[sane-devel] Xsane notes

[Henning Meier-Geinitz]

Hi,

On Tue, Nov 12, 2002 at 11:43:49PM +0200, Juhana Sadeharju wrote:
> 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).

That means that the file must be kept open until scanning is finished.
I'm not sure if there are other implications, e.g. when sane_start
results in something other than SANE_STATUS_GOOD.

> 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.  :-(

That's probably a backend bug. XSane issues a sane_cancel and with the
gt68xx backend there is no problem to scan again.

> 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).

That's either a backend or even kernel problem.

> 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.

But then picking white/gray etc. point wouldn't show up in the
histogram?

> 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.

Ctrl-Enter starts the scan, if this helps.

Bye,
  Henning