  Instead of starting from a theoretically motivated form of the color dipole
cross section in the dipole picture of deep inelastic scattering, we start with
a parametrization of the deep inelastic structure function for electromagnetic
scattering with protons, and then extract the color dipole cross section. Using
the parametrizations of $F_2(\xi=x \ {\rm or}\ W^2,Q^2)$ by Donnachie-Landshoff
and Block et al., we find the dipole cross section from an approximate form of
the presumed dipole cross section convoluted with the perturbative photon wave
function for virtual photon splitting into a color dipole with massless quarks.
The color dipole cross section determined this way reproduces the original
structure function within about 10\% for $0.1$ GeV$^2\leq Q^2\leq 10$ GeV$^2$.
We discuss the large and small form of the dipole cross section and compare
with other parameterizations.
