JPS61284457A - Method for processing dot matrix data - Google Patents

Abstract

PURPOSE:To provide a dot matrix data processing method capable of reducing the ROM capacity of a character generator to a large extent, by utilizing the characteristics possessed by a character font. CONSTITUTION:In the constitutional diagram (b) of ROM of a character font (a) constituted of longitudinal and lateral dots each consisting of 16 rows, the upper rank two bits of each longitudinal row data having 16 rows are codes showing the characteristics of the data of said rows and can show four kinds of characteristics. In this embodiment, when all of the longitudinal rows are white dots, the code of '00' is allotted and, in the same case as the previous row data, the code of '01' is allotted and, when upper and lower two dots are white dots, the code of '10' is allotted and, when upper and lower four dots are white dots, the code of '11' is allotted and data quantity is reduced in such a state that, in the cases of '00' and '01', all data of the rows thereof are omitted and, in the case of '10', upper and lower two bits are omitted and, in the case of '11', upper and lower four bits are reduced and stored in succession to each code.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for processing dot matrix data in order to store and reproduce graphic information by means of a binary code in such a way as to reduce storage capacity.

Conventional technology In general, in a dot printer, information on all the character fonts that can be printed is stored in a read-only memory (hereinafter simply referred to as ROM) for the character generator, but the state of the internal data is such that one dot corresponds to one bit. Increasing the number of dots constituting one character in order to improve printing quality leads to an increase in the capacity of the ROM, which increases product costs. Thin-length encoding is one method for compressing the amount of character font data in such cases. This can be done by converting the number of consecutive identical dots into a binary number and replacing it with the actual dots, which would require 24 bits if stored as is, in the case of dot data as shown in Fig. 4 A. It is abbreviated as shown in the opening.

Problems to be Solved by the Invention However, in many actual character fonts, the white dots and black dots change frequently, and delimiter data is required for each change, so it is not possible to use length encoding in this way. The method is not very effective in reducing ROM capacity.

The present invention is intended to solve these conventional problems, and is to provide dot matrix data that can greatly reduce the ROM capacity of the i-character generator by utilizing the characteristics of character 7 onts. The method for processing dot matrix data of the present invention is to provide a processing method for character 7.
When focusing on each column (or each row) of the ont data, we take advantage of the fact that it can be classified into some common characteristics, and pair each column (or each row) of data with a binary code that elucidates that characteristic. The dot matrix data processing method of the present invention is configured to configure ont data for each character in the form 2. When the data can be recovered using only the hexadecimal code, or 2
When the data can be restored from the binary code and the previously restored data in the previous row, all data is omitted, or when all the data can be restored from the binary code and part of the data, unnecessary parts of the data are deleted. /configure the data,
The ROM capacity required for the character generator can be greatly reduced compared to the conventional one. In addition, when reproducing the original character font from the 7-ont data processed in this way, data with the number of bits determined from the binary code indicating the characteristics of that column is extracted for each column, or in some cases, The original data can be restored through prescribed processing without having to extract the data.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an example of a character font composed of 16 columns of dots in both the vertical and horizontal directions. FIG. 2 is a state diagram of the ROM of the character generator when no processing is applied to the character font shown in FIG. Here, (1.'' is a black dot, 0.2 is a white dot), 266 bits are required for each character. The state diagram of a 7-ont ROM in Figure 1 is reduced to 112 bits.In Figure 5, the upper 2 bits of each of the 16 columns of data indicate the characteristics of the data in that column. Codes can represent four types of characteristics.

In this example, if all the columns are white dots, ζ”o'o
", if it is the same as the previous row data, @o. If the top and bottom two dots of 1FF are white dots, assign the code "10". If the top and bottom four dots are white dots, assign the code 111", and "00".
” , “01” means all data in that column will be omitted,
In the case of "10", the upper and lower two pits are omitted, and in the case of "t11", the upper and lower four bits are omitted, thereby reducing the amount of data and storing them successively for each code.

To restore the original character font from the character font data processed in this way, first the characteristics of the data in each column are determined from the first two bits of the data in that column, and then the accompanying data portion is If so, the data will be extracted and processed according to each code to restore the original data. To explain this in detail using Fig. 3, the first column and the second column
The first two bits of the column are "o o", so all of that column is white dots, and there is no accompanying data, so it is 1.
It is sufficient to generate 6 white dots. In other words, the first and second columns of the character font in FIG. 1 have been restored. Also, in the case of the third column in Fig. 3, the first two bits are “1”.
o”, the data obtained by adding two white dots to the beginning and end of the accompanying data becomes the restored data, that is, the data in the third column in Figure 1.The data in the seventh column in Figure 3 is In this case, since the first two bits are 1'o1'', there is no accompanying data, and the restored data is the same as the already restored data in the 6th column, and becomes the data in the 7th column in FIG.

In addition, in the above embodiment, the code indicating the feature was explained as being 2 bits, but it may also be 3 bits or 4 bits, and in that case, the types of features of the data that can be classified will increase, so it will be easier to use larger data. Effects of the invention that are thought to be able to reduce the amount of data As described above, according to the dot matrix data processing method of the present invention, by replacing the original data with a code that can be restored later, the character generator can be reduced. It is possible to significantly reduce the ROM capacity, which greatly contributes to cost reduction of products such as dot printers, and also enables the same RO
This enables high-quality printing with a large number of dots constituting one character at a capacity of M. Note that such data processing can be easily realized using software in printers controlled by recent microcomputers.

[Brief explanation of the drawing]

Figure 1 is a 16x16 character font diagram, Figure 2 is the character generator R corresponding to the character font in Figure 1.
OM bit state diagram; FIG. 3 is a bit state diagram in the ROM of the corresponding character generator of FIG. 1 processed by the present invention; FIG. 4 is data reduction using conventional run-length encoding. FIG. - E's saddle faction! ? Ro-Taku

Claims (1)

[Claims] A binary code indicating the format of the dot arrangement for each vertical column (or each horizontal row) of a pattern expressed in a dot matrix format, and a dot arrangement that is binary encoded according to rules determined according to each format. The data for the entire pattern is constructed by pairing it with the data of A dot matrix data processing method characterized by unique determination.