To provide an image forming device that supplies a high quality image where resolution of characters and gradation of photographs are made compatible.

A raster processing section 8 generates image data based on contents analyzed by an interpreter 14 to analyze input data and stores the data to an image data memory 9, and at the same time, attribute data of the input data are stored in an attribute discrimination memory 16. An image expansion section 10 expands the image data stored in the image data memory 9 and outputs from an engine interface 12 the expanded data with the attribute data stored in the attribute discrimination memory 16.