General question about color picker. Using DT 5.3.0+24
Trying to understand the color picker, but I don’t have much succes …
So, how is it working? How to understand the three icons in the live samples?
How to use a live sample in the parametric mask?
I tried to find info in the documentation, but i have the feeling, it is not up to date … 
It seems well described in the manual. Am I missing something here. Maybe a screen shot of what you are struggling with would help understand your problem.
https://darktable-org.github.io/dtdocs/en/module-reference/utility-modules/darkroom/global-color-picker/
I’m not 100% sure what you mean but basically if you are talking about the color picker module itself then you have a spot and area picker. You can add a live sample after picking and you can have this display that selection on the vectorscope or restrict the histogram to show only that selection and not the image histogram. Values that you get are based on the color profile selection that you use from the histogram profile…ie if you use rec2020 or srgb or other…In the mask it has its own picker and it will display a point on the slider if you use the spot picker so you can target that with the slider or you can use the second picker and have that set the mask based on the selection for that channel using that picker…
Spot
Area
Thanks. Ok, I try to be more specific with my questions.
About parameter masking and color picker.
Assume that I have at least one live sample (point or area mode). How to select exactly that live sample in the parametric mask?
The mask has its own picker…and that will display the value for the parameter where you set the picker in the preview with a line on the slider or if you use the area picker it will set the mask based on that area again for the single parameter that you are using so hue for example… its not the same as the live sample which is showing the color of the pixel based on the histogram profile in use and the value system used LCH or RGB or whatever… To be exact I guess you would have to use three channels and specify the components in each to restrict the mask to match the color from your live sample… even then I think when you use the mask the picker selections are reflecting the information at the input stage of the module and where it is in the pipeline… you can also enable the output sliders and then work at the level of the module output…but I believe that the global color picker is the data from the preview after processing the current pipeline so I don’t think linking the live color picker to masking is what you would do … Maybe I will try to go and have a look at the code to see if this explanation is correct but I think it is for the most part…it’s why is you move a module with a defined parametric mask to another part of the pipeline then the mask will get new input data, changing it and it might no longer be masking exactly what you intended and so this is why we have raster masks for this situation…
I think there is a bug or I cant get the steps right. I see that right-clicking the first time seems to work as expected and the sample replaces the active picker…a second right click on the same patch or another one disables the picker and then all right clicks seem to load the active picker back into what ever sample you click on. I tried but I couldn’t land on the right combination to get it so that the right click would consistently replace the active picker…
Maybe someone else here can have a quick test and see for example if you have 3 distinct color samples and a different one active…can you sequentially replace the active one with any of the selected patches or does the process break down…if its working correctly maybe someone can elaborate on the correct sequence of actions to keep the function on track…
Thanks. Basicaly we canot reuse live samples in parametric masks because they are taken at a different point in pipeline.
