  We study Sigma-Delta ($\Sigma\Delta$) quantization of oversampled bandlimited
functions. We prove that digitally integrating blocks of bits and then
down-sampling, a process known as decimation, can efficiently encode the
associated $\Sigma\Delta$ bit-stream. It allows a large reduction in the
bit-rate while still permitting good approximation of the underlying
bandlimited function via an appropriate reconstruction kernel. Specifically, in
the case of stable $r$th order $\Sigma\Delta$ schemes we show that the
reconstruction error decays exponentially in the bit-rate. For example, this
result applies to the 1-bit, greedy, first-order $\Sigma\Delta$ scheme.
