use strict;
use warnings;
use LWP::Simple;
use PDF::API2;

use constant {
    JPG => 'jpg.jpg',
    PDF => 'pdf.pdf',
    URL => 'https://jpeg.org/images/jpeg-home.jpg',
    A4W => 595,
    A4H => 842,
    RES => 72,  # image above is at 72 dpi
};

-f JPG 
    or is_success getstore URL, JPG
    or die;

my $pdf = PDF::API2-> new;
my $page = $pdf-> page;
$page-> mediabox( 'A0' );
my $content = $page-> gfx;

for my $row ( 0 .. 3 ) {
    for my $col ( 0 .. 3 ) {
        $content-> save;
        $content-> transform(
            -translate => [ A4W + $row * A4W, $col * A4H ],
            -rotate    => 90,
        );
        my $jpeg = $pdf-> image_jpeg( JPG );
        my $w = 72 / RES * $jpeg-> width; 
        my $h = 72 / RES * $jpeg-> height;
        
        $content-> translate(( A4H - $w )/2, ( A4W - $h )/2 );
        $content-> image( $jpeg, 0, 0, 72 / RES );
        $content-> restore;
    }
}
$pdf-> saveas( 'pdf.pdf' );