Color prediction method and computer readable recording medium having recorded therein color prediction program

A color prediction method for predicting a color of each patch when a color chart including a plurality of patches corresponding to ink densities of a plurality of levels is assumed to be created by applying an ink of a prediction target color to a prediction target medium with ink densities of the plurality of levels,

• the plurality of patches including a solid patch on which an ink is applied at a maximum ink density, a medium color patch on which an ink is not applied, and a plurality of halftone patches on which inks are applied at ink densities between the solid patch and the medium color patch,
• the color prediction method comprising:
• a first relational expression calculation step of obtaining a first relational expression for each of a plurality of similar candidate colors, the first relational expression representing a relationship between spectral characteristics of the solid patch in the reference medium and spectral characteristics of the solid patch in the prediction target medium, the plurality of similar candidate colors being a plurality of colors for which the spectral characteristics of the solid patch in a reference medium and the spectral characteristics of the solid patch in the prediction target medium are obtained, the reference media being a medium in which spectral characteristics of the solid patch for the prediction target color are obtained;
• a first similar color selection step of selecting a color close to the prediction target color from the plurality of similar candidate colors as a first similar color;
• a solid prediction step of obtaining predicted values of spectral characteristics of the solid patch in the prediction target medium for the prediction target color by applying the spectral characteristics of the solid patch in the reference medium for the prediction target color to the first relational expression for the first similar color;
• and
• a halftone prediction step of, based on the predicted values obtained in the solid prediction step, obtaining predicted values of spectral characteristics of the plurality of halftone patches in the prediction target medium for the prediction target color.

A non-transitory computer readable recording medium recording a color prediction program that predicts a color of each patch when a color chart including a plurality of patches corresponding to ink densities of a plurality of levels is assumed to be created by applying an ink of a prediction target color to a prediction target medium with ink densities of the plurality of levels,

• the plurality of patches including a solid patch on which an ink is applied at a maximum ink density, a medium color patch on which an ink is not applied, and a plurality of halftone patches on which inks are applied at ink densities between the solid patch and the medium color patch,
• the color prediction program causes a computer to execute:
• a first similar color selection step of selecting a color close to the prediction target color from among a plurality of similar candidate colors as a first similar color, the plurality of similar candidate colors being a plurality of colors for which spectral characteristics of the solid patch in a reference medium and spectral characteristics of the solid patch in the prediction target medium are obtained, the reference medium being a medium in which spectral characteristics of the solid patch for the prediction target color are obtained;
• a first relational expression calculation step of obtaining a first relational expression for the first similar color, the first relational expression representing a relationship between the spectral characteristics of the solid patch in the reference medium and the spectral characteristics of the solid patch in the prediction target medium;
• a solid prediction step of obtaining predicted values of spectral characteristics of the solid patch in the prediction target medium for the prediction target color by applying the spectral characteristics of the solid patch in the reference medium for the prediction target color to the first relational expression;
• and
• a halftone prediction step of, based on the predicted values obtained in the solid prediction step, obtaining predicted values of spectral characteristics of the plurality of halftone patches in the prediction target medium for the prediction target color.