3D Face modeling has been an active research topic of
computer vision and computer graphics, for the past three
decades. A complete overview can be found in Parke and
Waters' book [31]. Human face geometry provides the shape
information which plays a crucial role in building a 3D face
model along with the 20 texture data. The shape which can be
expressed as the depth information is invariant to changes
caused by illumination, viewpoint and background clutter and
also facilitates the detection and recognition of partially
occluding faces; hence the 3D face geometry is always
preferred over 2D data.