PHP - file_exists siempre da False

$filename = 'http://www.dominio.com/images/file.jpg';

$filename = filter_var($filename, FILTER_VALIDATE_URL);

$handle = curl_init($filename);

curl_setopt_array($handle, array(

	CURLOPT_FOLLOWLOCATION => TRUE,

	CURLOPT_NOBODY         => TRUE,

	CURLOPT_HEADER         => FALSE,

	CURLOPT_RETURNTRANSFER => FALSE,

	CURLOPT_SSL_VERIFYHOST => FALSE,

	CURLOPT_SSL_VERIFYPEER => FALSE

));

$response = curl_exec($handle);

$httpCode = curl_getinfo($handle, CURLINFO_HTTP_CODE);

curl_close($handle);

if($httpCode == 200){

	// Mostrar imagen

}else{

	// Mostrar cualquier otra cosa

}

$filename= 'https://www.google.pl/logos/2012/haring-12-hp.png';

$file_headers = @get_headers($filename);

if($file_headers[0] == 'HTTP/1.0 404 Not Found'){

      echo "The file $filename does not exist";

} else if ($file_headers[0] == 'HTTP/1.0 302 Found' && $file_headers[7] == 'HTTP/1.0 404 Not Found'){

    echo "The file $filename does not exist, and I got redirected to a custom 404 page..";

} else {

    echo "The file $filename exists";

}