1. A system for deriving a 3D model of a face from a 2D image captured with an image sensor, comprising: a computing device executing software for performing the functions of: (a) placing a plurality of fiducial points at landmarks on said face, each of said fiducial points corresponding to a fiducial point for a mean face calculated over a database set of faces; (b) calculating a function which captures the deviation of each fiducial point from said mean fiducial point; (c) using a thin-plate spline function to create a test face by minimizing a function which provides a measure of the smoothness of the function calculated in step (b); (d) selecting a set of uniformly-distributed points on said mean face; and (e) finding a set of points on said test face corresponding to said uniformly-distributed set of points on said mean face; and (f) for each point in said set of points on said test face, calculating a depth coordinate.