[sane-devel] Pixma lamp control

[m. allan noah]

I don't know specifically about the PIxma machines, but a number of
scanners from different brands require the software to perform calibration
scans with the lamp on and off. It is possible that one of those scanners
might also be willing to move its motor at the same time. I suggest you
investigate other, particularly cheaper scanners.

allan

On Sat, Nov 1, 2025 at 6:04 AM <jp at byjp.me> wrote:

> Hello,
>
> I'm interested in driving SANE to scan twice in succession (one with the
> lamp on, one with the lamp off), so I can scan against a lightbox (with
> *its* lamp off, and on, respectively) to manufacture an alpha layer for
> my scanned image.
>
> (I’m scanning postcards; some have unusually shaped edges, and with
> examples of every colour touching the edge of the card — my attempts at
> automating masking with alpha mattes work only some of the time)
>
> I have a Pixma scanner (CanoScan LiDE 400), for which SANE doesn't declare
> any lamp-related options (with scanimage -A). I’m a software & firmware
> engineer, so I’m comfortable getting into the detail, but I wanted to learn
> from the community first:
>
> - I’ve skimmed through the pixma backend code; it looks as though the lamp
> status is only ever *read* (and never written). Is anyone aware of a way
> to *set* the lamp status (even if currently unimplemented in SANE today)
> — ie. would the hardware permit this?
>
> - Is there any experience in the SANE dev community around this kind of
> RGBA style scanning? Are there other recommended approaches? (beyond alpha
> mattes)
>
> Many thanks,
> JP
>


-- 
"well, I stand up next to a mountain- and I chop it down with the edge of
my hand"
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