"Working profile" cannot be loaded from external file

[Beep6581]

Originally reported on Google Code with ID 1104

We can choose a directory with ICC profiles to be used as "Output profiles", but there
is no way of choosing a "working profile" other than the built-in ones. Would be nice
to have an "other" choice in the list, that launches a file-open window.

Reported by entertheyoni on 2011-11-07 02:11:35

[Beep6581]

Do you really have a profile that is more suited than any of those proposed? I'm not
a color handling specialist, quite the contrary, so i need to figure out if it's worth
it.

Reported by natureh.510 on 2011-11-21 08:50:54

[Beep6581]

The inability to choose a custom working space is the major reason why I almost never
use Rawtherapee, even though I really, really, really want to. Not everybody chooses
and then uses only one working space. I use several standard and also custom working
spaces (and camera input profiles) in my digital darkroom. So here is a mixed bag of
reasons why choice is good:

1. Some people who work with 8-bit images like the L-star type working spaces more
than they like sRGB. Other people like other working spaces for other reasons. 

2. Some people like to use linear gamma working spaces. Resizing an image is best done
in a linear gamma working space. Color-mixing produces cleaner, more believable results
done in a linear gamma working space than in a working space with a gamma other than
1. I'd like to compare sharpening results with Rawtherapee's RL Deconvolution used
in linear and non-linear gamma working spaces.

3. In my article "Custom Working Space with Negative Tristimulus Values" (http://ninedegreesbelow.com/photography/negative-primaries.html),
I show how and why standard working spaces can literally chop holes in your image's
blue channel, leaving behind black pits and splotches in places where the raw file
actually contained very useable information. 

4. Using Argyllcms, an IT8 camera profiling shot that was altered by systematically
decreasing/increasing saturation, and a bit of matrix math, I created a series of custom
(that is, tailored to my particular camera as profiled with Argyllcms) working spaces
that can be used to increase or decrease image saturation. 

5. I'm planning on creating a working space based on my monitor's primaries, to get
the maximum match between what I see on the screen and what is actually contained in
an image's RGB values. I think such a space might be especialy great for working with
black and white images.

Reported by L.Elle.Stone on 2012-02-25 16:30:28

[Beep6581]

HIi Elle, very interesting article.
I am happy to say that RawTherapee does not seem to be clipping the blue channel, actually.
The latest version has preview modes which allows to view channels - use shortcuts
r,g,b. Clipping indicators are showing clipping information for the channel previewed.
Looking at the yellow flower (input profile = Camera standard) blue channel does look
very dark, but it is not clipped (may be just a few pixels). Bumping up the brightness
a bit allows to see the full blue channel content.

Reported by michaelezra000 on 2012-02-25 20:25:44

[Beep6581]

Hi Michael, Thanks! for taking the time to read the article and play with the raw file.
What  color balance did you use? A more or less correct white balance is temp 5200
tint 1.

You are right! RT 3.0.0 does in fact preserve the blue channel, at least when saved
as a png. When saved as a tiff, neither gimp 2.6.11, nor showfoto 1.9.0, nor krita
2.3.3 on kde 4.6.7, nor geeqie 1.0 could open the tiff (I'm running Debian Sid) - is
this a known bug or should I report it? Gimp says "Not a TIFF or MDI file, bad magic
number 34410 (0x866a)".

Ufraw 0.18 (and other raw converters that I've tried in the past) lose the blue channel
details when converting to a standard working space. When saved as a tif, the blue
channel goes black over most of the flower. Ufraw 0.18 keeps a weird kind of pseudo-detail
IF I save the image as a png. I say "pseudo-detail" because I recognize it- for png
output, Ufraw seems to be sending the image through Lab space and clipping all the
raw file negative values in the process, before converting to the RGB output space.
It's not at all the detail that RT produces. RT produces the correct detail.

We seem to have left behind the topic of adding the ability to choose a working space
from file, rather than being limited to built-in working spaces. But I'm really impressed
that RT kept the blue channel detail.

Reported by L.Elle.Stone on 2012-02-26 13:16:12

[Beep6581]

How did you managed to download the raw files? When i click on the links, it send an
Error 404 (page not found)!?

for the TIFF problem, you have a checkbox whether you want a compressed TIFF or not.
Please try playing with it.

Actually, the working space useable in RT uses matrix only (correct me if i'm wrong),
so using a real icc profil is a real big change... too big to be done, imho.

Reported by natureh.510 on 2012-02-26 14:02:45

[Beep6581]

I would recommend you to try RT 4.0.7 instead.

Reported by michaelezra000 on 2012-02-26 14:28:29

[Beep6581]

If RT uses only matrix math to convert from one space to another, without invoking the
whole ICC color management thing, that might explain why RT isn't clipping values (just
a guess, I keep learning, but I'm no color management expert). I'm downloading the
source code for 4.0.7. Any hints as to where the matrix conversions from camera input
to the working space are written in the source code? 

The links to the raw files are correct now. Sorry

Reported by L.Elle.Stone on 2012-02-26 20:42:55

[Beep6581]

in RT4, the color conversion code is in rawimagesource.cc, look in the method colorSpaceConversion

Reported by ejm.60657 on 2012-02-26 20:59:47

[Beep6581]

Stale, closing.

Reported by entertheyoni on 2014-10-31 20:28:16

• Status changed: Invalid

[Beep6581]

Could this be reconsidered to allow the setting of a printer profile as the working
profile ?

Reported by dnw3039 on 2015-04-08 23:19:30

[Beep6581]

One should never use a printer profile as the working profile.. Printer profiles are
intended as output profiles only.

Reported by michaelezra000 on 2015-04-08 23:32:45

[Beep6581]

Ok, now I understand the difference between a print output profile and a print simulation
profile as used in GIMP for soft profiling. 

So, would the ability to select a simulation profile, be worth adding ?

Reported by dnw3039 on 2015-04-09 04:06:39