Please remember that you still need to cite these resources!!
The Chicago Manual of Style Online covers "Artwork and Illustrations," including those found online, in the following sections:
ARTstor is a database of images from museums, artists, libraries, colleges and universities, scholars, private collections, and photo archives available for teaching, education, and scholarship, with all images cleared for educational use.
Associated Press Images Collection is a searchable collection of recent and historical photos from the Associated Press, plus AP graphics, articles, and brief sound clips.