Example of generating transparent background image in php

//Transparent background image
header('content-type:text/html;charset=gbk');
$safess = $_get[safe];
$dir = dirname(__file__ ).”/simsun.ttc”;
$safe=iconv(“gb2312″,”utf-8″,$safess);
 $im=imagecreatetruecolor(160,18);
 $color=imagecolorallocate($im,229,231,230 );
 imagecolortransparent($im,$color); // Set to transparent color. If you comment out this line, the background set above will be output.
 imagefill($im,0,0,$color);
 $textcolor=imagecolorallocate( $im,0,0,0);
 imagettftext($im,9,0,30,12,$textcolor,$dir,$safe);
 //imagestring($im,30, 5, 3, $safe , $textcolor);
 header("content-type:image/png");
 imagegif($im);
?>