When an image object that is referred to from a plurality of portions overlaps under an area to which blotting-out instructions are given, the effect of blotting out is prevented from affecting another portion against a user's intention. An information processing apparatus determines, upon receipt of instructions to apply blotting out to a specified area, whether an image object that is referred to from a plurality of reference destinations overlaps the specified area. When the image objects overlap under the specified area, it increases the number of image objects to at least two by duplicating the image object. It sets so that reference destination overlapping the specified area refers to the duplicated data of the image object for which blotting out processing is performed, and reference destination non-overlapping the specified area refers to the data of the image object for which blotting out processing is not performed.