A marker detection block 20 scans a taken image of a plurality of markers of a fixture worn on the head of a user so as to detect a two-dimensional coordinate on the taken image of the plurality of markers. A viewpoint position correction block 30 corrects a viewpoint position of the user without use of a coordinate in a Z direction of the markers but by use of the detected two-dimensional coordinate of the plurality of markers. A stereoscopic image generation block 40 generates a parallax image obtained when a three-dimensional object is viewed from the corrected viewpoint position.