$labname = md5(JPATH_SITE.$rootfolder.$_images_dir_.'/'.$images[$a]);
$tmbname = md5($_images_dir_.$name);

// if labels do exist
if ($labels[$labname]!="") {
...

if ((!$_howmanythumbs_) || ($a<$_howmanythumbs_)) {
...
}

if ($labels[$labname]!="") {
  if ((!$_howmanythumbs_) || ($a<$_howmanythumbs_)) {
   // get thumb image size
   $image_info = @getimagesize(JPATH_SITE.$tempfolder.$tmbname.".".$format);
   $caption_width = $image_info[0];
   $final_caption = htmlentities($labels[$labname],ENT_QUOTES);
   // if word limitation is defined
   if ($caption_limit) {
   $word_arr = str_word_count($final_caption, 2, '&;');//Fix:Param '&;' for &uuml;
   $c = 0;
   foreach ($word_arr AS $k => $v) {
    if ($c == $caption_limit) {
    if(function_exists("mb_string")) {
     $final_caption = mb_substr($final_caption, 0, $k).'...';
    } else {
     $final_caption = substr($final_caption, 0, $k).'...';
    }
    break;
   }
   $c++;
   }
  }
  if (!$caption_hide) {
   $html .= '<span class="sig_pseudocaption" style="width:'.($caption_width-4).'px"><b>'.$final_caption.'</b></span><span class="sig_caption" style="width:'.($caption_width-4).'px" title="'.$clickopen.'">'.$final_caption.'</span>';
  }
 }
}

if (file_exists(JPATH_SITE.$tempfolder.md5($_images_dir_.$name).".".$format) &&
filemtime (JPATH_SITE.$tempfolder.md5($_images_dir_.$name).".".$format) +
$cache_expire_time * 60 > time()) {

if (file_exists(JPATH_SITE.$tempfolder.$tmbname.".".$format)) {
  if (($cache_expire_time == 0) || (filemtime (JPATH_SITE.$tempfolder.$dirname.".".$format)
+ $cache_expire_time * 60 > time()))