The images in this collection were scanned from photocopies, which nearly make up the whole of the document collection. Staff made photocopies from original documents, photostats, microfilm, and other facsimile media. The photocopies were then scanned as black and white images at 300 dots per inch (dpi) resolution. Each page of a document was saved as a separate Tagged Image Format File (TIFF), utilizing TIFF category 4 image compression. Document image files were then concatenated into a single, multi-page TIFF and named with the same number used as the document ID in the database.
A number of documents were scanned in color from the original documents. These documents were scanned at either 600 or 300 dpi, 24-pit color, and saved as uncompressed TIFF files. Image files were then concatenated into single, multi-page djvu files. Djvu, a product of Lizardtech (www.lizardtech.com), allows for multi-layered compression into very small file sizes.
A very small number of documents were scanned as gray-scale images. Only those photocopies, which were illegible as black and white images but readable as gray-scale images, were scanned in that format. This decision was made in the interest of file size.
Except for reversing negative-image copies into positive images, no attempt was made to enhance images electronically. A very small number of negative-image documents were not reversed because changing them to positive-image documents rendered the image illegible.
Document images are stored in a directory named for the case or nonlitigation File ID to which they pertain. File IDs are grouped under directories named by general court jurisdiction, e.g., Federal, Sangamon, ISC.