1. A device for estimating a head pose, the device comprising: a processor to control one or more processor-executable units; a head area extracting unit to extract a head area including a head from an input depth image; a head pitch angle estimating unit to estimate a pitch angle of the head in the head area; a head yaw angle estimating unit to estimate a yaw angle of the head in the head area; and a head pose displaying unit to display a head pose based on the estimated pitch angle of the head and the estimated yaw angle of the head.