Use | Resolution | Bit Depth | Color Space | Dimen- sions |
Editing/ Processing |
File Format/ Compression | Storage | |
---|---|---|---|---|---|---|---|---|
Archival |
Long-term archive |
600 ppi1 |
24-bit |
RGB |
At least 4,000 pix on LS |
TIFF, with little endian (IBM PC) Byte Order; no compression; save with embedded ICC Color Profile |
Stored on 2 media: CD, DVD, tape, spinning disk |
|
Working |
-To create derivatives. -Publication printing. |
sRGB
|
-Change file format.4 -Tone & color adjusted -Sharpened |
Same as AM, but may be compressed with LZW compression if saving storage space is essential.5 |
If kept, same as AM. |
|||
Static |
Internet delivery |
150 dpi |
W: 640 px |
-Reduced dimensions -Sharpened |
JPEG, medium quality, 5-7; or high quality, 8-10 (of 10)6 |
Spinning disk and backup tape |
[1] - Increase resolution for small photos if necessary in order to achieve 4,000 pixels on the long side. If the original material is larger than 8 x 10 inches, see Digitizing Oversize Objects.
[2] - Grayscale factors: minimum number of visible steps: 18; minimum number of f-stops: 5.5; Y channel noise: <=5%.
[3] - Color accuracy: DeltaE < 8, ICC Profile (decrease if image is very large).
[4] - If you are using Photoshop to edit the Working Master, change the file's TIFF format to PSD, Photoshop's native file format, which allows for more editing functionality.
[5] - To provide zoom and pan functionality for an image, you can upload the Working Master (TIFF) file to a "full resolution" CONTENTdm collection. CONTENTdm will then convert the TIFF format to a JPEG2000 format.
[6] - This dimension is used to achieve optimal viewing of an image in HDR. Providing more pixels on the long side, say 1200 pixels, increases its size and will require the user to select an option to enlarge it for full viewing