To perform appropriate calibration of a printer at all times regardless of the type of an instrument for measuring the density of a patch.

The type of a measuring instrument selected by a user is determines (Step 1, 2), and if the selected instrument is a scanner, a patch for scanner is printed (Step 3) and measured (Step 4) and then calibration data is calculated based on the measurements (Step 5). If a decision is made that the selected instrument is a densitometer, a patch for densitometer is printed (Step 6). Similarly, a patch is measured and calibration data is calculated based on the measurements (Step 7, 8). When the patch being printed is differentiated depending on the measuring instrument, appropriate calibration can be carried out at all times regardless of the type of the measuring instrument.