[sane-standard] More device properties

[Olaf Meeuwissen]

Étienne Bersac <bersace03 at laposte.net> writes:

> Hi,
>
> Developing Gnome Scan, i realize that device with ADF may introduce the
> paper from different side. i have at home two HP All-in-one printers,
> one has ADF at right side of the paper, the other has ADF at bottom of
> the paper.

Some things to keep in mind with ADF units:

  - simplex vs duplex
  - automatic page size detection (may include orientation as well)
  - alignment of original to scan origin or not (centered feeds)
  - sheet feeding from the top or the bottom of the stack
  - capability to leave a page on the scan area (useful for preview)

The only things I think are useful as options, in that a user can/may
control behaviour:

  - choice of simplex/duplex
  - limiting scan area to page size
  - rotation of original
  - "ADF preview" (feed first page, do a preview scan, leave it on the
    scan area so the user can fiddle with whatever other options before
    starting a scan of a 100 page document.  You may even want to allow
    for repeating the preview with the same page.)

> If the frontend can access such property, it will be able to
> automatically select the right scan area if the user select ADF source.
> This is very useful since user can't preview a paper in ADF.

See above.

> Some ADF may not center the document on the side, maybe a "adf-padding"
> option should be useful for that.
>
> Please comment.

Hope this helps,
-- 
Olaf Meeuwissen                          EPSON AVASYS Corporation, SE1
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