1. A display device, comprising: a display unit having at least a first display area and a second display area; a storage unit that stores display area information for specifying respective shapes and sizes of the first display area and the second display area of the display unit; and a control unit connected to the display unit and the storage unit, said control unit configured to: extract a first region and a second region respectively corresponding to the first display area and the second display area from an image of the object to be displayed by the display unit; compare the first region and the second region extracted from the image of the object to be displayed to the first display area and the second display area specified on the basis of the display area information, the control unit calculating, on the basis of this comparison, a first adjustment factor for adjusting a size of the first region and a second adjustment factor for adjusting a size of the second region; adjust the respective sizes of the first region and the second region of the image of the object to be displayed in accordance with the calculated first adjustment factor and the second adjustment factor; and cause the display unit to display the adjusted image of the object to be displayed.