1. An image processing apparatus that processes a color image composed of color signals of a plurality of colors, comprising: tone correcting means that performs different tone corrections on pixels at different positions in the color image; false contour detecting means that calculates the degree of false contour occurrence for the color image based on the difference in signal saturation level between the color signals; and controlling means that controls characteristics of the tone corrections based on the result of the calculation by the false contour detecting means.