In this work we present a new algorithm for fringe pattern normalization, t
hat is. background suppression and modulation normalization. Normalization
is necessary for several fringe pattern processing techniques. For example,
this is the case of the regularization and phase sampling methods. In gene
ral, background suppression can be accomplished by high-pass filtering, how
ever if modulation is not constant or almost constant over the field of vie
w, normalization is a difficult task. The solution proposed is based in the
use of two orthogonal bandpass filters, from which a normalized irradiance
distribution is obtained. We have applied the method to simulated as well
as experimental data with good results. (C) 2001 Published by Elsevier Scie
nce B.V.