JPH01290449A - Dot font minification system - Google Patents

Abstract

PURPOSE:To minify a font pattern to a specified size similar to its original font pattern by thinning out a font pattern stored in a dot font pattern memory with a first thin-out means, then taking the same procedures with a second thin-out means. CONSTITUTION:Registers LD1-LD4 are provided on a minification processing means 32. The means retrieves odd-number row data from a memory M1 and then stores it in the register LD1. Next, the means retrieves even-number row data from the same memory M1, then stores it in the register LD2. If an address for the former is assumed to be AD, the latter is AD+1. Next, data stored in the register LD1-LD2 is ORed and the output is stored in the register LD3. After this, only the effective bits are retrieved from the register LD3 and compressed. This compressed bits are stored in the register LD4 and then the register LD4 is stored in a 12-dot font buffer. As a result, a font pattern quite similar to its original font pattern can be obtained.

Description

[Detailed Description of the Invention] [Summary] Regarding a dot font reduction method for reducing the dot font pattern of a character in an image display device to a predetermined size, the object is to reduce the dot font pattern in a shape close to the original font pattern before reduction. In a dot font reduction method for an image display device that displays characters using multiple dot matrices,
A first thinning means for thinning out the vertical dots of the dot matrix by a logical sum between adjacent dots, and a second thinning means for thinning out the horizontal dots of the dot matrix (IJ) unconditionally, After the original font pattern stored in the font pattern memory before reduction is thinned out by the first thinning means, the thinned out original font pattern is reduced by the second thinning means.

[Industrial application field]

The present invention relates to a dot font reduction method for character display in an image display device, and more particularly to a dot font reduction method for reducing a dot-displayed character from, for example, a 24×24 dot display to a 12×I2 dot display to a quarter square.

When displaying characters on an image display device, a dot matrix method is usually used.

In this method, when character data stored in the video RAM is displayed in 24x24 dots (hereinafter referred to as 24 dot font), vertical and horizontal dots are set to "1" or "0" to match a predetermined character. Displayed by In this case, the visibility of one character improves as the number of vertical and horizontal dots increases, but there are certain limitations due to the memory capacity of the video RAM.

[Conventional technology]

When displaying characters on a display device or printing them on a printer, the characters may be reduced in size for ease of use. For example, this is the case when 24 dot fonts are reduced to 12 dot fonts to a quarter square. Here, font means "font," and it is important for visibility that the same character shape as in 24-dot font can be reproduced even when 12-dot font is used.

5 to 7 are diagrams for explaining the conventional dot font reduction method. In these figures, (a) is the character “
¥” is displayed as 24x24 dots, (b) is thinned out according to a certain rule, and (C) is the character in (a) reduced to 12x12 dots. The even numbered rows in the horizontal direction are unconditionally thinned out, and the state after thinning is as shown in (b), and when the dot spacing is reduced, it is reduced as shown in (C).If you look at the character in (C), As is clear, the horizontal line is completely ignored and it is difficult to read it as the original "\".The method shown in Figure 6 unconditionally thins out odd-numbered columns in both the vertical and horizontal directions, and the reduced state (C) shows a font pattern in which horizontal lines are ignored. Figure 7 shows that when determining whether a dot in an odd row in the vertical direction is "1" or "0", the even row of dots in the horizontal direction is An OR logic is performed with the state, and if the intersection with the horizontal even-numbered column is "1", the dot in the horizontal odd-numbered column is displayed as "l", and the same operation is performed in the horizontal direction. This is also done when determining whether the dots in the odd-numbered rows are "1" or "0", and then the even-numbered rows in the vertical direction are thinned out to obtain the font pattern shown in (b). If the font pattern is thinned out according to the conditions, as is clear from (b), the number of character information blocks becomes too large, resulting in a font pattern that is legible but too crowded as shown in (c).

SUMMARY OF THE INVENTION An object of the present invention is to provide a dot font reduction method for reducing a character displayed as a dot in a predetermined shape as close to the original font pattern as possible.

[Means and operations for solving the problems] FIG. 1 is a diagram showing the basic configuration of the present invention. As shown in the figure, the present invention employs a dot font reduction method in an image display device that displays characters using a plurality of dot matrices. means (2) and a second thinning means (3) for unconditionally thinning out dots in the horizontal direction of the dot matrix, the original font pattern before reduction stored in the dot font pattern memory (1) is After thinning out by the first thinning means, the second thinning means reduces the original font pattern.

〔Example〕

FIG. 2 is a diagram illustrating the reduction method of the present invention.

Generally, typefaces have thick vertical lines and thin horizontal lines.

By utilizing this property for thinning during reduction, it is possible to reduce the font pattern faithfully to the original character font pattern. In FIG. 2, (a) is the 24-dot font character "\" as described above. After the even numbered columns in the vertical direction of this dot pattern are thinned out using an OR condition, the dot patterns are thinned out in the horizontal direction. That is, when determining whether a dot in an odd numbered row in the vertical direction is "1" or "0", if the intersection with an even numbered row in the horizontal direction is "1", the dot in the odd numbered row in the horizontal direction is set to "1" by OR logic. ''. Then, by thinning out even-numbered columns in the horizontal direction, a font pattern as shown in (b) is obtained.

In this case, the glancing angle is shown as a black dot based on OR logic for the sake of explanation.

FIG. 3 is a block diagram of the main parts of an apparatus that executes the reduction process as shown in FIG. 2. Ml is a memory that stores the original 24 dot font characters, 1 to 24 in the vertical direction (column direction).
Addresses m to m+23 are given in the kanji direction and row direction). M2 is a memory that stores 12 dot font characters after reduction, 1 to 12 in the vertical direction and n-n+ in the horizontal direction.
ll address is given. The character information "¥" in the memory M1 is input manually to the address calculation processing means 31, and then reduced to 12 dots by the reduction processing means 32, returned to the address calculation processing means 31, and stored in the memory M2.

Here, the address calculation processing means 31 operates as follows. That is, the address calculation processing means has a counter CNT (not shown) therein, and initially the initial value is 0.
Each time it is set and called, it is incremented by "+1" along with the storage address (ad). Then, the fetch address (AD) is incremented by "+2". The initial value of the fetch address AD from the memory M1 is the starting address m of the 24-dot font buffer, and the storage address ad is 1.
This is the start address n of the 2-dot font buffer. If the counter CNT reaches 12 after the above-described processing is completed, the caller is notified that the processing has ended. When called again, the retrieval address AD, storage address ad, and counter CNT are returned to their initial values and returned.

The processing in the reduction processing means 32 is shown in FIG. The reduction processing means 32 includes registers LDI to LD4 (not shown).
are provided, and a reduced font pattern is obtained by sequentially inputting and outputting to and from these registers. That is, first, odd-numbered column data is taken out from the memory M1 and stored in the register LDI (step 1). Next, take out even-numbered column data from the same memory M1 and store it in register LD.
2 (step 2). In this case, if the former address is AD, the latter is AD+1.

Next, the OR logic of the data stored in registers LDI and LD2 is taken and stored in register LD3 (step 3
). Next, only valid bits are extracted from register LD3, compressed, and stored in register LD4 (step 4). Then, the register LD4 is stored in the 12-dot font buffer (step 5). In addition, when extracting and compressing only the valid bits in step 4, there are two cases in which only the odd-numbered bits of the data stored in the register LD3 are stored as valid bits in the register LD4, and there are cases in which only the even-numbered bits are stored in the register LD4 as valid bits. Either case may be adopted in the present invention.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain a font pattern that is extremely close to the original font pattern when reducing a dot font.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle configuration of the present invention, FIG. 2 is a diagram explaining the reduction method of the present invention, FIG. 3 is a diagram showing the configuration of main parts of the present invention, FIG. ~7
The figure is a diagram illustrating a conventional reduction method. (Explanation of symbols) Ml, M2...Memory, 31...Address calculation processing means, 32...Reduction processing means. Thick embedding configuration diagram of the present invention Diagram explaining the reduction method of the present invention Second processing flowchart of the present invention $4 days (a) (b) Diagram explaining the conventional reduction method (Part 1) (a)
(b) Diagram showing the key points of the conventional reduction method (Part 2) Figure 6

Claims (1)

[Claims] 1. In a dot font reduction method in an image display device that displays characters using a plurality of dot matrices, the first thinning means thins out vertical dots of the dot matrix by logical sum of adjacent dots. (2) and a second thinning means (3) for unconditionally thinning out dots in the horizontal direction of the dot matrix, the original font pattern before reduction stored in the dot font pattern memory (1) is After thinning by the first thinning means,
A dot font reduction method characterized in that the second thinning means reduces the thinned out font pattern.