JP2004187146A5 - Color conversion method - Google Patents

Description

[0001]
Field of the Invention
The present invention relates to control of the color of the gray line.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to output gray line colors with an image output device with a preferable color tone.
The present invention also makes it possible to lighten the color of a gray line by controlling the locus of the chromaticity of the gray line based on the chromaticity point of the white printing color, the chromaticity point of the black printing color and the chromaticity point of the preferred gray. The purpose is to make it possible to reproduce well.

[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention relates to a method for converting the tint of an image processing apparatus that converts an input black and white signal into a color signal of an image output device, and relates to the input black and white signal. Converting the signal relating to the distance on the chromaticity point locus of the reproduced color of the image output device; converting the input black and white signal into the color signal of the image output device based on the signal relating to the converted distance; And the output step, the chromaticity point locus includes a predetermined chromaticity point.
Further, the present invention is a color conversion method for setting the gray scale gradation and color of a color printer, which is a chromaticity point of white printing color, a chromaticity point of black printing color and a preferable gray color Set the degree point, input the lightness information on the gray line, and based on the chromaticity point of white print color, the chromaticity point of black print color and the preferred gray chromaticity point, the chromaticity value according to the lightness information The locus of chromaticity of the gray line passes from the chromaticity point of the white print color through the chromaticity point of the desired gray to reach the chromaticity point of the black print color. It is characterized by

[0060]
【Effect of the invention】
As described above, according to the present invention, it is possible to output in the preferred tint the color of the gray line with the image output apparatus.
In addition, by controlling the locus of the chromaticity of the gray line based on the chromaticity point of the white printing color, the chromaticity point of the black printing color, and the chromaticity point of the preferable gray, the color of the gray line is favorably made according to the lightness. It can be reproduced.

Claims (6)

A color conversion method of an image processing apparatus, which converts an input black and white signal into a color signal of an image output apparatus,
Converting the input black and white signal into a signal related to the distance on the chromaticity point locus of the reproduction color of the image output device related to the black and white signal;
And converting the input black and white signal into a color signal of the image output device based on the converted signal relating to the distance, and outputting the converted signal.
The color point conversion method of an image processing apparatus, wherein the chromaticity point locus includes a predetermined chromaticity point. A color conversion method for setting the gradation and color of a gray line of a color printer,
Set the white print color chromaticity point, the black print color chromaticity point and the preferred gray color point,
Enter the lightness information on the gray line,
A color conversion method for setting a chromaticity value according to the lightness information based on a chromaticity point of white printing color, a chromaticity point of black printing color and a chromaticity point of preferable gray,
The locus of chromaticity of the gray line passes from the chromaticity point of the white print color through the chromaticity point of the desired gray to reach the chromaticity point of the black print color. In the middle lightness part, it has the preferred gray chromaticity point,
In the high brightness portion, the chromaticity changes in accordance with the change in lightness from the chromaticity point of the white print color to the chromaticity point of the preferable gray,
In the low lightness portion, the chromaticity changes in accordance with the change in lightness from the preferable gray chromaticity point to the black printing color chromaticity point;
3. The color conversion method according to claim 2, wherein a change rate of chromaticity in the high lightness part and the low lightness part is limited.   3. A method according to claim 2, further comprising the step of tone-converting the input lightness of the gray line within the range of the lightness of the white print color and the lightness of the black print color.   A program for causing a computer to execute the color conversion method according to any one of claims 1 to 4.   A computer readable recording medium storing the program according to claim 5.