  We present deep B- and R-band surface photometry for a sample of 21 galaxies
with morphological types between S0 and Sab. We present radial profiles of
surface brightness, colour, ellipticity, position angle and deviations of
axisymmetry for all galaxies, as well as isophotal and effective radii and
total magnitudes. We have decomposed the images into contributions from a
spheroidal bulge and a flat disk, using an interactive, 2D decomposition
technique.
  We study in detail the relations between various bulge and disk parameters.
In particular, we find that the bulges of our galaxies have surface brightness
profiles ranging from exponential to De Vaucouleurs, with the average value of
the Sersic shape parameter n being 2.5. In agreement with previous studies, we
find that the shape of the bulge intensity distribution depends on luminosity,
with the more luminous bulges having more centrally peaked light profiles. By
comparing the ellipticity of the isophotes in the bulges to those in the outer,
disk dominated regions, we are able to derive the intrinsic axis ratio q_b of
the bulges. The average axis ratio is 0.55, with an rms spread of 0.12. None of
the bulges in our sample is spherical, whereas in some cases, the bulges can be
as flat as q_b = 0.3 - 0.4. The bulge flattening seems to be weakly coupled to
luminosity, more luminous bulges being on average slightly more flattened than
their lower-luminosity counterparts. Our finding that most bulges are
significantly flattened and have an intensity profile shallower than R^{1/4}
suggests that `pseudobulges', formed from disk material by secular processes,
do not only occur in late-type spiral galaxies, but are a common feature in
early-type disk galaxies as well. (abridged)
