PSF treatment applied to stars: in the top-left panel we show the stars ellipticity before the Im2shape deconvolution. The corresponding distribution in terms of ellipticity components (e1, e2) is shown in the top-right panel. Bottom-left panel shows the stars after the deconvolution by the PSF field (see text), and the bottom-right panel the corresponding distribution of (e1, e2), which is more uniformly distributed than before the deconvolution. Both left panels shows in red the scale corrsponding to a semimajor axis of 1′′.