[sane-devel] SnapScan - AcerScan 300f (Newbie)

Oliver Schwartz Oliver.Schwartz@gmx.de
Thu, 2 Aug 2001 09:49:15 +0200


> However if I select 600 dpi I get
> an image which is compressed in the sense of width. I read on the scanner's
> manual that the optical sensor provided has a 300x600 dpi resolution, so my
> guess is that this asimmetry in the sensor reflects upon the scanned image.
> Is that so? 

You're right. There's currently no interpolation in the snapscan backend, so 
you only get the optical resolution from the scanner. It would be nice to 
have some kind of interpolation in the backend, so that the higher resolution 
in y-dimension can be used - however, at the moment nobody is working on such 
an interpolation in the backend. 

On the other hand, the 'real' resolution of your scanner is probably lower 
than 300x600 dpi anyway. "600dpi" in this case means that the tray 
can be moved in 600 steps per inch - but you may still get an average value 
for each position that's made up from the adjacent lines. 

In the moment, the only solution to your problem is to do the interpolation 
in x-dimension in an image manipulation application, e.g. gimp. Although this 
will generate you some work it should yield the same results as a high 
resolution scan in windows.