Image processing apparatus that prevents an occurrence of contouring, non-transitory computer-readable recording medium storing an image processing program, and image processing method

摘要

An image processing apparatus includes a color conversion processing unit, a modulation difference creating unit, a color value modulating unit, and an output unit. The color conversion processing unit performs color conversion from an input color value of a target image to a corresponding output color value to obtain a tentative output color value. The modulation difference creating unit creates modulation differences. The modulation differences include combinations that are obtained by either setting or not setting a value equivalent to the minimum resolution of the tentative output color value for each color component of the tentative output color value. The color value modulating unit performs modulation on the tentative output color value by adding or subtracting a modulation difference selected at random to or from the tentative output color value. The output unit outputs the target image according to the color value obtained after modulation.

主权项

1. An image processing apparatus comprising:
a color conversion processing unit configured to perform color conversion from an input color value of a target image to a corresponding output color value to obtain a tentative output color value, wherein the tentative output color value includes a combination of color component values, and wherein the color component values correspond to a set of predetermined color components; a modulation difference creating unit configured to create a plurality of modulation differences, wherein each modulation difference includes a combination of color component values that correspond to the set of predetermined color components, and wherein each color component value of the modulation difference is obtained by either setting or not setting the color component value as a value equivalent to a minimum resolution of the tentative output color value; a color value modulating unit configured to perform modulation on the tentative output color value by, for each predetermined color component, adding to the color component value of the tentative output color value or subtracting from the color component value of the tentative output color value a corresponding color component value of a particular modulation difference, wherein the particular modulation difference is selected at random from the plurality of modulation differences; and an output unit configured to output the target image according to the modulated tentative output color value.