Lightroom offers a tool under the Camera Calibration pane (Not Lens Correction) that modifies the camera color matrix variables. Here is a photo of the Lightroom panel.
After some looking I was able to find a very in depth guide that talks and explains more about how this works on color. (Approx 21 min.)
I’ve used RawTherapee, Photoflow and now work primarily in Darktable, and find that none of them have something comparable to this.
This tool also exists in Adobe’s DNG Profile Editor:
But it is claimed that it does not work correctly, and I want as possible to remove Adobe software from my workflow.
DNG’s color matrix values are what this tool claims to change.
Does anyone know of a tool that allows some similar form of corrections to be conducted that is open source and non-destructive?
This is another great idea for a manual recreation! This seems faster than the HSL method I’m using to get there now, thank you for the find.
As mentioned within the video on the RGB Primaries these effects can also be almost recreated using HSL adjustments such as the HSV curves/Color zones. These paths are indeed means to get there.
The color balance Lift/Gamma/Gain is a strong tool as well. I’ve used the color wheels in video production. It has nice clean control depending on the brightness levels you want to work on.
I’ve had some great effect from the color contrast on the hue groups it aims at as well.
There are a lot of tools that can work together to attempt to recreate the RGB sliders. Nothing comes to the ease of changing one option like in Lightroom, but we can get close.
I absolutely love the RGB channel mixer, however, I must admit I have not yet managed to reproduce the Lightroom effect of the R,G,B primaries. Wish we had a proper tutorial on that …or if perhaps the code is not actually allowing for it, an additional tool?
this is fantastic, however, two things.
1: why the need to choose between RGB channels and RGB primaries? I could see people, myself being one of them, who would likely want to do a little bit of both.
Also, what the primaries does, it seems, is to take luminosity into account and only deal with the hue …in some awkward and math requiring sort of way, this ought to be doable with RGB channels - or?
RawTherapee team, i think this would be a lovely thing to implement and I’m sure mr @agriggio agriggio will gladly share code
2: the same issues I have here, the choosing between one or the other, I have with RGB curves. why the need to do either GRB curves or RGB luminance curves when a combination of the two can be quite handy in so many instances.
I take no offense in you being blunt earlier when you said you don’t think there is need for an extra tool; please don’t take offense in my asking for the implementation I did not to so to be demanding or lazy …i just lack the coding ability and was appealing to the awesome crowd here that has it. So yes, really, I did in fact dare ask for that and I will accept it if y’all don’t want to
This is very encouraging! for I have many times tried to and I did not figure out how to change the hues properly without messing up the luminosity or saturation of some colour. An example is making the red more orange, I do that by going into Blue and setting its red value to like -15; depending on the image, this can overexpose the saturation of the red. I’m curious if there is some simpler rule of thumb one can use to do this manually in RGB channels or if there is more serious math involved. I suspect the serious math
P.S.
Hey I’m sorry if I sounded demanded, annoying, or unappreciative of your efforts in the previous comment when I volunteered your code for RT people to implement. I didn’t mean it to come across like that. I think what you do is amazing and we are all better off because of it.
I must apologize, I think I overreacted a little bit… sorry about that. Maybe I’m starting to freak out for the endless lockdown… I don’t know.
Anyway, you can certainly make requests, absolutely! What triggered me was the style more than anything else… it sounded like an order, and that I didn’t like. Maybe it’s just a language barrier. On any case, sorry again.
I have always been of the opinion that the channel mixer is actually quite tricky to use, particularly if you want to do color correction (as opposed to more creative colouring).
Here’s the matrix corresponding to moving the Red primary hue slightly to the right (towards orange):
103.2 -2.6 -0.3
14.2 88.1 -1.5
0.2 -0.2 100.0
not quite intuitive to me… but maybe I’m just not getting it.
It’s a bit of linear algebra, here’s the paper that explains it.
gosh thank you! and I’ll take a look at the math paper too.
Orders aren’t nice, I hear you. I definitely didn’t mean that, and it’s too bad it came across that way. I’m glad it’s figured out. I certainly have no hard feelings and I’m glad you don’t think I’m some monster.
I fully second that! Although I can’t complain too much, over here in southern Ontario the rules aren’t too strict, nor does the police randomly stop you to ask for the reason of being in town, which I hear is the case in other countries, but still …not being able to go to a restaurant or bar or cafe …is really unsettling in a strange subconscious way. I don’t even necessarily want to go anywhere …I just wish I could I’m slowly getting better at this and filling my time with blogging and doing things I thought I had no time for before; that and I eat more Since we have to suffer like this anyway, I hope the world politicians come up with some improvements once The World 2.0 launches; maybe something will less pollution but who knows.
Thanks for this! I’ve been trying to understand the connection between the Calibration panel in LR and color primary matrices for a long time with no luck. What I really want to be able to do is translate a color space conversion matrix into Lightroom calibration hue/saturation settings. I read the paper and I have to admit that my understanding just isn’t up to putting it all together on my own. Is there a formula or spreadsheet that would let me plug in 3x3 matrix transforms and output hue/sat slider values? Thanks so much!
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I did not to so to be demanding or lazy …i just lack the coding ability and was appealing to the awesome crowd here that has it. So yes, really, I did in fact dare ask for that 
and I’ll take a look at the math paper too.
