After I started to use the “area color mapping” feature of the module “color calibration” to areal match of the chromaticity of very similar images, I cannot use “color calibration” module as usual, i. e. to adjust the white balance of the picture via custom and areal color picker.
The area mode of “area color mapping” switches alternately in “measure” and “correction” modes, so I do not know how to stop area color mapping. Here a screenshot of the concerning feature:
I think I have not understood the philosophy behind thoroughly. I use the released version 4.6.1 of DT. Any hint is appreciated.
Hi Mustafa this is a great feature in the color calibration module. I use it a lot when color matching between images is important. Have you read the user guide? Here is the link if you haven’t darktable 4.6 user manual - color calibration
To use the area color mapping you open the image with desired color and set area mode to measure. Then when I open the next image I want to correct the area mode has been set to correct. This feature allows me to color balance images so well.
Now if I would like the color mapping to neutralize colors or match a grey card in an image I just set the chroma slider to 0.0. I feel set the chroma slider to 0.0 will give you the behaviour that you expect. There is no bug in what you describe. It is the expected and desirable behaviour of the module.
Hi Terry,
yes, it is really a very useful feature. I am not sure, if setting only the chroma slider to 0.0 is sufficient. Meanwhile I found out that, when I reset all three sliders then I can adjust WB using color picker. What I do not know and I am unsure is whether or not the option “take channel mixing into account” should be active or inactive.
Default is 50 0 and 0… the issue with this feature is that if you do a measure the value is sticky…even with a module reset…so you have to manually reset the the 3 sliders or it will give you weird results for WB the next time you use it…
@priort I have found that with the exception of putting lightness slider at 0% the hue and lightness sliders have no effect if chroma is set to 0.0 so being lazy that is what I do if a neutral grey is the desired color match.
I defer to more knowledgeable people who may answer this question after my post. The default has the option active and since I don’t know any valid reason to change it I just leave it as I found it. It is discussed in the user guide but I didn’t see why I would inactivate it.
Chroma is like an amount slider…its the same sort of thing in 4 ways if you apply a correction in the shadows say with the auto picker and then set chroma to 0 then it takes that away… same for the illuminant in the CC module… you could set it to as shot or what ever and then toggle to custom …dial back the chroma to zero and no adjustment would be applied… but double clicking on the sliders in the color match section will set them to 50 0 and 0 so that is why I suggested it…It also makes it clear that you are in the default condition and not having 3 sliders left at weird numbers only disabled by setting chroma to 0… but everyone works the way they work…
