Zoomed-in view of NGC 1275 highlighting the inner masks. North is up and east is left. The original image in the left panel shows star formation and dust towards the north and north-west. These regions were masked in the second panel. The third panel shows the residuals after subtracting the isophote model from NGC 1275. Here, the regions mentioned before plus more filamentary structures in the sound-east and south become readily visible. The masked residual image in the fourth panel shows the accurate masking of these regions.