I'm trying to see if I can have rating for the images only, and not the gallery. Ideally it would be great to have these ratings shown below each thumbnail. Any thoughts?

Thanks

I assume with "Gallery" you actually mean an album. So just remove the rating function from your theme's album.php.
Also it might work to place the rating function within the next_image()loop on album.php to show it with each thumbnail (I did not try that yet).