To provide a printing system wherein a user can select whether speed is prioritized at the sacrifice of the quality of preview display or whether the quality of preview is prioritized at the sacrifice of the speed, a user desiring a high-speed preview is provided with a high-speed preview, and a user wanting a high-quality preview is provided with a high-quality preview.

In this printing system, when displayed resolution for previews is changed by an instruction of a user, conversion into image data for preview takes place corresponding to the changed resolution for preview, the data being held in a preview file 109. A preview image obtained from the held image data for preview is displayed on a display 112.