How to crop pages?

[Sebastian Rahtz]

Berthold Crysmann writes:
 > How do I set a crop box with pdftex/hyperref?
 > 
 > I know ther's this pdfpagescrop option to hyperef, but what are the
 > appropriate parameters? Is it the same as a PS bounding box, coordinates
 > in points measured from the lower left corner or is it something else? 
unless I am going mad, yes, thats it. I see i have some bizarrely
complicated code to create it, though:

\dimen@\paperheight
  \advance\dimen@ by -\cropheight
  \advance\dimen@ by -\croptop
  \divide \dimen@ by 7227
  \multiply \dimen@ by 7200
  \edef\BboxA{\strip at pt\dimen@}%
\dimen@\cropwidth
  \advance\dimen@ by \cropleft
  \divide \dimen@ by 7227
  \multiply \dimen@ by 7200
   \edef\BboxB{\strip at pt\dimen@}%
\dimen@\paperheight
  \divide \dimen@ by 7227
  \multiply \dimen@ by 7200
  \edef\BboxC{\strip at pt\dimen@}%
\hypersetup{pdfpagescrop={0 \BboxA\space\BboxB\space\BboxC}}

where \cropwidth, \cropheight, \cropleft are the parameters dictated
by the page layout

Sebastian