Bleed widths are set for finishing pages. An imposition method that requires to execute binding processing of sheets is set. Bleed regions including the finishing pages are determined based on the set bleed widths for the finishing pages, and the size of the finishing page. The allocation of manuscript data is so determined as to align the center of the manuscript data to be allocated to that of a bleed region on the side to undergo the binding processing of the determined bleed regions, based on the setting contents.