  Polarimetric imaging is one of the most effective techniques for
high-contrast imaging and characterization of circumstellar environments. These
environments can be characterized through direct-imaging polarimetry at
near-infrared wavelengths. The SPHERE/IRDIS instrument installed on the Very
Large Telescope in its dual-beam polarimetric imaging (DPI) mode, offers the
capability to acquire polarimetric images at high contrast and high angular
resolution. However dedicated image processing is needed to get rid of the
contamination by the stellar light, of instrumental polarization effects, and
of the blurring by the instrumental point spread function. We aim to
reconstruct and deconvolve the near-infrared polarization signal from
circumstellar environments. We use observations of these environments obtained
with the high-contrast imaging infrared polarimeter SPHERE-IRDIS at the VLT. We
developed a new method to extract the polarimetric signal using an inverse
approach method that benefits from the added knowledge of the detected signal
formation process. The method includes weighted data fidelity term, smooth
penalization, and takes into account instrumental polarization. The method
enables to accurately measure the polarized intensity and angle of linear
polarization of circumstellar disks by taking into account the noise statistics
and the convolution of the observed objects by the instrumental point spread
function. It has the capability to use incomplete polarimetry cycles which
enhance the sensitivity of the observations. The method improves the overall
performances in particular for low SNR/small polarized flux compared to
standard methods.
