[Plugin: NextGEN Gallery] Importing images from existing folders

I have a site where my post images are in many different subfolders.

Eg:

images/people/young
images/people/old
images/animals/fish
images/animals/birds
…

You get the idea. Now, is there a way to convert/import these folders to NEXTGen galleries? Can I create galleries that reference these folders?

Thanks.

https://www.ads-software.com/extend/plugins/nextgen-gallery/