Selective color PS to GIMP

[Krikor]

Hello, I would like to know if there is something in Gimp that comes close to what is seen in the shoot screens below (taken from a PS tutorial video)

       

In the video tutorial this step is called "Add selective color adjustment".
What I could understand is that:
First the red color was selected and then the Magenta color slider slid to the right (increasing the green, I think);
Then the color yellow was selected, and the same slider was adjusted slightly to the right again.

I looked in the Gimp menus and even in G'MIC but I didn't find anything like it - something that fixes a color and adjusts the colors in the CMYK standard.

How could I do this tutorial step using Gimp?

Thx.

[sallyanne]

I'm sure you have already looked through everything. I could only find a few things that might be what you are looking for.
In Gimp - color balance or Hue-saturation (the saturation) or Levels, Curves, and
In GMIC-Qt - CMYK Tone or Mixer CMYK
I'm sure someone will come up with a better answer for you. Maybe someone who knows photoshop.

[rich2005]

(04-05-2024, 12:43 AM)Krikor Wrote: ...snip... - something that fixes a color and adjusts the colors in the CMYK standard.

How could I do this tutorial step using Gimp?

I am guessing that the PS tool also gives a real-time preview. Nothing I know of with Gimp or G'mic.

A possibility but a bit convoluted.

G'mic can decompose the RGB channels into layers. (edit: For that Yellow mix you would have to decompose to CMY) As an example putting those into a layer group. (maybe using Saul Goodes script )  Put the Red and Green layers into lighten mode and they combine back to the original image.

Now using G'mic Mixers[CMYK] on the relevant layer(s). 

example: https://i.imgur.com/ZUiK5oy.mp4

...and that sort of looks a little like that PS filter, but of course the parameters are different (not a percentage)

edit: Not with sliders but I often use G'mic color curves - the CMYK option for adjusting the image.

------
That is not going to fly

I wonder what that PS filter actually does ? What is the end result of that PS video ?
Gimp is strictly RGB so adjusting Yellow using Magenta will affect both red and blue

   

So what is probably needed is some sort of mask separating yellow from the rest of the image.

[Krikor]

Hi Sally and rich2205!

My initial idea was to find some filter in GIMP that could be a translation of what was done in PS in that section of the tutorial.

But after seeing rich2005's post above and how complicated things got, I thought of a different approach.

The idea would be not to exactly follow the steps and filter used by PS, but to understand what was actually obtained with this "step - PS filter" and then recreate it using GIMP.

The video tutorial is very quick, and without audio (just a musical background that I left muted), so it's difficult (at least it was for me as I don't use PS) to really understand what was going on.

I captured two images from the video, one before and the other after the effect was applied.

The idea was to try to understand what actually changed, and then have freedom with GIMP to obtain the same result.

But the changes I detected were very subtle.

Using Sample Point on both images:

   

Approximate curve that would produce the effect in the final image:

   

I ended up simply using Colors - Hue - Saturation...:
First, selecting the red color and increasing the saturation, then selecting the yellow color and reducing the saturation a little.
I don't know if it's anything close to what was done in the specific step of the tutorial, but it was the temporary solution I used.

rich2005, the tutorial aims to achieve an effect that seems to be trendy among the social media crowd. That's why they asked me for this type of effect in some images.

This MrBeast Face Effect exaggerates the contrast and whiteness of the teeth and eyes (at least that's what I got from watching this tutorial).

In my test I tried to follow the tutorial using GIMP for now this is what I got in the first and only attempt:

   

Sally and rich2005, thank you for your attention and help with my question!

-----------------------------
Ahh, I almost forgot, the topic I covered here in this post can be seen in this video between minutes 4:30 and 4:42

https://youtu.be/Ogbf3wxXjCc?si=VTNA12C2WYDZD85b&t=270 - MrBeast Thumbnail Face Effect (Photoshop Tutorial)

[rich2005]

maybe G'mic photoillustration filter

   

   

[Krikor]

G'MIC has excellent filters, unfortunately most of them are unknown and unusable due to lack of documentation or tutorials explaining how these filters work.

I believe that I use much less than 30 (which I have some idea of how they work) of the 586 filters that my G'MIC has, which gives about 5% of use.

This Photoillustration is very interesting, I don't know if I've used it before, but I was amazed by the options it offers.

Next week I will try to find time to explore it a little more.

rich2005, considering the settings you defined; As per the image in your previous post, I only made two changes:
In Smoothing Style I chose Bilateral;
In Detail Reconstruction Style, I chose Gritty.

fx_tk_photoillustration 0,0.25,1,0.3,0.5,0.5,1,0,5,0,1.28,69.8,-28.4,1.459,0.56,-4.36,1.24,100,5,0_c1.5,8,0,0,0,0,1,0

rich2005, thank you!