At the time of setting a correction value for a certain density (subject density), a higher side density that is higher than the certain density and a lower side density that is lower than the certain density to be referenced according to the measured value of a region printed at the certain density are arbitrarily specified, and a correction value for the certain density is set by using at least one of a measured value of the density of a region printed at the arbitrarily specified higher side density and a measured value of the density of a region printed at the arbitrarily specified lower side density.