Search the UNC Libraries Catalog to find books with images you can scan and transform to create new works of art. Scanners are available at the Sloane Art Library for you to use. Please remember that the images you scan may be protected by copyright. see the articles included in this guide on fair use and copyright.
Plus, UNC Libraries has tons of books on digital photography!
These institutions offer free downloading of images of artworks from their collections which are in the public domain:
Images in ARTstor with the IAP tag can be used for publishing and educational use, without the need to request additional permissions from contributing museums. More info about the IAP program can be found here: http://www.artstor.org/what-is-artstor/w-html/services-publishing.shtml