Hi all,
Here is my first contribution for DarkTable: a vibrance slider in the Basic Adjustments tool. Basically, it affects the saturation of the more saturated pixels. It can be used to make your colors mode vibrant without becoming unnaturally saturated.
It works in tandem with the saturation slider, so you can use these two sliders also to work on less saturated pixels.
It is similar to the vibrance slider in Lightroom, but I’m not sure that it uses the same formula. It has also different results than the Vibrance tool (this one also has negative values, for a faded look).
Before pushing it to the main branch, I would like to ask you to test it! I don’t really know how does the testing work for this software and where to ask for testers… Anyway, there is no build at the moment, you have to do it yourself 
Here’s my fork: GitHub - kbarni/darktable: darktable is an open source photography workflow application and raw developer
What do you think? Do you like the results?
The OpenCL part is untested (don’t have the hardware), so it needs to be checked too.
Here are some examples of its results (photo taken from internet):
- Saturation almost at max:
- Vibrance at max. Note that the colors pop out, but stay more natural:
- Vibrance at minimum. It desaturates the image, while still keeping some colors:
- Vibrance combined with saturation.It fades the background colors while keeping the skin tone:
