  Shannon proved that if we can transmit bits reliably at rates larger than the
rate distortion function $R(D)$, then we can transmit this source to within a
distortion $D$. We answer the converse question ``If we can transmit a source
to within a distortion $D$, can we transmit bits reliably at rates less than
the rate distortion function?'' in the affirmative. This can be viewed as a
direct converse of the rate distortion theorem.
