In a color correction apparatus for correcting the color image data, a color adjustment amount for canceling a difference between the optimum value predetermined for the fixed-color pixel and the result of the summing-up is obtained. A portion of the partial response signal is dropped and the resulting truncated signal is used to modulate a carrier signal. A selection of a category that the potential expert wants to be admitted is also received. Further, capacitance between wirings is reduced by providing a longer distance between adjacent wirings by the manufacturing method which can selectively form a pattern. The second set of diffraction signals was measured using a second optical metrology tool from the fleet of optical metrology tools.