To search a wide variety of images, use Jstor! These results will not be included when you search in SLUth (the main search box on the library homepage). Instead, you must access Jstor specifically. Once inside, there are useful tools to help limit your search, browse images from different traditions, and download for use in papers and presentations.
You may even save images for later use in Jstor, but you must register for an account and remember to log in whenever you'd like to access your Workspace.