[sane-devel] Problem with new Canon iSensys MF746Cx
strredwolf at gmail.com
Tue Sep 8 16:23:55 BST 2020
What I'd do is scan them into Gimp and tweak them using the Colors >>
Levels command to remove the bleed-through. I think 300 dpi is
sufficient; anything over 450 would be overkill in this case.
With a quick check... ahhh. Gimp will let you export to a multipage
PDF. It defaults to the first page being the bottom layer.
On Tue, Sep 8, 2020 at 11:09 AM Andrea Croci <andrea.croci at gmx.de> wrote:
> Hi Kelly,
> no, I'm not scanning text for OCR, I receive some documents per Mail
> that I need to sign, scan and send back. When the document is printed on
> both sides, the back side shows up if I don't adjust the brightness. I
> haven't tried to process it in the PC, though. Maybe that works too.
> I would love to force the scanner to not auto-adjust, but I don't know
> how to do that. Or how to force it to auto-adjust for that matter. All I
> know is that with my Epson printer/scanner and the epkowa backend I have
> a lot of options including adjusting the brightness. If I set that to a
> value between 30 and 40 I don't get the back of the document to show
> through. I would like to be able to do that in the new scanner as well.
> All I use Imagemagick for is the conversion of the huge .tiff out of the
> scanner to a still big, but acceptable in most cases, .pdf.
> On 08.09.20 16:53, Kelly Price wrote:
> > I take it you're scanning text for OCR?
> > Consider it line art, and take some advice from Sean Michael Robinson
> > in the Cerberus The Aardvark Restoration Project.
> > http://momentofcerebus.blogspot.com/2017/02/paper-to-pixel-to-paper-again-part-five.html
> > In short:
> > * Scan in 24-bit color. It doesn't slow it down.
> > * Set the brightness/saturation/contrast/gamma to the defaults, and
> > don't touch 'em.
> > * Force the scanner to not auto-adjust.
> > * Your PC is better at adjusting the color values and forcing it to
> > greyscale than the scanner is.
> > To which I add:
> > * ImageMagick and some shell scripting can bulk-process anything.
> > On Tue, Sep 8, 2020 at 10:32 AM Andrea Croci <andrea.croci at gmx.de> wrote:
> >> Hi Alexander,
> >> thank you for your reply. That did work indeed: the scanner gets
> >> recognised as 'airscan:e0:Canon MF745C/746C'. However the list of
> >> options for that device is very short. For instance there is no
> >> "brightness", which would be very helpful when scanning a page printed
> >> on the backside too. That's what I always have to adjust with the Epson
> >> scanner in order not to see the back printing through.
> >> In addition I just checked in my laptop, which has Ubuntu 20.04
> >> installed instead. That has recognised the scanner automatically with
> >> the "escl" backend. I don't see an "escl.conf" in my desktop with 18.04.
> >> Is this just a matter of sane-version?
> >> Is there any way to activate other functions for the scanner?
> >> Thank you and regards,
> >> Andrea
> >> On 08.09.20 12:30, Alexander Pevzner wrote:
> >>> Hi Andrea,
> >>> On 9/8/20 7:20 AM, Andrea Croci wrote:
> >>>> I have just installed a new Canon iSensys MF746Cx on Ubuntu 18.04 and I
> >>>> can't get it to scan. It' connected over the network. I haven't found
> >>>> any driver or software for scanning on Canon's Website, so I was hoping
> >>>> I could do it with sane. I have read on the list of supported devices
> >>>> that the MF741/743 are fully supported by the pixma backend.
> >>> The sane-airscan will probably work for you:
> >>> https://github.com/alexpevzner/sane-airscan - the project page
> >>> https://download.opensuse.org/repositories/home:/pzz/ - binary
> >>> packages for many distros
Kelly "STrRedWolf" Price
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