Soft-thresholding technique and restoration of 3C273 jet

We outline the necessity of regularizing a deconvolution procedure, in the general framework of the inverse problems involved in astronomy. We show that this regularization depends in particular on a signal-to-noise ratio criterion. We concentrate on the application of the soft-thresholding statistical method for estimating the noise. We give the corresponding guidelines by commenting, from an image processing point of view, on the 2D astrophysical example of the restoration of the HST image of 3C273 optical jet.