For example, display image input units 131R, 131L detect additional information indicating left and right directionality from images for display. Then, in a stereoscopic display device having a display device for the right eye and a display device for the left eye, a switcher 132 capable of switching the connections between input and output input-output is controlled so that the correct image fordisplay is provided to the correct display device. With such a configuration, even when the cables are connected incorrectly, it is still possible to input stereoscopic images to the stereoscopic display device so that such images are always displayed in the correct left-right relation.