1. An image forming apparatus comprising: an acquisition unit configured to acquire a drawing object included in a page in which drawing is to be performed; an updating unit configured to update a threshold value, which is used when one of a mask drawing and an edge drawing is selected to draw the drawing object depending on a relationship between the drawing object acquired by the acquisition unit and another drawing object included in the page; a selection unit configured to select, as a drawing method, one of the mask drawing and the edge drawing to draw the drawing object based on the threshold value updated by the updating unit and the drawing object acquired by the acquisition unit; and a drawing unit configured to draw the drawing object acquired by the acquisition unit by the drawing method selected by the selection unit.