kopia lustrzana https://gitlab.com/sane-project/website
131 wiersze
4.4 KiB
HTML
131 wiersze
4.4 KiB
HTML
<!-- received="Sat Nov 22 01:52:31 1997 PST" -->
|
|
<!-- sent="Sat, 22 Nov 1997 10:47:05 +0100" -->
|
|
<!-- name="Stanislav Brabec" -->
|
|
<!-- email="utx@k332.feld.cvut.cz" -->
|
|
<!-- subject="xscanimage / "gamma button" bug" -->
|
|
<!-- id="199711220947.KAA07955@k332.feld.cvut.cz" -->
|
|
<!-- inreplyto="" -->
|
|
<title>sane-devel: xscanimage / "gamma button" bug</title>
|
|
<h1>xscanimage / "gamma button" bug</h1>
|
|
<b>Stanislav Brabec</b> (<a href="mailto:utx@k332.feld.cvut.cz"><i>utx@k332.feld.cvut.cz</i></a>)<br>
|
|
<i>Sat, 22 Nov 1997 10:47:05 +0100</i>
|
|
<p>
|
|
<ul>
|
|
<li> <b>Messages sorted by:</b> <a href="date.html#128">[ date ]</a><a href="index.html#128">[ thread ]</a><a href="subject.html#128">[ subject ]</a><a href="author.html#128">[ author ]</a>
|
|
<!-- next="start" -->
|
|
<li> <b>Next message:</b> <a href="0129.html">Olof OLOFSANE Karin: "Re: xscanimage / "gamma button" bug"</a>
|
|
<li> <b>Previous message:</b> <a href="0127.html">Daniel Stephens: "Re: Umax Astra 1200S problems!"</a>
|
|
<!-- nextthread="start" -->
|
|
<li> <b>Next in thread:</b> <a href="0129.html">Olof OLOFSANE Karin: "Re: xscanimage / "gamma button" bug"</a>
|
|
<li> <b>Reply:</b> <a href="0129.html">Olof OLOFSANE Karin: "Re: xscanimage / "gamma button" bug"</a>
|
|
<!-- reply="end" -->
|
|
</ul>
|
|
<!-- body="start" -->
|
|
Hi sane developers,<br>
|
|
<p>
|
|
I have found following bug in xscanimage / Astra 1200S:<br>
|
|
<p>
|
|
If I press "custom gamma table" and then press "gamma" button, the<br>
|
|
result of scan is bad (most light parts become darker and darker,<br>
|
|
white becomes black).<br>
|
|
<p>
|
|
But in other "custom gamma" selections, all is OK.<br>
|
|
<p>
|
|
And more: If I press "gamma", then "save device settings", then "load<br>
|
|
device settings", the custom gamma table semms to be the same, but<br>
|
|
_works OK_!!! (This is the reason I am not sending setup file.)<br>
|
|
<p>
|
|
This bug is really simply deferrable, but can cause many problems, if<br>
|
|
you don't know about it.<br>
|
|
<p>
|
|
<pre>
|
|
---
|
|
<p>
|
|
Tips frontend:
|
|
==============
|
|
<p>
|
|
Batch scanning:
|
|
<p>
|
|
Due to stupidity of some users (includes me) please add option "warning
|
|
overwrite" or "batch scanning". If this option will be on, user will
|
|
be warned before overwriting files or, eventually, file will be
|
|
written with new name.
|
|
<p>
|
|
<pre>
|
|
---
|
|
<p>
|
|
Gamma button:
|
|
<p>
|
|
Gamma button in custom gamma table should remember it's value (in
|
|
settings).
|
|
<p>
|
|
<pre>
|
|
---
|
|
<p>
|
|
Color picker tool:
|
|
<p>
|
|
Color picker tool, which shows RGB values (original/after custom gamma
|
|
correction) in preview window is very useful for good scanning.
|
|
<p>
|
|
<pre>
|
|
---
|
|
<p>
|
|
Default filter
|
|
<p>
|
|
Default filter should be very useful "midend" option. Such external
|
|
optional filter should perform some standard operation for scanning.
|
|
The "midend" interface should be shell script filter with commandline
|
|
arguments, which should represent scanner, mode (flatbed...), DPI,
|
|
position on scanned area (x,y). Thus "midend" could for example
|
|
perform:
|
|
<p>
|
|
Standard re-focusing (dependent on DPI)
|
|
Standard de-striping (dependent on absolute position on scanner)
|
|
Descreening (dependent on DPI and externally set LPI)
|
|
...and everything what user will prepare as script...
|
|
<p>
|
|
<pre>
|
|
---
|
|
<p>
|
|
Gamma for >8bit scanners:
|
|
<p>
|
|
Now the gamma looks as follows:
|
|
0 0 0 5 5 5 5 5 5 11 11 11 11 11 16 16 16 16 16 21 21 21 21 21 21 27
|
|
27 27 27 27 32 32 32 32 32 37 37 37 37 37 37
|
|
Should be it interpolated?
|
|
<p>
|
|
<pre>
|
|
---
|
|
<p>
|
|
Contract & gamma:
|
|
<p>
|
|
User could want to scan with custom gamma table, which represents
|
|
gamma=value and contrast auto stretch. If you have picture with low
|
|
contast, you can get also in such case level-smooth results in 8bit
|
|
mode for >8bit scanners.
|
|
<p>
|
|
The simplest way to do it: add button for linear transformation of
|
|
existing curve.
|
|
<p>
|
|
<pre>
|
|
---
|
|
<p>
|
|
--Stanislav Brabec
|
|
<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">majordomo@mostang.com</a>
|
|
</pre>
|
|
<!-- body="end" -->
|
|
<p>
|
|
<ul>
|
|
<!-- next="start" -->
|
|
<li> <b>Next message:</b> <a href="0129.html">Olof OLOFSANE Karin: "Re: xscanimage / "gamma button" bug"</a>
|
|
<li> <b>Previous message:</b> <a href="0127.html">Daniel Stephens: "Re: Umax Astra 1200S problems!"</a>
|
|
<!-- nextthread="start" -->
|
|
<li> <b>Next in thread:</b> <a href="0129.html">Olof OLOFSANE Karin: "Re: xscanimage / "gamma button" bug"</a>
|
|
<li> <b>Reply:</b> <a href="0129.html">Olof OLOFSANE Karin: "Re: xscanimage / "gamma button" bug"</a>
|
|
<!-- reply="end" -->
|
|
</ul>
|