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joelk

Member

Registered: 2017-04-16

Posts: 15

Brother MFC-L2750DW duplex scanning doesn't work with Xsane [solved]

I installed the Brother scanner driver from AUR: brscan4 (also brscan-skey).  The scanner is recognized by sane and can scan single-sided with no problems.  The xsane 0.999 window has choices for ADF left aligned, Duplex and ADF, centrally aligned, Duplex but when either of these is chosen it still scans only 1 side of the document.

Also, using brscan-skey and initiating the scan directly on the scanner's touchscreen, when duplex scan is selected it still scans only 1 side.  I also edited /opt/brother/scanner/brscan-skey/scantofile.config to set source=ADF and duplex=ON but the behavior is the same -- only 1 side scanned.

Duplex scanning works fine under Windows 10 using Brother's iScan program, so the problem is not the scanner.

Hss anyone been able to get duplex scanning to work with xsane on this Brother machine?

Last edited by joelk (2023-04-12 03:38:08)

joelk

Member

Registered: 2017-04-16

Posts: 15

Re: Brother MFC-L2750DW duplex scanning doesn't work with Xsane [solved]

I took a different approach.  I came across something (can't remember where) that suggested that this Brother might be escl compliant, so I started up avahi-daemon and ran

avahi-browse -rt _uscan._tcp

and the scanner responded.  So, I removed brscan4 and brscan-skey and tried scanning a multipage 2-sided document using

scanimage -d 'escl:http://LAN-ADDRESS:80' --mode Gray --resolution 200 --source 'ADF Duplex' -l 0 -t 0 -x 215.9 -y 279.4 --batch='out%d.pnm'

and it worked perfectly.  Scanned all 6 images from 3 sheets fed into the adf.

Then I tried Xsane.  It found the scanner.  I set it to ADF Duplex, Gray, Full color range, 200 resolution, letter portrait, created a multipage project, and ran Scan.  It fed the 3 sheets through the adf, then popped up an error message: "Failed to start scanner; Invalid argument".  The multipage project folder contained no images.  So I don't know what happened to Xsane which has never given me any problems before with other scanners.  But it seems now that the problem isn't the scanner, and it isn't Sane.

Any ideas on how to find out which "Invalid argument" Xsane is complaining about?

joelk

Member

Registered: 2017-04-16

Posts: 15

Re: Brother MFC-L2750DW duplex scanning doesn't work with Xsane [solved]

Did some more testing.  It's possible that I had a too-small area selected in the preview window.  With that corrected, Xsane can scan a single image, whether placed on the flatbed or in the document feeder.  If I put multiple pages on the document feeder, it feeds all the pages but only produces a single image of the first page.  Same thing whether set to ADF or ADF Duplex.

joelk

Member

Registered: 2017-04-16

Posts: 15

Re: Brother MFC-L2750DW duplex scanning doesn't work with Xsane [solved]

Well, after playing with it for a few days all scanning options (flatbed, ADF and ADF Duplex) are working.  Not sure what I changed.  As long as all relevant settings are correct, Xsane does perform duplex scanning and multipage projects (scanning multiple pages, single-sided or duplex and saving the result in a single pdf) well.

And by the way, this scanner doesn't need the Brother driver (brscan4) at all.  It works perfectly well using the escl driver and avahi-daemon.

In the process, I compared the performance of Xsane to Gnome Document Scanner (simple-scan) and to the command line scanimage.  Simple-scan was well-named.  Its interface is very simple and easy to configure.  It does duplex and multipage scanning competently, but MUCH slower than Xsane and scanimage.  I don't understand what causes it to scan so slowly -- I used the same dpi setting in both programs.  So for a GUI frontend I'd choose Xsane.

But it seems that, especially for large multipage projects scanimage is the best.  It's a little inconvenient to type out all the options, but once that's done it scans at about the same speed as Xsane but produces a significantly smaller pdf of the project.

For  comparison, I just scanned 2 2-sided sheets at 100 dpi with Xsane producing a 1.4 MiB pdf and scanimage producing a 363 KiB file.  I can't see a difference between the two documents.  I then scanned the same 2 pages with scanimage at 200 dpi producing a 1 MiB pdf that's considerably sharper, with no perceptible difference in speed.

For scanimage I used this command:

scanimage -d 'escl:http://192.168.1.143:80' --mode Gray --resolution 200 --source 'ADF Duplex' -l 0 -t 0 -x 215.9 -y 279.4 --format=pdf --batch='scanimage_project%d.pdf'