Claire B. Blog 4: African Poster Collection at Northwestern University

This collection of posters published in Africa is a representative segment of the African poster collection housed in the Melville J. Herskovits Library of African Studies at Northwestern University. The digitized posters represent visual images created by governments (independent and colonial) and international agencies, as well as political, labor, social, religious, educational and cultural organizations in Africa from the late 1960s to the 1980s, roughly.

Collection Principles

The Melville J. Herskovits Library is the largest separate Africana collection in the world. This selection of posters from the library's collection was identified in 1995 as ideal material for a digitization project because of their visual interest and the access potential of an online database. The posters were digitized and the site was developed between 1995 and 1998, and from 2003 to 2004 (not sure why there was a break in the work – could be any number of reasons).

The posters generally represent three themes: the 1970's liberation movements in the former Portuguese colonies; the Anti-Apartheid groups flourishing outside of South Africa in the 1970's and 1980's; and political campaign posters from the historic South African election of 1994. The site contains 590 posters, selected as a representative sampling of the collection for searching and viewing.

Object Characteristics

The archival digital images were saved in photo CD format (I’m not too sure what that means, but I think it means a scanning of color negative film and captured onto photo CD disks. This supposedly offers compatibility across platforms and multiple levels of resolution).

The original medium resolution images were cropped to remove reference targets (including grayscale and color cards as well as inventory numbers). They were re-saved as low-compression, high quality JPEG images using batch processing in 24 bit color at high quality, 72 dpi. They were also saved in GIF format in 8 bit color to create smaller-scale "thumbnail" images (two sizes in GIF format). Original proportions were retained.

The site offers 7 or 8 levels of zooming and a menu at the top of the detail page for more image manipulation tools, plus a helpful viewer window to show exactly which portion of the poster you are zooming further into. A beta viewer in Flash also allows different zooming options.

Metadata

An extensive documentation section was really helpful for understanding how this collection was put together and how it is maintained. Project staff created individual records for each poster in both the library's online catalog and an online web database to allow full access. Full-level MARC records were created and then converted to SGML for use in the web database. The data structure for the web database incorporates selected fields from the MARC record, and the conversion was conducted through a customized batch process. The records for the posters were completely uploaded in 2004.

Posters can be browsed by date, title, or a limited number of subjects and searching is possible in free-text, by title, date, or agency. An advanced searching feature offers ways to search by other MARC fields (artist, date, series, language, object no.).

The documentation mentions that in the 856 (electronic resource) field of each MARC record, two links appear to the user: one directly to the JPEG image and the second leading to the URL for the web image database if the viewer prefers incorporating visual browsing with search results. Additionally, hidden links allow for the incorporation of thumbnail images in the various summary displays. This sort of confused me, frankly.

Intended Audience

This collection – plus its extensive searching, browsing, and viewing capabilities – likely holds wide appeal. African historians, historians of labor and social movements, and people interested in the visual arts would probably all find this site useful. I could see people interested in semiotics and linguistics finding this site fascinating as well. While the main page is not completely intuitive in terms of where to go to view the posters, once you start looking through the site there are some fascinating images to view and manipulate.