use Image::Magick;
my $html2ps = '/usr/local/bin/html2ps';
print "Content-type: application/pdf\n\n";
open ( FIN, "$html2ps http://mypage.com/index?param=x&foo=y' |" );
my $image = Image::Magick->new;
# I don't think binmode is necessary in ps or pdf, but 
# I'm adding it just in case it makes a difference.
binmode FIN; 
my $status = $image->Read(file=>\*FIN);
warn( "Read status = $status" );
$image->set(format=>'pdf');
binmode STDOUT;
$image->set(file=>\*STDOUT);
$status = $image->Write();
warn( "Write status = $status" );
$image->set(file=>\*STDERR);
$status = $image->Write();