Estimation precision of degree of polarization in the presence of signal-dependent and additive Poisson noises

We address precision of estimation of the degree of polarization (DOP) from the orthogonal state contrast image (OSCI) in the presence of both signal-dependent Poisson noise due to useful signal, and additive Poisson noise due to dark current and / or background light. We determine the Cramer Rao Lower Bound and deduce from it figures of merit for DOP estimation. In particular, we show that the additive Poisson noise has larger influence on DOP estimation than on intensity estimation when light is highly polarized

Segmentation non supervisée d'images polarimétriques passives

Ce papier montre l'intérêt de la segmentation par grille active multi-composantes dans le traitement d'images obtenues par un système d'imagerie polarimétrique de Stokes. L'utilisation conjointe d'un système d'imagerie non-conventionnel performant et d'une méthode de traitement (segmentation) adaptée peut ainsi être mis à profit pour des applications de contrôle non-destructif. L'exemple présenté illustre en particulier la possibilité de segmenter l'image d'un objet suivant l'orientation géométrique de ses diverses facettes

On the equivalence of optimization metrics in Stokes polarimetry

Optimization of polarimeters has historically been achieved using an assortment of performance metrics. Selection of an optimization parameter is, however, frequently made on an ad hoc basis. We rigorously demonstrate that optimization strategies in Stokes polarimetry based on three common metrics, namely the Frobenius condition number of the instrument matrix, the determinant of the associated Gram matrix, or the equally weighted variance, are frequently formally equivalent. In particular, using each metric, we derive the same set of constraints on the measurement states, correcting a previously reported proof, and show that these can be satisfied using spherical 2 designs. Discussion of scenarios in which equivalence between the metrics breaks down is also given. Our conclusions are equally applicable to optimization of the illumination states in Mueller matrix polarimetry

Comparative study of the best achievable contrast in scalar, Stokes and Mueller images

We compare the relative performance of different active polarimetric imaging architectures for target detection applications. We show that if the noise that affects the measurements is additive and if the only relevant parameter is the contrast between an object of interest and a background with different Mueller matrices, the most efficient imaging architecture consists in acquiring a single intensity image while optimizing the illumination and analysis states of polarization

A UMP unbiaised test for target detection in active coherent images

Physics in Signal and Image ProcessingInternational audienc

Active spectro-polarimetric imaging: signature modeling, imaging demonstrator and target detection

We report on the synthesis of our work on the analysis of active spectro-polarimetric imaging concept of real-world scenes. These synthesis extend from the investigation of depolarization mechanisms up to image analysis and processing. We show in particular that depolarization effects are wavelength dependent and strongly correlated with light absorption of materials. Multi-wavelength images of degree of polarization are recorded and analyzed, evidencing that the polarimetric image must be interpreted in conjunction with its counterpart intensity image in order to extract, the most relevant information from the scene. For real field operation, the noise characteristics of polarimetric images are also investigated under coherent laser illumination. The potential increase of target detection performance brought by properly processing the active polarimetric image is illustrated on a very low contrast scene