How to get width and height of user pictures? It seems that Drupal doesn't store the width and height of uploaded user profile pictures (standard profile, not profile2).

I would like to be able to link the profile thumbnail to a larger version if the uploaded image is larger than 480 pixels.

Is that possible without jumping through too many hoops?

I can require new users to upload pictures with a minimum size but I have imported lots of profile pictures and many are smaller than 480 pixels wide or high.
You can add an image field to the user entity. Then you can create a custom field formatter that can check if images are over a certain size and display a link to the larger size if they are. Here is an article on creating a field formater in Drupal 7: http://www.computerminds.co.uk/articles/creating-new-field-formatters-drupal-7