A printing system is capable of displaying a preview of an image with a low resolution without causing degradation in performance and affinity for an operating system. When previewing is performed, preview printer information corresponding to the low resolution is set as printer information in a printer graphics driver by a print processor. The printer graphics driver produces a preview file by converting (rasterizing) an EMF spool file into low-resolution data. The resultant preview file is displayed as a print image on a display by a previewer.