  A setup to frequency-convert an arbitrary image encoded in the spatial
profile of a probe field onto a signal field using four-wave mixing in a
thermal atom vapor is proposed. The atomic motion is exploited to cancel
diffraction of both signal and probe fields simultaneously. We show that an
incoherent probe field can be used to enhance the transverse momentum bandwidth
which can be propagated without diffraction, such that smaller structures with
higher spatial resolution can be transmitted. It furthermore compensate linear
absorption with non-linear gain, to improve the four-wave mixing performance
since the propagation dynamics of the various field intensities is favorably
modified.
