FEATURE: Parametric Tone Curve.

[mmadesignerunknown]

Feature Description

Hi everyone,
I think it will be great if we get to use the Parametric Tone Curve, like in Lightroom, with sliders for Darks, Shadows, Highlights, Lights.

What do you guys think?

Regards,

Additional Context

No response

Similar feature requests

• I have searched existing issues and discussions and didn't find a duplicate

[savukadoo]

Been playing with this mocup idea, what do you think ?

[mmadesignerunknown]

Thanks alot @savukadoo .
I really love the mockup, but here's one thing I would like to suggest.

My plan is to unlike lightroom, which has Parametric Curve only for Luma, implement it for individual Red, Green, and Blue too.

And for that, the UI of tabs I thought of is:
L, R, G, B, L*, R*, G*, B*.

(The "*" indicating that they are Parametric Mode)

The rest of the UI including Graph, Splitters, Sliders exactly like your mock-up.
What do you think about this.

And for the progress, i have been trying to implement the backend, but eventually fail at a certain point. However I am sure I will find a way :).

[savukadoo]

I see what you mean, what if the parametric curve tool has the L R G B , like the normal curve tool and if you choose one of those, you can adjust the specific colour. I am also in the testing phase and its not an easy feature to implement and its quick complicated to get right On 5 Apr 2026, at 19:32, mmadesignerunknown ***@***.***> wrote: [https://avatars.githubusercontent.com/u/189126365?s=20&v=4]mmadesignerunknown left a comment (CyberTimon/RapidRAW#951)<#951 (comment)> Thanks alot @savukadoo<https://github.com/savukadoo> . I really love the mockup, but here's one thing I would like to suggest. My plan is to unlike lightroom, which has Parametric Curve only for Luma, I want to implement the Parametric Curve for individual Red, Green, and Blue too. And for that, the UI of tabs I thought of is: L, R, G, B, L*, R*, G*, B*. (The "*" indicating that they are Parametric Mode) The test of the UI including Graph, Splitters, Sliders exactly like your mock-up. What do you think about this. And for the progress, i have been trying to implement the backend, but eventually fail at a certain point. However I am sure I will find a way :). — Reply to this email directly, view it on GitHub<#951 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AMFFH7OBTC4IJGVVWIBQGF34UIRZRAVCNFSM6AAAAACXJFCFHWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DCOBYGYYDIMJVHE>. You are receiving this because you were mentioned.Message ID: ***@***.***>

[mmadesignerunknown]

I see what you mean, what if the parametric curve tool has the L R G B , like the normal curve tool and if you choose one of those, you can adjust the specific colour.

I am also in the testing phase and its not an easy feature to implement and its quick complicated to get right

Totally agreed @savukadoo , because unlike point-based curve, the parametric curve has to be "smooth" when adjusted, and implementing all this is quite hard and complicated. So i am thinking of this approach right now, first make it only for Luma and One Color. Once it gets correct, implement the remaining 2 colors. It won't be easy, but I am sure we will find a way, if you require any help, do inform me, I will try my best. :)

Regards

[savukadoo]

Attached, it has the Curves file, it as the adjustments file and then the shader file as I had to have some changes as well due to the way the pipeline is managed. It may require a rethink of how the pipeline is managed to really have a better solution as the current one may be challenging to keep retro fitting or bolting things on, however you may solve the problem ;-) Cheers On 5 Apr 2026, at 22:31, mmadesignerunknown ***@***.***> wrote: [https://avatars.githubusercontent.com/u/189126365?s=20&v=4]mmadesignerunknown left a comment (CyberTimon/RapidRAW#951)<#951 (comment)> @savukadoo<https://github.com/savukadoo> Sorry for this, but if you don't mind, can I please take a look at your code for some inspiration. :) Only if it's okay with you. Regards, — Reply to this email directly, view it on GitHub<#951 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AMFFH7MVLAVPYRAZ6E4AUNT4UJGYLAVCNFSM6AAAAACXJFCFHWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHM2DCOBYHAYTQNJYHE>. You are receiving this because you were mentioned.Message ID: ***@***.***>

[mmadesignerunknown]

Attached, it has the Curves file, it as the adjustments file and then the shader file as I had to have some changes as well due to the way the pipeline is managed.

It may require a rethink of how the pipeline is managed to really have a better solution as the current one may be challenging to keep retro fitting or bolting things on, however you may solve the problem ;-)

Cheers

Extremely sorry for the inconvenience, but i can't find the files, can you please send them again.

Regards,

[mmadesignerunknown]

I have created a preview of the curve I will be implementing, please ignore The UI in the preview, it will be adjusted to fit RapidRAW's UI. any other ideas are much more than appreciated.
here is the file:
Parametric Curve Preview.html

Sorry for the ping @CyberTimon @savukadoo , But I will really appreciate if you could provide your feedback before I actually start implementing this in RapidRAW. Sincere apologies for the disturbance.

Regards,

[CyberTimon]

Looks pretty cool. I have no experience with parametric tone curves and I'm unsure what a clean UI for them would be. But yes, @mmadesignerunknown, it would be cool if you could create a prototype PR or something like this (then we can take a better look / decide what works best). Thanks so much!

[mmadesignerunknown]

Sure @CyberTimon , will start to work on it tomorrow ;)
It will be better though if I can see how @savukadoo implemented the UI, so if possible, please share the files again, if you don't mind, IDK why but I didn't received the files you sent last time, Sorry for disturbing you.
Thanks for the feedback.

Regards,

[savukadoo]

files.zip

These are the files you were after, hope it helps @mmadesignerunknown

[mmadesignerunknown]

I'm sure it will, thank you @savukadoo .

[mmadesignerunknown]

@savukadoo @CyberTimon ,
Sorry for the delay, but I now have opened a draft PR here, implementing the frontend only, with some modifications to the math #1017 It will be great if you could provide a review there. Thanks.

Regards,

[mmadesignerunknown]

Implemented the complete functionality. It's now open for review

[Flohhhhh]

@mmadesignerunknown @CyberTimon Right now it's currently "choose parametric or point curves" you can't stack the effects like in Lightroom.

The primary issue with this is that the parametric controls have no sliders for the black and white levels, so you can't make any white or black rolloffs like shown below.

In Lightroom I can set up a point tone curve that has the rolloff i want, then switch to parametric for further exposure adjustments if i choose and the effects will stack.

In the new implementation here, if I make my point curve with the rolloff I want then switch to the parametric tab my changes get reset. Which makes it impossible to have any fimlic rolloff while using parametric curves.

The easiest solution would probably be to just add black and white level controls to the parametric curve to be honest. That would be a lot easier than dealing with stacking and conflict resolution I think, but i'm not super familiar with the implementation method. I know stacking in the pipeline might be non-trivial, which is why I’m suggesting extra controls instead.