1. An image processing apparatus comprising: a face detection unit configured to detect a face area of a person from an image; a head detection area setting unit configured to set a head detection area based on the detected face area of the person; an edge detection unit configured to detect an edge from the set head detection area, and generate an edge image which is comprised of the detected edge; an edge deletion unit configured to delete an edge existing between the face and hair from the edge image, wherein the edge deletion unit further comprises a skin color area detection unit configured to detect a skin color area from the head detection area based on a color of the face area, and an expansion unit configured to expand the skin color area and delete an edge existing in the expanded skin color area; and an ellipse detection unit configured to detect a candidate ellipse corresponding to a head area from an edge image from which an edge is deleted by said edge deletion unit.