Illustration of the decomposition steps and residual images. For each galaxy in our sample each respective panel shows from top to bottom on the left-hand column, the original picture with sky background removed (1), then disc-subtracted (2). After fitting and subtracting a synthetic boxy or elliptical bar (3), the process is completed by modelling an elliptical bulge, trying to minimize the residuals (4). In the right column, the corresponding synthetic data show at the top the fitted disc+bar+bulge image followed by the bar+bulge image, and finally, the synthetic bulge alone. The colour scale units are expressed in ADUs.