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List:       kde-devel
Subject:    Re: Volunteering to port Kooka to KDE4
From:       Kåre_Särs <kare.sars () iki ! fi>
Date:       2009-10-19 7:08:46
Message-ID: 200910191008.46153.kare.sars () iki ! fi
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Hi,

On Monday 19 October 2009, John Layt wrote:
> On Sunday 18 October 2009 20:26:10 Kåre Särs wrote:
> > With Skanlite it should already be possible to scan from a document
> > feeder and auto-generate a name for each image (I do not own a scanner
> > with an ADF), but from this "settings for each selected scan region" I
> > sounds like something more advanced... I would be happy to hear more
> > about what you need. The coding sprint in November could be a good time
> > for new features ;)
> 
> My use case is fairly simple, but I'm sure fairly common.  I have 100
>  photos I want to scan, so to speed things up I put 3 of them on the
>  flatbed at the same time, fire up the scan program and hit preview.  This
>  gives me a preview of 3 photos.  I then select the first photo, click on
>  auto-levels, and add it to the batch list, and repeat that for the second
>  and third photos, then click scan.  The program then scans the 3 separate
>  scan areas in a single pass of the scan head at the individually selected
>  levels.  Xsane used to have a problem with this as it used the same
>  brightness, contrast and gamma levels for all 3 scan areas, I'm not sure
>  if it is still an issue or not.
The big problem here is that there is no "auto-levels" button in libksane. 
Libksane does not have any image manipulation features at all, so all the 
gamma/brightness/contrast options are provided by the scanner/backend.

> 
> So each scan area on the batch list should be able to have all the settings
> set independently, resolution, bit depth, brightness, etc, and you should
>  be able to edit the settings of all the existing items in the batch list
>  before you hit scan.  Would the batch list be the app or libksane?
There is already multiple selection support, but all with the same settings 
and no external API. That external API is not hard to add if needed, but the 
separate settings is a little bit more work.

> 
> While I think the levels are post-processing by the scan app (?), the
> resolution and other sane level settings may not be possible either in a
> single pass of the scan head or a single call to the Sane API?  So libksane
> should be able to accept a list of scan areas with scan settings and be
>  smart enough to figure out the minimum number of calls to sane required to
>  return the required scans.  I guess overlapping scan areas would need the
>  same treatment?
If I add the "separate settings for each selection" do you have a good idea of 
how those separate settings would be shown to the user? Is the benefit greater 
that the complexity that we might get with it?

If the separate settings would be mostly for post-processing "levels", why not 
let applications that are written explicitly for that do the post processing? 
That does not not exclude that the application using libksane would do the 
post processing before saving.

> 
> And the real tough part, auto-select of the multiple scan areas.
There is already auto-selection of multiple scan areas :-)

But I'm not happy with the results yet. If the preview resolution is too high, 
you might get many small selections of dirt on the scan area, and you also get 
a border around the real image. So the auto selection does need some love.

> 
> No, not asking a lot really :-)
Problems are there to be solved :) 

-- 
Kåre Särs
 
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