![](slide0012_image031.gif)
CCD camera
Light source
glass flat
linear polarizer (PAR or PER)
linear polarizer
![](slide0012_image033.gif)
![](slide0012_image034.gif)
A CCD
camera views the skin through a linear polarizer oriented either parallel (PAR) or
perpendicular (PER) to the source/skin/camera
triangle. A polarizer in front of the light source is oriented as PAR. The
illumination is oblique and a glass
flat on the skin surface deflects surface glare.
H
V
P
R
H
V
P
R
HH
HV
HP
HR
VH
VV
VP
VR
PH
PV
PP
PR
RH
RV
RP
RR
Uses only HH and HV elements of Data Matrix