Canon Pixma G3501 & *Ubuntu 18.04 LTS: though I CAN print, I CANNOT scan.

[Brian]

On Sun 05 Apr 2020 at 15:55:12 -0400, Little Girl wrote:

> Hey there,
> 
> Brian wrote:
> >Little Girl wrote:
>  
> >> This may or may not be the same for you with your Canon printer,
> >> but my Brother printer does wired or wireless printing, but can
> >> only do wired scanning from my Ubuntu MATE machine. This is
> >> definitely a GNU/Linux driver issue, because the same printer does
> >> wireless scans with no issues from Windows, from an Android
> >> tablet, and from my iPad.
> 
> >SANE does not provide a backend for Brother MFDs.
> 
> This is inaccurate. I can print while the printer is wired or
> wireless and I can only scan while the printer is wired. Therefore,

I changed "SANE" to "SANE project" to emphasise that the project does
not provide a backend for Brother MFDs. If I am mistaken, you will,
of course, provide the name of the backend that the SANE project ships
for Brother devices.

Being able to print is one thing; being able to scan is another. There
is absolutely no connection between printing and scanning, so I do mot
know what point you are making. 

> the only accurate conclusion that can be drawn is that SANE does,
> indeed, provide a partial GNU/Linux back end for at least one Brother
> scanner (mine), but does not provide a full GNU/Linux back end for
> that same Brother scanner.

"Partial" and "full" backends are not concepts I am familiar with.
You should now name them to clarify what it is you mean.

> >The Android tablet and the iPad do not use SANE but AirScan, which
> >Ubuntu 18.04 can also use.
> 
> That's interesting. More information on how Ubuntu can use AirScan
> would have been nice, but I'll look that up to see if it's something
> I'd like to set up.
> 
> >Lack of wireless scanning is not a GNU/Linux driver issue.
> 
> This is inaccurate. You used "backend" above when referring to what
> SANE provides and you were right that SANE provides a back end. SANE's
> back end, however, consists of drivers. Therefore, you agree that
> it's a driver issue.

I actually said that SANE does not provide a backend for Brother MFDs.
It would be incorrect for me to claim otherwise.

> See the Architecture section of the
> https://en.wikipedia.org/wiki/Scanner_Access_Now_Easy page for more
> information on the definition of back end when it comes to SANE. I've
> pulled this quote from it for you:
> 
> 	"SANE differs from TWAIN in that it is cleanly separated into
> 	"front ends" (user programs) and "back ends" (scanner
> 	drivers)."

That's accurate.
 
> I'll give you the possibility that this may not be a GNU/Linux issue,
> since that's a rather huge piece of real estate and the possibility
> exists that SANE provides everything needed by my scanner in some
> other variant of GNU/Linux. I would, however, have to say that it's
> at least an Ubuntu MATE issue, since that's where I, personally, am
> experiencing it after downloading and installing the Linux drivers
> provided by Brother (note that "GNU/" was added by me - they always
> only refer to it as "Linux" on their site).
> 
> >Additionally, it is probably not the same issue as with the Canon
> >MFD.
> 
> Thank you for sort of confirming my "may or may not be the same for
> you" statement above.

The nature of the DE has no bearing or influence on the funtioning of
SANE.

-- 
Brian.