Question

is there a way to use imagecreatefromstring() and get somehow what is the image type?

Answer 1

When you use imagecreatefrom… methods, the image is loaded into memory as the uncompressed bitmap. there is not really a image type at this point. you can save it back out as whatever type you wish using the image… function.

$img = imagecreatefromstring($data);

imagepng($img, "file path and name");

imagedestroy($img);

https://www.php.net/manual/en/function.imagecreatefromstring.php