Attenuation of the exoplanet signal (${\eta }_{●}^{\text{inj}}{\eta }_{●}^{\text{proc }}$, in dashed lines) and the corresponding contrast limit ($C_{\text{speckle }}=3{\eta }_{\star }^{\text{inj}}{\eta }_{\star }^{\text{proc }}/{\eta }_{●}^{\text{inj}}{\eta }_{●}^{\text{proc }}$, in solid lines) after post-processing of the stellar speckle, as a function of angular separation. The three colour curves represent three levels of polynomial fitting strength (n_poly of 3, 7, and 11) used for filtering the coherent speckles. The dotted curves show the attenuation of the exoplanet signal, illustrating that a lower polynomial order yield a smaller inner working angle. The solid curves indicate the contrast limit after post-processing of the stellar speckle, demonstrating that higher polynomial orders result in a better contrast limit. The upper plot represents observations with a 100m baseline, while the lower plot corresponds to a 200 m interferometer baseline.