use strict;
use warnings;
use PDF::API2;
sub _p ($) { $_[ 0 ] / 25.4 * 72 } # mm to postscript points
my $pdf = PDF::API2-> open( 'docu.pdf' );
my $logo = $pdf-> image_png( 'logo.png' );
for my $i ( 1 .. $pdf-> pages ) {
my $p = $pdf-> openpage( $i );
my ( $llx, $lly, $urx, $ury ) = $p-> get_mediabox;
my $gfx = $p-> gfx( 1 ); # prepend content
$gfx-> save;
$gfx-> translate( 0, _p -20 ); # shift 20 mm down
$gfx = $p-> gfx; # append content
$gfx-> restore;
my $scale = 0.25; # scale 0 .. 1, adjust as desired
my $x = # let's make it centered!
( $urx - $llx - $scale * $logo-> width ) / 2;
my $y = $ury - _p 20; # 20 mm from top
$gfx-> image( $logo, $x, $y, $scale );
}
$pdf-> update; # you had a backup, right?
