According to the Department of Image Collection Chief, the "new web presence give the researcher a quick overview of the various collections from scholars, photographers, and our rare holdings. The new pages also serve as the portal to Mercury, the National Gallery of Art Library’s online catalogue where you can search for images by the usual strategies of artist, subject and keyword. By selecting the advanced search option one can also try image source (e.g. Alinari, Brumfield, Kress) building location, or name/subject authorities and many other options. While there are not item records for all 7 million photographs and reproductive prints, 7.5 million images in microform, 225,000 slides or 200,000 digital files, there will be a summary record for each artist or building indicating our holdings. Many item records will have a thumbnail that will open Oculus, our digital image database, where many images are already scaled for use in digital presentations (for information on publishing use, please contact us)."
To find the web page, Please point your browser to www.nga.gov. Under the tab for research, select Library and on the Library’s page you will find an icon for Image Collections. Please click. (or bookmark this url: http://www.nga.gov/content/
ngaweb/research/library/ imagecollections.html )