To efficiently rasterize print data when making printing based on multi-valued image data.

A rasterizing section 33 color separates intermediate type print data and generates rasterized data for each of YMCK. A rasterized data transferring section 34 transfers image data (M, C, and K) other than that of the generated color in its charge to other RIP units 12M to 12K, and the image data (Y) in its charge to a rasterized data receiving section 35 of its own unit. The rasterized data receiving section 35 receives the rasterized data of the color (Y) in its charge, generated in its own unit, and rasterized data of the color (Y) in its charge, which are transferred from rasterized data transferring sections of the other units. A rasterized data reconciling section 36 reconciles the image data of the color in its charge, generated in its own unit, with the image data in its charge, generated in the other units.