Difference between revisions of "Digitization Guidelines"
| Line 14: | Line 14: | ||
=== Color depth === | === Color depth === | ||
Bitonal scans (b/w) are generated with a color depth of 1 level (1 bit) per pixel. Greyscale images are digitized with 256 levels (8 bit = 1 byte) per pixel. Color images use 3 color channels (red, green, blue) with 1 byte per channel (= 24 bit | Bitonal scans (b/w) are generated with a color depth of 1 level (1 bit) per pixel. Greyscale images are digitized with 256 levels (8 bit = 1 byte) per pixel. Color images use 3 color channels (red, green, blue) with 1 byte per channel (= 3 byte = 24 bit) per pixel, enabling 256 x 256 x 256 = 16.7 million colors per pixel. | ||
24 bit provide a sufficiently high color depth for color scans. Scanning with 48 bit color depth makes sense only in few cases where images need to be corrected or reworked after the scanning process. | 24 bit provide a sufficiently high color depth for color scans. Scanning with 48 bit color depth makes sense only in few cases where images need to be corrected or reworked after the scanning process. | ||
== Notes == | == Notes == | ||
<references/> | <references/> | ||
Revision as of 10:53, 17 March 2008
- work in progress
In the following you find a relevant subset of the DFG guidelines for digitization[1] and, in addition, a description of a workflow for digitizing and submitting digital documents for digital collections maintained by the MPDL.
Scanning[edit]
Resolution and Image Quality[edit]
For scanning greyscale or colored prints a minimum resolution of 300 dpi is suggested. Documents containing handwriting or maps with fine lines and small descriptions might require a scan resolution of up to 400 dpi. For generating bitonal scans, 600 dpi are requested.
Color depth[edit]
Bitonal scans (b/w) are generated with a color depth of 1 level (1 bit) per pixel. Greyscale images are digitized with 256 levels (8 bit = 1 byte) per pixel. Color images use 3 color channels (red, green, blue) with 1 byte per channel (= 3 byte = 24 bit) per pixel, enabling 256 x 256 x 256 = 16.7 million colors per pixel. 24 bit provide a sufficiently high color depth for color scans. Scanning with 48 bit color depth makes sense only in few cases where images need to be corrected or reworked after the scanning process.