PHP: getimagesize() failing on LAMP server

I'm using this function:

function image_resizer($max_width,$max_height,$img_path) {
    list($width, $height) = getimagesize($img_path);
    if (($width > $max_width) or ($height > $max_height)) {
        $ratioh = $max_height/$height;
        $ratiow = $max_width/$width;
        $ratio = min($ratioh, $ratiow);

        $width = intval($ratio*$width);
        $height = intval($ratio*$height);
    }
    return 'width="' . $width . '" height="' . $height . '"';
}

...called with this code (the defines are in another file pasted here for illustration):

define("SITE_URI", "http://dev.projectname.co.uk/");
define("PRODUCT_IMAGES_URI", "images/collection/");
<?php echo image_resizer(280, 375, SITE_URI . PRODUCT_IMAGES_URI . $display_image); ?> alt="<?php echo $display_image; ?>

...where $display_image is coming from the DB (successfully). And getting the following error:

Warning: getimagesize(http://dev.projectname.co.uk/images/collection/filename.jpg) [function.getimagesize]: failed to open stream: HTTP request failed! HTTP/1.1 401 Authorization Required in /var/www/projectname.co.uk/dev/admin/includes/functions_admin.php on line 59 width="" height="" alt="filename.jpg" />

I'm using getimagesize() to get the size of an image from a folder that I initially gave rights to the www-d开发者_如何学Pythonata user on the server, then when I got the error again I just chmod 777 to the image folder. I'm now at a loss.

---

The answer was simple, I was attempting to use a url to access a folder on the server, I needed the absolute path to the folder on the server instead. This had worked on the local machine and slipped through the cracks to the development server.

---

The problem isn't getimagesize(), the problem is that you're trying to retrieve it from a password-protected URL. Either pass the username and password as part of the URL, or get it some other way.