  I present the results of multi-component decomposition of V and R broadband
images of a sample of 17 nearby galaxies, most of them hosting bars and active
galactic nuclei. I use BUDDA v2.1 to produce the fits, allowing to include bars
and AGN in the models. A comparison with previous results from the literature
shows a fairly good agreement. It is found that the axial ratio of bars, as
measured from ellipse fits, can be severely underestimated if the galaxy
axisymmetric component is relatively luminous. Thus, reliable bar axial ratios
can only be determined by taking into account the contributions of bulge and
disc to the light distribution in the galaxy image. Through a number of tests,
I show that neglecting bars when modelling barred galaxies can result in a
overestimation of the bulge-to-total luminosity ratio of a factor of two.
Similar effects result when bright, type 1 AGN are not considered in the
models. By artificially redshifting the images, I show that the structural
parameters of more distant galaxies can in general be reliably retrieved
through image fitting, at least up to the point where the physical spatial
resolution is ~ 1.5 Kpc. This exercise shows that disc parameters are
particularly robust, but bulge parameters are prone to errors if its effective
radius is small compared to the seeing radius, and might suffer from systematic
effects. In this low resolution regime, the effects of ignoring bars are still
present, but AGN light is smeared out. I briefly discuss the consequences of
these results to studies of the structural properties of galaxies, in
particular on the stellar mass budget in the local universe. With reasonable
assumptions, it is possible to show that the stellar content in bars can be
similar to that in classical bulges and elliptical galaxies. (Abridged)
