Re: [Gimp-user] ICC Profiles: UFRaw + GIMP => 2x correction?

[peter kostov <gimp light-bg com>]

On 01/31/2012 03:07 AM, Frank Gore wrote:
> On Mon, Jan 30, 2012 at 7:50 PM, Gary Aitken<garya dreamchaser org>  wrote:
> > I have a question regarding the use of ICC profiles in UFRaw + GIMP.
> >
> > If I load an image into UFRaw and specify an ICC profile for my camera,
> > then output a .tiff image, that image is color-corrected.  At least that is
> > my assumption...
> >
> > Now, if I load the .tiff image into GIMP, and again specify an ICC profile
> > for the camera, the image is corrected again, I think.  Which amounts to
> > over-correction.  Correct?
>
> ICC is not a correction. It is a profile. It tells the application how
> to interpret the colours that are encoded in the file. If you specify
> an ICC profile in UFraw, that profile gets saved into the image file,
> and Gimp uses that profile information when it opens the image file.
> If you re-specify a new ICC profile within Gimp after you've opened
> the image, you're not "over-correcting" anything, you're just doing an
> extra useless step that results in nothing happening.

That's only true if you are assigning a color profile, but if you 
convert to a profile that is a correction and doing it twice is likely 
to result in an over-correction.

> In your case, I'd say you've got absolutely no reason whatsoever to be
> doing colour management. Sticking to standard sRGB for your entire
> workflow would be entirely acceptable and would give you the best
> results.

I do not agree with this. Color management, when done properly, is a 
good an useful thing and in most cases will ensure better results than 
not doing it. Especially if the source file is not sRGB which might 
easily be the case, because there are many cameras that can produce 
images with AdobeRGB for example.

Peter

> --
> Frank Gore
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