Fig 1. Computation of the SNR in a 2-dimensional LEGI model.

We account for different orientations of the gradient $\overrightarrow{g}$ by computing the SNR for 500 different values of the angle θ ∈ [0, 2π]. For each value of θ, we estimate $\sqrt{SNR}$ in the edge cell, namely the cell measuring the highest concentration of the signal (colored in red). In the examples depicted here, for θ = θ₁ (left) and θ = θ₂ (right), the edge cells are cell 4 and cell 0, respectively.