Перевод текста в картинку

function Txt2Png( $text) 
{   
    $png2display = md5($text);
    $filenameforpng = $_SERVER['DOCUMENT_ROOT']."/cache/". $png2display . ".png";
    $filename = "http://".$_SERVER['SERVER_NAME']."/cache/". $png2display . ".png";
    if (!file_exists($filenameforpng)) # we dont need to create file twice (md5)
    {   
        # definitions
        $font = $_SERVER['DOCUMENT_ROOT'] . "/fonts/open_sans_regular.ttf";
        # create image / png
        $fontsize = 20;
        $textwerte = imagettfbbox($fontsize, 0, $font, $text);
        $textwerte[2] += 8;
        $textwerte[5] = abs($textwerte[5]);
        $textwerte[5] += 4;
        $image=imagecreate($textwerte[2], $textwerte[5]);
        $farbe_body=imagecolorallocate($image,255,255,255); 
        $farbe_b = imagecolorallocate($image,0,0,0); 
        $textwerte[5] -= 2;
        imagettftext ($image, $fontsize, 0, 3,$textwerte[5],$farbe_b, $font, $text);
        #display image
        imagepng($image, "$filenameforpng"); 
    }
 
    $text = "<img src='$filename' border='0' alt='email' />";
    return $text;
}
 /*а на вывод*/
echo Txt2Png("1234567890");