> I want to use it for G3 fax, ie. 204x98 or 204x196 dpi, with accurate scaling;
> dropping or doubling lines is no good idea and I'm looking for some better
> (generic) way than interpolating from a higher resolution... Any ideas ?
The typical Fax-Application is sending black text/simple graphics on white
background. Thus I would suggest scanning at 204 dpi and or-ing (|) the
lines you would otherwise drop with the previous ones.
If you scan in Lineart mode, I think this is the way to go. "Dropping" 8
lines per inch will result in such an "artifact-line" every 3 mm what should
be close enough not to be too much annoying.
Real interpolation will require using a grayscale image and weighted adding
of the lines. I don't believe it will give much better results, except if
you are sending greyscale images or weird patterns.
What I actually do (inspired by my system setup) is always converting the
scan (resolution chosen at scan-time) to postscript and sending it to one
of my printer-queues (one of which is a FAX driver). So I leave the problem
to Ghostscript. Works pretty well for me, though I probably don't have
exact scaling.
CU,Andy
-- Andreas Beck | Email : <becka@sunserver1.rz.uni-duesseldorf.de>
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