Isophotal parameters as a function of the semi-major-axis distance and photometric decomposition of IC 5181. The radial profiles of position angle (PA), ellipticity (ϵ), and Cousins I-band surface brightness (μ_I) are plotted (from top to bottom). The dashed, dotted, and solid lines represent the surface-brightness radial profiles of the bulge, disc, and model obtained from the photometric decomposition, respectively.