hvordan bruges imagettftext() på et billede fra mappe

PHP kode 

 $im = imagecreatefrompng("css/images/forside billede_2.png");
 
 //#### Create the badge
     
     //#### define some colours to use with the image
     $white = imagecolorallocate($im, 255, 255, 255);
 
     //#### Define font and text
     $font = "arial";
     $fontSize = 40;
     $angle = 0;
     $text = "TEST";
     $angle = 0;
     $x = 100;
     $y = 100;
 
    imagettftext($im, $fontSize, $angle, $x, $y, $white, $font, $text);
 
     // output the image
     // tell the browser what we're sending it
     Header('Content-type: image/png');
     // output the image as a png
     imagepng($im);
 
     // tidy up
     imagedestroy($im);
     }