Book People Archive

Re: Feedback requested on the Plustek OpticBook 3600 -- alternatives?

Jon Noring wrote:
 > Interesting. So what that means is that the "track" is 0.35 degrees
 > off from an exact right angle with the scanning bar?
Easier to think the other way around -- the scanning bar
is not precisely perpendicular to the guide rails.  Same
problem with the HP see-through scanner

 > This suggests that if one scans a calibration chart, one may be able
 > to determine the shear and apply a "de-shearing" correction in
 > post-processing.
Yes, that's exactly what I do, starting with scanning a piece
of graph paper. It's really the kind of auto-calibration that
could and should be built into scanner software in general --
indeed, they could just print a two-line shear-correction grid
inside the scanner cover.

    Doug