[sane-devel] Colour problem with Canon Maxify MB5150

[Andrea Croci]

Servus,

I'm not replying as an expert here, only to ask a question: Does you
Maxify scan both sides in one shot from ADF or does it turn the page to
scan the other side? It seems to me having seen 3 or 4 of them, that
most Canons nowadays include the one-shot-scanning feature (it probably
has a real name). That could make a difference in the appearance as
compared to flatbed scanning, because I would guess the sensors to be
different.

Regards,

Andrea

On 19.05.21 17:46, Dr Rainer Woitok wrote:
> Greetings,
>
> since our good ol'  Canon Pixma MX885  has eventually reached its End Of
> Life, we've bought a Canon Maxify MB5150.  And because
>
>     http://www.sane-project.org/sane-mfgs.html
>
> listed this scanner  as using the same  "pixma" backend  as the MX885, I
> just had to update the IP address in "~/.config/sane/pixma.conf" to acc-
> ess the new scanner via "scanimage".   However, scanning the same single
> page from flatbed or via ADF produced significantly different results:
>
>    - The PNG file from the flatbed clearly showed the original paper hav-
>      ing been rather thin, since some colours from the reverse side shone
>      slightly through, and the background colour having been faintly grey
>      rather than white.   In other words, this PNG file was a fairly good
>      copy of the original.
>
>    - But the PNG file from the ADF did show almost no shine through and a
>      more or less purely white background.  Dark colours appeared slight-
>      ly darker and light colours slightly lighter than the original.  The
>      effect was somewhat similar to using ImageMagick's "-normalize" opt-
>      ion.
>
> While this sort of normalization seems good to have,  if one needs it, I
> would prefer controlling it  via options to "scanimage"  rather than via
> the scanning source.
>
> Is there some way  to prevent this normalization effect  for the  MB5150
> when scanning via ADF?
>
> Oh, almost forgot:  using "media-gfx/sane-backends" version 1.0.31-r2 on
> Gentoo.
>
> Sincerely,
>    Rainer
>
>