Patent ID: 7706628

Claim:
An image processing apparatus which receives a luminance signal indicating luminance or an amount of brightness and an input signal indicating a plurality of color differences, the apparatus comprising: a signal generator generating a signal Z depending on the luminance signal and the input signal indicating the plurality of color differences, in which the luminance signal and the input signal are of the same image signal; a gain generator generating a transformation gain k(Z) by using the signal Z; and a tone transformation unit which multiplies the luminance signal or a linear transformation signal of the luminance signal by the transformation gain k(Z) to calculate a luminance signal after tone transformation, wherein the signal generator calculates the signal Z by an equation Z=V+w1·C1+w2·C2, changing values of w1 and w2 depending on values of C1 and C2, where C1 and C2 are input signals indicating the plurality of color differences and V is the luminance signal indicating the luminance or the amount of brightness.