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

[Kevin Brubeck Unhammer <unhammer fsfe org>]

Gary Aitken <gimp dreamchaser org> writes:

> On 2/1/2012 12:08 AM, Kevin Brubeck Unhammer wrote:
>
> > When I apply an Output Profile in UFRaw and send to GIMP, GIMP asks me
> > whether to keep the embedded profile or convert to sRGB, so I do know
> > that it's noticing a profile there. You can set GIMP to ask on the
> > bottom drop-down of that menu.
>
> I don't see any dialog at all.  The image just appears in the gimp
> image window.
>
> > Also, just to check "if it's plugged in", if you run ImageMagick's
> > "identify -verbose myfile.tif", does it have a section like
> >
> >       Profile-icc: 3004 bytes
> >         Description: Pink
> >         Manufacturer: IEC http://www.iec.ch
> >         Model: IEC 61966-2.1 Default RGB colour space - sRGB
> >         Copyright: Copyright (c) 1998 Hewlett-Packard Company Modified using Adobe Gamma
> >
> > ?
> >
> > Or, if you click Image→Image Properties (alternatively:
> > Image→Mode→Set/Convert Colour Profile), does it say that the current one
> > is sRGB built-in, or that it is YourProfileName?
>
> It says the profile is "sRGB built-in, Default RGB working space"
> but it displays with the profile applied in ufraw.

The Display profile in UFRaw is not embedded, the output profile (middle
of the three) is. No matter what output profile you select, the preview
in UFRaw shouldn't change, if I understand things correctly.

> Edit/Preferences/Color Management shows no profile for RGB.
>
> > > Now set the RGB Profile to the one you used in ufraw when generating
> > > the .tif image.
> > >    You will see the image transformed again.
> > >    In effect, the profile is being applied twice.
> >
> > I don't see this. What I do see is that no matter what crazy embedded
> > Output Profile I use in UFRaw (and I select "keep embedded" in GIMP),
> > changing the RGB Profile in that part of GIMP doesn't change what the
> > image looks like, and they all look the same no matter what profile they
> > have (or even if they don't have a profile).
> >
> > However, if I open an image without an embedded profile, clicking
> > Image→Image Properties tells me that the profile is "sRGB built-in", and
> > if I have RGB Profile set to something weird in Preferences then, the
> > image gets weird colours.
> >
> > Tested using UFRaw version 0.18, GIMP version 2.7.4, on Arch Linux.
> >
> > > BTW, I'm using gimp 2.7.5 (2.8 preview); I don't know if this is
> > > specific to 2.7.5 or not.  It may also be that these are temporary
> > > issues with the transition to full color management and 16bit colors.
> > > But if they are issues not already on the gimp development plate, they
> > > should probably be raised so they are at least well-known.
> >
> > Ah. Perhaps the difference is to do with Windows?
>
> dangit.
> Could be windoze related;
> or something that creeped in between 2.7.4 and 2.7.5.
> Anyone running 2.7.5 on any os who can confirm 2.7.5 behavior one way
> or the other?
>
> Ugh.  Global .gimprc says
>   #(color-profile-policy ask)
> my .gimprc says
>  (color-profile-policy convert)
> which I don't believe I ever set, but I could be lying.
>
> I now see, at bottom of preferences/color management, option to ask,
> keep, or discard (convert)
>
> However...
> I changed it to "keep",
> exited,
> my .gimprc now says keep
> The image comes across with the profile, but image/properties still
> says sRGB default.
> Change it to ask and the behavior is the same -- I still don't get a
> dialog, and it still says the profile is the default despite the
> original one being applied.

Can you use a third program to ensure that the colour profile is
actually embedded and not just destructively applied? I guess
ImageMagick is not as simple to use on Windows, though you could try
just uploading it to http://regex.info/exif.cgi which runs ImageMagick
etc. for you, if you feel alright uploading it to random websites …




-- 
Kevin Brubeck Unhammer