US Patent 8355019 3D optical illusions from off-axis displays

A 3D viewing system captures offset images from off-axis camera perspectives inclined to a normal of base plane of a scene that includes one or more objects projecting from the base plane. The offset images, which take a planar form, are displayed from a display surface at an off-axis viewing perspective that is inclined to a normal of the display surface similar to the inclination of the off-axis camera perspective to the normal of the base plane. The offset images undergo a distortion to counteract a keystone distortion associated with the off-axis viewing perspective. The base plane of the scene is oriented parallel to the display surface, and the objects projecting from the base plane appear to project from the display surface.