To prevent an unprinted void part from being generated in a booklet after being cut due to the inclination of a fold with respect to a paper center line.

An MFP 2 outputting a printed paper for which paper folding processing and cutting processing are executed generates a print image I including a finished image I1 to be printed inside a cutting line L by the cutting processing, obtains the inclination angle θ with respect to a paper center line AB of a fold CD by the paper folding processing, determines the enlargement factor m of the finished image I1 based on the inclination angle θ, and enlarges the finished image I1 in the print image I with the enlargement factor m, to print the finished image I1 on a paper.