Polarimetric imaging vs. conventional imaging: evaluation of image contrast in fog

Abstract

We compare conventional intensity imaging against different modes of polarimetric imaging by evaluating the image contrast of images taken in a controlled foggy environment. A small-scale fog chamber has been designed and constructed to create the necessary controlled foggy environment. A division-of-focal-plane camera of linear polarization and a linearly polarized light source has been used for performing the experiments with polarized light. In order to evaluate the image contrast of the different imaging modes, the Michelson contrast of samples of different materials relative to their background has been calculated. The higher the image contrast, the easier it is to detect and segment the targets of interest that are surrounded by fog. It has been quantitatively demonstrated that polarimetric images present an improvement in contrast compared to conventional intensity images in the situations studied.