a method of quantizing other coordinate data so as to be substantially equal to a line width between coordinate data, and the character to be output. Comparing means for comparing a size with a predetermined character size, wherein, if the character size is smaller than the predetermined character size, the first quantization means Instead the coordinate data quantized by said second quantizing means, and a further comprising a means for generating a character pattern dot development.

[0018]

According to the present invention, at least one coordinate is set so that the line width between the quantized coordinate data is substantially equal to the line width between the coordinate data only for a character size smaller than a predetermined size. The data is quantized by a method different from the method of quantizing other coordinate data, thereby correcting the collapse of the generated character pattern due to the quantization error. Therefore, for a large character size for which the correction process can be omitted, a light process of quantizing the coordinate data by a predetermined method is sufficient, so that a character pattern can be generated from the contour data at high speed.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a character pattern generator according to an embodiment of the present invention. In FIG. 1, 1 is character outline data, 22 is a linear conversion circuit,
3 is a correction processing circuit, 4 is a selection circuit, 5 is a dot pattern conversion circuit, 6 is a dot pattern storage memory, 7 is a character size threshold register, 8 is a character size comparison circuit, and 9 and 1
0 is a work memory. The memory 1 for storing character outline data, the correction processing circuit 3, the dot pattern conversion circuit 5, the dot pattern storage memory 6, and the work memories 9 and 10 may be the same as those of the conventional character pattern generator in FIG. .

The linear conversion circuit 22 outputs the size of the character being converted in addition to the operation of the conventional linear conversion circuit. This is obtained by applying a linear transformation to the original character size.

FIG. 2 is a block diagram showing the internal configuration of the linear conversion circuit 22. In FIG. 2, 100 is a first conversion matrix register, 101 is a second conversion matrix register, 102 is a third conversion matrix register, 103 is a fourth conversion matrix register, 104
Is a multiplier, 105 is an accumulator, 106 is a character size register, and 107 is a control circuit. The values of the first to fourth conversion matrix registers are set by the host CPU. These four registers store four conversion coefficients A, B, C, and D as described below.

The coordinate system of the font data before conversion is P
(X, y), the coordinate system of the converted font data is P '
Assuming that (x ′, y ′), the conversion of P → P ′ is expressed as x ′ = A * x + B * y y ′ = C * x + D * y. The multiplication and addition in the above equation are performed by the multiplier 10
4. This is performed in the accumulator 105. The size of the font data of the original size is similarly converted and stored in the character size register 106. These operations and storage in the register are performed based on a control signal output from the control circuit 107.

The character size threshold register 7 contains the host C
A character size serving as a threshold for performing or not performing a correction process by the PU is stored.

The character size comparison circuit 8 inputs and compares the value of the character size held in the character size threshold register 7 with the value of the character size under conversion output from the linear conversion circuit 2,
If the former value is larger than the latter value, the value "1" is output, otherwise the value "0" is output.

When the value of the input selection signal is'
When the value is "0", the value stored in the work memory 10 is selected and output. When the value of the selection signal is "1", the value stored in the work memory 9 is selected and output. That is, when the value of the selection signal is "0", the contour data of the character subjected to the correction processing is output, and when the value of the selection signal is "1", the contour data of the character not subjected to the correction processing is output.

FIG. 3 is a block diagram showing the internal configuration of the correction processing circuit. 3, reference numeral 108 denotes a general-purpose register file, 109 denotes an arithmetic unit, 110 denotes a memory interface circuit, 111 denotes a microcode storage memory, 112
Is a control / decode circuit. The microcode storage memory 111 stores software for performing the correction processing described in FIG. Control / decode circuit 1
Reference numeral 12 outputs an address to the microcode storage memory and inputs the microcode stored at the address. Furthermore, the input microcode is decoded, various control signals are generated, and the general-purpose register file 1 is decoded.
08, arithmetic unit 109, memory interface circuit 11
0, controls the microcode storage memory 111. The general-purpose register file 108 includes a plurality of registers for storing input / output of the arithmetic unit 109. The arithmetic unit 109 performs an operation using a value input from the general-purpose register file 108 or the memory interface circuit 110, and outputs a result to the general-purpose register file 108 or the memory interface circuit 110. Memory interface circuit 1
Reference numeral 10 controls an interface between the general-purpose register file 108 and the arithmetic unit 109 and the external memory, and performs input and output to and from the external memory.

[0027]

As described above, according to the present invention, in a character pattern generator for converting character outline information into a dot pattern, correction processing is performed for a relatively large character size for which correction processing can be omitted. There is no merit that the conversion from the contour information to the dot pattern can be performed at high speed. In addition, for character sizes that require correction processing, there is an advantage that a dot pattern with good character quality can be obtained by performing correction processing as before.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of a linear conversion circuit 22 according to the embodiment of the present invention.

FIG. 3 is a block diagram illustrating an internal configuration of a correction processing circuit according to an embodiment of the present invention.

FIG. 4 shows the configuration of a conventional character pattern generating device.

FIG. 5 is an outline of a character “three” after linear conversion in a conventional character pattern generator.

FIG. 6 shows a character pattern obtained only by rounding to a dot grid in a conventional character pattern generator.

FIG. 7 shows a character pattern subjected to correction processing in a conventional character pattern generation device.

FIG. 8 is a flowchart in a case where a horizontal bar above a character “three” is corrected in the conventional character pattern generation device.

[Explanation of symbols]

 1… Character outline data 2… Linear conversion circuit 3… Correction processing circuit 4… Selection circuit 5… Dot pattern conversion circuit 6… Dot pattern storage memory 7…… Character size threshold value register 8…… Character size Comparison circuit 9, 10 Work memory

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G09G 5/28 G09G 5/24

Claims (1)

(57) [Claims] 1. A character pattern generator for calculating coordinate data indicating a character outline corresponding to a character size from character outline data, and generating a dot-expanded character pattern by quantizing the coordinate data. First quantizing means for quantizing the data by a predetermined method; and at least one other coordinate data so that the line width between the quantized coordinate data is substantially equal to the line width between the coordinate data. A second quantization means for performing quantization by a method different from the quantization method for the coordinate data, a comparison means for comparing the character size to be output with a predetermined character size, and a character size by the comparison means. Is smaller than the predetermined character size, the coordinate data is quantized by the second quantizing means instead of the first quantizing means,
Means for generating a character pattern developed by dot development.