Change in |⟨B_l⟩| (left), as well as in the continuum (middle) and line-core intensity (right) introduced by image restoration with K₂, as a function of the original value. Both the continuum and line core intensities are normalized to the quiet-Sun level. The red and blue series follow the values derived from the sunspot and pore features encircled by the similarly colour-coded contours in Fig. 14. The black and green curves (left) correspond to the change in |⟨B_l⟩| in the quiet Sun field depicted in Fig. 19, and in a 201 × 201 pixel active region field near disc centre (μ > 0.92), respectively. The dashed lines mark the zero level.