- header: documentation ( source)
<?php
header("Content-type: image/jpeg");
$imgPath = 'http://i.imgur.com/yS5hPLa.jpg';
$image = imagecreatefromjpeg($imgPath);
$color = imagecolorallocate($image, 255, 255, 255);
$string = "meow";
$fontSize = 3;
$x = 115;
$y = 185;
imagestring($image, $fontSize, $x, $y, $string, $color);
imagejpeg($image);
?>