1.21 and the new sigmoid

[foto (Syv)]

Thanks for 1.21 and I’m very interested in Sigmoid.

I have tried it. I see the effects but it looks like I don’t understand it. Like what problem does it try to solve and what conditions…

Could somebody points me to either some explanation or some yt video?

Thanks

[123sg (Steven)]

In darktable, sigmoid is a tone mapper, so you use it instead of the base curve or filmic. It’s basically a curve controlled by an algorithm, with some extra stuff to control hue twisting and so on.

I don’t know about the ART version though.

[priort (Todd Prior)]

If the code follows or emulates DT code then this would be where you can get lots of information about the transform… if its different @agriggio can elaborate…

New Sigmoid Scene to Display mapping

Hi there, first time posting both here and in the darktable github repository. I spent some time getting familiar with the darktable source code this Christmas and ended up with something actually interesting and figured I might as well share it with the rest of the community. It’s a tone mapping / look transform / scene to display conversion (or whatever you want to call it) that is based on a sigmoid function instead of a cubic spline like the base curve. I’m not 100% how the filmic module i…

[agriggio (Alberto)]

Hi,
It’s literally the same code
It’s meant to showcase what is possible with ctl scripts, and since it’s a good module I thought of shipping it with art rather than using it just as an example.

HTH

[foto (Syv)]

Thanks

[priort (Todd Prior)]

Great idea…