Update of /cvsroot/ufraw/ufraw
In directory sfp-cvsdas-2.v30.ch3.sourceforge.com:/tmp/cvs-serv15969
Modified Files:
README-processing.txt
Log Message:
point to more archived posts about the
gamma/shadow-fog/poor-perceptual-spacing-LUT issue.
Index: README-processing.txt
===================================================================
RCS file: /cvsroot/ufraw/ufraw/README-processing.txt,v
retrieving revision 1.23
retrieving revision 1.24
diff -u -d -r1.23 -r1.24
--- README-processing.txt 12 Apr 2009 12:17:16 -0000 1.23
+++ README-processing.txt 1 Mar 2010 01:50:50 -0000 1.24
@@ -222,18 +222,20 @@
http://sourceforge.net/mailarchive/message.php?msg_name=481D7313.10009%40telenet.be
-on 2009-04-11, Martin Ling posted to ufraw-devel and hypothesized (or
-pointed our his earlier hypothes) that unpleasing fogginess when the
+On 2009-04-11, Martin Ling posted to ufraw-devel and hypothesized (or
+pointed out his earlier hypothesis) that unpleasing fogginess when the
objectively correct gamma processing is done is due to fixed-point
quantization errors in lcms.
-Probably ufraw should use a linear-encoded connection space and avoid
-most of this, but that's a separate issue.
-
Argyll CMS uses LUTs that intend to be equally spaced perceptually and
linear encodings break this assumption:
http://www.freelists.org/post/argyllcms/icclink-G-and-source-gamuts-profiles,5
+http://www.freelists.org/post/argyllcms/icclink-G-and-source-gamuts-profiles,9
+
+Another semi-relevant message:
+
+http://www.freelists.org/post/argyllcms/icclink-G-and-source-gamuts-profiles,1
==== Way Forward
@@ -241,9 +243,8 @@
using a gamma encoding different from the sRGB specification and then
assuming the pixels are in sRGB. It is generally agreed that this is
not strictly correct, but that images produced this way are more
-pleasing than images with the ostensibly correct values. Martin Ling
-has hypothesized that the 0.45/0.10 encoding compensates for
-quantization noise in fixed-point lcms code.
+pleasing than images where the input linear encoding is passed to a
+CMS directly, rather than being transformed to a perceptually uniform space.
As part of the discussion, a goal of some is to use lcms to apply the
input profile mapping even in the case of Color Matrices, and to
@@ -252,8 +253,8 @@
link it to the sRGB profile to get a combination profile to go from
(linear) camera space to sRGB with the standard encoding.
-This is blocked until the image quality issues are resolved because
-currently it would be a functional step backwards.
+Currently, the obstacles are a lack of spare time and that this is not
+quite fully agreed on or understood.
=== Highlight processing
------------------------------------------------------------------------------
Download Intel® Parallel Studio Eval
Try the new software tools for yourself. Speed compiling, find bugs
proactively, and fine-tune applications for parallel performance.
See why Intel Parallel Studio got high marks during beta.
http://p.sf.net/sfu/intel-sw-dev
_______________________________________________
ufraw-cvs mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/ufraw-cvs
