Nextgen transparent hover image mouse over

Hi,

I’m looking for a solution to create a mouse over effect when hovering the thumbnails in the Nextgen Gallery.

I’d like to have a half transparent image with a + sign in it when hovering the thumbnail.

Are there any solutions out there. I’ve seen some effects around but don’t know how to integrate them into Nextgen.

For the effect have a look at: http://codecanyon.net/item/dynamic-lightbox/full_screen_preview/1960109