Analysis of the relationship between G₀ and P_th. (a) Scatter plot of the MMSE pixel values for G₀ and P_th, that shows a strong positive correlation. The pixels such that G₀ (MMSE) ≤ 3 G₀ (FIR) are highlighted in blue, and the other pixels are in light grey. A power law fit on those highlighted pixels is shown in red, compared with previous power law relations proposed in the literature (in yellow). (b) Map of ratio of the MMSE for P_th and the P_th predicted from G₀ with our power law fit. In both maps, the black contour identifies the regions where G₀ (MMSE) ≤ 3 G₀ (FIR), as in Fig. 10.