A display device includes a display panel including a plurality of pixels, and a panel driver including N registers, where N is an integer greater than 1. The panel driver is configured to divide the display panel into N first detection regions, to perform a first still image detection operation on each of the N first detection regions by using the N registers, to divide the display panel into N second detection regions different from the N first detection regions by using a result of the first still image detection operation, and to perform a second still image detection operation on each of the N second detection regions by using the N registers.