JP2002166603A - Print processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a print processing method in which shaggy outline part of a character can be made inconspicuous in a printing employing four color members of CMYK. SOLUTION: For a character to be printed, difference of density is determined between a specific pixel constituting that character and a plurality of pixels on the periphery thereof. If a specified number or more of peripheral pixels have difference of density not lower than a specified level, a decision is made that the specific pixel is a pixel at the outline part of a character and that pixel is subjected to coloring with a black coloring member produced by mixing coloring members of cyan, magenta and yellow.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a printing method for printing using four colored members of CMYK.

[0002]

2. Description of the Related Art In recent years, as an output device of a computer,
Color printers are widely used.

Here, as a type of color printer, an ink jet printer, a thermal transfer printer, a laser printer and the like are known.

[0004] Full-color printing can be performed with three colored members of cyan (C), magenta (M) and yellow (Y).
In addition to the color, black (K) is provided. This is because characters are often printed in black in the case of printing documents such as characters and lines, and in particular, there is an effect of increasing the speed of printing, reducing the amount of coloring members, and providing a sharp character.

Since the printer driver can determine whether the object to be printed is a character, if the object to be printed is a character, a black (K) colored member is used.

[0006]

However, when printing black characters at a low resolution, since printing by a printer is performed in units of dots of a size corresponding to the printing resolution, shaggy (staircase) is applied to the outline of the characters. And the print quality was degraded.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a printing method capable of making shaggy in a character outline portion in printing using four colored members of CMYK inconspicuous.

[0008]

In order to solve this problem, a print processing method according to the present invention calculates a density difference between a specific pixel constituting the character and a plurality of pixels surrounding the specific pixel. If there is a predetermined number or more of surrounding pixels whose density difference with the specific pixel is equal to or more than a predetermined value, the specific pixel is determined to be a pixel of the outline portion of the character, and the specific pixel determined as the outline portion is determined. The coloring process is performed by a black coloring member obtained by mixing cyan, magenta and yellow coloring members.

Thus, the pixels in the outline portion of the character are colored by a black coloring member obtained by mixing cyan, magenta and yellow coloring members.
It becomes possible to make the jaggies in the character outline less noticeable.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION
For a character to be printed, a density difference between a specific pixel constituting the character and a plurality of surrounding pixels is obtained, and a predetermined number or more of surrounding pixels whose density difference with the specific pixel is a predetermined value or more are present. Determines the specific pixel as the pixel of the outline part of the character, and cyan,
This is a printing method in which a coloring process is performed by using a black coloring member in which magenta and yellow coloring members are mixed, and black coloring in which cyan, magenta, and yellow coloring members are mixed in pixels at the outline portion of a character. Since the coloring process is performed by the member, it is possible to make the jaggies in the character outline part inconspicuous.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In these drawings, the same members are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is a block diagram showing a printing apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram showing a control circuit of a color printer in the printing apparatus of FIG. 1, and FIG. 4 is a block diagram showing members required for processing from input to output, FIG. 4 is a flowchart showing character outline part discrimination processing in the printing apparatus of FIG. 1, and FIG. It is explanatory drawing which shows the detection operation of a contour part.

In FIG. 1, a printing apparatus according to the present embodiment includes an input device such as a scanner 12 and a keyboard 13 for inputting print data, a computer 1 for performing various processes on the input print data, and a computer 1. Printer 14 that outputs print data processed by
It is composed of

Here, the computer 1 stores in advance an input interface unit 2 for receiving print data from an input device, a CPU 3 for controlling the operation of the computer 1, and programs and data necessary for executing various arithmetic processes in the CPU 3. A stored ROM (read only memory) 4, a RAM (random access memory) 5 for temporarily reading and writing various programs and data necessary for executing various arithmetic processing by the CPU 3, and a color display of print data. CRT 6, a floppy (registered trademark) disk drive 7 for reading from and writing to a floppy disk as external storage means, a hard disk 8 as internal storage means for the computer 1, and an output for outputting print data processed by the computer 1 to the color printer 14. interface Equipped with a 10, these bus 1
1 interconnected.

A printing operation is performed by loading and executing a predetermined program on the computer 1 by such a printing apparatus.

Next, as shown in FIG. 2, the operation of the color printer 14 is controlled by a control circuit 20. The control circuit 20 controls the operation panel 27, the print head 32,
The F motor 33 and the CR motor 34 are controlled. The print head includes a black print head 28 that performs printing with a black (K) coloring member, a cyan print head 29 that performs printing with a cyan (C) coloring member, and a magenta that performs printing with a magenta (M) coloring member. Print head 30, yellow print head 31 for printing with a yellow (Y) colored member
Consists of

The control circuit 20 includes a ROM 22 for storing programs and the like, a RAM 23 for temporarily storing programs and the like, an I / F dedicated circuit 24 for dedicated interface with an external device, and an I / F dedicated circuit. Head drive circuit 2 connected to circuit 24 for driving print head 32
5, a motor drive circuit 26 for driving the LF motor 33 and the CR motor 34, a connector 35 of a parallel interface having a built-in I / F circuit 24, and a CPU 21 for controlling the operation of these components.

The color printer 14 is connected to the computer 1 via a connector 35, and receives a print signal output from the computer 1.

Next, FIG. 3 shows members required for processing from input of data to output to the color printer 14.

In FIG. 3, data input from a scanner 12, a keyboard 13, etc.
Video driver 40 for displaying on RT6, computer 1
An application 41 that operates internally, a printer driver 42 that controls the operation of the color printer 14, a rasterizer 43 that converts data from the application 41 into color information in dot units, and a printer 14 that converts the data converted into color information in dot units And an image processing module 44 for converting the data into data that can be output to a computer.

Next, a description will be given, with reference to FIG. 4 and FIG.

In FIG. 4, the printer driver 42 determines whether the print target is a character (step 1). When the print target is a character, eight pixels around a specific one pixel (specific pixel) A (FIG. 5) and the pixel A
The density difference of black (K) is determined (step 2).

Then, it is determined whether there are three or more pixels having a density difference of 128 or more between the two (step 3).
If there is, it is regarded as a contour part (step 4). Also,
If not, it is determined that the part is not a contour part (step 6), and a printing process using a normal black (K) coloring member is performed (step 7).

In the present invention, the numerical value of the density difference between the specific pixel and its surrounding pixels is not limited to 128 in the present embodiment, but can be set freely. Further, the number of surrounding pixels with respect to a specific pixel to be determined as an outline portion is not limited to three or more pixels in the present embodiment, but can be set freely. Further, in the present embodiment, the density difference is detected for a specific pixel and all eight pixels surrounding the specific pixel, but a part of the density difference may be detected.

If an outline is detected in step 4, instead of a black (K) coloring member, a black (hereinafter, referred to as "composite black") coloring member in which three CMY colors are mixed is used. Step 5).

Here, composite black means CMY
Is a technology that expresses black using the three colored members
For example, when expressing black of an arbitrary density, black (K)
It can be realized by mixing the coloring members of the three colors CMY with the same density as the coloring members.

Since such composite black has a lighter black color than the black (K) colored member, if composite black is used in the outline of the character, the jaggies in the outline of the character become noticeable, and printing is performed by the anti-aliasing effect. Quality can be improved.

The present invention is not limited to an ink jet type color printer, but may be applied to various other color printers such as a thermal transfer type color printer and a color laser printer. is there.

[0029]

As described above, according to the present invention, the pixels in the outline portion of the character are colored by the black coloring member obtained by mixing the cyan, magenta and yellow coloring members. An advantageous effect is obtained in that jaggies in the character outline can be made inconspicuous.

As a result, there is obtained an effective effect that the printing quality can be improved by the anti-aliasing effect.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a printing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a control circuit of a color printer in the printing apparatus of FIG.

FIG. 3 is a block diagram showing members required for processing from input of data to output in the printing apparatus of FIG. 1;

FIG. 4 is a flowchart showing a character outline portion discriminating process in the printing apparatus of FIG. 1;

FIG. 5 is an explanatory diagram showing a character outline detecting operation in the character outline determining process of FIG. 4;

[Explanation of symbols]

 1 Computer 2 Input Interface 3 CPU 4 ROM 5 RAM 6 CRT 7 Floppy Disk Drive 8 Hard Disk 9 Serial I / O Interface 10 Output Interface 11 Bus 12 Scanner 13 Keyboard 14 Color Printer 20 Control Circuit 21 CPU 22 ROM 23 RAM 24 I / F dedicated circuit 25 Head drive circuit 26 Motor drive circuit 27 Operation panel 28 Black print head 29 Cyan print head 30 Magenta print head 31 Yellow print head 32 Print head 33 LF motor 34 CR motor 35 Connector 40 Video driver 41 Application 42 Printer driver 43 Rasterizer 44 Image processing module

Continued on the front page F term (reference) 2C262 AA02 AA03 AA04 AA24 AB13 BA12 DA02 DA03 DA09 EA04 5C077 LL05 MP07 MP08 PP33 PP38 PP47 PP61 PQ08 PQ20 TT02 5C079 HB03 KA15 LA01 LA21 NA02 PA03

Claims (1)

[Claims] 1. A method according to claim 1, wherein a density difference between a specific pixel constituting the character and a plurality of pixels surrounding the specific pixel is determined for a character to be printed. When the specific pixel is present, the specific pixel is determined to be a pixel of the outline portion of the character, and the specific pixel determined as the outline portion is mixed with cyan, magenta, and yellow coloring members. A printing method comprising performing a coloring process with a coloring member.