A couple of different ways to make labels using different options.

<?php
exec
("/usr/local/bin/convert -background lightblue -fill blue -font Courier -pointsize 72 label:Anthony label/label.gif ");
?>


<?php
$Name
='Funtus';
$filename 'label/ImageName.jpg';
$ImgName=$filename;
       
exec("/usr/local/bin/convert -pointsize 42 -gravity Center -size 928x40 label:$Name $filename");
?>


Adding a lable to the bottom of an image; note you can use -label \"Piglet\" or -label Piglet.

<?php
exec
("/usr/local/bin/montage -geometry +0+0 -background skyblue -label \"Piglet\" piglet.gif label/label_montage1.jpg");
?>


<?php
exec
("/usr/local/bin/montage -geometry +0+0 -background white -font Courier-Oblique -label Piglet piglet.gif label/label_montage2.jpg");
?>