[sane-devel] Re: sane-devel digest, Vol 1 #807 - 11 msgs

[Nightwulf]

Hi,

Am Dienstag 21 Juni 2005 07:34 schrieb=20
sane-devel-request@lists.alioth.debian.org:
> =A0=A0=A0=A0=A0=A0=A0=A0The test16.pnm picture you posted is perfectly fi=
ne (I'm using
> Imagemagick to see it). The trouble you get is related to the image viewer
> you use. After trying konqueror to display it, I saw the same artifacts y=
ou
> get. So it's a kde a bug related to 16 bits pictures.
I doubt that Stef...I tried to open the pic with gimp 2.2 and I get an erro=
r=20
message "PNM: invalid maximum value". So there really seems to be something=
=20
wrong with the pic. Perhaps Imagemagick ignores some header information or =
is=20
more liberal while dealing with damaged pics.
I can't say of course wether it is a failure of the backend, the image libr=
ary=20
or whatever.

> =A0=A0=A0=A0=A0=A0=A0=A0For the other bug -trying to scan outside usable =
area- bound
> checking is done. I think it may be a bug in scan area origin detection
> bug. Origin may be wrongly detected a few mm too much toward "buttons
> side", so the scanning head goes to far. You may check it by scanning a
> triangle shaped paper, with one corner touching the very top of the
> scanning area. If expect that a few mm of it will be missing.
Tried that and found that you are right. The topmost part of the edge is=20
missing until I set the size to A4.

> =A0=A0=A0=A0=A0=A0=A0=A0You may also wait ~45 s after powering before tes=
ting. I think
> origin detection may fails if scanner isn't warm enough.
I remember how long it took under windows to do the first scan. It was appr=
ox=20
1 min while the program said "warming up lamp". Is there any possibility fo=
r=20
the backend to force the frontend to block scans or give error messages?
I did not encounter any hangup in approx 5 test scans incl. preview after I=
=20
started to wait 1 min after the initialization of the scanner.

> =A0=A0=A0=A0=A0=A0=A0=A0When all debug is activated, the backend write de=
bug pnm files
> containing data is scans. I'd like to have these:
> =A0=A0=A0=A0=A0=A0=A0=A0- search_position16.pnm
> =A0=A0=A0=A0=A0=A0=A0=A0- search_position.pnm
> =A0=A0=A0=A0=A0=A0=A0=A0- laplace.pnm
> =A0=A0=A0=A0=A0=A0=A0=A0- xsobel.pnm
> =A0=A0=A0=A0=A0=A0=A0=A0- ysobel.pnm
I deleted those pnm's already so I did another scan with full debug and put=
=20
the pic, the log and all debug pnm's into a tar.gz:

http://www.night-wulf.de/debugmaterial.tar.gz

So I think there is no serious bug remaining. The picture format bug can on=
ly=20
be a small failure in the header since xsane viewer and imagemagick show th=
e=20
pics allright and the warming up is a matter of simply knowing it. If you c=
an=20
do something about it, it would be great since it would solve the origin=20
detection problem too.

Thank you very much for your great work Stef!

Greets,
Torsten