#!/usr/bin/perl

my($geom,$gray,$pdf,$jpg);

foreach(@ARGV)
{
  $pdf=$1 if(/^(.*\.pdf)$/i);
  $jpg=$1 if(/^(.*\.jpg)$/i);

  $gray='-colorspace Gray' if(/^--?gray$/);
  $geom='-geometry $1'     if(/^(\d+x\d*)$/);
  $geom='-geometry $1'     if(/^(\d*x\d+)$/);
}

$jpg="$1-%02d.jpg" if(!$jpg && $pdf=~/^(.*)\.pdf$/);

qx(convert -page A4 -quality 20 -interlace none -density 300 $geom $gray $pdf $jpg) if($pdf && $jpg);