Multiple problems with networked scanner

I used to have a networked USB Canon flatbed 9000F Scanner on a Synology box and it worked with Paperwork - perfectly! Unfortunately the box died and when I bought a new one it does not support USB devices (it’s a v7 DSM issue, apparently). OK, so I have networked my scanner using a Raspberry Pi and it appears to work very well - except on Paperwork! I have a Windows 10 machine and Paperwork just cannot see the scanner. Other scan programs can see the networked scanner and work perfectly. I also have a Linux (Mint) machine. Paperwork is v1.3.1. (and the instructions to install it just do NOT work. I had to use the Mint version). It tells me that a new version is available: Version 2.1.2 at https://openpaper.work/download/ - except that that page does NOT exist. If I try to setup my Canon scanner in this old (Linux) version, it can ‘see’ it but tells me that 'Error while scanning:libsane-quark:libinsane-opt[resolution] → set_value() error; 0x4000000 invalid value(4) - and this no matter what value I try!!
With such a plethora of problems where DO i go from here?

so I have networked my scanner using a Raspberry Pi and it appears to work very well - except on Paperwork!

To be blunt, I haven’t tested Paperwork + Windows + network scanners. I wasn’t even aware that Windows can access Linux network scanners.
Anyway, it’s a bit weird as there is nothing in the code preventing network scanners from working as far as I know. Which applications did you try ? Does Windows Fax and Scan work with your scanner ? (I’m asking because scanning on Windows is a big mess, but Windows Fax and Scan is usually a good reference for WIA2 support).

the instructions to install it just do NOT work

Which instructions ? There are about 5 ways to install Paperwork on Linux currently.

https://openpaper.work/download/ - except that that page does NOT exist.

My bad. I didn’t realize that this URL was still referenced in old versions of Paperwork (Paperwork 1.3.1 is about 3 years old). I’ve fixed the URL (it’s a simple redirect to the home page now).

If I try to setup my Canon scanner in this old (Linux) version, it can ‘see’ it but tells me that 'Error while scanning:libsane-quark:libinsane-opt[resolution] → set_value() error; 0x4000000 invalid value(4) - and this no matter what value I try!!

Can you try submitting a test scan report with IronScanner please ? Even if the test fails, the test report should help me figure out what’s wrong.

With such a plethora of problems where DO i go from here?

My suggestion:

  1. first, a test scan report with IronScanner
  2. wait for me to have a look, see if I can fix the support of your Canon scanner (don’t hesitate to ask me again about it if you don’t get any reply from me for a while)
  3. once it’s done, have a look at Paperwork - GNU/Linux - OpenPaperwork to get a more recent version of Paperwork (one flaggued “Fresh from OpenPaper” to have the fix for your scanner included)

Thank yo so much, Jerome. I really appreciate your assistance! I know that the problem - fundamentally - is a Synology one, but I know they’ll not be interested. When I had the scanner ‘networked’ on the old Synology box, OpenPaper worked perfectly. And I found that I must have originally put the successful results of my Canon 9000F scanner in the Paperwork database - I recognise the scanned picture!! Anyway I have run Iron Scanner on the Linux (Mint v 20.3) and it worked. It did give me an error message which I repeat here:

Scanning page 1 …
[WARNING] [paperwork_backend.docscan.libinsane] [LibInsane] …/subprojects/libinsane/src/workarounds/opt_names.c:L113(opt_desc_filter): Found option ‘scan-resolution’ but option ‘resolution’ already exists too, so we can’t rename it.
[WARNING] [paperwork_backend.docscan.libinsane] [LibInsane] …/subprojects/libinsane/src/workarounds/opt_names.c:L113(opt_desc_filter): Found option ‘scan-resolution’ but option ‘resolution’ already exists too, so we can’t rename it.

But despite this it scanned and the correct image was shown.

I’ve also had a look on the Windows (10 64 bit) machine. It is very interesting. I have a program on this machine - SANEWin 1.0 (7786) - that scans via the networked scanner perfectly. It ‘sees’ the Canon scanner and will scan exactly as requested. The Paperwork version on this machine is v 2.1.2-40-g70f5542d. If I launch this and go into ‘settings’ I can only see a HP6950 inkjet printer/scanner that I have on the network. The Canon scanner does not show at all if I click on ‘device’. I also ran Windows Fax and Scan and it does NOT find the scanner and so it can’t be ‘run’. But, as I said above SANEWin does see it and runs perfectly! Now I realise this is an intermediate report on what is happening. I’ll investigate further - try up loading new versions of Paperwork etc as you have suggested but I thought you might like some information. Thank you again! Mike

Hi Jerome

A further comment:

Screenshot from 2023-03-17 09-58-27

You can see why I said the instructions don’t work!!

Kind regards

Mike

It did give me an error message which I repeat here:

Scanning page 1 …
[WARNING] [paperwork_backend.docscan.libinsane] [LibInsane] …/subprojects/libinsane/src/workarounds/opt_names.c:L113(opt_desc_filter): Found option ‘scan-resolution’ but option ‘resolution’ already exists too, so we can’t rename it.
[WARNING] [paperwork_backend.docscan.libinsane] [LibInsane] …/subprojects/libinsane/src/workarounds/opt_names.c:L113(opt_desc_filter): Found option ‘scan-resolution’ but option ‘resolution’ already exists too, so we can’t rename it.

That’s no error messages. That’s just warnings. They are a bit weird. They say your scanner driver provides 2 options to do the same thing (and I can see in your report that the 2nd option is actually a mess, but Libinsane uses the valid one anyway). Anyway, it appears to be harmless.
This kind of warning happens with all the scanner drivers. They all have their own weird hiccups like this one. That’s what makes supporting all the scanners in the world an impossible task.

I have a program on this machine - SANEWin 1.0 (7786) - that scans via the networked scanner perfectly

Actually, that makes sense.

TL;DR: Try installing wiasane instead. You may have better luck. I’ve never tried it, but it seems to fit the bill.

Long version:

Scanner support on Windows and Linux are entirely different:

  • On GNU/Linux, scanner drivers are part of Sane Project and have to expose the Sane API. The Sane Project also provide a way to share scanner on the network using they own protocol.
  • On Windows, scanner drivers expose a WIA2 or TWAIN API. I guess it’s possible to share scanners across Windows hosts, but I don’t know how. It is possible to build Sane on Windows, but the only thing working then is the client code to access Sane network scanners.

Sane, WIA2 and TWAIN have nothing in common. That’s why I’ve made Libinsane. It’s mainly an abstraction layer on top of Sane/WIA2/TWAIN. Libinsane supports Sane on Linux, and WIA2 and TWAIN on Windows. It does not support Sane on Windows.

Your Synology NAS is based on Linux. Therefore it is likely to use Saned to share the scanner on the network. SANEWin is a program built with Sane support on Windows ; in other words, it is especially designed to run on Windows and to be a network client for Saned. It’s something that Paperwork/Libinsane don’t know how to do.

I also ran Windows Fax and Scan

This is a good way to know if a scanner driver expose a WIA2 API. If the scanner appears, then it does expose a WIA2 API, and then Paperwork is likely to support it (not always however).

You can see why I said the instructions don’t work!!

I understand now.

Regarding the language package, it’s paperwork-gtk-l10n-en and not paperwork-gtk-l10n-eng.

Regarding paperwork-shell, the root of the problem is that old Linux distributions provide a very old version of Paperwork: Paperwork 1.3.1. This version didn’t have the shell interface yet (package paperwork-shell). Therefore those distributions only provide the package paperwork-gtk at the moment.
By old distributions, I mean all the distributions based on the current Debian stable. This problem will be solved soon: Debian testing (bookworm) will become Debian stable in the coming months. Then all the distributions based on Debian will upgrade too in the following months.