On 5/1/09 8:27 PM, Lars Aronsson wrote:
> Does anybody have a printed test sheet that we can scan or photo, 
> and then compare the resulting digital images?  It should have 
> lines at various densities and areas of different colours, just 
> like an old TV test image.  Can you buy such calibration sheets?

archive.org scans typically include a color card target
image near the back (or front) of the book, e.g.

http://www-steve.us.archive.org/public/data/eg/birdsthateverych00doub/birdsthateverych00doub_jp2/birdsthateverych00doub_0371.jp2

typical specs for our scanning rig (scribe) are roughly:

   1 8x8x5' scribe structure
   2 Canon EOS 5Ds
   2 light boxes
   1 orthogonal glass platen and cradle
   1 foot pedal, pulley system
   Linux PC
     LAMP stack
     custom web-based UI
     gphoto, imagemagick, leptonica, rsync
   fast internet


we scan over 1,000 books a day with about 100 scribes like this.


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