It depends on what kind of gallery it is. Most do specialize in paintings, but there are a few that do allow pictures that are artistic. Photography is an art, but the image is captured differently.
I would try different web sites (I'm not sure which ones they are), as there are some where you can post pictures and people will pay to download them it they like certain ones.
My friend told me about such a site, but it was a few years ago--before I had the internet, so I didn't pay too much attention.

Sorry I can't be of better help.
Maybe try Googling something.

Edit!!!

I just found something that may help. Try setting up a Photobucket account. It may not be what you're looking for, but it's worth a try!

Here's the link

www.photobucket.com