Two step robust fringe analysis method with random shift

Abstract

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.