[sane-devel] Pixma lamp control

[Ralph Little]

Hi,
I would add that there are some devices that allow you to select the color
to use when scanning in grey. That might get you some way to what you want
to do.

Cheers,
Ralph


On Sat, Nov 1, 2025, 08:49 Ralph Little <skelband at gmail.com> wrote:

> Hi,
>
>
> On Sat, Nov 1, 2025, 03:04 <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:
>>
>
> The Lide 400 uses the pixma backend which uses a high level protocol to
> request scans. If you intend to manipulate the scan lamp then you would
> need to access the hardware directly in which case you would probably not
> be using SANE. There is a huge variety of ways in which scanners are
> controlled. The multifunction devices by Canon, Xerox, HP, etc all use very
> higher level protocols and hardware is handled internally by the device's
> firmware so there isn't usually any provision for you to manipulate the
> device at a low level. To go that route you need to go for a device that is
> controlled more finely such as the Genesys scanner-on-a-chip models. See
> the Genesys backend to see what models are currently supported. Other
> backends also support devices that are controlled at the lower level where
> lamp control may be possible.
>
> Cheers,
> Ralph
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://alioth-lists.debian.net/pipermail/sane-devel/attachments/20251101/45732184/attachment.htm>