Traditionally, historical research, both in Japan and elsewhere, has been based primarily on written documents. Yet the existing Japanese historical materials include an immense array of pictorial sources as well, such as maps, portraits, picture scrolls, book illustrations, and more. The Center for the Study of Visual Sources was established in 1997 to apply new computer and scanner technologies to the study of historical pictures and maps. The staff at the center are working with researchers in the other five departments of the Institute and CDPS to create a systematic database of visual sources. Precision photography is used to examine paper quality and document aging, and the computers are used to identify handwriting, monograms, and seals. One project focuses on ancient and medieval estate maps with the Center producing compilations of these maps in the Nihon Shoen Ezu Shuei.