【PHP】判斷連結圖片是否存在，如果不存在將他移除

// 建立白名單
require_once('../class/htmlpurifier/HTMLPurifier.auto.php');
$config = HTMLPurifier_Config::createDefault();
$config->set('HTML', 'Allowed', 
'
,area[accesskey|alt, coords|href|name|shape|tabindex|target]
,img[alt|border|height|ismap|src|usemap|width]
,b,blockquote[cite],br,dd,dl,dt,em,h1,h2,h3,h4,h5,h6
,hr,i,li[value],map,ol[start|type]
,nav[accesskey|contenteditable|contextmenu|data-*|draggable|dropzone|hidden|spellcheck|tabindex|translate]
,ol[start|type],p,pre,rp,rt,ruby,s,small,source,strike,strong,style,sub,sup,
,table[border|cols|summary|cellpadding|cellspacing|align]
,tbody[valign],td[bordercolor|colspan|rowspan],tfoot[valign]
,th[colspan|rowspan|scope],thead[valign],tr[colspan|rowspan]
,tt,u,ul,video[autoplay|controls|height|loop|muted|poster|preload|src|width]
,div[style|class|id]
,span[style|class|id]
'
);

$purifier = new HTMLPurifier($config);
$rs['description'] = $purifier->purify($rs['description']);


// 判斷連結圖片是否存在，如果不存在將他移除
preg_match_all("//", $rs['description'], $img_arr);

if ($img_arr)
{

 foreach($img_arr[1] as $key=>$img)
 {
  $size_arr = getimagesize($img);

  if (!$size_arr)
  {
   $img_arr[0][$key];
   $rs['description'] = str_replace($img_arr[0][$key], '', $rs['description']);
  }
 }
}