  We propose a two steps fringe analysis method assuming random phase step and
changes in the illumination conditions. Our method constructs on a Gabor
Filter--Bank (GFB) that independently estimates the phase from the fringe
patterns and filters noise. As result of the GFB we obtain the two phase maps
except by a random sign map. We show that such a random sign map is common to
the independently computed phases and can be estimated from the residual
between the phases. We estimate the final phase with a robust unwrapping
procedure that interpolates unreliable phase regions. We present numerical
experiments with synthetic and real date that demonstrate our method
performance.
