Digitizing the Negatives |
During 2004 and 2005, JJT, Inc., of Austin, Texas, scanned the Matson Negatives. They used an overhead Sinar 54 digital camera to scan more than 13,700 glass negatives (measuring in sizes ranging between 4 x 5 inches or smaller and 10 x 12 inches). The images were captured in grayscale at a spatial resolution of approximately 5,000 pixels on the long side and a tonal resolution of 8 bits per pixel.
With today's resources, these high-resolution images require significantly increased costs, particularly in time spent capturing, inspecting, and loading the files. For most collections in the Prints and Photographs Division, online digital images, even at lower resolutions, play an important preservation role as surrogates that reduce handling of the original pictures. The high quality master and derivative files are available online. Digital images of each negative display in each bibliographic record.
Specifications for the Collection
Uncompressed Archival Images
| Spatial Resolution: | 5,000 pixels on the long side with the short side scaled in proportion for file names ending in u.tif (10-73 megabytes) |
| Tonal (pixel depth) resolution: | 8 bits per pixel (grayscale) |
| Image enhancement: | None. |
| File format: | Tagged Image File Format (TIFF) ver. 6.0 |
| Compression: | None |
Compressed Service Images
| Spatial resolution: | 640 pixels on the long side with the short side scaled in proportion for file names ending r.jpg (20-126 kilobytes); 1024 pixels on the long side with the short side scaled in proportion for file names ending v.jpg (42-377 kilobytes) |
| Tonal (pixel depth) resolution: | 8 bits per pixel (grayscale) |
| Image enhancement: | Mild sharpening |
| File format: | JPEG |
| Compression: | Compressed to yield an average compression ratio of 10:1 |
Thumbnail Images
| Spatial Resolution: | 150 pixels on the long side with the short side scaled in proportion for file names ending in t.gif (approximately 10-20 kilobytes) |
| Tonal (pixel depth) resolution: | 8 bits per pixel (grayscale) |
| Image enhancement: | Mild sharpening |
| File format: | Archived copy: TIFF - Tagged Image File Format Online copy: GIF - Graphics Interchange Format |
| Compression: | Archived copy: Uncompressed Online copy: Compression native to the GIF format |
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Library
of Congress( July 6, 2005 )