Moreover, according to the Deshpande et al. method, it is premised that calorimetric values corresponding to dot percentages in increments of 10% are obtained; however, in recent years, a variety of operations have been made for targets of colorimetry. For example, in a case in which only three colorimetric values corresponding to three patches with dot percentages of 100%, 50%, and 0% are obtained for a certain color, spectral reflectances of any patch of another color is sometimes predicted on the basis of information on the three colorimetric values for the certain color. Therefore, preferably, spectral reflectances at any gradation value can be predicted regarding the prediction target color.

In view of such circumstances as described above, it is an object of the present invention to enable high accuracy, prediction or spectral characteristics of a prediction target gradation value for a prediction target color using information on known spectral characteristics in a case in which there is an intermediate gradation value for which spectral characteristics such as spectral reflectances are known regarding the prediction target color.

One aspect of the present invention is directed to a spectral characteristics prediction method for predicting spectral characteristics obtained by applying ink on a base material, the spectral characteristics prediction method including:

a prediction target color setting step of setting, to a prediction target color, an ink color for which spectral characteristics of a maximum gradation value, spectral characteristics of a minimum gradation value, and spectral characteristics of at least one intermediate gradation value are obtained;