First of all let me say this looks like a great plugin!
I have an image gallery and I have added categories to the images using your plugin. The reason that I am doing this is to use the Isotope jQuery script to allow users to filter the image gallery by category. What I am now having trouble with is figuring out how to output the assigned category for each image as a class so Isotope can show or hide it accordingly.
Do I need to somehow edit the output of the plugin or is there a more simple shortcode value that I am missing?
Thanks for any help you can offer!