MDS-940DW - Partial page scan only

[gitentropy]

Hi,

Firstly, thanks for the awesome image to utilise, it's a really convenient way to bring documents straight into my digital filing cabinet.

I do have an issue that has stumped me, and I was hopeful I've just missed something.

Quick summary:

The scans only capture the top ~1/4 of the page, the remainder is blank (pure white).

Detailed:

I have a portable Brother Scanner MDS-940DW, while using the native app via my mobile/desktop/sd card, I am able to scan complete pages.

What I've tested:

1. Increasing the resolution 300 > 600 > 1200. But even at the higher end I only get ~3/4 of the page.

• This is also the upper limit I can apply before the it forcible rounds down.

Few problems with this 'solution':

• Scan still doesn't capture the full page as expected
• The physical scans take 4 x longer due to the resolution
• File size can be 20MB+

2. Change the blank pages from 0.0 to 1.0, incrementally by 0.1

• Didn't notice any change

3. Change the x/y parameters to match the document exactly

• This doesn't appear to have any affect on the outcome
• More often the values were rounded to larger values
• I've now defaulted it to the max allowed

Setup

• Brother MDS-940DW connected via wifi
• Docker running under Debian 12
• Image: ghcr.io/philippmundhenk/brotherscannerdocker:v1.1.1

enviroment:
            - WEBSERVER=true
            - DISABLE_GUI_SCANTOIMAGE=true
            - DISABLE_GUI_SCANTOOCR=true
            - RENAME_GUI_SCANTOFILE="Start new scan"
            - RENAME_GUI_SCANTOEMAIL="Scan additional pages"
            - REMOVE_BLANK_THRESHOLD=0.3

Log after Blank Threshold 0.3 and Resolution 300.

setting up user & logfile:
Allowing use of questionable username.
Adding user `Scanner' ...
Adding new user `Scanner' (1000) with group `NAS' ...
Creating home directory `/home/Scanner' ...
Copying files from `/etc/skel' ...
-----
setting up interface:
using interface: eth0
-----
setting up host IP:
-----
whole config:
=
IMAGE="bash  /opt/brother/scanner/brscan-skey/script/scantoimage.sh"
OCR="bash  /opt/brother/scanner/brscan-skey/script/scantoocr.sh"
EMAIL="bash  /opt/brother/scanner/brscan-skey/script/scantoemail.sh"
FILE="bash  /opt/brother/scanner/brscan-skey/script/scantofile.sh"
SEMID=b
eth=eth0
ip_address=***
-----
starting scanner drivers...
-----
setting up webserver:
starting webserver for API & GUI...
running on port 33355
webserver started
-----
capabilities:
Output format is not set, using pnm as a default.
Created directory: /var/lib/snmp/cert_indexes
scanimage: open of device brother4:net1;dev0 failed: Invalid argument
startup successful
/opt/brother/scanner/brscan-skey/script/scantofile.sh: line 7: UID: readonly variable
filename: /tmp/2025-03-26-22-48-33/2025-03-26-22-48-33-front-page%04d.pnm
scanimage: rounded value of br-x from 211.881 to 211.881
scanimage: rounded value of br-y from 355.567 to 355.567
Scanning infinity pages, incrementing by 1, numbering from 1
Scanning page 1
Scanned page 1. (scanner status = 5)
Scanning page 2
Scanned page 2. (scanner status = 5)
Scanning page 3
scanimage: sane_start: Document feeder out of documents
Batch terminated, 2 pages scanned
conversion process for 2025-03-26-22-48-33 is running in PID: 1297
converting to PDF for 2025-03-26-22-48-33...
SSH environment variables not set, skipping inotify trigger.
TELEGRAM_TOKEN or TELEGRAM_CHATID environment variables not set, skipping Telegram trigger.
FTP environment variables not set, skipping inotify trigger.
cleaning up for 2025-03-26-22-48-33...
OCR environment variables not set, skipping OCR.

[yashdavisgupta]

When you have the above problem, are you connected via wifi direct or lan? Are the other tests with mobile/phone also wifi direct/lan?

I had this issue with my scanner at first, I entered the web configuration on the scanner and one of the option changes made it work.

[gitentropy]

When you have the above problem, are you connected via wifi direct or lan? Are the other tests with mobile/phone also wifi direct/lan?

I had this issue with my scanner at first, I entered the web configuration on the scanner and one of the option changes made it work.

Using the webui via desktop is LAN, using it via mobile is Wifi. The scanner is naturally connected via Wifi.

Could you elaborate on the configurations you're referring to and I'll attempt to make similar changes.

[PhilippMundhenk]

Is this issue really from March 2025? My apologies! I must have totally missed it!!

Not quite sure what is wrong here. The logs show a correct scan of two pages. Could it be connectivity issues between scanner and server? An instable WiFi connection or something? This is basically all handled in the scanner driver by Brother, but I'm only aware of two cases, where this has happened: Either loss of connectivity, or scanner reports end of page (either because really finished, or because stop button pressed).
What stumps me here is that the resolution makes a difference.
I think @yashdavisgupta is referring to the settings of the scanner itself, not the web GUI of this project. Not sure which option, though.

Is the page actually fully scanned but doesn't show up? Or is it scanned 1/4 only and then quickly run through for the rest of the way (as if you press stop after 1/4)?

[yashdavisgupta]

Looking back, updating the firmware to the latest version and resetting the device fixed it for me.

[gitentropy]

@PhilippMundhenk Nothing to apologies for, thanks for making the software available for everyone.

I have a fair good wifi setup, and I have tested with the scanner directly next to the router.

The scanner appears to be processing the whole page when it scans, particularly noticeable on the higher resolutions as it scans very slowly from start to finish.

I may have to try resetting everything or setting the container up on another system if I can.

@yashdavisgupta Thanks for checking. I believe mine is fully up to date, currently v1.61. I can't see anywhere in the mobile app prompting/allowing an update.

Example scan with some guidelines:

[yashdavisgupta]

Try attaching to the container, I'm curious if just running a standard scanimage command with minimal arguments might work? Don't specify any geometry? It really looks like an issue with the scanner settings or the brother driver, but trying to reduce failure points.

You confirmed that the mobile app scans fine, so probably not the scanner settings.

[gitentropy]

I ran the below within the container:

root@brotherscanner:/# scanimage -o /scans/container-test.png --format png
scanimage: rounded value of br-x from 211.9 to 211.881
scanimage: rounded value of br-y from 355.6 to 355.567
root@brotherscanner:/# scanimage -o /scans/container-test.jpeg --format jpeg
scanimage: rounded value of br-x from 211.9 to 211.881
scanimage: rounded value of br-y from 355.6 to 355.567
root@brotherscanner:/# scanimage -o /scans/container-test.tiff --format tiff
scanimage: rounded value of br-x from 211.9 to 211.881
scanimage: rounded value of br-y from 355.6 to 355.567
root@brotherscanner:/# scanimage -o /scans/container-test.pnm --format pnm
scanimage: rounded value of br-x from 211.9 to 211.881
scanimage: rounded value of br-y from 355.6 to 355.567

All of these produce the same result, which is more inline with the higher resolution results of 3/4 of the page, likely more, missing about 20mm off the bottom, but then has dead space after what would be the end of the page.