I am trying to put together a brightness/contrast node group.
I am aware of the one in Blender, but the algorithm is lacking in my opinion.
Here's an example:
Here's an adjustment made in Photoshop:
I am looking for something that is close to the non-legacy algorithm used in Photoshop. Something more gentle, that doesn't blow out the color and saturation. I've done a google search and came across some algorithms but I don't know which yields the best result.
Edit: Here is some information I found after digging a little bit about how Photoshop does Brightness/Contrast:
Prior to CS3, Brightness/Contrast applies a linear transformation to the transfer curve: adjusting brightness alters the polynomial constant, sliding the curve to one side; while adjusting contrast alters the polynomial scalar, expanding or compressing the curve. In later versions, the core behavior was changed to a non-linear transformation, while this linear behavior is retained as Legacy mode.
So it sounds like I need a non-linear transformation that alters the "polynomial scalar". I'm not sure exactly what that means in practice.
Edit2: More information found here (Emphasis mine):
The current library implementation (v20.6 on the moment of writing) uses default Photoshop algorithm that preserves the full tonal range from the shadows to highlights, but it doesn't yet support legacy behavior.
Edit3: I did some more digging:
I'm hoping someone with background in image processing could lend a helping hand here.
Thanks so much for any help.