inters themselves.  The
<B>-clump</B> option alters the number of pixels in a clump.  This is
usually an integer between 2 and 100 (default 5).  Smaller clump sizes
smear the image less and are less grainy, but seem to loose some grey
scale linearity. Typically a PGM image will have to be scaled to fit
on a laser printer page (2400 x 3000 pixels for an A4 300 dpi page),
and then dithered to a PBM image before being converted to a
postscript file.  A printing pipeline might look something like:

<pre>
    pa