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Storage requirements for a digitisation workstation
It is important to realise the huge storage requirements that may occur with scanning a large number of images at very high quality. Equally it is important to have some method for backing up the archival quality images to a secure long term storage medium. The following figures are based around scanning slides at 2400 dpi for archival quality TIFF.
Formats
The archival format is an uncompressed TIF, considered to be too large for day to day use. The working TIFF and the working JPG are considered to be easier to move around the various situations. The formats will be batch produced from the archival image. Photoshop Batch Actions can handle this activity.
- 5000 pixel Archival TIFF
- 3000 pixel Working TIFF (LZW compression)
- 3000 pixel Working JPG
- 1000 pixel Presentation JPG
- 200 pixel Thumbnail JPG
How much hard disk space is needed to store all these files ?
1. 5000 pixel Archival TIFF
- 50 MB per image,
- 100 GB for 2000 images,
200 GB doubled for temp files
2. 3000 pixel Working TIFF (LZW)
- 10 MB per image,
- 20 GB for 2000 images,
40 GB doubled
3. 3000 pixel Working JPG
- 1.6 MB per image,
- 3.2 GB for 2000 images,
6.4GB doubled for temp files
4.1000 pixel Presentation JPG
- 0.5 MB per image,
- 1 GB for 2000 images,
2 GB doubled for temp files
5. 200 pixel Thumbnail JPG
- 30 kB per image,
- 60 MB for 2000 images,
0.12 MB doubled for temp files
Conclusion around 250 GB is needed to store 2000 images in all formats with room for temp files.
The recommendation is an external 250gig hard disk to handle these files.