Embed a Copyright Notice. Later on, any honest viewer can read the same information and get in touch with you if they choose to do so. Go Low and Small. It won't be great art, but it gives the viewer an idea of what's available and has the added advantage of loading quickly. The viewer can then contact you if a higher-quality image is desired.
Many web pages do a marvelous job of concealing their creator's identity.
It may occur to some viewers to check the address bar for your home page, and maybe there's contact information there. But maybe there isn't. Take a run through your own site and see if you can find yourself. If not, you know what to do. And like everything else here, there's no guarantee that viewers will do the right thing.