1. An object detecting device comprising: a calculating unit configured to calculate gradient intensity and gradient orientation of luminance for a plurality of regions in an image, calculate a frequency distribution of the luminance gradient intensity as to said calculated luminance gradient orientation for each of said regions, and calculate an edge intensity distribution for each of said regions, based on the calculated frequency distribution; and a determining unit configured to identify an object included in said image by using an outline of the object that is obtained based on the calculated edge intensity distribution and by using an evaluation score.