The polarizing and depolarizing properties of an optical system can be
derived from the experimental determination of its Mueller matrix. Co
nstructing an algorithm to treat an experimental Mueller matrix based
on the knowledge of the measurement errors, and connected to the study
of the depolarization effects in the Poincare space, allows us to cha
racterize and classify any optical system. Different samples of materi
als and surfaces are analysed by this method while polarimetric image
coding provides the spatial distribution of the depolarization for eac
h target.