1. A method of determining a head-pose measurement of a person, said head pose measurement including a rotational displacement and translation displacement, said method including the steps of: (a) capturing images of the face and head of said person from at least two viewpoints; (b) computing an initial estimate of head-pose; (c) computing the three dimensional location of two or more facial features; and (d) determining a rotational displacement and translation displacement which best match a head-model to the computed location of said two or more facial features.