Patent ID: 7450737

Claim:
A head detecting apparatus comprising: a foreground extracting section for extracting a foreground region, in which a person has been taken, from an input image; a first main axis computing section for computing a main axis of the foreground region, said first main axis computing section including a first moment computing section for computing a moment around a center of gravity of the foreground region, and calculating the main axis of the foreground region based on the moment around the center of gravity of the foreground region; a head region computing section for computing a head region included in the foreground region as a part thereof, based on the main axis of the foreground region and a shape of the foreground region; an ellipse determining section for determining an ellipse to be applied to the head of the person, based on a shape of the head region; and an input section for inputting a plurality of frame images constituting a moving image as a plurality of the input images; and wherein the first main axis computing section includes: a first orthogonal axes computing section for computing two orthogonal axes in the foreground region, based on the moment around the center of gravity of the foreground region; and a first main axis selection section for selecting one axis in the two orthogonal axes calculated by the first orthogonal axes computing section, which forms smaller angle with the main axis of the foreground region calculated in at least one of a previous frame and a next frame, as the main axis of the foreground region.