Watermark text and shadow

<?php  
$cmd = "input.jpg -font ../verdana.ttf -pointsize 30 ".
" -gravity north -fill black ".
" -annotate +0+12 \"Copyright of rubblewebs\" ".
" -gravity north -fill white ".
" -annotate +2+11 \"Copyright of rubblewebs\"  ";
exec("convert $cmd output.png"); 
?>