php在图片上写指定字体的文字

<?php
header(&#39;Content-type: image/gif&#39;);
 
$image = imagecreate( 400, 200 );
$red = imagecolorallocate($image, 255,0,0);
$blue = imagecolorallocate($image, 0,0,255 );
$font = &#39;ARIALBD.TTF&#39;;
imageTTFtext( $image, 50, 0, 20, 100, $blue, $font, &#39;outofmemory.cn&#39; );
imagegif($image);
?>