An display apparatus includes: a display panel; and a controller configured to: process source data, received from an external device, to control the display panel to display an image on a screen of the display panel, the source data including the image, identify a first aspect ratio of the screen of the display panel and a second aspect ratio of the image, based on the first aspect ratio being different from the second aspect ratio, determine, within the screen of the display panel, an image area where the image is displayed and a black area where the image is not displayed, and move the image area periodically or substantially periodically along a direction in which the black area is located within the screen of the display panel.