[sane-devel] Xsane notes

[Juhana Sadeharju]

Hello. Here I have yet new bug reports for xsane 0.84 (I will update
later to more recent version), but first about the project save/load:

Yes, all settings should be saved, including the preview image. The
reasons for saving the preview image are:
 -Visual continuity of different sessions of the same project
 -No need to make another preview if the same project continues
  (saves the scanner mechanics)
 -The saved and later loaded preview image gives visual proof that
  one has the correct scanner settings (now one stares at Xsane logo
  and wonders if all settings really are the same)
 -Histogram tool shows the histogram of the preview image (or of that
  Xsane logo if preview is not saved)
For those who does not need to save previews, there could be
"do not save preview for this project" option.

Yes, the exact scan area and the enchangements settings typically changes
for different scanning, but for an individual project I usually select
a large enough scanarea and always disable enchangements. This
saves a lot of previews.

Bug: The scanning mode is not saved at all. It should be part of the
project save/load as well.

Bug: In Save scanning mode, after browsing a new filename, the
path is visible as "/home/juhana/scann", not as "annings/123.pnm"
as should be. Note: the next, incremented filename is shown correctly.

Bug: In Save mode, scanning is started before verifying if the file
can be opened. The result is that the scanner stops at middle of scanning
if the file cannot be opened. The file should be verified before also
in the case where a file is going to be overwritten (if xsane asks for
overwritings at all). I would not want that scanner mechanics are
used unnecessarily this way. (Replicate: Make "scannings/temp/ dir,
scan to "temp/001.pnm", quit xsane, delete "temp/" dir, run xsane, scan
to the memorised "temp/002.pnm" -- ping.)

Bug: xsane cannot recover from the above problem. Pressing
the start button gives an error "failed to start scanner: invalid
argument". Turned scanner power off and on; no help. Quitting xsane
made the xsane wild, giving the following errors in an infinite loop:
 [epson] error in receive - status = 9
 [epson] error in receive - status = 9
Well, Linux did not jam and at least "kill -KILL" helps.  :-(

Suggestion: "reset the scanner" button so that the start button works
again without "kill -KILL". I also have had problems in finding
the scanner from usb line; some "query scanner" button could help
(oh, but the xsane won't start because it does not find the scanner).

Suggestion: Histogram could show the histogram of the scanned image,
not of the preview. This saves in taking the previews, but one
would still immediately notice any problems in patch scanning.

Suggestion: In Save mode, the scanned image could be displayed as well.
Preferably in some smaller size, e.g., 600x400. The next image
would appear in the same window so that user does not need to delete
the window away before the next scan.

Suggestion: The start button could be larger and square. Sometimes it
takes too much time to aim to the relatively tiny start button.
The current width of the button seems to be ok, just make it square.

Suggestion: An adjustable time delay before the scanning
really starts after pressing the start button. Say, 0,1,2,3,4,5
seconds are enough. This setting should be easily available, not
puried to preferences. The delay should work even if one presses
the start button of the scanner. The reason is that the big, fat books
needs manual help from user: instead of pressing the book down flat
and thus breaking the scanner, it helps if the other half of the book
is lifted up and the center is gently hold on scanner. A couple of
seconds delay gives time to prepare for the actual scanning.

Best regards,

Juhana