Comparison of the inferred atomic line parameters using the spatially average and the coupled methods. Top panel: the difference between inferred and expected log(gf) values versus the line core depth from the spatially averaged method (squares) and from mode 3 in Sect. 3 (triangles). The colours of the symbols correspond to the wavelength shift Δλ with respect to the central wavelength from Table 1 (only for mode 3 results). Bottom panel: the difference between inferred and expected log(gf) values versus the line blending factor from Table 1. Colour coding is the same as in the top panel.