GM -normalize without clipping highlights
Charlie De <[email protected]> Tue, 20 Jul 2010 00:20:12 -0700 (PDT)
| Newsgroups | gmane.comp.video.graphicsmagick.core |
|---|---|
| Message-ID | <[email protected]> |
--===============3884098571692356046==
Content-Type: multipart/alternative; boundary="0-1963583313-1279610412=:37689"
--0-1963583313-1279610412=:37689
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: quoted-printable
Hello all,=0A=0A=0AI've joined up this list so I could make a simple featur=
e request. Please =0Aconsider improving the already excellent -normalize o=
ption, making it work =0Awithout clipping highlights. I appreciate that th=
e clipping and the natural =0Aquality of output of this option are related,=
so you don't want to improve one =0Aand lose the other. My own feeling is=
that the correct output would require a =0Amore complex procedure than mer=
ely setting clipping values to 0x0. Such a =0Asimple solution would likely=
undo the natural looking contrast and colour =0Abalance that the option cu=
rrently delivers. I suspect a curve approach is =0Aneeded, one that retain=
s the current results in midtones, but then more gently =0Aslopes over a "k=
nee" into the highlights, preventing clipping. My concern is =0Areally onl=
y the highlights, I haven't noticed anything untoward in the shadows =0Ain =
the -normalize output.=0A=0AAs a bit of context, I'm currently using GM -no=
rmalize on the rather dark and =0Alow contrast output of dcraw, run with th=
e following relevant options: -w to =0Aretain camera white balance, -H 2 fo=
r smooth highlights (in as much as dcraw is =0Acapable, this isn't much dif=
ferent from -H 0), and -W to prevent dcraw from =0Acontrast stretching the =
highlights (I like dcraw doing only the basic =0Aconversion, not processing=
the output). Then, to make this basic output =0Aactually useable, I run G=
M -normalise on it. I have found this option to be the =0Abest at achievin=
g a natural looking image, alas with blown highlights. Nothing =0Aelse I h=
ave tried is as good, and I have tried all options in many permutations =0A=
of settings, both with GM and IM.=0A=0AThat's it - thank you for listening =
and best wishes with the coding! :-)=0A=0A=0A
--0-1963583313-1279610412=:37689
Content-Type: text/html; charset=iso-8859-1
Content-Transfer-Encoding: quoted-printable
<html><head><style type=3D"text/css"><!-- DIV {margin:0px;} --></style></he=
ad><body><div style=3D"font-family:"times new roman", "new york", "times", =
serif;font-size:12pt"><div>Hello all,<br></div><div><br></div><div>I've joi=
ned up this list so I could make a simple feature request. =A0Please consid=
er improving the already excellent -normalize option, making it work withou=
t clipping highlights. =A0I appreciate that the clipping and the natural qu=
ality of output of this option are related, so you don't want to improve on=
e and lose the other. =A0My own feeling is that the correct output would re=
quire a more complex procedure than merely setting clipping values to 0x0. =
=A0Such a simple solution would likely undo the natural looking contrast an=
d colour balance that the option currently delivers. =A0I suspect a curve a=
pproach is needed, one that retains the current results in midtones, but th=
en more gently slopes over a "knee" into the highlights, preventing clippin=
g.
=A0My concern is really only the highlights, I haven't noticed anything un=
toward in the shadows in the -normalize output.</div><div><br></div><div>As=
a bit of context, I'm currently using GM -normalize on the rather dark and=
low contrast output of dcraw, run with the following relevant options: -w =
to retain camera white balance, -H 2 for smooth highlights (in as much as d=
craw is capable, this isn't much different from -H 0), and -W to prevent dc=
raw from contrast stretching the highlights (I like dcraw doing only the ba=
sic conversion, not processing the output). =A0Then, to make this basic out=
put actually useable, I run GM -normalise on it. =A0I have found this optio=
n to be the best at achieving a natural looking image, alas with blown high=
lights. =A0Nothing else I have tried is as good, and I have tried all optio=
ns in many permutations of settings, both with GM and IM.</div><div><br></d=
iv><div>That's it - thank you for listening and best wishes with the
coding! :-)</div>=0A=0A=0A</div><br>=0A=0A=0A=0A=0A=0A=0A=0A </body><=
/html>
--0-1963583313-1279610412=:37689--
--===============3884098571692356046==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
------------------------------------------------------------------------------
This SF.net email is sponsored by Sprint
What will you do first with EVO, the first 4G phone?
Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first
--===============3884098571692356046==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
_______________________________________________
Graphicsmagick-core mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/graphicsmagick-core
--===============3884098571692356046==--