[sane-devel] HP Scanjet 7650 (hp5590 backend) inserts ghost pages when using "ADF Duplex"

[Ralph Little]

Hi,

On 2022-02-09 07:12, hm wrote:
> Hi,
>
> I am using a Scanjet 7650 in the "ADF Duplex" mode and I have noticed 
> it inserts "ghost" blank pages at random.
>
> My setup:
>
> Using a 2 sheets/4 pages document in the ADF, I scan with:
>
> $ scanadf \
>   --device-name hp5590 \
>   --source "ADF Duplex" \
>   -x 210.0 -y 297.0 \
>   --mode Gray \
>   --resolution 300 \
>   --output-file /tmp/file-%04d.pnm \
>   --verbose
>
> And more often that not, it will insert a ghost blank page between the 
> two sheets (i.e. between page 2 and page 3).
>
> Same thing if using --start-count 1 --end-count 4; page 3 will be a 
> "ghost blank" and page 4 is the actual page 3 (actual page 4 is 
> dropped altogether in this case).
>
> I have also tried scanimage in batch mode with the same result:
>
> $ scanimage \
>   --batch \
>   --device-name hp5590 \
>   --source "ADF Duplex" \
>   -x 210.0 -y 297.0 \
>   --mode Gray \
>   --resolution 300 \
>   --verbose
>
> Here are the versions I'm using on Mint 20.3:
>
> $ scanimage --version
> scanimage (sane-backends) 1.0.32; backend version 1.0.29
>
> $ scanadf --version
> scanadf (sane-frontends) 1.0.14
>
>
> Any idea what I might be doing wrong? Or how can I assist in squashing 
> the bug?
>
> Thanks,
> HM
>
If you believe that this is a bug and not a hardware glitch with your 
machine, your best bet would be to raise an issue over at: 
https://gitlab.com/sane-project/backends/-/issues

Perhaps capture the output of the following and attach to the issue there.

SANE_DEBUG_HP5590=100 scanimage {your usual args here}

I do have an hp5590 supported scanner here but it does not have an ADF 
unfortunately.

Can you also confirm for us that the the "ghost" page is full size and 
completely blank (i.e. perfect white)?

Cheers,.
Ralph