A little note about duplex scanning: since my beginnings I have always been using simplex scanners to get both sides of the documents. In every application that I have programmed, my software first asks for the first pass (all front sides of the pile of documents). At the end of the first pass the operator is asked to reinsert the pile of sheets in the ADF, and then the application makes a second pass to scan the back side of the sheets.
Then the application makes the following software operations:
a) makes sure that the number of sheets in both passes are the same
b) numbers the output TIFF files in the correct order (this is necessary, of course, because during the second pass the sheets are scanned in reverse order, plus it is necessary to anternate one front and one back according to odd and even pages).
In normal office activity, a secretary deals with both sided documents in a minority of cases. This is why my approach works fine for my customers.
My trick cuts hardware costs quite a lot. (Also in the early ’90s duplex scanners were difficult to find and very expensive.)
Why give so much money to the scanner manufacturers when you can have your customers saving on hardware, and shifting that saving into your earnings ?
So I never worried about programming duplex scanners… and this is my suggestion for everyone !
For other useful software tricks about scanning documents have a look at http://www.gentle.it/alvise/ffsplitad.htm and http://www.gentle.it/alvise/ffsplitbc.htm (there is a sketch linked in the “specification” section of these web pages that explains it well).
Regards. Alvise.