A method for extracting depth information, which may include extracting depth information relating to an object by using an actual nonlinear waveform instead of a mathematically ideal waveform and simultaneously may include effectively removing errors due to random noises that may be caused in a light source, an light modulator, an imaging device, or the like, is provided. The method may include performing simple multiplex and addition on captured images and performing a search of a look-up table. Thus, correct distance information may be extracted without being affected by a type of waveform being used, and an amount of memory which is used and calculated for removing random noise may be reduced.