Imaging Standards
The following tables aggregate standards based for digital preservation based on consortial requirements and based on the work of national governance bodies and interest groups.
Printed and handwritten text
|
Scan Type |
Bit Depth |
Resolution (ppi/dpi) |
Color space |
Scale |
File format |
|
Black and white print |
1-bit |
600 |
Bitonal |
1:1 |
TIFF with Group 4 lossless compression AND PDF/A |
|
Black and white + illustrations, or handwritten |
8-bit |
400 |
Grayscale |
1:1 |
Uncompressed TIFF AND PDF/A |
|
Text with color images, or handwritten |
24-bit |
400 |
RGB |
1:1 |
Uncompressed TIFF AND PDF/A |
Printed photographs
|
Type |
Bit Depth |
Resolution (ppi/dpi) |
Color space |
Scale |
File format |
|
Black and white |
8-bit |
600 |
Grayscale |
1:1 |
Uncompressed Tiff |
|
Color |
24-bit |
600 |
RGB |
1:1 |
Uncompressed TIFF |
Large Format Maps and Posters
|
Type |
Bit Depth |
Resolution (ppi/dpi) |
Color space |
Scale |
File format |
|
Black and white |
8-bit |
5000 - 10,000 pixels on the longest side |
Grayscale |
1:1 |
Uncompressed TIFF |
|
Color |
24-bit |
5000 - 10,000 pixels on the longest side |
RGB |
1:1 |
Uncompressed TIFF |
Negatives and transparencies
|
Type |
Bit Depth |
Resolution (ppi/dpi) |
Color space |
Scale |
File format |
|
Black and white |
8-bit |
5000 pixels on the longest side* |
Grayscale |
1:1 |
Uncompressed TIFF |
|
Color |
24-bit |
5000 pixels on the longest side* |
RGB |
1:1 |
Uncompressed TIFF |
*Common film sizes and corresponding resolutions to achieve 5000 pixels on the longest side.
|
35 mm |
4000 dpi |
|
2x3 in |
2400 dpi |
|
6x9 cm |
2400 dpi |
|
6x7 cm |
2400 dpi |
|
6x6 cm |
2400 dpi |
|
7x9 cm |
2400 dpi |
|
4x4 cm |
4000 dpi |
|
4x5 in |
1200 dpi |