JP3539203B2 - Bitmap data reduction method, information processing apparatus and information recording medium - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for reducing bitmap data such as font data and image data, an information processing apparatus that performs processing using the reduction method, and an information recording medium on which a program for realizing the method is recorded.
[0002]
[Prior art]
A conventional technique will be described with reference to FIG. FIG. 4A is an example of normal size bitmap font data of the printing apparatus. In a conventional printing apparatus capable of performing reduced printing of bitmap data, bitmap data of 2n (hereinafter, n is an integer of 1 or more) or 2n-1 dot length before reduction is reduced to n dot length. When the data is expanded in the memory in the printing apparatus, the logical sum of two dot lines is sequentially calculated from one end of the bitmap data to convert the data into one dot line. There is a way to create it. FIG. 4B shows the result of reducing the bitmap font data shown in FIG. 4A in the height direction of the character by this method. As another method, there is a method in which bitmap data is simply thinned out at intervals of one dot line to create a reduced pattern. FIG. 4C shows the result of reducing FIG. 4A by this method. As another method for reduced printing, font data for reduced printing is stored in advance in a ROM or the like in a printing apparatus separately from font data of normal size, and printing is performed using the font data for reduced printing. There is also a method of developing and printing in a memory in the apparatus.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventional technique, in the method of calculating the logical sum of every two dot lines described first and converting it into one dot line to create a reduced pattern, the background portion of the bitmap data is crushed. In particular, when the bitmap data is font data, there is a problem that it becomes difficult to read characters as shown in FIG.
[0004]
In the second method of creating a reduced pattern simply by thinning out at one dot line intervals, the thinning may erase dots that should not be erased by, for example, one dot line. Also in this case, there is a problem that it becomes difficult to read the characters as shown in FIG.
[0005]
Further, the method of preparing font data for reduced printing described in the third step in advance leads to an increase in memory capacity and a problem that manufacturing cost increases.
[0006]
The present invention has been made in order to solve the above-described problems, and a reduction method and an information processing apparatus capable of minimizing crushing and missing dots when bitmap data such as font data and image data are reduced. And an information recording medium for realizing this.
[0007]
[Means for Solving the Problems]
The invention for achieving the above object is the following invention.
[0008]
The method for reducing bitmap data according to the present invention includes:
(1) A reduction method for successively converting two consecutive dots from one end of bitmap data into one dot to create a reduced pattern,
The image side of each bit of the bitmap data is represented by {1}, and the background side is represented by {0}, and the two-dot data to be reduced is formed in the form of {ab} in order from the side where reduction processing is started. When expressed as
A preprocessing step in which the previous conversion target is {00} and the conversion result is {0};
If the current conversion target is {11}, a first conversion step of converting to {1};
If the current conversion target is {00}, a second conversion step of converting to {0};
If the current conversion target is {10}, a third conversion step of converting the conversion result of the previous conversion target into a logical negation;
When the current conversion target is {01} and the previous conversion target is {01}, a fourth conversion step of converting the conversion result of the previous conversion target into a logical negation;
When the current conversion target is {01} and the previous conversion target is not {01}, a fifth conversion step of converting to {1} is provided.
(2) In the bitmap data reduction method according to (1), when the length of the bitmap data before reduction is an odd number,
A step of assuming that {0} is at the head of the bitmap data string and / or a step of assuming that {0} is at the end of the bitmap data string.
Also, the information processing apparatus of the present invention
(3) An information processing apparatus for sequentially converting two consecutive dots from one end of bitmap data into one dot to create a reduced pattern,
The image side of each bit of the bitmap data is represented by {1}, the background side is represented by {0}, and the two-dot data to be reduced is sequentially converted into a {ab} format from the side where the reduction processing is started. When expressed as
Preprocessing means for setting the previous conversion target to {00} and setting the conversion result to {0};
If the current conversion target is {11}, first conversion means for converting to {1};
If the current conversion target is {00}, a second conversion unit that converts the conversion target to {0};
If the current conversion target is {10}, a third conversion unit that converts the conversion result of the previous conversion target into a logical negation;
When the current conversion target is {01} and the previous conversion target is {01}, a fourth conversion unit that converts the conversion result of the previous conversion target into a logical negation,
If the current conversion target is {01} and the previous conversion target is not {01}, a fifth conversion unit for converting to {1} is provided.
(4) In the information processing device according to (3), when the length of data before reduction is an odd number,
A means for assuming that {0} is at the beginning of the bitmap data string and / or a means for assuming that {0} is at the end of the bitmap data string are provided.
[0009]
According to the present invention, when reducing the bit map data having a length of 2n dots to the length of n dots, not only the process of converting only the current conversion target into one dot but also the combination pattern of the previous conversion target and its By taking the conversion result into consideration and determining the current conversion result, it is possible to avoid crushing the background portion of the bitmap data or erasing the dots that should not be erased by a line of one dot line as much as possible. It is possible to create an easy-to-read reduced pattern that balances the collapse and omission of data.
[0011]
Further, a reduction result can be output using an information processing device that realizes the above-described reduction method. A printing device or a display device can be considered as an information processing device capable of outputting a reduction result.
[0012]
Further, the above-described reduction method can be supplied as a control program executable by the information processing apparatus, and can be provided via a recording medium on which the control program is recorded. Alternatively, it is also possible to provide a control program via a computer network such as the Internet and record and use the control program on a recording medium of an information processing device on the user side.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0014]
FIG. 1 is a diagram illustrating a schematic configuration of a printing apparatus according to an embodiment of the present invention. As shown in FIG. 1, the printing apparatus 1 of the present embodiment is connected to a host 2 and operates based on data transferred from the host 2. The printing apparatus 1 includes an interface 11 connected to the host 2. The CPU 12 processes data received by the interface 11 according to a control program stored in the control ROM 13. The control ROM 13 stores a program 13a describing a method of reducing a character pattern as one of the control programs. When the data received from the host 2 is character data, information necessary for developing characters such as the currently specified character size and character decoration is read from the RAM 15 and read from the font ROM 14 accordingly. The data is processed and expanded in the print buffer 16. Each font stored in the font ROM 14 is formed in a bitmap pattern. The print data developed in the print buffer 16 is printed on a sheet by a printing mechanism 17.
[0015]
The CPU 12 operates according to a program stored in the control ROM 13. If the control ROM 13 is realized by an erasable / writable ROM, it is easy to update and modify the program. A program to be introduced into an information processing apparatus such as a printing apparatus can be recorded on an information recording medium such as a floppy disk or a hard disk.
[0016]
Next, a method in which the printing apparatus 1 creates reduced characters in a print buffer using the bitmap font data stored in the font ROM 14 when reduced printing of characters is designated by the host 2 will be described. Here, when the dot length of the bitmap data to be reduced is 2n-1 length, (1) a method of performing reduction processing by assuming that {0} is at the end of the bitmap data; 2) A description will be given of two types of methods for performing the reduction process assuming that {0} is at the head of the bitmap data. In the following description, dots to be printed are expressed as {1}, and dots not to be printed are expressed as {0}. The reduction process is performed for each two-dot line in order from one end of the bitmap data. Two dots to be converted in the reduction process are expressed as {ab}. First, referring to the flowcharts of FIGS. 6, 7 and 8, if the bitmap data before reduction is composed of 2n-1 dot length, the bitmap data having {0} at the end thereof A method of performing the deemed reduction process will be described.
[0017]
As pre-processing for performing the reduction processing, the previous conversion target is set to {00}, and the conversion result is set to {0} (S601).
[0018]
Next, it is determined whether the remaining reduction target dot length of the bitmap data (hereinafter, simply referred to as “remaining dot length”) is one dot (S602). If S602 is true, the first dot to be converted this time is set as the remaining one dot data (S603), and the second dot to be converted this time is set to {0} (S604). Thereafter, the process proceeds to S701. On the other hand, if S602 is false, the process directly proceeds to S701.
[0019]
Next, it is determined whether the current conversion target is {11} (S701). If S701 is true, the conversion result of the current conversion target (hereinafter, simply referred to as “this conversion result”) is set to {1} (S702), and the process proceeds to S711. On the other hand, if S701 is false, the process proceeds to S703.
[0020]
Next, it is determined whether the current conversion target is {00} (S703). If S703 is true, the current conversion result is set to {0} (S704), and the process proceeds to S711. On the other hand, if S703 is false, the process proceeds to S705.
[0021]
Next, it is determined whether the current conversion target is {10} (S705). If S705 is false, it is determined whether the previous conversion target is {01} (S709). If S709 is false, the current conversion result is set to {1} (S710), and the process proceeds to S711. On the other hand, if S705 is true or S709 is true, the previous conversion result (hereinafter, simply referred to as "previous conversion result") is determined (S706). Here, if the previous conversion result is {1}, the current conversion result is set to {0} (S707), and if the previous conversion result is {0}, the current conversion result is set to {1} (S708). Thereafter, the process proceeds to S711.
[0022]
As described above, when the current conversion result is determined, the conversion result is developed in the print buffer 16 (S711).
[0023]
Next, the remaining dot length is determined (S801). If the remaining dot length is three or more, the two dots processed this time are subtracted (S802), the conversion target is advanced by two dots (S803), and the process returns to S602. If the remaining dot length is 2 dots or less in S802, the reduction process ends.
[0024]
The CPU 12 controls the printing mechanism 17 according to the control ROM 13 and prints the reduced image developed in the print buffer 16 by a print line feed command or the like transmitted from the host 2.
[0025]
When the data shown in FIG. 4A is reduced by the above-described reduction method, reduced characters that are easy to read can be obtained as shown in FIG. 4D.
[0026]
Next, in the case where the bitmap data before reduction has a length of 2n-1 dots, a method of performing reduction processing on the assumption that {0} is at the head of the bitmap data will be described with reference to FIGS. 10, will be described with reference to the flowchart of FIG.
[0027]
First, as a pre-process for performing the reduction process, the previous conversion target is set to {00}, and the conversion result is set to {0} (S901). Next, it is determined whether the remaining dot length is an odd number (S902). If S902 is true, the first dot to be converted this time is set to {0} (S903), and the second dot to be converted this time is set as the leading data of the bitmap data before reduction (S904). Thereafter, the process proceeds to S701. On the other hand, if S902 is false, the process proceeds to S701.
[0028]
Subsequent processes from S701 to S711 are as described above, and description thereof will be omitted.
[0029]
After S711, it is determined whether the remaining dot length is an odd number (S1001). If S1001 is true, 1 is subtracted from the remaining dot length (S1002), and the remaining dot length is determined (S1003). If the result of this determination is that the remaining dot length is 0 dots, the reduction process ends. If the remaining dot length is not 0 dots, the conversion target is advanced by one dot (S1004), and the process returns to S701. On the other hand, if S1001 is false, 2 is subtracted from the remaining dot length (S1005), and the remaining dot length is determined (S1006). If the result of this determination is that the remaining dot length is 0 dot, the reduction process ends. If the remaining dot length is not 0 dot, the conversion target is advanced by 2 dots (S1007), and the process returns to S701.
[0030]
As described above, assuming that {0} is at the head of the bitmap data before reduction, the head data of the bitmap data before reduction and the head data after reduction are the same. Therefore, this method is used when the leading data of the bitmap data before reduction has an important meaning, for example, when the leading dot data is difficult to read unless it is printed by the reduction processing. This makes it possible to leave the leading dot of the data before reduction at the head of the data after reduction.
[0031]
Therefore, it is possible to coexist the two reduction processes described above, that is, the reduction process in which it is assumed that there is {0} at the end of the bitmap data before reduction and the reduction process in which it is assumed that there is {0} at the beginning. Desirably, by properly using the two methods according to the character, a character that is easy to read even after reduction can be obtained. Here, the reason why the reduced pattern is created by the above-described conversion processing will be described with reference to FIGS.
[0032]
FIG. 2 shows the combination patterns (A to D) to be converted this time and the conversion results. In the figure, ● represents {1}, and ○ represents {0}. In the case of patterns A and B, they are converted into {1} and {0}, respectively, as shown. Further, for patterns C and D, the conversion result cannot be determined only from the combination pattern of these two dots. Therefore, it means that the determination is made using the information of the two dots that were the previous target, that is, the previous conversion target. ? ｝.
[0033]
Next, a method for determining patterns C and D in FIG. 2 will be described with reference to FIG. FIG. 3 shows a pattern C and a pattern D in FIG. 2 with respect to a current conversion target (dots indicated by a cd line in FIG. 3) and a previous conversion target (dots indicated by an ab line in FIG. 3). This shows all possible combinations, and shows the conversion result of the current conversion object (cd row data) in consideration of the combination pattern of these four dots. {#} In FIG. 3 is determined as {0} when the previous conversion result in FIG. 3 is {1}, and {1} when it is {0}.
[0034]
Hereinafter, the reasons for determining the pattern C will be described individually.
[0035]
In the case of the pattern C1, the previous conversion result is always {1}, and the state before conversion is that {1} is continuous for three dots. It is thought that there is no. Therefore, the current conversion result is {0}.
[0036]
In the case of the pattern C2, there is a high possibility that the pattern is a complicated line or point, but if printing is performed in all cases, the background will be crushed, and if simply thinned out, dots will be continuously missing. there is a possibility. In such a case, it is necessary to thin out appropriately. Therefore, the current conversion result is determined as {0} if the previous conversion result is {1}, and {1} if it is {0}.
[0037]
In the case of the pattern C3, since {1} is continuous for two dots in the bc line, the pattern A in FIG. 2 is divided at the center, and either one (the b line or the c line) should be printed. It is. Therefore, the current conversion result is determined to be {0} if the previous conversion result is {1}, and {1} if it is {0}.
[0038]
In the case of pattern C4, the previous conversion result is always {0}, and the dots before and after {1} on line c are {0}. Should. Therefore, the current conversion result is determined to be {1}.
[0039]
Next, the reason for determining the pattern D will be described.
[0040]
Of the pattern D, only the pattern D3 determines the current conversion result. If the previous conversion result is {1}, it is determined as {0}, and if the previous conversion result is {0}, it is determined as {1}. This is for the same reason as the determination method in the case of the pattern C2.
[0041]
Also, regarding the remaining patterns D1, D2, and D4 of the pattern D, the current conversion result is {1}.
[0042]
The determination reason in the case of the pattern D1 will be described with reference to FIG. In the case of reducing the character in FIG. 5A, if the pattern D1 is set to {0}, the shape is remarkably deformed as shown in FIG. On the other hand, when the pattern D1 is {1}, the shape does not collapse as shown in FIG. As in this example, even when the character configuration is simple, the pattern D1 appears frequently, and in consideration of this, the pattern D1 is set to {1}.
[0043]
In the case of the pattern D2, {0} is continuous by two dots in the bc row. If {1} appears after {0} continues for two or more dots, the information of {1} is determined to be of high importance and is left without being erased.
[0044]
In the case of the pattern D4, {1} is set for the same reason as described in the case of the pattern D2.
[0045]
As described above, in the present invention, not only the current conversion target, but also the previous conversion target and the previous conversion result are taken into account, and the current conversion target is subjected to the conversion processing, so that the balance of data collapse and omission is easy to see. A reduced pattern can be created.
[0046]
The reduction method of the present invention can be realized by any printing apparatus that can print bitmap data of a normal size without using a special circuit or the like. In order to realize this, the processing in the flowcharts of FIGS. 6 to 10 may be performed, or a logical operation that can obtain a conversion result equivalent to this using a known technique may be used. In the case of realizing by a logical operation, several types of operation methods are conceivable, but if a method with a small number of operations is adopted, the reduction processing can be performed at high speed.
[0047]
In the above-described embodiment, an example in which the character is reduced in the height direction has been described. However, the present invention is not limited to this, and can be applied to a case in which the character is reduced in the width direction.
[0048]
Further, the object of the reduction processing can be applied not only to characters but also to graphic data composed of bitmap data and the like.
[0049]
Further, in the above-described embodiment, the printing apparatus has been described as an example, but a completely similar reduction method can be applied to the display apparatus. That is, in FIG. 1, the display device to which the present invention is applied can be realized by replacing the print buffer 16 with a display buffer and the printing mechanism 17 with a display mechanism.
[0050]
In addition, the present invention is not limited to the above-described embodiment, and can be modified without departing from the spirit of the present invention.
[0051]
【The invention's effect】
As described above, the use of the technique of the present invention can minimize crushing and missing dots when bitmap data such as font data and image data is reduced. If bitmap data is stored in a storage device such as a ROM in the information processing device, dedicated font data of a reduced size for separately printing or displaying characters is separately provided. Since there is no need to hold the data, there is no problem that the memory capacity increases due to the addition of the reduction function and the manufacturing cost increases.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating a schematic configuration of a printing apparatus according to an embodiment of the invention.
FIG. 2 is a diagram illustrating a pattern to be converted this time and a result of the conversion when performing a reduction conversion according to the present invention;
FIG. 3 is a diagram in which all conceivable patterns to be converted last time correspond to patterns C and D in FIG. 2;
FIG. 4 is a diagram showing bitmap data (character “heavy”) of normal size, a reduction result by a conventional reduction method, and a reduction result by the present invention.
FIG. 5 is a diagram showing bitmap data of a normal size (character “≦”) and its reduction result.
FIG. 6 is a flowchart illustrating a reduction method according to the present invention.
FIG. 7 is a flowchart illustrating a reduction method according to the present invention.
FIG. 8 is a flowchart illustrating a reduction method according to the present invention.
FIG. 9 is a flowchart illustrating a reduction method according to the present invention.
FIG. 10 is a flowchart illustrating a reduction method according to the present invention.
[Explanation of symbols]
1 printing device 2 host 11 interface 12 CPU
13 Control ROM
13a A program describing a character pattern reduction method in a control ROM 14 A font ROM
15 RAM
16 print buffer 17 printing mechanism

Claims (8)

A reduction method for sequentially converting two consecutive dots into one dot from one end of bitmap data to create a reduced pattern,
The image side of each bit of the bitmap data is represented by {1}, and the background side is represented by {0}, and the two-dot data to be reduced is formed in the form of {ab} in order from the side where reduction processing is started. When expressed as
A preprocessing step in which the previous conversion target is {00} and the conversion result is {0};
If the current conversion target is {11}, a first conversion step of converting to {1};
If the current conversion target is {00}, a second conversion step of converting to {0};
If the current conversion target is {10}, a third conversion step of converting the conversion result of the previous conversion target into a logical negation;
When the current conversion target is {01} and the previous conversion target is {01}, a fourth conversion step of converting the conversion result of the previous conversion target into a logical negation;
If the current conversion target is {01} and the previous conversion target is not {01}, a fifth conversion step of converting to {1} is provided. How to reduce. 2. The method for reducing bitmap data according to claim 1, wherein the length of the bitmap data before reduction is an odd number,
A step of assuming that there is {0} at the beginning of the bitmap data string and / or a step of assuming that there is {0} at the end of the bitmap data string. Reduction method. An information processing device for sequentially converting two consecutive dots into one dot from one end of bitmap data to create a reduced pattern,
The image side of each bit of the bitmap data is represented by {1}, the background side is represented by {0}, and the two-dot data to be reduced is sequentially converted into a {ab} format from the side where the reduction processing is started. When expressed as
Preprocessing means for setting the previous conversion target to {00} and setting the conversion result to {0};
If the current conversion target is {11}, first conversion means for converting to {1};
If the current conversion target is {00}, a second conversion unit that converts the conversion target to {0};
If the current conversion target is {10}, a third conversion unit that converts the conversion result of the previous conversion target into a logical negation;
When the current conversion target is {01} and the previous conversion target is {01}, a fourth conversion unit that converts the conversion result of the previous conversion target into a logical negation,
An information processing apparatus comprising: a fifth conversion unit that converts the current conversion target to {01} when the current conversion target is {01} and the previous conversion target is not {01}. . 4. The information processing apparatus according to claim 3, wherein when the length of the data before reduction is an odd number,
An information processing apparatus comprising means for assuming that {0} is at the head of the bitmap data string and / or means for assuming that {0} is at the end of the bitmap data string. 5. The information processing apparatus according to claim 3, further comprising a printing unit that prints the reduced pattern. 5. The information processing apparatus according to claim 3, further comprising a display unit that displays the reduced pattern. A control program for an information processing apparatus for sequentially converting two consecutive dots into one dot from one end of bitmap data to create a reduced pattern,
The image side of each bit of the bitmap data is represented by {1}, and the background side is represented by {0}, and the two-dot data to be reduced is formed in the form of {ab} in order from the side where reduction processing is started. When expressed as
A preprocessing step in which the previous conversion target is {00} and the conversion result is {0};
If the current conversion target is {11}, a first conversion step of converting to {1};
If the current conversion target is {00}, a second conversion step of converting to {0};
If the current conversion target is {10}, a third conversion step of converting the conversion result of the previous conversion target into a logical negation;
When the current conversion target is {01} and the previous conversion target is {01}, a fourth conversion step of converting the conversion result of the previous conversion target into a logical negation;
If the current conversion target is {01} and the previous conversion target is not {01}, a fifth conversion step of converting to {1} is provided. The recorded information recording medium. 8. The control program according to claim 7, wherein when the length of the data before reduction is an odd number,
Recording a control program characterized by comprising a step of assuming that {0} is at the beginning of the bitmap data string and / or a step of assuming that {0} is at the end of the bitmap data string. Information recording medium.

Images