simple-scan-team team mailing list archive

[Michael Nagel <ubuntu@xxxxxxxxxxxxxxxxx>]

> The thing is that SANE provides two ways to set the resolution:
> >
> > A: "resolution" set to some value
> > B: "x-resolution" and "y-resolution" are set to some value
> >
> > Simple Scan supports only method A.
> > xsane and scanimage support A and B.
> >
> > Ususally this is not a problem, but the values for A are very limited
> > with your scanner, see the next list.
That is to be expected as it is the intersection of the x-resolution and
y-resolution lists.


> Additionally, the list of resolutions displayed in Simple Scan is not
> > the list of resolutions supported by the hardware. The list is static,
> > and you can select whatever you want. When scanning the next available
> > resolution is chosen. In your case the choice is limited to
> > 300/2400/4800 as Simple Scan only supports only method A.
> >
> >>From my point of view there are two things to do:
> > 1) Simple Scan should support method B.
Indeed it should.  As a matter of fact, the SANE API doesn't even
guarantee that you can use method A :-)  See section 4.5.2 of the
specification for details.


As a third and complementary approach, Simple Scan can scale the image
to the resolution that the user selected.  Image Scan! for Linux does
that.  Right now, Simple Scan gives the user the false impression that a
certain resolution is used to get and create an image.  All it really
does is let the user select a lower bound on the resolution.  And it
does that without clearly saying so.  The user will expect an image with
the UI selected resolution (no matter what was used to get it).  If the
selected resolution is wildly different (and smaller) than that used to
acquire the image, users may get impatient because it takes such a long
time but that's another issue.

Hope this helps,
-- Olaf Meeuwissen, LPIC-2 FLOSS Engineer -- AVASYS CORPORATION FSF Associate Member #1962 Help support software freedom http://www.fsf.org/jf?referrer=1962

-- 
You received this bug notification because you are a member of Simple
Scan Development Team, which is the registrant for Simple Scan.
https://bugs.launchpad.net/bugs/891586

Title:
  resolution control: setting x/y resolution independently

Status in Simple Scan:
  Triaged

Bug description:
  Details in my Ubuntu Forum thread: 
  http://ubuntuforums.org/showthread.php?t=1648771
  Quote:
  "Firstly - congratulations for Simple Scan, which lives up to its name admirably!
  Xsane is no doubt wonderfully competent, but far too complicated for casual use.
  But I am having a problem with Simple Scan, in that I can't seem to get selected resolutions to have any effect.
  A typical A4 mainly-text document I am playing with, ends up as:
  165K when scanned & saved as text pdf at 75/150/300 or 600dpi...
  1.5MB when scanned & saved as text jpg at 75-600dpi
  2.2MB when scanned & saved as photo pdf or jpg at 75-600dpi.
  My Epson V200 scanner allows normal resolution selection with Xsane or with Epson's iscan application.
  Thanks for any suggestions!" - unquote.

  I started that thread in December 2010 & still have the same problem today.
  As a summary - the resolution control has absolutely no effect on the results.
  No error messages (unless I try 2400dpi) & nothing in simple-scan --debug >simple-scan.log
  I now have Simple Scan 2.32.0.1-0Ubuntu2 in Ubuntu 11.04.
  The scanner is an Epson Perfection V200 Photo & has normal resolution selection in XSane & Iscan.
  Thanks!

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