<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii">
<TITLE>Message</TITLE>
<META name=GENERATOR content="MSHTML 8.00.6001.19393"></HEAD>
<BODY bgColor=#ffffff text=#000000>
<DIV><SPAN class=656440023-06012013><FONT color=#0000ff size=2
face=Arial>Stef,</FONT></SPAN></DIV>
<DIV><SPAN class=656440023-06012013><FONT color=#0000ff size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=656440023-06012013><FONT color=#0000ff size=2 face=Arial>Thank
you.</FONT></SPAN></DIV>
<DIV><SPAN class=656440023-06012013><FONT color=#0000ff size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=656440023-06012013><FONT color=#0000ff size=2 face=Arial>I just
built and tested sane-backends 1.0.24git and the images are not as dark.
I've found `</FONT></SPAN><SPAN class=656440023-06012013><FONT color=#0000ff
size=2 face=Arial>gamma4scanimage 1.5 0 181 255 65535` </FONT></SPAN><SPAN
class=656440023-06012013><FONT color=#0000ff size=2 face=Arial>to work about the
best. And for text, "[0]0-[181]65535-[255]65535"</FONT></SPAN></DIV>
<DIV><SPAN class=656440023-06012013><FONT color=#0000ff size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=656440023-06012013><FONT color=#0000ff size=2
face=Arial>R/</FONT></SPAN></DIV>
<DIV><SPAN class=656440023-06012013><FONT color=#0000ff size=2
face=Arial>Michael</FONT></SPAN></DIV>
<DIV><SPAN class=656440023-06012013><FONT color=#0000ff size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><SPAN class=656440023-06012013><FONT color=#0000ff size=2
face=Arial></FONT></SPAN> </DIV>
<BLOCKQUOTE style="MARGIN-RIGHT: 0px">
<DIV></DIV>
<DIV dir=ltr lang=en-us class=OutlookMessageHeader align=left><FONT size=2
face=Tahoma>-----Original Message-----<BR><B>From:</B> Stef
[mailto:stef.dev@free.fr] <BR><B>Sent:</B> Sunday, January 06, 2013 3:54
PM<BR><B>To:</B> Michael Watson<BR><B>Cc:</B>
sane-devel@lists.alioth.debian.org<BR><B>Subject:</B> Re: [sane-devel] FW:
Sane Scanimages Too Dark<BR><BR></FONT></DIV>
<DIV class=moz-cite-prefix>On 05/01/2013 01:45, Michael Watson
wrote:<BR></DIV>
<BLOCKQUOTE cite=mid:08A41DECF44947B990C9D3EBE1EA5D09@wat000 type="cite">
<META name=GENERATOR content="MSHTML 8.00.6001.19393">
<DIV><FONT color=#0000ff size=2 face=Arial><SPAN class=165424000-05012013>I
may have answered one of my questions after researching the sane
pages. The "curve tool" is a transfer function
graph.</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff size=2 face=Arial><SPAN
class=165424000-05012013></SPAN></FONT> </DIV>
<DIV><FONT color=#0000ff size=2 face=Arial><SPAN class=165424000-05012013><A
href="http://www.scantips.com/curve2.html"
moz-do-not-send="true">http://www.scantips.com/curve2.html</A></SPAN></FONT></DIV>
<DIV><FONT color=#0000ff size=2 face=Arial><SPAN
class=165424000-05012013></SPAN></FONT> </DIV>
<DIV><FONT color=#0000ff size=2 face=Arial><SPAN
class=165424000-05012013>Good stuff.</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff size=2 face=Arial><SPAN
class=165424000-05012013></SPAN></FONT> </DIV>
<DIV><FONT color=#0000ff size=2 face=Arial><SPAN
class=165424000-05012013>R/</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff size=2 face=Arial><SPAN
class=165424000-05012013>Michael</SPAN></FONT></DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV dir=ltr lang=en-us class=OutlookMessageHeader align=left><FONT size=2
face=Tahoma>-----Original Message-----<BR><B>From:</B> Michael Watson [<A
class=moz-txt-link-freetext
href="mailto:mwatson33@comcast.net">mailto:mwatson33@comcast.net</A>]
<BR><B>Sent:</B> Friday, January 04, 2013 5:28 PM<BR><B>To:</B> '<A
class=moz-txt-link-abbreviated
href="mailto:sane-devel@lists.alioth.debian.org">sane-devel@lists.alioth.debian.org</A>'<BR><B>Subject:</B>
Sane Scanimages Too Dark<BR><BR></FONT></DIV>
<DIV><SPAN lang=EN>
<P><FONT size=2 face=Arial>Request insights from the brain trust. Sane
scanimage files are too dark while windows<SPAN
class=056531522-04012013>'</SPAN> scans (Canon drivers<SPAN
class=056531522-04012013>/</SPAN><SPAN
class=056531522-04012013>applications</SPAN>) are fine?</FONT></P>
<P><FONT face=Arial><FONT size=2>I have an archlinuxarm box and an Lide210
scanner. Utilizing SaneTwain on a windows box the <SPAN
class=056531522-04012013>network </SPAN>scans were too dark. Similarly,
scanimage (local) scans were also too dark. Trying to compensate the
SaneTwain gamma was experimented with. What worked well was a straight
line curve that maxed <SPAN class=056531522-04012013>out </SPAN>at the
top <SPAN class=056531522-04012013>while </SPAN><SPAN
class=056531522-04012013>3/4</SPAN> of the way <SPAN
class=056531522-04012013>to the right </SPAN>(0,0 --> 191,65535 -->
65535, 65535)<SPAN class=056531522-04012013> and not the top right corner
((0,0 --> 65535, 65535).</SPAN></FONT></FONT></P>
<P><FONT size=2 face=Arial>With this information the scanimage (local) was
adjusted with gamma4scanimage 1.75 0 181 255 65535, <SPAN
class=056531522-04012013>which</SPAN> works well.</FONT></P>
<P><FONT size=2 face=Arial>I do not understand why the upper limit is at
approximately 191 and not 255.</FONT></P>
<P><FONT size=2 face=Arial>From the sane debug it appears the gamma is
initially set to 1.7, which produces dark image<SPAN
class=056531522-04012013>s</SPAN> because the initial gamma table is
equivalent to gamma4scanimage 1.7 0 255 255 65535?</FONT></P>
<P><FONT size=2 face=Arial>[genesys] sanei_genesys_create_gamma_table: size
= 256, maximum = 65535, gamma_max = 65535, gamma = 1.7</FONT></P>
<P><FONT size=2 face=Arial><SPAN class=056531522-04012013>Also, SaneTwain
will send the gamma table to the scanner when initially set. If it is
saved (ini file) and SaneTwain is started up, the custom gamma table
checkbox (custom-gamma=yes/no) has no visible impact on the scanned image -
too dark.</SPAN></FONT></P>
<P><FONT size=2 face=Arial>Any insights appreciated.</FONT></P>
<P><FONT size=2 face=Arial>R/<BR>Michael</FONT></P>
<P><FONT face=Arial><BR></FONT> </P></SPAN></DIV><BR>
<FIELDSET class=mimeAttachmentHeader></FIELDSET>
<BR></BLOCKQUOTE><BR> Hello,<BR><BR> I
have recently fixed an issue with gamma table handling in the genesys backend.
This should improve the darkness issue you see. To test it you'll have to
compile the latest source code available from SANE's git
repository.<BR><BR>Regards,<BR>
Stef<BR></BLOCKQUOTE></BODY></HTML>