1. An image processing method for processing a display image by using an image forming apparatus that comprises a display section, and a position detecting section detecting a position of contact with a display screen of the display section, and that forms an image on a recording medium based on the display image displayed on the display section, the method comprising the steps of: a step of displaying an image comprising an object image indicative of an object for an image formation, and a medium image indicative of the recording medium; a step of shifting to an edit mode, when the display screen is contacted at two points, to modify magnification of the object image with respect to the medium image, and without modifying the medium image, on the basis of contact positions detected by the position detecting section and to display an area occupied by the object image modified in the medium image; a step of selecting one recording medium of a plurality of selectable recording mediums on the basis of the contact positions detected by the position detecting section; and a step of finishing the edit mode according to a predetermined operation.