1. An apparatus for detecting an obstacle for an around view monitoring system, the apparatus comprising: a processor configured to: store a plurality of images captured through an imaging device; convert a view of the plurality of images; generate a plurality of view conversion images corresponding to the plurality of images; compare the plurality of view conversion images corresponding to the plurality of images captured at a different time interval; extract a plurality of overlapping areas between the plurality of view conversion images; calculate a degree of mismatch of the plurality of overlapping areas between the plurality of view conversion images; detect a mismatch area in each overlapping area; classify the mismatch area as an obstacle area; and display a position of the obstacle on a display of a vehicle.