A method for an image forming device, an electronic medium, and an image processing program, which enables external output of image data and font data for the image data with ease. The image forming device includes an input unit, a font data memory unit, a font data read-and-write control unit, a font control unit, and an output unit. The input unit inputs image data. The font data memory unit stores font data by associating it with a character code. The font data read-and-write control unit controls read-and-write operation on the font data of the font data memory unit. The font control unit acquires the font data to be used for the image data and controls conversion of the acquired font data according to an image forming mode. The output unit controls external output of the image data from the image control unit and the converted font data to be used to for the image data.