Evolution of the S/N (blue) for various priors for a point source observed with IRDIS, and whose spectrum corresponds to the red mark. The x-axis gives various values of the priors. The S/N corresponding to the [0.5, 1] prior (significantly different from the normalized contrast of the injected source) is below the 4σ threshold used for this analysis, while the S/N reached for spectral prior [1, 0.1] (similar to the normalized contrast of the injected source) leads to a clear detection with a significance above the 5σ detection threshold (dashed black line).