Patent ID: 7944594

Claim:
An image processing device comprising: a setting unit setting a color material curbing mode that curbs an amount of color material in an image forming device that carries out color reproduction using a plurality of color materials; a color information inputting unit that inputs input color information; a converting unit that, when the color material curbing mode is set by the setting unit, converts the input color information inputted by the color information inputting unit into output color information in a color material curbing region on the basis of correspondence relationships that are set in advance such that a region that is color-reproducible by the image forming device is kept within the color material curbing region that is narrowed such that an amount of the color material is curbed, the output color information is expressed in a third color space that expresses a combination of color elements corresponding respectively to the plurality of color materials; a total amount limit value setting unit designating a total amount limit value that limits a total sum of respective color elements in the third color space, wherein the narrowed color material curbing region is a color-reproducible region satisfying a condition for limiting in accordance with the total amount limit value designated by the total amount limit value setting unit, and wherein the total amount limit value setting unit designates a greater total amount limit value for a natural image than for a graphic image; a limit value setting unit designating an arbitrary maximum gradation limit value or a maximum gradation value condition relating to a maximum gradation limit value; and a boundary generating unit generating a boundary point group structuring a color gamut boundary in the third color space: a total amount limit boundary point generating unit that, on the basis of the total amount limit value designated at the total amount limit value setting unit, changes the boundary point group generated at the boundary generating unit, wherein: the narrowed color material curbing region is a color-reproducible region satisfying a condition for limiting in accordance with the maximum gradation limit value designated by the limit value setting unit, or in accordance with the maximum gradation limit value based on the maximum gradation value condition, wherein the maximum gradation limit value is set greater for a graphic image than for a natural image, the changing of the boundary point group sets the sum of all toner values to be less than or equal to the toner total amount limit value by fixing a toner value of one color and maintaining a constant ratio of toner values of the remaining colors to each other.