The source images digitized for the online William P. Gottlieb Collection include photographic negatives and color transparencies, annotated contact prints for some of the negatives, and selected prints of the photographs that were published in a book. The photographic negatives and color transparencies in the collection are primarily nitrate and acetate film cut into three sizes: 2-1/4 x 2-1/4, 3-1/4 x 4-1/4, and 4 x 5 inches. The contact prints selected for the online presentation are 3-1/4 x 4-1/4 inches or less and marked with cropping, burning, and other annotations. The published prints are from The Golden Age of Jazz (Simon and Schuster, 1979; Pomegranate Artbooks, 1995) and are 8-1/2 x 11 inches or less except for a few that are spread over two pages. Since the published prints are duotone reproductions, moiré patterns often appear in the digitized images; an image enhancement algorithm was applied to reduce this effect. The existing 8x10-inch reference prints--representing only "Series A" (about half of the negatives)--were not scanned because higher quality digital reproductions can be created from the negatives and transparencies. The reference prints may be viewed in the Music Division Reading Room at the Library of Congress.
The William P. Gottlieb Collection is one of the first American Memory photographic projects to be digitized with a camera at high levels of spatial resolution. JJT Incorporated of Austin, Texas, scanned the negatives, transparencies, annotated contact prints, and published prints directly with an overhead-capture MARC II digital camera and processed the images with custom software. Three service images were produced from an uncompressed master file: a compressed reference image, a very high-resolution compressed display image, and a thumbnail. Each digital image was assigned a unique filename composed of the item identification number (last four digits of the local call number) followed by a format indicator, image category indicator, and file extension. The negatives, transparencies, and annotated contact prints were captured in their entirety, including edges and extraneous background features. The published prints represent the photographer's artistic wishes and are cropped accordingly.
An Agfa Horizon Ultra flatbed scanner was used to capture Down Beat articles from bound volumes and microfilm printouts. Bound Down Beat volumes from the late 1940s presented a digitization problem because text printed in the gutter of the issue could not always be captured by the scanner, and the paper itself is quite brittle--especially that of articles published in the latter part of 1947, when Down Beat experimented with newsprint. To capture the complete text of an article, it was sometimes necessary to scan a microfilm printout instead of the original even though the resulting bitonal image may not be as aesthetically pleasing. A compressed service image, with a spatial resolution ranging from about 600 to 1000 pixels wide, was derived from an uncompressed master file. Grayscale images are 8 bits-per-pixel while colored Down Beat covers are 24 bits-per-pixel.
Specifications for the Photographic Materials
Thumbnail Image
Tonal depth: 8 bits-per-pixel
Format: Graphic Interchange Format (GIF)
Compression: native to GIF format
Spatial resolution: approximately 150 pixels on the long side of the image
Basic Compressed Service Image
Tonal depth: grayscale: 8 bits-per-pixel; color: 24 bits-per-pixel
Format: JPEG File Interchange Format (JFIF)
Compression: JPEG at a quality setting that yields an average compression of 15:1
Spatial resolution: approximately 640 pixels on the long side of the image
Larger Compressed Service Image
Tonal depth: grayscale: 8 bits-per-pixel; color: 24 bits-per-pixel
Format: JPEG File Interchange Format (JFIF)
Compression: JPEG at a quality setting that yields an average compression of 8:1
Spatial resolution: approximately 1000 pixels on the long side of the image
Uncompressed Archival Image (NOT AVAILABLE)
Tonal depth: grayscale: 8 bits-per-pixel; color: 24 bits-per-pixel
Format: Tagged Image File Format (TIFF)
Compression: None
Spatial resolution: approximately 5000 pixels on the long side of the image