To perform calibration appropriately even when enormous volume of identical information is to be printed by a printer for printing operation according to a print job being fed from a host unit.

When 9 sheets of single page data are to be outputted, a host unit performs job division (print jobs 1-5) based on predetermined calibration execution timing information (200 sheets). Newest calibration information is obtained from the printer side for every divided job and the density correction value on a γ correction table is updated based on the calibration information. The divided job is printed using the γ correction table subjected to calibration.