For most image citations, each style (MLA, APA, Chicago, etc) will have its own guidelines and examples, so check the style websites or the Purdue OWL for examples.
It can seem impossible to figure out the actual origin, name, or any information about images found from Google Image Search. With so many results going back to Pinterest or Tumblr (both of which erase identifying information), it's important to know how to identify an image, both for proper citation, but also because many images can have false information attached to them on repost sites like Pinterest and Tumblr.
Reverse Google Image Search allows you to search in Google using the image file itself rather than doing a keyword search. This is useful for pinpointing images that are the same or similar to the image your are looking for. Either go to images.google.com and drag and drop your image file into the search box, or if using the Google Chrome browser, right-click/ctrl-click on an online image and select "Search Google for image."
Image captions should include both the location of the work of art itself, as well as the location of where you found the image. Below is an example of an image from the Metropolitan Museum of Art's collection and how you would cite it depending on where you found the image. Captions should be used when depicting an image in a paper, and are different from citations.
Title: Josephine Baker
Artist: Adolph de Meyer
Date: 1825 - 1826
Medium: Direct carbon print
Location of work: Metropolitan Museum of Art
Fig. 1. Adolf de Meyer, Josephine Baker, 1825 - 26. Direct carbon print. Metropolitan Museum of Art.
Fig. 1. Adolf de Meyer, Josephine Baker, 1825 - 26. Direct carbon print. Metropolitan Museum of Art. metmuseum.org.
Fig. 1. Adolf de Meyer, Josephine Baker, 1825 - 26. Direct carbon print. Metropolitan Museum of Art. The New Vision: Photography between the World Wars, Ford Motor Company Collection at the Metropolitan Museum of Art. By Maria Morris Hambourg. New York: Metropolitan Museum of Art, 1989.