DISPLAY CONTROLLING DEVICE AND DISPLAY CONTROLLING METHOD

To achieve excellent ease in operations in relation to the display output of an in-vehicle display device. Comprises: image acquiring means for acquiring a captured image wherein the vicinity of a vehicle has been imaged; region setting means for setting a prescribed region between displaying means, installed within a cabin of the vehicle and a position wherein a vehicle occupant is within the cabin of the vehicle; function setting means for setting a display function associated with a prescribed region; viewpoint position detecting means for detecting a position relating to a viewpoint of the vehicle occupant; and image controlling means for controlling the displaying means so as to display the captured image, wherein: when the position relating to the viewpoint is detected as being in a prescribed region, the controlling means execute the display function on the captured image displayed by the displaying means.