Patent ID: 7477415

Claim:
An image processing method, comprising: receiving an input value combination that includes a plurality of input values for a plurality of primary colors and that is indicative of image information; converting the input value combination into a first output value combination, the first output value combination including a plurality of output values for a plurality of printing-components including black, the converting the input value combination into the first output value combination including: converting, by using a first conversion table, the received input value combination into an intermediate value combination that includes a plurality of intermediate values for a plurality of intermediate components, the first conversion table defining a plurality of grid points that are arranged in a predetermined color space, in which the input value combination is located, the plurality of grid points being in one-to-one correspondence with a plurality of different primary-color-value combinations for the plurality of primary colors, the grid points including a darkest grid point that is indicative of a darkest point among all the grid points, the grid points further including at least (N+1) number of grid points that are successively arranged in a predetermined direction from the darkest grid point, N being an integer greater than or equal to one (1), the grid points including an N-th grid point and an (N+1)-th grid point that are located N-th and (N+1)-th among the at least (N+1) number of grid points, respectively, the first conversion table listing up an intermediate-component-value combination at each grid point, the intermediate-component-value combination, at at least one grid point that is located between the darkest grid point and the (N+1)-th grid point in the predetermined direction and that includes the N-th grid point, being determined through interpolation based on the intermediate-component-value combination at the darkest grid point and on the intermediate-component-value combination at the (N+1)-th grid point; setting the output value for black based on the intermediate value combination; and setting the output values for the other printing-components based on the output value for black; and printing the first output value combination.