PURPOSE: A display system is provided to produce a subtitle capable of reducing fatigue of a user. CONSTITUTION: A display device extracts a main object from a 3D image(S610). The display device calculates depth information of the extracted main object(S620). The display device creates subtitle information using the depth information of the main object prediction area(S630). The display device synthesizes the subtitle with the 3D image by the generated subtitle information(S640). The display device displays the 3D image(S650).
