list($width, $height) = getimagesize($url);
echo "Width: ".$width."<br/>";
echo "Height: ".$height."<br/>";

if($width==1 && $height==1){
   echo "<img src='../images/book_cover.png' alt='' class='cover'/>";
}else{
   echo "<img src=$url alt='' class='cover'/>";
}

if(!exif_imagetype($url)){
   echo "<img src='../images/book_cover.png' alt='' class='cover'/>";
}else{
   echo "<img src=$url alt='' class='cover'/>";
}