JPH05188914A - Character font scale conversion device - Google Patents

Abstract

PURPOSE:To increase the operation speed of scale conversion by determining plural dots after conversion by single-time memory access. CONSTITUTION:Data nearby four points corresponding to the positions of the dots after the scale conversion are read out of a font work memory 24 by the single-time memory access by a scale conversion control part 25 and sent to plural dot determination control parts 26-1 to 26-n. Then the dot determination control parts 26-1 to 26-n select a scale conversion table corresponding to the dot pattern of the received data nearby the four points among scale conversion tables T11-T16 and the scale conversion table is utilized to determine the dots after the scale conversion. Thus, the dots after the conversion can be determined at a time by gaining access once, and the scale conversion is performed at a high speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character font scale conversion device, and more particularly to a character font scale conversion device for performing scale conversion with a character font interpolation function.

[0002]

2. Description of the Related Art Conventionally, when scale conversion of a character pattern with an interpolation function is performed, four points of data (four-point vicinity data) closest to the conversion target dot data which is the basis of the scale conversion are stored in a font memory. , And the scale conversion table used for the scale conversion is determined according to the contents of the four-point neighborhood data. 6 and 7 each show an example of the scale conversion table.

The scale conversion table T11 of FIG. 6 corresponds to 4-point neighborhood data BD1 in which only the upper left one dot is "1" (black) and the other three dots are all "0" (white). As shown, the dot pattern is composed of 8 × 8 dots. This scale conversion table T11
Is used, scale conversion can be performed up to 8 times in both X and Y directions.

For example, the content of the converted data in the X direction (when y = 0) corresponding to one dot d1 to be converted is 1 /
In steps of 8 steps, "1", "1", "1",
It becomes "1", "0", "0", "0", "0", and the contents of the converted data in the Y direction (when x = 0) are "1", "1", "1", "1",
It becomes "0", "0", "0", "0".

In the scale conversion table T12 of FIG. 7, the upper two dots are "0" (white) and the lower two dots are "1".
This corresponds to the 4-point neighborhood data BD2 (black).
Even when using this scale conversion table T12,
Scale conversion can be performed up to 8 times in both X and Y directions.

For example, the content of the converted data in the X direction corresponding to one dot d2 to be converted is "0", "0", "0", "0", "0" in steps of 1/8 step. ",
It becomes "0", "0", "0", and the contents of the converted data in the Y direction are "0", "0", in steps of 1/8 step.
It becomes "0", "0", "1", "1", "1", "1".

Here, the scale conversion table T11 corresponding to the 4-point neighborhood data BD1 and the 4-point neighborhood data BD2.
Although only the scale conversion table T12 corresponding to the above has been described, since the scale conversion table is prepared for each content of the 4-point neighborhood data, 16 scale conversion tables in total are actually used. Next, the operation principle of scale conversion of a character font using such a scale conversion table will be described with reference to FIG.

When converting 8 / n times in the X direction, the step in the X direction is n / 8. When determining the D dot after scale conversion, INT {n / 8 × D}, that is, n /
The 8 × D integer part indicates the dot position of the 4-point neighborhood data including the original conversion target dot, and its decimal part, DEC {n /
8 × D} indicates the position (the number of steps) between the four points.

[0009] For example, when performing a conversion of 8/4 times in the X direction, the step in the X direction is 4/8. When determining the contents of the 0th dot after scale conversion, first INT
The position of the original dot data is calculated by the calculation of {4/8 × 0}. Here, since the integer part of {4/8 × 0} is “0”, the data “1” of the 0th dot in the conversion target character font becomes the original dot data, and 4 points including that data “1” The neighborhood data BD1 is read from the font memory.

Next, the read four-point neighborhood data BD1
The scale conversion table T11 corresponding to the contents of is selected. Then, by the calculation of DEC {4/8 × 0},
Which data in the scale conversion table 11 is to be used as the converted data is determined. Here, {4/8
Since the minority part of × 0} is “0”, the data “1” at the “0” step of the scale conversion table T11 is determined as the 0th dot data after conversion.

Then, the same operation is performed to determine the contents of the first dot after the scale conversion. That is,
The position of the original dot data is calculated by the calculation of INT {4/8 × 1}. Here, the integer part of {4/8 × 1} is “0”, so the data “1” of the 0th dot in the conversion target character font becomes the original dot data, and 4 points including that data “1” The neighborhood data BD1 is read from the font memory.

Next, the read out 4-point neighborhood data BD1
The scale conversion table T11 corresponding to the contents of is selected. Then, by the calculation of DEC {4/8 × 1},
Which data in the scale conversion table T11 is used as the converted data is determined. Here, {4 /
Since the decimal part of 8 × 1} is “4/8”, the data “0” at the “4/8” step of the scale conversion table T11.
Is determined as the converted first dot data. Thereafter, similarly, the contents of the second dot, the third dot, ... After scale conversion are sequentially determined.

As described above, in the conventional scale conversion system, steps are divided vertically and horizontally (in the X and Y directions) to determine the scaled data for each dot. In this method, in order to select the scale conversion table to be used, the original data 4
The point neighborhood data must be read from the font memory. Therefore, 1 is set each time one dot after conversion is determined.
Memory access was required and scale conversion took a lot of time.

[0014]

Conventionally, after conversion, 1
There is a drawback that one memory access is required every time a dot is determined and a large amount of time is required for scale conversion.

The present invention has been made in view of the above circumstances, and provides a character font scale conversion device capable of determining a plurality of dots after conversion by one memory access and performing scale conversion at high speed. The purpose is to provide.

[0016]

In the character font scale conversion device of the present invention, a character font is stored, and a plurality of neighboring dot data each consisting of a plurality of adjacent dots in the font are designated by the same address. Memory means configured as described above, a plurality of scale conversion tables in which dot patterns for scale conversion corresponding to the contents of the dot pattern of the neighboring dot data are respectively registered, and a plurality of dot positions after scale conversion Access means for reading a plurality of neighboring dot data from the memory means by one memory access, and a plurality of neighboring dot data read by the accessing means, respectively, and corresponding to the dot pattern of the received neighboring dot data Refer to the scale conversion table Characterized by comprising a plurality of dots determining means for determining a dot after scaling each by the.

In this character font scale conversion device, a plurality of neighborhood dot data corresponding to a plurality of scale-converted dot positions are read from the memory means with one memory access, and the read plurality of neighborhoods are read. The dot data is sent to each of the plurality of dot determining means. Then, in each dot determination means, the scale-converted dots are determined by referring to the scale conversion table corresponding to the dot pattern of the received neighboring dot data. Therefore, it becomes possible to determine the converted multiple dots at once with one memory access.
It is possible to perform scale conversion at high speed.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a character font scale conversion device with an interpolation function according to an embodiment of the present invention. This character font scale conversion device, similar to the conventional conversion device described in FIG. 8, uses the scale conversion table for interpolation corresponding to the four-point neighborhood data including the conversion target dots to convert the converted dots. It is a method of determining, and includes a microprocessor 21, a font expansion control unit 22, a font memory 23, and a font work memory 2.
4, scale conversion control unit 25, dot determination control unit 26-
1 to 26-n, scale conversion tables T11 to T16,
And a data output unit 27.

The microprocessor 21 controls the entire character font scale conversion device. Under the control of the microprocessor 21, the font expansion control unit 22 extracts from the font memory 23 a predetermined 1 to be converted.
The character font data for the characters is read and stored in the font work memory 24.

The font memory 23 stores dot pattern data respectively corresponding to a plurality of character fonts. The dot pattern of the conversion target character font is developed in the font work memory 24.

The font work memory 24 has a memory bank structure in which a plurality of data in the vicinity of four points in the font can be read simultaneously by the same address. Details of the memory bank configuration of the font work memory 24 will be described later with reference to FIG.

Under the control of the microprocessor 21, the scale control converter 25 collectively calculates a plurality of dot positions of the original data respectively corresponding to the plurality of converted dot positions and the number of steps at the time of conversion. , A plurality of 4-point neighborhood data are simultaneously read from the font work memory 24. The dot position of the original data is INT {N /
256 × D}, and the number of steps is calculated by DEC {N / 256 × D}.

Here, 0/256 is set in both the X and Y directions.
Assuming a scale conversion table consisting of 256 steps from 1 to 255/256, D indicates a dot position after conversion, and INT {N / 256 × D} is {N / 256 ×.
DEC {N / 256 x indicates the integer part of the operation result of D}
D} indicates the decimal part of the calculation result of {N / 256 × D}. N / 256 is the scale conversion magnification (256
It is the reciprocal of / N).

The 4-point neighborhood data is INT {N / 256 ×
It is 4-point data including dots designated by D}. Multiple 4 read simultaneously from the fontwork memory 24
The point neighborhood data is combined with the corresponding number of steps at the time of conversion, and the dot determination control unit 26-1
26-n are distributed and supplied.

Each of the dot determination control units 26-1 to 26-n scales on the basis of the four-point neighborhood data sent from the scale conversion control unit 25 and the value of the number of steps representing the distance after the decimal point of the dot. The dots after conversion are determined, and 16 scale conversion tables T11 to T
16 is provided. Scale conversion tables T11 to T1
6 corresponds to the contents of the four-point neighborhood data, as described with reference to FIGS. 6 and 7, and each stores the dot pattern data for scale conversion of 256 × 256 dots after scale conversion with interpolation. Has been done.

Each of the dot determination control units 26-1 to 26-n selects a scale conversion table to be used according to the contents of the received 4-point neighborhood data, and selects the dot data corresponding to the received step number. It is read from the scale conversion table and determined as the converted dot data. In this way, the dot determination control unit 26-
The converted dot data determined by each of 1 to 26-n is supplied to the data output unit 27. The data output unit 27 collectively outputs the data (n dots) respectively determined by the dot determination control units 26-1 to 26-n. Next, the memory bank configuration of the font work memory 24 of FIG. 1 will be described with reference to FIG.

The fontwork memory 24 is composed of two bank memories 241 and 242.
The corresponding byte data in the bank memory 241 and the second bank memory 242 are simultaneously read by the same address. That is, the first bank of the first bank memory 241
The 8-bit data of the byte (B1) is designated by the same address as the 8-bit data of the first byte (B1) of the second bank memory 242 and is read simultaneously.
Similarly, the second byte of the first bank memory 241 (B
2), 3rd byte (B3), 4th byte (B4)
The second byte of the second bank memory 242 (B
2), the third byte (B3) and the fourth byte (B4) are simultaneously read.

Here, for the sake of simplicity, for example, assuming that the character font data is 8 × 8 dots, the first byte (B1), the second byte (B2), and the third byte of the first bank memory 241 are assumed. Byte (B3), 4th byte (B
In 4), the data of the odd-numbered lines of the character font data, that is, the data of the first line, the data of the third line, the data of the fifth line, and the data of the seventh line are stored.
The first byte (B1), the second byte (B2), the third byte (B3), and the fourth byte (B4) of the second bank memory 242 have even-numbered lines of character font data, respectively. That is, the data of the second line, the data of the fourth line, the data of the sixth line, and the data of the eighth line are stored.

Therefore, in principle, by accessing the first byte (B1) of the first bank memory 241 and the second bank memory 242, seven 4-point neighborhood data BD11 to BD16 are simultaneously read as shown in the figure. It becomes possible. Actually, the scale conversion magnification is set to 256 / N, and N / 256 steps are engraved both vertically and horizontally, so if the horizontal dot position after scale conversion is D,
The integer part of N / 256 × D is the bit position of the 4-point neighborhood data, and the decimal part thereof is the distance data between the 4-point neighborhoods, that is, the number of steps.

In this case, if the font work memory 24 is read in byte (8 bits) units, the integer part of N / 256 × D ÷ 8 is the horizontal byte position to be accessed.

If the 4-point neighborhood data necessary for determining the Ds-th dot after scale conversion and the 4-point neighborhood data necessary for determining the Dt-th dot are in the font work memory 24 at the same address, In other words, [INT
{N / 256 × Dt ÷ 8}] = [INT {N / 256 ×
Ds ÷ 8}] is satisfied, Dt−Ds
It is possible to read four pieces of near-point data for one piece in one access cycle to the font work memory 24.

When there are a total of 16 dot determination control units, it is preferable to read 16 4-point neighborhood data from the font work memory 24 at once. Therefore,
If the number of Dt-Ds is smaller than 16, it is necessary to access the font work memory 24 a plurality of times. In this case, INT is set to the work memory 24.
{N / 256 × D15 ÷ 8} -INT {N / 256 × D0
By performing ÷ 8} access cycles, it is possible to read out 16 pieces of 4-point neighborhood data.

As can be seen from this equation, the smaller the value of N, the more the number of accesses to the work memory 24 can be reduced. Here, D0 is the D0th dot position after enlargement, and D15 is the D15th dot position after enlargement. FIG. 3 shows how data is transferred from the scale conversion control unit 25 to the dot determination control units 26-1 to 26-n.

The dot determination control units 26-1 to 26-16
Assuming that there are 16 data items up to 16 points, the fourteen-point neighborhood data read from the font work memory 24 by the scale conversion control unit 25 are supplied to the dot determination control units 26-1 to 26-16, respectively. .. In this case, to each 4-point neighborhood data, distance data between the 4-point neighborhoods, that is, data indicating the number of steps corresponding to the converted dot position is added.

For example, the dot determination control unit 26 outputs 4-point neighborhood data of the original data corresponding to the converted 0th dot.
When it is sent to 1, the value of DEC {N / 256 × 0} is also sent to the dot determination control unit 26-1 together with the 4-point neighborhood data. Next, the operation for the scale conversion processing by the scale conversion control unit 25 will be described with reference to the flowchart in FIG.

The scale conversion control unit 25 first receives a plurality (for example, 16) of converted dot position information from the microprocessor 21 (step S11). Then
The scale conversion control unit 25, according to the conversion magnification (256 / N) designated by the microprocessor 21, converts the dot positions of the original data corresponding to the converted dot positions D0, D1, ... D15 [INT {N / 256x
D}], and the number of steps [DEC {N / 256 ×
D}] is obtained (step S12).

Then, the scale conversion control unit 25 accesses the font work memory 24 to read, for example, 16 pieces of 4-point neighborhood data (step S12). After that, the scale conversion control unit 25 creates a combination of the corresponding 4-point neighborhood data and the number of steps (step S1).
4), the dot decision control units 26-1 to 26-1
26 to 16 respectively (step S15). Next, the dot determination operation of each of the dot determination control units 26-1 to 26-16 will be described with reference to the flowchart of FIG.

Each of the dot determination control units 26-1 to 26-16 starts with 16 scale conversion tables T11 to T.
The scale conversion table corresponding to the contents of the received 4-point neighborhood data is selected from 16 (step S2).
1). Next, the dot determination control units 26-1 to 26-16
Each reads the dot data corresponding to the received step number from the selected scale conversion table and determines it as the converted dot (step S22). After that, each of the dot determination control units 26-1 to 26-16 supplies the determined converted dots to the data output unit 27. The data output unit 27 includes the dot determination control unit 26.
16-bit data received from -1 to 26-16 are collectively output.

The operations of the flow charts of FIGS. 4 and 5 are repeated until all the bits in the horizontal direction have been determined, and once all the bits in the horizontal direction have been determined, this time step vertically. The same operation is repeated with.

As described above, in the character font scale conversion device of this embodiment, a plurality of 4-point neighborhood data corresponding to a plurality of scale-converted dot positions can be accessed by the scale conversion control unit 25 once. The plurality of four-point neighborhood data read out from the fontwork memory 24 are read by a plurality of dot determination control units 26-
1 to 26-n, respectively. Then, in each of the dot determination control units 26-1 to 26-n, the scale conversion table corresponding to the dot pattern of the 4-point neighborhood data received in the scale conversion tables T11 to T16 is selected, and the scale conversion table is referred to. By doing so, the dot after scale conversion is determined. Therefore,
A plurality of dots after conversion can be determined at once by one memory access, and scale conversion can be performed at high speed.

In this embodiment, in order to operate all 16 dot determination control units 26-1 to 26-16 together, 16 4-point neighborhood data are read out by one or more accesses. However, the dot determination control unit may be operated by the number of pieces of 4-point neighborhood data that can be read by one access. In addition, this scale conversion is performed by various printers such as laser printers that require high-speed printing, LCDs that require high-speed display,
It is suitable for a display device such as a PDP.

[0043]

As described above, according to the present invention, a plurality of converted dots can be determined by one memory access, and scale conversion can be performed at high speed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a specific configuration of a font work memory in the same embodiment.

FIG. 3 is a diagram showing how data is transferred from the scale conversion control unit to a plurality of dot determination control units in the embodiment.

FIG. 4 is a flowchart illustrating an operation of a scale conversion control unit according to the same embodiment.

FIG. 5 is a flowchart illustrating an operation of a dot determination control unit in the embodiment.

FIG. 6 is a diagram showing an example of the contents of a scale conversion table used in a conventional scale conversion device.

FIG. 7 is a diagram showing another example of the contents of a scale conversion table used in a conventional scale conversion device.

FIG. 8 is a diagram for explaining an operation principle of scale conversion in a conventional scale conversion device.

[Explanation of Codes] 21 ... Microprocessor, 22 ... Font expansion control unit, 23 ... Font memory, 24 ... Font work memory, 25 ... Scale conversion control unit, 26-1 to 26-n ...
Dot determination control unit, T11 to T16 ... Scale conversion table, 27 ... Data output unit.

Claims (2)

[Claims] 1. A memory means configured to store a character font and to designate a plurality of neighboring dot data each consisting of a plurality of neighboring dots in the font by the same address, and a dot pattern of the neighboring dot data. A plurality of scale conversion tables in which dot patterns for scale conversion corresponding to the contents of the above are registered, and a plurality of neighboring dot data corresponding to a plurality of dot positions after scale conversion are accessed once from the memory means. And the access means for reading out the plurality of neighboring dot data read by the accessing means, respectively, and referring to the scale conversion table corresponding to the dot pattern of the received neighboring dot data, the dots after scale conversion are respectively performed. Multiple dot decisions to determine A character font scale conversion device comprising: a setting means. 2. The memory means includes a first memory module that stores dot pattern data of odd-numbered lines of the character font, and a second memory module that stores dot pattern data of even-numbered lines of the character font. The character font scale conversion device according to claim 1, including: