  We review a recently proposed framework for studying the approach to the
unitarity limit in small-x processes in ep and pp scattering within the DGLAP
approximation. Our formulation is based on the correspondence between the
standard QCD factorization theorems for hard processes and the dipole picture
of small-x scattering in the leading logarithmic approximation. It allows us to
incorporate information about the transverse spatial distribution of gluons in
the proton (GPD) from exclusive vector meson production at HERA. We show that
the interaction of small-size color singlet configurations with the proton
approaches the "black-disk limit" (BDL) due to the growth of the DGLAP gluon
density at small x. This new dynamical regime is marginally visible in
diffractive DIS at HERA, and will be fully reached in central pp collisions at
LHC.
