A display device includes a display panel including a plurality of pixels, the display panel having an active region in which an image is displayed and an inactive region adjacent to the active region, an image processor setting image data of the inactive region to dummy data, and performing a rendering operation for a boundary pixel of the plurality of pixels based on the dummy data to generate output image data, the boundary pixel located in the active region and adjacent to the inactive region, and a panel driver providing a driving signal to the display panel to display the image corresponding to the output image data.