High-Speed Acquisition and Pre-processing of Polarimetric Image Sequences

We have developed an imaging polarimeter working in the visible range. It is composed of a CCD camera with a bistable ferroelectric liquid crystal modulator as a polarizing rotator; therefore the degree of polarization (DOP) is evaluated from two successive acquisitions. Apparent motion in the scene induces a false evaluation of the DOP, especially on the edges of the objects. We present our acquisition system and two methods to correct defects in DOP images of moving objects. First, we propose a post-processing temporal median filtering, correcting the DOP once computed. The second method consists in performing a motion estimation to correct the object's displacement between the two polarization state pictures. Comparison based on qualitative and quantitative results with real data is provided.