1. An apparatus for setting an exposure time, the apparatus comprising: a section setting module which sets one or more luminance sections based on a luminance distribution of an input image; an image division module which divides the input image into two or more regions; a region classification module which classifies the regions into the luminance sections; and an exposure-time setting module which sets an exposure time for each of the regions with reference to a target luminance value, the target luminance value being set based on the results of the classification performed by the region classification module.