1. A method for counting objects using an image sensor and a depth sensor, the method comprising: acquiring an image by the image sensor, and acquiring a depth map from the depth sensor, the depth map indicating depth information on the subject in the image; acquiring edge information of objects of interest in the image; generating a corrected depth map by applying the edge information to the depth map; identifying depth patterns of the objects of interest from the corrected depth map; and counting the identified objects of interest.