my @color = $image->getpixel(
     x => [ 13, 15, 17, 17, 20 ],
     y => [ 17, 14, 18, 19, 15 ] );
for my $clr ( @color )
{
  my ( $r, $g, $b, $a ) = $clr->rgba();
  print " shade = $r, $g, $b\n";
}