getimagesize() returns false on some images

Question

I'm running getimagesize() to determine whether or not an uploaded file is a valid image and also it's MIME type. A user of my webapp reported that some of his images where getting an "invalid filetype" error after uploading them. So I asked him to send me some of them to check.

The error string itself is meaningless as it's just a generic text written by me when the functions fails (returns FALSE). I tried increasing PHP's memory limit with no success. Also, logs don't show anything unusual. Is there a problem with the files or is it something else? is there a better way to do this operation?

I'm accepting any file that getimagesize() accepts (meaning it has a width/height), I'm just checking that it doesn't return FALSE (although my real scope would be jpg|jpeg|png|gif|bmp|tif|tiff). The server is running PHP/5.2.6-1+lenny3. I repeat, this happens only with the image linked and some others from the same series, so I'm more inclined to think it's related to what Lizard is hinting.

$_FILES seems to be empty before getting to getimagesize($_FILES['Filedata']['tmp_name']) so the file is never really checked. I'll have to figure out why these files are not submitted like the rest (too big for PHP perhaps? any ideas?).

Answer 1

Until you give more information, I can't really help much. The following code:

$file = "http://img27.imageshack.us/img27/9159/dsc00799e.jpg";
$info = getimagesize($file);

echo "<pre>" . print_r($info,true) . "</pre>";

(Where $file is equal to the location of the image given in the question), outputs:

Array
(
    [0] => 2736
    [1] => 3648
    [2] => 2
    [3] => width="2736" height="3648"
    [bits] => 8
    [channels] => 3
    [mime] => image/jpeg
)

This seems okay. I'm assuming an error somewhere else in your checks?