php通过imagick库把PDF转成PNG格式

function pdf2png($PDF,$Path){
   if(!extension_loaded('imagick')){
       return false;
   }
   if(!file_exists($PDF)){
       return false;
   }
   $IM = new imagick();
   $IM->setResolution(120,120);
   $IM->setCompressionQuality(100);
   $IM->readImage($PDF);
   foreach ($IM as $Key => $Var){
       $Var->setImageFormat('png');
       $Filename = $Path.'/'.md5($Key.time()).'.png';
       if($Var->writeImage($Filename) == true){
           $Return[] = $Filename;
       }
   }
   return $Return;
}