Using PHP to get the dimensions of an image

The following code will get the dimensions of an image:

<?php
    list($width, $height, $type, $attr) = getimagesize(PATH_TO_IMAGE);

I found this useful when using a lightbox to load an image that I didn't initially know the size of, to ensure the lightbox positioned itself in the middle, based on the height and width of the image.

The contents of $attr is useful for slotting straight into an <img> tag, like so:

<img src="URL" <?php echo $attr?> />

This will produce, for example:

<img src="URL" width="200" height="300">