There is a great product called slideshow pro director which is a PHP gallery backend for a popular web slideshow system. It also uses mysql. I think it would be an ideal candidate for CloudSE.
It's a well-written product with lots of potential, but unfortunately the developer is missing in action from the forums.
Here is more information on the product.
http://slideshowpro.net/inc/modals/dir-slideshows/ (video works in chrome)
It's main claim to fame is that it creates a 1:1 pixel version of each image for the target display device regardless of size and it can also do this for fullscreen. I am a photographer and I searched high and low for a system that would do this because all other systems introduce perceived blur due to image stretching if you wan to show fullscreen.