Patent ID: 8428347

Claim:
A color processing apparatus comprising: a first calculation unit that calculates a second color signal from a first color signal by using successive approximation, the first color signal being given by repeatedly calculating a first successive solution using an inverse matrix of a sensitivity matrix of an input/output characteristic function of an output device; a determination unit that determines whether or not the first successive solution calculated by the first calculation unit is divergent; and a second calculation unit that calculates a second successive solution using a method different from a method used by the first calculation unit when the determination unit determines that the first successive solution is divergent, the second calculation unit including (i) a linear equation generation unit that generates a plurality of linear equations with changing unknown numbers to be fixed, each of the plurality of linear equations being a linear equation in which an unknown number in a linear equation using the sensitivity matrix is set to a fixed value, the linear equation generation unit fixing the unknown number so that a color signal representing a boundary of a color gamut reproduced by the output device is obtained, (ii) a minimization operation unit that determines a solution that minimizes each of the linear equations, (iii) a prediction unit that predicts a color signal corresponding to each solution using the input/output characteristic function on the basis of the solutions that minimize the linear equations, and (iv) a selection unit that selects a linear equation that minimizes a difference between the predicted color signal and the first color signal, and that uses the solution obtained by the selected linear equation as the second successive solution.