Profilometry is a technique which measures the shape of a surface. Thi
s method provides the height z of every point of a surface above a ref
erence plane. A pattern of bright and dark parallel stripes is oblique
ly projected onto the object which acts as a screen and the pattern of
lines is distorted if the object is not a plane. The distorsion is re
lated to the shape of the surface. The presented system uses the spati
al phase-stepping technique which allows shape determination from a si
ngle video frame, so that it is possible to study a living subject. It
is a non-invasive optical technique which allows non-contact measurem
ents. As examples, the method is applied to observations of a hand and
of a forefinger.