  The Crab pulsar has striking radio emission properties, with the two dominant
pulse components -- the main pulse and the interpulse -- consisting entirely of
giant pulses. The emission is scattered in both the Crab nebula and the
interstellar medium, causing multi-path propagation and thus scintillation. We
study the scintillation of the Crab's giant pulses using phased Westerbork
Synthesis Radio Telescope data at 1668\,MHz. We find that giant pulse spectra
correlate at only $\sim 2 \%$, much lower than the $1/3$ correlation expected
from a randomized signal imparted with the same impulse response function. In
addition, we find that the main pulse and the interpulse appear to scintillate
differently; the 2D cross-correlation of scintillation between the interpulse
and main pulse has a lower amplitude, and is wider in time and frequency delay
than the 2D autocorrelation of main pulses. These lines of evidence suggest
that the giant pulse emission regions are extended, and that the main pulse and
interpulse arise in physically distinct regions which are resolved by the
scattering screen. Assuming the scattering takes place in the nebular
filaments, the emission regions are of order a light cylinder radius, as
projected on the sky. With further VLBI and multi-frequency data, it may be
possible to measure the distance to the scattering screens, the size of giant
pulse emission regions, and the physical separation between the pulse
components.
