Creating a color conversion table by performing color conversion using a 3D and 1D table after limiting total color material amount

A color conversion table creating method which creates a color conversion table for color conversion from input image data including cyan, magenta, yellow, and black to output image data including cyan, magenta, yellow, and black, the method comprising:

• performing color material amount limiting which limits a total amount of color components for each combination of an input value in the color conversion table;
• performing color conversion on a cyan component, a magenta component, and a yellow component after the color material amount limiting by the color material amount limiting processing step, using a three dimensional table for color conversion from a cyan component, a magenta component, and a yellow component of the input image data to a cyan component, a magenta component, and a yellow component of the output image data;
• performing color conversion on a black component after the color material amount limiting by the color material amount limiting processing step using a one dimensional table for color conversion from a black component of the input image data to a black component of the output image data;
• combining the cyan component, the magenta component, and the yellow component after the color conversion using the three dimensional table with the black component after the color conversion using the one dimensional table;
• performing inverse conversion of the color material amount limiting on the cyan component, the magenta component, the yellow component, and the black component combined by the combining step;
• and
• setting the cyan component, the magenta component, the yellow component, and the black component after the inverse conversion of the color material amount limiting by the color material amount limiting inverse conversion processing step as a combination of an output value in the color conversion table.

A non-transitory computer-readable storage medium having a program stored thereon for controlling a computer which creates a color conversion table for color conversion from input image data including cyan, magenta, yellow, and black to output image data including cyan, magenta, yellow, and black, the program to control the computer to function as:

• a color material amount limiting processing section which performs color material amount limiting which limits a total amount of color components for each combination of an input value in the color conversion table;
• a first color conversion processing section which performs color conversion on a cyan component, a magenta component, and a yellow component after the color material amount limiting by the color material amount limiting processing section, using a three dimensional table for color conversion from a cyan component, a magenta component, and a yellow component of the input image data to a cyan component, a magenta component, and a yellow component of the output image data;
• a second color conversion processing section which performs color conversion on a black component after the color material amount limiting by the color material amount limiting processing section using a one dimensional table for color conversion from a black component of the input image data to a black component of the output image data;
• a combining section which combines the cyan component, the magenta component, and the yellow component after the color conversion using the three dimensional table with the black component after the color conversion using the one dimensional table;
• a color material limiting inverse conversion processing section which performs inverse conversion of the color material amount limiting on the cyan component, the magenta component, the yellow component, and the black component combined by the combining section;
• and
• an output value determining section which sets the cyan component, the magenta component, the yellow component, and the black component after the inverse conversion of the color material amount limiting by the color material amount limiting inverse conversion processing section as a combination of an output value in the color conversion table.