A display device includes: a display panel displaying a still image and a motion picture; a display panel which displays a still image and a motion picture; a signal controller which controls signals to drive the display panel; and a graphics processing unit which transmits input image data to the signal controller, where the signal controller includes a frame memory which stores compressed image data generated by compressing the input image data, and a mixer which mixes compression recovered image data generated by recovering the compressed image data and the input image data to generate mixed image data.