1. An apparatus for restoring a cubical object, comprising: a vanishing point computing part configured to compute vanishing points corresponding to an image; an image depth computing part configured to compute an image depth of a cubical object in the image; a central rectangle computing part configured to compute a central rectangle based on a representative rectangle of the image and the vanishing points; a restored rectangle computing part configured to compute a restored rectangle corresponding to the central rectangle and a projection center point using a coupled line camera (CLC) method; a cube depth computing part configured to computed a restored cubical object depth based on the central rectangle, the restored rectangle and the projection center point; and a cube restoring part configured to restore a cubical object having the restored rectangle as one surface thereof and having a depth of the restored cubical object depth.