kopia lustrzana https://gitlab.com/sane-project/website
140 wiersze
5.4 KiB
HTML
140 wiersze
5.4 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
|
|
"http://www.w3.org/TR/REC-html40/loose.dtd">
|
|
<HTML>
|
|
<HEAD>
|
|
<TITLE>sane-devel: Re: 3091 backend: Brightness, Contrast etc.</TITLE>
|
|
<META NAME="Author" CONTENT="Marian Eichholz (marian.eichholz@freenet-ag.de)">
|
|
<META NAME="Subject" CONTENT="Re: 3091 backend: Brightness, Contrast etc.">
|
|
</HEAD>
|
|
<BODY BGCOLOR="#FFFFFF" TEXT="#000000">
|
|
<H1>Re: 3091 backend: Brightness, Contrast etc.</H1>
|
|
<!-- received="Thu Mar 8 01:01:24 2001" -->
|
|
<!-- isoreceived="20010308090124" -->
|
|
<!-- sent="Thu, 08 Mar 2001 10:21:05 +0100" -->
|
|
<!-- isosent="20010308092105" -->
|
|
<!-- name="Marian Eichholz" -->
|
|
<!-- email="marian.eichholz@freenet-ag.de" -->
|
|
<!-- subject="Re: 3091 backend: Brightness, Contrast etc." -->
|
|
<!-- id="3AA74F01.76BDA0F9@freenet-ag.de" -->
|
|
<!-- inreplyto="20010307211805.A20763@aruba.remote.org" -->
|
|
<STRONG>From:</STRONG> Marian Eichholz (<A HREF="mailto:marian.eichholz@freenet-ag.de?Subject=Re:%203091%20backend:%20Brightness,%20Contrast%20etc.&In-Reply-To=<3AA74F01.76BDA0F9@freenet-ag.de>"><EM>marian.eichholz@freenet-ag.de</EM></A>)<BR>
|
|
<STRONG>Date:</STRONG> Thu Mar 08 2001 - 01:21:05 PST
|
|
<P>
|
|
<!-- next="start" -->
|
|
<LI><STRONG>Next message:</STRONG> <A HREF="0114.html">Frederik Ramm: "Re: 3091 backend: Brightness, Contrast etc."</A>
|
|
<UL>
|
|
<LI><STRONG>Previous message:</STRONG> <A HREF="0112.html">Ulrich Deiters: "Re: 3091 backend: Brightness, Contrast etc."</A>
|
|
<LI><STRONG>In reply to:</STRONG> <A HREF="0107.html">Frederik Ramm: "3091 backend: Brightness, Contrast etc."</A>
|
|
<!-- nextthread="start" -->
|
|
<LI><STRONG>Next in thread:</STRONG> <A HREF="0116.html">Ulrich Deiters: "Re: 3091 backend: Brightness, Contrast etc."</A>
|
|
<!-- reply="end" -->
|
|
<LI><STRONG>Messages sorted by:</STRONG>
|
|
<A HREF="date.html#113">[ date ]</A>
|
|
<A HREF="index.html#113">[ thread ]</A>
|
|
<A HREF="subject.html#113">[ subject ]</A>
|
|
<A HREF="author.html#113">[ author ]</A>
|
|
</UL>
|
|
<HR NOSHADE><P>
|
|
<!-- body="start" -->
|
|
<P>
|
|
Frederik Ramm wrote:
|
|
<BR>
|
|
<P><EM>> What's more, my scanner supports a few settings with funny names I
|
|
</EM><BR>
|
|
<EM>> cannot make sense of. Maybe somebody knows what they are, or what they
|
|
</EM><BR>
|
|
<EM>> might be. It would be interesting for me if it is worthwile to make
|
|
</EM><BR>
|
|
<EM>> them available through the backend.
|
|
</EM><BR>
|
|
<EM>>
|
|
</EM><BR>
|
|
<EM>> * Initial Slice: Specifies the initial binary threshold value when in
|
|
</EM><BR>
|
|
<EM>> floating slice mode.
|
|
</EM><BR>
|
|
<EM>> * Up value: Specifies the +UP count value used in floating slice mode.
|
|
</EM><BR>
|
|
<EM>> (Valid settings: 0-3, default: 1)
|
|
</EM><BR>
|
|
<EM>> * Down value: ... as above
|
|
</EM><BR>
|
|
<EM>> * Lower Limit Slice: Specifies the lower limit slice used in floating
|
|
</EM><BR>
|
|
<EM>> slice mode (0-15, default: 6)
|
|
</EM><BR>
|
|
<P>Hmmm.. "floating slice"... This sounds familiar... Our big Fujitsu
|
|
<BR>
|
|
document scanner has (two) "dynamic threshold" modes. Perhaps the FS
|
|
<BR>
|
|
mode is something like DT.
|
|
<BR>
|
|
<P>DT is a line art mode, where the scanner automatically adapts the
|
|
<BR>
|
|
threshold between "white" and "black" parts. This is particularly
|
|
<BR>
|
|
useful, when You have a gradient color in the background. The DT mode
|
|
<BR>
|
|
however made use of several parameters, and the tuning of these
|
|
<BR>
|
|
parameters is an art of it's own.
|
|
<BR>
|
|
<P>There was a "simplified DT" mode with a straighter parameter set.
|
|
<BR>
|
|
<P>Enhancement mode was a kind of spacial high pass filtering. Thus, edges
|
|
<BR>
|
|
are amplified.
|
|
<BR>
|
|
<P>The main reason for implementing this - and some very nifty nonlinear
|
|
<BR>
|
|
filters for OCR - within the scanner is speed: You get a perfectly
|
|
<BR>
|
|
preprocessed G4-compressed line art from the scanner within a second or
|
|
<BR>
|
|
two, and it needs no CPU on Your machine.
|
|
<BR>
|
|
<P>After all, if scanning speed and CPU cycles are irrelevant, there is
|
|
<BR>
|
|
absolutely nothing, that You cannot do within the driver. Most
|
|
<BR>
|
|
manufacturers seem to size the scanner API down with this "vision" in
|
|
<BR>
|
|
mind...
|
|
<BR>
|
|
<P>Hope it helps...
|
|
<BR>
|
|
<P>-- Marian Eichholz
|
|
<BR>
|
|
<P><PRE>
|
|
--
|
|
Source code, list archive, and docs: <A HREF="http://www.mostang.com/sane/">http://www.mostang.com/sane/</A>
|
|
To unsubscribe: echo unsubscribe sane-devel | mail <A HREF="mailto:majordomo@mostang.com?Subject=Re:%203091%20backend:%20Brightness,%20Contrast%20etc.&In-Reply-To=<3AA74F01.76BDA0F9@freenet-ag.de>">majordomo@mostang.com</A>
|
|
</PRE>
|
|
<P><!-- body="end" -->
|
|
<HR NOSHADE>
|
|
<UL>
|
|
<!-- next="start" -->
|
|
<LI><STRONG>Next message:</STRONG> <A HREF="0114.html">Frederik Ramm: "Re: 3091 backend: Brightness, Contrast etc."</A>
|
|
<LI><STRONG>Previous message:</STRONG> <A HREF="0112.html">Ulrich Deiters: "Re: 3091 backend: Brightness, Contrast etc."</A>
|
|
<LI><STRONG>In reply to:</STRONG> <A HREF="0107.html">Frederik Ramm: "3091 backend: Brightness, Contrast etc."</A>
|
|
<!-- nextthread="start" -->
|
|
<LI><STRONG>Next in thread:</STRONG> <A HREF="0116.html">Ulrich Deiters: "Re: 3091 backend: Brightness, Contrast etc."</A>
|
|
<!-- reply="end" -->
|
|
<LI><STRONG>Messages sorted by:</STRONG>
|
|
<A HREF="date.html#113">[ date ]</A>
|
|
<A HREF="index.html#113">[ thread ]</A>
|
|
<A HREF="subject.html#113">[ subject ]</A>
|
|
<A HREF="author.html#113">[ author ]</A>
|
|
</UL>
|
|
<!-- trailer="footer" -->
|
|
<HR NOSHADE>
|
|
<P>
|
|
<SMALL>
|
|
<EM>
|
|
This archive was generated by <A HREF="http://www.hypermail.org/">hypermail 2b29</A>
|
|
: <EM>Thu Mar 08 2001 - 01:02:40 PST</EM>
|
|
</EM>
|
|
</SMALL>
|
|
</BODY>
|
|
</HTML>
|