About the Project
Purpose and Functional Requirements
The purpose of the Sanborn® Fire Insurance Maps for Georgia Towns and Cities, 1884-1922 project is to create an Internet-accessible database connecting users to all of the Georgia Sanborn® maps currently in the public domain. Functional requirements for the project include browsing by city and year, as well as searching by street address, named buildings and other features, county, city, and year. Each index map in the collection includes numbered sections that correspond to individual sheet maps. The database uses these index maps by making each numbered section a hyperlink to its corresponding sheet map. Users are able to zoom in on portions of sheet maps and index maps for close-in examination.
In February of 2004, the Digital Library of Georgia--with support from the Georgia HomePLACE initiative--began a pilot effort to start image capture and investigate the navigation requirements of the project. Metadata creation, database development, and Web design began in November 2004 with a demonstration database available in September 2005.
Prior to digitization, maps were selected from the Map Collection at the University of Georgia Libraries and brought to the digitization lab for scanning. For image capture, DLG staff utilized a PhaseOne Power Phase high resolution scanning back housed on a Toyo 45II camera, which was mounted on a Kaiser Repro copy stand with a 30” x 40” vacuum easel. For lighting, we used four Buhl HD lights mounted on stands. The Phase camera was connected via SCSI to an Apple G4 computer with 1 GB of RAM and dual 80 GB and 120 GB hard drives.
Each 21” x 25” map was digitized at 300 ppi, 24-bit color which included a GretagMacbeth ColorChecker®. The Phase was color calibrated prior to each day's image capture using PhaseOne color management software. Each image was saved as a 90 MB, uncompressed TIFF (Tagged Image File Format) without any additional color management applied. These master images were saved to the Digital Library of Georgia archival storage system.
Working files were created from the master TIFFs after a color correcting script (created in Adobe Photoshop) was applied and the images were cropped. This version was also saved to archival storage. Copies of these files were saved to a working files hard drive. From these working TIFFs, thumbnails and MrSid images were created. MrSid is developed and maintained by Lizardtech. This file format allows the viewer to zoom in or out on each image to see finer detail. Also, this format allows the user to print a zoomed and/or cropped portion of the image to any available paper size.
To add to the functionality of the browsable pages, the index maps were scaled and saved as 400 pixel wide JPGs. Using Macromedia Fireworks, each JPG was rendered a PNG (Portable Network Graphics) file to include applied Java scripting that creates the darkening effect when a mouse rolls over the image. (For more information, please see "Interactive index map" in the Glossary.)
The metadata unit of the Digital Library of Georgia was responsible for reviewing every map and generating descriptive records. The type of information captured for each map includes, but is not limited to, the city, county, year, type, title of map, sheet number, publisher, volume number (if applicable), scale, features, address ranges and available specials.
The GALILEO and Database Support unit of the University of Georgia Libraries developed the database using a locally developed system called “Ultimate,” which is written primarily in Perl and CGI.
The project benefited from additional expertise provided by Web designers employed by the Office of Information and Instructional Technology, Board of Regents, University System of Georgia.