利用PHP函数 imagecreatefromstring() 来读取图片信息

$pic_url = 'https://ss0.bdstatic.com/5aV1bjqh_Q23odCf/static/superman/img/logo/logo_white_fe6da1ec.png';
$data = file_get_contents($pic_url);
$pic_status = imagecreatefromstring($data);
if( $pic_status != false ){
	echo '图片状态正常！！';
}else{
	echo '图片已损坏！！';
}