Load invisible images with a specific class

[massic80]

Hi,
I was wondering whether there was an option to set loadInvisible = true and, at the same time, having the possibility to tag some hidden images as "loadable"; for instance, I would like not to download images appearing into the (closed) header, but at the same time I would like to load some images which are part of an animation, hidden on landing. The solution which comes in my mind would be a "downloadable-when-hidden" class.