An image forming apparatus acquires a drawing object included in a page in which drawing is to be performed, updates a threshold value, which is used when one of mask drawing and edge drawing is selected to draw the drawing object according to a relationship between the acquired drawing object and another drawing object included in the page, selects, as a drawing method, one of the mask drawing and the edge drawing to draw the drawing object based on the updated threshold value and the acquired drawing object, and draws the acquired drawing object by the selected drawing method.