Color Balance RGB: select by hue presets

Hi,
I just want to share here a small set of simple presets I have created for Color Balance RBG.
I would like to do all color grading in scene referred workflow and Color Balance RBG is great, but it lacks the capability to manipulate selective colors, something Color Zones has, but in display referred.
So I created some simple pre-defined parametric masks in order to quickly select the main hues in Color Balance RBG by using multiple instances. The presets only contain the mask and I have tried to make the hue selection as accurate as possible by using color wheels from various sources and color checker images.
Of course the mask can be created ad-hoc, but these predefined are quicker and they are complementary to each other, so not to apply multiple corrections to the same area.
In the atteched zip, you will find 9 presets (Red, Orange, Yellow, Green, Cyan, Blue, Violet, Magenta, Neutral).
The Neutral preset selects areas with low saturation, while the others will select the specific hue, with medium and high saturation.
Feel free to comment, change or criticize.

cb_select_hues.zip (5.9 KB)

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Those are a nice set of (initial) presets.

We could have a discussion about the label correctness of violet vs purple and the size of the magenta preset. Those two (violet + magenta) might need an extra preset in between and maybe a name shuffle. But: That’s just my 2c and I’m not going to nitpick… :sweat_smile:

Anyway: These might come in handy.

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Many thanks, really useful

I raised this in another post and Aurélien mentioned that something similar might be coming to the color calibration module in the future. But it’s definitely something I’ve been missing from color balance RGB and I can see you have too. I’ll try these out, thanks!
Incidentally, I sometimes use color lookup table to do the same thing, and it’s surprisingly good, but only if you make very small adjustments. The color patches work very like prebuilt parametric masks.

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I do the same and you can replace a patch with any color in your image…I really find it a nice easy way to darken a sky and or bump saturation of the blues…

Agreed. Not sure I could understand the code, but I’d be interested to know how the module separates the colours into ranges. It seems to do a really good job without bleeding into other colours. But you can’t push it very far.

Light touch makes it work…I often just tweak the three blue patches for a blue sky edit and the three green patches when trying to tame or enhance foliage…

Yes, if you are touching color here and there, Color LUT is ok, but for a complete color grading I find it impractical.
A LUT work as a whole. Every patch selects a specific range of colors, i.e. hue, saturation and lightness, which also depends on the other adjacent patches. If if change multiple patches the result if often unpredictable.
What we need is a scene referred version of Color Zones

But how is this different from using multiple instances of color balance RGB and parametric masks like your presets?

I think it’s quite different. When you change the L,a,b values in a patch of Color LUT you affect also adjacent colors because the algorithm will do an optimization (least squares?) trying to minimize the global deltaE.
If you also replace colors (with SHIFT+click) in the patches it is even worse because the LUT can quickly become not well-behaved.
Color Balance RGB + mask will only affect the selected area instead

I’m probably missing something obvious but I can’t find any hint of how to use these. When I click the hamburger in this module it just gives the option to store new preset (which stores what adjustments you have just made) but I can find no option to load new preset.

You need to go to the presets section of the preferences dialog.

@MarcoNex Works great, thanks a lot.

I had to tweak the cyan one at least for my Datacolor Spyderchecker24…the mask would select Aqua not my primary cyan which seems to be the color most off in my images…just redid the parametric and updated the preset…the rest were good matches for selecting the patches on my color checker… I think true primary cyan is defined around hue angle 193ish which is quite a bit lower . Using the new restrict histogram indicator in the vector scope I was able to align all the 6 primaries on the color checker by just using hue rotation on magenta cyan and yellow…rest were in line…not sure if this is 100% accurate as the vector scope uses Jzczhz for display. I will have to compare this approach to the color checker mode in CC and compare the colors that I get…

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When you’re done, please post back your result

Many thanks, I find them very useful.

I may try to do a summary but there are a lot of moving parts to this. First, the vectorscope is using Jzczhz, and secondly I am not sure if it is handling values in a way that the other scopes were or maybe still are. Because the data goes form working profile to display profile to histogram profile you need to set your display profile = to your working and histogram profile to be sure the data is not clipped when it is mapped in the smaller display profile. This should be branched so that working goes strait to histogram which is where the picker data comes from and not through display and I think this is being looked at but I think it is still an issue. In any case using the vector scope in conjunction with picker values to make calibration adjustments might need care. I was hoping to evaluate the 6 primary color in the spyderchecker24 with the vector scope and look at them before and after colorchecker calibration in CC module and then after making targeted changes to each using the rgb colorbalance module masked for each patch. Initially I just rotated each so the sample of the patch aligned to the color locus on the hue ring. This is similar to what you see people do in Davinci with a hue vs hue curve. The colors did not look quite right. So instead I changed the picker to HSL and used the instances of rgb CB for each patch mostly with hue rotation but also with global sat ,chroma and luma to dial in the HSL values as close as I could to those given by Datacolor. This looked the best to eye when I compared it to the actual color chart but I have no idea if it could be used on other images. This was all done without filmic turned on…turning it on seems to shift things a bit depending on the color preservation mode…In any case I am not sure about the actual relationship of the picker values to what is displayed in the vector scope. Maybe I will try to organize all this fiddling around and post if it proves to have any merit…

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Thank you! Very nice presets.

Thank you!!

This doesn’t seem to to work in 4.2. The presets are grayed out in the module. Probably because the color science for the module got upgraded (at 4.0?)? Has anybody updated the presets to work with later versions of dt?