How do I protect an image in a new Window from being downloaded?

I'm working on a website that contains a link that when clicked on, will open a new html page loaded with a photo gallery. These photos are small; 300 width x height=auto.

The user may click on an image and from that point, it will open a new Window Tab. What I need to be able to do is protect the images from being downloaded on this new larger sized image Tab. Any ideas on this?

Thanks,