This module applies a zoom to an image using Fourier interpolation.
In the case of a direct zooming, the high frequencies are set to zero
(this is the so-called {\em zero-padding} method). In the case
of an inverse zooming, the high frequencies are simply lost and the
low frequencies are unchanged.
\index{Fourier Transform}
\index{zoom!of an image}
\index{zoom!zero-padding}
\index{interpolation!of an image}
