source: branches/Ver2.4/xpressme_integration_kit/module_icon.php

<?php
$mydirpath = dirname(__FILE__);
$mydirname = basename($mydirpath);
$icon_cache_limit = 3600 ; // default 3600sec == 1hour

session_cache_limiter('public');
header("Expires: ".date('r',intval(time()/$icon_cache_limit)*$icon_cache_limit+$icon_cache_limit));
header("Cache-Control: public, max-age=$icon_cache_limit");
header("Last-Modified: ".date('r',intval(time()/$icon_cache_limit)*$icon_cache_limit));
header("Content-type: image/png");

$icon_fullpath = $mydirpath.'/module_icon.png' ;

if(function_exists( 'imagecreatefrompng' ) && function_exists( 'imagecolorallocate' ) && function_exists( 'imagestring' ) && function_exists( 'imagepng' ) ) {

        $im = imagecreatefrompng( $icon_fullpath ) ;

        $color = imagecolorallocate( $im , 0 , 0 , 0 ) ; // black
        $px = ( 92 - 6 * strlen( $mydirname ) ) / 2 ;
        imagestring( $im , 3 , $px , 34 , $mydirname , $color ) ;
        imagepng( $im ) ;
        imagedestroy( $im ) ;

} else {

        readfile( $icon_fullpath ) ;

}

?>