  We studied the insulator-quantum Hall conductor transition which separates
the low-field insulator from the quantum Hall state of the filling factor
$\nu=4$ on a gated two-dimensional GaAs electron system containing
self-assembled InAs quantum dots. To enter the $\nu=4$ quantum Hall state
directly from the low-field insulator, the two-dimensional system undergoes a
crossover from the low-field localization to Landau quantization. The
crossover, in fact, covers a wide range with respect to the magnetic field
rather than only a small region near the critical point of the
insulator-quantum Hall conductor transition.
