FIG. 4 is a flowchart illustrating a procedure of the spectral reflectances prediction process in the present embodiment. Note that, until this spectral reflectances prediction process is executed, it is necessary to obtain the spectral reflectances of the maximum gradation value, the spectral reflectances of the minimum gradation value, and the spectral reflectances of at least one intermediate gradation value regarding each of the appropriate number of ink colors (hereinafter, referred to as “sample colors”). However, herein, it is assumed that, regarding each of the plurality of sample colors, spectral reflectances of all gradation values in increments of 0.1 from the minimum gradation value (gradation value of 0) to the maximum gradation value (gradation value of 1) are obtained. In order to achieve this, for example, it is sufficient if the printing of such a CHF chart as illustrated in FIG. 1 (which may be replaced by a simple CHF chart) and the colorimetry thereof are already performed for each of the sample colors. As such sample colors, for example, 32 spot colors are used. Note that the process colors may be included in the sample colors. A flow illustrated in FIG. 4 will be described below.
