f="#16-bit-image"><b>16-bit-image</b></a>, return it or a copy of
it.  If <i>image</i> is an <a
href="#8-bit-image"><b>8-bit-image</b></a>, return a <a
href="#16-bit-image"><b>16-bit-image</b></a> that has the same width,
height, and number of channels as <i>image</i>, but where each element
is the corresponding element in <i>image</i> multiplied by 257.  The
effect of this multiplication is to stretch the dynamic range of the
image to utilize the increased bit depth.</p>

<hr>

<p><a name="decode"><i>Funct