Archival Formats for Digitized Images
Archival images should represent as closely as possible the information contained in the original. They should be high quality, uncompressed, unedited images able to serve as long-term sources for any files made from them and also serve as stand-ins for the originals.
Archival images should be scanned at a high resolution, usually 300dpi or higher. Ideally, for preservation or archival purposes, 24-bit color is a good bit depth to use, but other formats may be suitable in specific cases (for more information, see the page on scanning quality). Furthermore, the image size should be the same or close to the original document size. When saving the image, uncompressed TIFF is the best file-format choice. These files will be very large in size (often greater than one megabyte per single image), but they are ideal for obtaining derivative images such as presentation JPEGs or GIFs.
The TIFF images should be copied, and the original scans archived on some type of back-up medium such as CD-ROM, digital tape, or a large (several gigabyte) hard drive. This allows the scan to be used for other purposes at a later date. All further manipulations should be done on the copies.
Shown below are two 3" x 5" Biao Min notecards that have been scanned at a resoulution of 300dpi and saved in TIFF format. Click on the thumbnails to view the TIFF format of the digital images.
Image Details: Width: 1480 pixels; Height: 876 pixels; Bit Depth: 24 bits per pixel; Color Representation: True color RGB; Compression: Uncompressed; Size: 3.71 MB
Image Details: Width: 1480 pixels; Height: 876 pixels; Bit Depth: 24 bits per pixel; Color Representation: True color RGB; Compression: Uncompressed; Size: 3.73 MB
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