[sane-devel] Avision scanimage & image quality

[René Rebe]

On Wednesday 25 July 2007 16:19:32 Richard Reina wrote:
> Rene,
> 
> Thanks for the quick reply.  My printer is a Samsung ML-2550.  I am printing to it  via $:lpr ducument.tiff.  I have tried to attach a sample document but it gets rejected by the list moderator.  The documents are shipping documents that are often on thin pre printed forms like carbon copys but often are carbonless -- if that makes sense.  Here a link that shows some:

Hm - so a b/w laser printer. Maybe the printout is rathered and due to a
background color contains dithering dots all over the printout?

Maybe send me a original scan and a scan of a printout to just my private
address.

> http://www.ncrforms.com/home.php?xid=ab66d64884c5a7342c7641bec2ec6bb0
> 
> René Rebe <rene at exactcode.de> wrote: On Wednesday 25 July 2007 15:10:08 Richard Reina wrote:
> > Rene,
> >  
> >  Since dropping the "mode --Dithered" from my scanimage command the quality has improved somewhat.  However, when I print the document it does not look anywhere near as good as it did when viewed with $:display document.tiff.  Will optimize2bw help this?  Or do I have a printing quality issue?
> > 
> >  Thanks for the help thus far.
> 
> As with all technical systems the devil is in the details. And espeially with all
> the different color scanning and also printing techniques - including different
> materials.
> 
> The questions is what kind of techniques your printer does utilize, which
> printer is it by the way?
> 
> If the document looks good no the screen and totally different when printed
> out then you more likely have some problem in your print queue.
> 
> However with many print spoolers and rasterizers (including printer
> firmware rasterizers) it also depends how the PostScript/PDf is generated
> as there several different methods to embed image raster data in those
> files and most spoolers and firmware handle them differently.
> 
> If you expect this  free and open source scanner related list to help you
> out you certainly need to drop some more details what printer you use
> and what you try to archive.
> 
> Optimize2bw is an automatic thresholding application doing some
> sharpening and background color removal on the image and trying
> to preserve as much detail as possible to create 1bit b/w image for
> archival.
> 
> Yours,
> 
> > René Rebe  wrote: On Tuesday 24 July 2007 18:29:12 Richard Reina wrote:
> > > I have an Avision AV210 that I use to scan in documents with the scanimage command:
> > > 
> > > scanimage --mode Dithered --resolution 200 --format tiff > file_name
> > > 
> > > Can anyone recommend syntax to darken the document it and make it more clear?
> > 
> > All color tuning, including brightness, contrast and gamma also work in the
> > Dithered mode (in the Avision backend). Btw. Why do you use dithered at all?
> > 
> > If you want automatic thresholding you can scan in Gray (or Color) and use
> > optimize2bw from ExactImage:
> > 
> >   http://www.exactcode.de/site/open_source/exactimage/econvert/
> >   http://www.exactcode.de/site/open_source/exactimage/utilities/
> > 
> > Yours,
> > 
> > -- 
> >   René Rebe - ExactCODE GmbH - Europe, Germany, Berlin
> >   Geschäftsführer: Susanne Klaus, René Rebe
> >   Sitz: Berlin, Amtsgericht Charlottenburg HRB 105 123 B
> >   USt-IdNr.: DE251602478
> >   http://exactcode.de | http://t2-project.org | http://rene.rebe.name
> > 
> 
> 
> 
> -- 
>   René Rebe - ExactCODE GmbH - Europe, Germany, Berlin
>   Geschäftsführer: Susanne Klaus, René Rebe
>   Sitz: Berlin, Amtsgericht Charlottenburg HRB 105 123 B
>   USt-IdNr.: DE251602478
>   http://exactcode.de | http://t2-project.org | http://rene.rebe.name
> 



-- 
  René Rebe - ExactCODE GmbH - Europe, Germany, Berlin
  Geschäftsführer: Susanne Klaus, René Rebe
  Sitz: Berlin, Amtsgericht Charlottenburg HRB 105 123 B
  USt-IdNr.: DE251602478
  http://exactcode.de | http://t2-project.org | http://rene.rebe.name