kopia lustrzana https://gitlab.com/sane-project/website
107 wiersze
6.3 KiB
HTML
107 wiersze
6.3 KiB
HTML
|
<!-- received="Fri Aug 29 13:55:17 1997 MST" -->
|
||
|
<!-- sent="Fri, 29 Aug 1997 22:28:35 +0200" -->
|
||
|
<!-- name="Rainer Krienke" -->
|
||
|
<!-- email="krienke@mailhost.uni-koblenz.de" -->
|
||
|
<!-- subject="Re: Backtracking in color scanning" -->
|
||
|
<!-- id="9708291813.AA19446@gypsy.atlantic.infi.net" -->
|
||
|
<!-- inreplyto="Backtracking in color scanning" -->
|
||
|
<title>sane-devel: Re: Backtracking in color scanning</title>
|
||
|
<h1>Re: Backtracking in color scanning</h1>
|
||
|
<b>Rainer Krienke</b> (<a href="mailto:krienke@mailhost.uni-koblenz.de"><i>krienke@mailhost.uni-koblenz.de</i></a>)<br>
|
||
|
<i>Fri, 29 Aug 1997 22:28:35 +0200</i>
|
||
|
<p>
|
||
|
<ul>
|
||
|
<li> <b>Messages sorted by:</b> <a href="date.html#105">[ date ]</a><a href="index.html#105">[ thread ]</a><a href="subject.html#105">[ subject ]</a><a href="author.html#105">[ author ]</a>
|
||
|
<!-- next="start" -->
|
||
|
<li> <b>Next message:</b> <a href="0106.html">Rogier Wolff: "Re: Backtracking in color scanning"</a>
|
||
|
<li> <b>Previous message:</b> <a href="0104.html">shendrix@gypsy.atlantic.infi.net: "Re: Backtracking in color scanning"</a>
|
||
|
<li> <b>Maybe in reply to:</b> <a href="0101.html">Rainer krienke: "Backtracking in color scanning"</a>
|
||
|
<!-- nextthread="start" -->
|
||
|
<li> <b>Next in thread:</b> <a href="0107.html">Michael Ritzert: "Re: Backtracking in color scanning"</a>
|
||
|
<li> <b>Reply:</b> <a href="0107.html">Michael Ritzert: "Re: Backtracking in color scanning"</a>
|
||
|
<li> <b>Reply:</b> <a href="0116.html">Wolfgang Jung: "Re: Backtracking in color scanning"</a>
|
||
|
<!-- reply="end" -->
|
||
|
</ul>
|
||
|
<!-- body="start" -->
|
||
|
David Mosberger-Tang schrieb:<br>
|
||
|
<i>> </i><br>
|
||
|
<i>> >>>>> On Fri, 29 Aug 1997 17:04:01 +0200, Rainer krienke <<a href="mailto:krienke@mailhost.uni-koblenz.de">krienke@mailhost.uni-koblenz.de</a>> said:</i><br>
|
||
|
<i>> </i><br>
|
||
|
<i>> Rainer> When I scan color images at resolutions of say 300dpi the</i><br>
|
||
|
<i>> Rainer> scan process works right, but is very slow. This is because</i><br>
|
||
|
<i>> Rainer> the scanner scans some line and then goes back (that's</i><br>
|
||
|
<i>> Rainer> backtracking if I understood it right) and then scans the</i><br>
|
||
|
<i>> Rainer> next lines. Looking at the scanner it seems the the way the</i><br>
|
||
|
<i>> Rainer> scanner goes back is just a little smaller then the way it</i><br>
|
||
|
<i>> Rainer> has scanned before. Scanning a paper of size DINA4 (~30cm at</i><br>
|
||
|
<i>> Rainer> length, ~21cm wide) at 300dpi takes about 2min and 45</i><br>
|
||
|
<i>> Rainer> sec. If I scan at 100 dpi the effect is basically still</i><br>
|
||
|
<i>> Rainer> there but the sanner then scans a larger area in one step</i><br>
|
||
|
<i>> Rainer> before going back only a little. So the whole thing works</i><br>
|
||
|
<i>> Rainer> faster.</i><br>
|
||
|
<i>> </i><br>
|
||
|
<i>> Rainer> What suprises me a lot, is that under windows doing the same</i><br>
|
||
|
<i>> Rainer> scanprocess at the same resolution (via the mustec-twain</i><br>
|
||
|
<i>> Rainer> driver) does not cause backtracking to occur and is</i><br>
|
||
|
<i>> Rainer> completed much much faster (not even half the time).</i><br>
|
||
|
<i>> </i><br>
|
||
|
<i>> What size scan-buffer are you using? If you're using the default size</i><br>
|
||
|
<i>> of 32KB, could you try increasing it to 127.5KB? See sane-scsi(5) for</i><br>
|
||
|
<i>> info on how to do that.</i><br>
|
||
|
<i>> </i><br>
|
||
|
<i>> If increasing the scan buffer size to 127.5KB doesn't help, the</i><br>
|
||
|
<i>> backtracking could be due to timing problems. If the scanner software</i><br>
|
||
|
<i>> is too slow to issue the next "read data" command then backtracking</i><br>
|
||
|
<i>> would occur. What kind of computer are you using and how much memory</i><br>
|
||
|
<i>> does it have?</i><br>
|
||
|
<i>> </i><br>
|
||
|
<i>> --david</i><br>
|
||
|
<i>> </i><br>
|
||
|
<p>
|
||
|
As I already told in my mail. The scanbuffer is 127K large (in Kernel<br>
|
||
|
and sane).Scanning works allrightfor me (the results are allright but<br>
|
||
|
not the scantime). My computer is a 90Mhz Pentium it has 48Mb RAM<br>
|
||
|
installed. So it cannot be the buttleneck. But I really think it's got<br>
|
||
|
to do with data xfer since it does not happen when scanning at a lower<br>
|
||
|
resolution or in Lineart mode where less data has to be xferred. <br>
|
||
|
<p>
|
||
|
Could it be that its because the scanner and the harddisk on which the<br>
|
||
|
data has to be stored is on the same controller (ADAPTEC 2940) like the<br>
|
||
|
scanner so that there is a problem. <br>
|
||
|
<p>
|
||
|
By the way I really do not understand why backtracking is needed after<br>
|
||
|
all, cause I don't know whats really happening. Can someone give me a<br>
|
||
|
pointer to information on this ?<br>
|
||
|
<p>
|
||
|
I think I did not say this but it should be said: Sane is a real great<br>
|
||
|
piece of software besides all problems that there are (naturally), or<br>
|
||
|
has anyone seen a windows release without bugs ....<br>
|
||
|
<p>
|
||
|
Rainer <br>
|
||
|
<p>
|
||
|
----------------------------------------------------------------------<br>
|
||
|
Rainer Krienke <a href="mailto:krienke@informatik.uni-koblenz.de">krienke@informatik.uni-koblenz.de</a><br>
|
||
|
Universitaet Koblenz, <a href="http://www.uni-koblenz.de/~krienke">http://www.uni-koblenz.de/~krienke</a><br>
|
||
|
Rechenzentrum, Voice: +49 261 9119-641<br>
|
||
|
Rheinau 3-4, 56075 Koblenz, Germany Fax: +49 261 9119-499<br>
|
||
|
----------------------------------------------------------------------<br>
|
||
|
<p>
|
||
|
<pre>
|
||
|
--
|
||
|
Source code, list archive, and docs: <a href="http://www.azstarnet.com/~axplinux/sane/">http://www.azstarnet.com/~axplinux/sane/</a>
|
||
|
To unsubscribe: mail -s unsubscribe <a href="mailto:sane-devel-request@listserv.azstarnet.com">sane-devel-request@listserv.azstarnet.com</a>
|
||
|
</pre>
|
||
|
<!-- body="end" -->
|
||
|
<p>
|
||
|
<ul>
|
||
|
<!-- next="start" -->
|
||
|
<li> <b>Next message:</b> <a href="0106.html">Rogier Wolff: "Re: Backtracking in color scanning"</a>
|
||
|
<li> <b>Previous message:</b> <a href="0104.html">shendrix@gypsy.atlantic.infi.net: "Re: Backtracking in color scanning"</a>
|
||
|
<li> <b>Maybe in reply to:</b> <a href="0101.html">Rainer krienke: "Backtracking in color scanning"</a>
|
||
|
<!-- nextthread="start" -->
|
||
|
<li> <b>Next in thread:</b> <a href="0107.html">Michael Ritzert: "Re: Backtracking in color scanning"</a>
|
||
|
<li> <b>Reply:</b> <a href="0107.html">Michael Ritzert: "Re: Backtracking in color scanning"</a>
|
||
|
<li> <b>Reply:</b> <a href="0116.html">Wolfgang Jung: "Re: Backtracking in color scanning"</a>
|
||
|
<!-- reply="end" -->
|
||
|
</ul>
|