font>' commands, depending on the
file format.  If the file is "raw", with no embedded information about
things like the width and height, then we need to specify everything, as
in the first format given below.  The other formats make use of the
header information in, e.g. PGM files.
<p>
<b>Headerless images</b>
<p>
<TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%">
<TR>
<TD>
<PRE>
<font color="#82140F">
`read image .rows. .cols. \
  [box .xleft. .ybottom. .xright. .ytop.] \
  [bycolumns]'
