1. An object detection apparatus, comprising: a first direction contour component extraction unit configured to extract, from an input image, a contour component in a first direction of the image; a second direction continuity detection unit configured to detect, in a second direction perpendicular to the first direction, a continuity of the contour component extracted by the first direction contour component extraction unit; and an object area detection unit configured to detect a contour of an object in the image based on the continuity of the contour component in the second direction detected by the second direction continuity detection unit.