JPH0435948B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image processing method for reducing binary pattern data such as characters and images, and particularly relates to an image processing method for reducing binary pattern data in 1-byte units. It is about the method.

[Prior Art] Generally, in order to perform a reduction process to obtain pattern data of a desired size from an original pattern such as a character or image, the position of a black pixel in the original pattern data is set to the position coordinates after reduction. It is necessary to perform a process to replace it.

Conventionally, this process has been carried out by constructing a scanning section 8 (FIG. 2) with a shift register, etc., as disclosed in, for example, Japanese Patent Application Laid-Open No. 52-68326, and supplying information on all bit positions to a logic circuit section 9. It was done using a method.

[Problems to be Solved by the Invention] In the above-mentioned conventional method, a process is performed to obtain the positions after reduction of all pixels including not only black pixels but also white pixels of the original pattern.

Therefore, the reduction processing by the above-mentioned conventional method takes an extremely long time, and an image processing method that can perform reduction processing at a higher speed has been awaited.

[Means for Solving the Problems] The present invention has been made based on the above points, and an object of the present invention is to provide an image processing method that can perform pattern data reduction processing at higher speed, and its characteristics are as follows. , in an image processing method that changes the size of an image by performing a predetermined calculation on the position data of a black pixel of interest, a mask that stores mask data necessary to mask information up to the processed bit position. Based on the logical product of the data table, the mask data successively output from the mask data table, and the original pattern data, the most significant bit "1" included in the unprocessed data that has passed through the mask is determined. and a priority encoder that detects the position of the bit "1" and detects that there is no black pixel if the bit "1" does not exist, and the output of the priority encoder is used as the black pixel of interest for use in the calculation. In addition to the position data, the data is used as read address data for the mask data table.

[Operation] In the present invention, when reducing the original pattern data in units of bytes, the priority encoder determines the position of the highest black pixel among the black pixels included in the unprocessed data that has passed through the mask. ,
In other words, the bit “1” contained in the unprocessed data
The position of the most significant bit "1" is detected, and processing is performed to obtain the reduced position only for that position, thereby increasing speed.

[Embodiment] FIG. 1 is a block diagram showing the configuration of an image processing system according to an embodiment of the present invention.

1 is a register, 1 line (1 byte)
It holds the original pattern data.

2 is an AND gate, which takes the AND of the output of register 1 and the output from mask table 3, which will be described later.

3 is a mask data table, register 1
It holds data as a table for sequentially masking one line (one byte) of original pattern data held in the memory up to the already processed position, and outputs mask data in accordance with the output of register 5, which will be described later. be.

4 is the priority encoder, AND
At gate 2, based on the result of ANDing the original pattern data for one line (one byte) in register 1 and the predetermined mask data in mask data table 3, the bit "1" corresponding to the black pixel is The most significant bit position of "1" is detected and a position code corresponding to that position is output.

A register 5 holds a position code indicating the position of the most significant "1" bit output from the priority encoder 4.

A multiplier 6 multiplies the position code held in the register 5 by a reduction rate input in advance, and outputs the result as an address of a bit data table 7, which will be described later.

Reference numeral 7 denotes a bit data table, which holds a data table for outputting a bit "1" to a predetermined bit position after reduction, corresponding to the address specified by the output of the multiplier 6.

Reference numeral 8 denotes an OR gate, which is used to logically OR the data output from the bit data table 7 and the contents held in the register 9, which will be described later.

A register 9 holds the output data of the OR gate 8 and outputs it as reduced pattern data after processing for one line is completed.

Next, an image processing method according to an embodiment of the present invention will be explained by explaining the data processing operation of the image processing system having the above configuration. In the following explanation, a case will be explained in which the original pattern data of 1 byte (8 bits) shown in FIG. 3 is reduced to 1/2 and converted into the pattern shown in FIG. 3. In addition, when the target is 1 byte (8 bits) of original pattern data, the contents of the mask data table 3 and bit data table 7 shown in Fig. 1 are changed to the states shown in Fig. 2, 1 and 2. It is set.

(First Operation Cycle) First, among the original pattern data supplied to the register 1, 1-byte data "01110011" shown in FIG. 3 is held in the register 1. In the initial state, the mask data table 3 is in a state where it outputs data "11111111" at address 8, and this data and the data held by the register 1 are applied to the AND gate 2.

The AND gate 2 outputs the AND of the data from the register 1 and the mask data table 3, ie, "01110011" in this case, and applies it to the priority encoder 4. The priority encoder 4 detects the position of the most significant "1" bit of the input data and outputs its position code. In this embodiment, as shown in FIG.
Since "1" is the highest position, the priority encoder 4 outputs the position code "6". The position code "6" output from the priority encoder 4 is applied to the register 5 and held there. The position code “6” held in this register 5 is applied to the multiplier 6 of the mask data table 3.

When this multiplier 6 receives the position code "6" from the register 5, it multiplies this "6" by 1/2 of the specified reduction rate. As a result, the reduced position code "3" is output as the address of the bit data table 7. When the bit data table 7 receives the output from the multiplier 6, it reads out the data "00001000" at the designated address "3" and applies it to the OR gate 8. This data "00001000" is applied to the register 9 after being logically summed with the data stored in the register 9 by the OR gate 8. In this case, this is the first processing, and since data "00000000" is stored in register 9 in the initial state, the data output by OR gate 8 is "00001000", which is held in register 9. .

Data held by this register 9 “00001000”
is the top position data of black pixel “01000000” by 1/
This is the position data of the black pixel when reduced to 2.

(Second operation cycle) At this time, the mask data table 3 receives the highest position data "6" applied from the register 5, and outputs data "00111111" at the corresponding address 6. I'm in a state where I can. Therefore, input this data AND
At gate 2, when the output data "00111111" of mask data table 3 and the output data "01110011" of register 1 are ANDed, the result becomes "00110011", and this data "00110011" is It is applied to the priority encoder 4. Then, in the same way as above,
The most significant bit of this data “00110011” is “1”
, and applies the highest position code "5" to the register 5. Thereafter, the code "5" held by the register 5 is applied to the multiplier 6 and multiplied by the reduction rate to calculate the reduced position code "2" (or "3"). The bit data table 7 contains the position code "2" output from the multiplier 6, similar to the process described above.
The data "00000100" of address 2 corresponding to is output, and the OR gate 8 which inputs this data is logically summed with the data "00001000" held by the register 9. As a result, the position data "00001100" is held in the register 9.

(Third and subsequent operation cycles) Processing is performed in the same manner from now on, but since the information at bit positions 3 and 2 of the original pattern data is "0", if the information at bit positions 4 to 7 is masked, the priority encoder The information output from bit position 4 jumps from ``4'' to ``1'', and the operating cycles associated with these bit positions 3 and 2 are omitted.

By performing such a processing operation until the priority encoder 4 detects "no black pixel", the original pattern data "01110011" shown in FIG. 3 1 is reduced to 1/2 as shown in FIG. 3 2. It is possible to obtain the position data "00001101" for the case.

FIG. 4 1 is a diagram showing an 8×8 dot image pattern, and FIG. 4 2 is an image pattern after reduction when the image pattern shown in FIG. 4 1 is reduced to 1/2 only in the X direction. FIG.

In this embodiment, 1 byte, that is, 1 in the figure.
By performing the above processing for each line of ~8,
An image pattern obtained when the image is reduced by 1/2 in the X direction is obtained.

Generally, in two-dimensional patterns, the same one-byte pattern is often repeated multiple times. In the pattern shown in FIG. 4, lines 1 to 5 and lines 6 to 8 are each composed of the same pattern. Therefore, if the pattern data is set to have one byte of pattern data and information on its repeat count as shown in Figure 5, it is possible to use the same pattern data without having to obtain the reduced data for each line. Image processing can be performed by repeating.

In particular, when pattern data is composed of 1 byte of pattern data and data about the number of times it is repeated, an image is created by repeating 1 byte of pattern data three times, as shown in Figure 6. In the case of a pattern, the pattern data after reducing one byte of pattern data in the If you reduce it to 2 times, Y
A reduction in the direction can also be performed.

Note that although the present invention relates to reduction, the same can be applied to enlargement processing. Further, although the above embodiment performs reduction processing in units of 1 byte, the present invention is not limited to processing in 1 byte.

[Effects of the Invention] According to the present invention, since reduction processing is performed only on black pixels of the original pattern, processing time is significantly reduced compared to conventional reduction processing performed on all pixels including white pixels. can be shortened.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an image processing system according to an embodiment of the present invention. FIGS. 2 and 2 are diagrams showing the contents of the mask data table and bit data table shown in FIG. 1, respectively. Figures 1 and 2
are diagrams showing the original pattern data of 1 byte and 8 bits and the data when it is reduced to 1/2, respectively.
Figures 4 1 and 2 are diagrams showing an 8 x 8 dot pattern and a pattern reduced to 1/2 in the X direction, respectively. Figure 5 is a diagram showing pattern data consisting of 1 byte of pattern data and the number of repeats. FIG. 6 is a diagram showing the original pattern reduced to 1/2 in the X-Y direction. 1, 5, 9...Register, 2...AND gate,
3...Mask data table, 4...Priority encoder, 6...Multiplier, 7...
Bit data table, 8...OR gate.

Claims (1)

[Claims] 1. In an image processing method that changes the size of an image by performing a predetermined operation on the position data of a black pixel of interest, Based on the logical product of the mask data table storing the mask data and the mask data and original pattern data successively extracted from the mask data table, bits "1" included in the unprocessed data that have passed through the mask are determined. Bit “1” at the top
and a priority encoder that detects the position of the target black pixel and detects that there is no black pixel if the bit "1" does not exist, and the output of the priority encoder is used as the position of the black pixel of interest to be subjected to the calculation. An image processing method characterized in that the data is read address data for the mask data table.