1. A light source estimation device comprising: a light-source-estimation area setting section configured to detect a background in an image and to set a light-source-estimation area based on a result of the background detection, wherein the light-source-estimation area setting section detects a subject of interest in the image, and determines an area excluding an area corresponding to the subject of interest from the image to be the background; and a light source estimation section configured to estimate a type of a light source when the image is captured based on the light-source-estimation area, wherein if the subject of interest is equal to or greater than a predetermined size, the light-source-estimation area setting section is configured to set an entire area of the image as the light source-estimation area.