Results of a series of tests on a simulated image using the flux prioring method. Different histograms refer to separate runs on the same LRI. The yellow bars are the fluxes f measured without imposing any constraints (run A). In all the other runs, a given set of flux priors with a corresponding uncertainty has been given to all the sources, and the histograms show the measured fluxes: f_constr,B = f ± 0.5 (cyan), f_constr,C = 10 ± 0.1 (blue), f_constr,D = 10^-3 ± 0.1 (red), f_constr,E = 10^-3 ± 10^-4 (black). We note that (i) the run without constraints (yellow) yields very similar results to the run where each source has its “true” input flux as prior (B, cyan); (ii) in the other runs the flux is forced to a fixed value which is retrieved consistently with the allowed uncertainties. See text for more details.