Upper left: Features detected for each galaxy with the help of the I_E images and residuals. Upper right: I_E surface brightness map of the features. Those for which I_E photometry can be performed are coloured according to their surface brightness and labelled. Their photometry is given in Table 5. They are discussed in the context of each galaxy they belong to in Sect. 4.2. Questions relative to their classification and nature are addressed in Sect. 5.1. Those for which this study is not possible are delineated in black. Especially, the photometry of the shells, of the uncertain features between NGC 1549 and NGC 1553, and of the features close to the galactic centres is not estimated. Lower left: I_E − J_E integrated fluxes colour map. The features with uncertain detection in the NIR bands appear in grey. Lower right: I_E − J_E GCs colour map. The average colours are weighted based on the uncertainties of the magnitudes that contribute to them. The features that encompass less than three bright GC candidates appear in grey. Surface brightness and colours are given respectively in mag arcsec⁻² and in mag.