gimp gmic mixer filters

Software G'MIC
1

One of the members of gimp-forum came up with this. The Colors → Mixers filters

With anything other than All-tones in the Tones Range drop down, creates a desaturated result. This the RGB mixer, the others similar.

1238×728 175 KB

1 Like
2

Thanks, I’m checking this…

3

Filters updated, press the “Update Filters” button to get the fix (requires at least G’MIC 2.9.9).

gmic_mix_rgb
gmic_mix_rgb1545×904 245 KB

4

New day, another go. Unfortunately still getting a desaturated result:

This time kubuntu 20.04 / Gimp 2.10.24 (from PPA) gimp_gmic_qt 3.0 from gmic.eu
The updatexxx.gmic for 2.99 and 3.0 both 4685061 B All the Mixer(XXX) versions the same.

904×482 111 KB

6

Now fixed :slight_smile:

1 Like
7

Yes, now it’s fixed. :+1:

8

@David_Tschumperle,

Please can you also take a look at the “Freaky Details” filter, the amplitude and scale sliders do nothing there. It’s been like this for a while.

9

This does make a difference for me. What version are you using?

10

freaky_probleem2
freaky_probleem21920×563 124 KB

[gmic_gimp2.10_win64.zip](https://gmic.eu/files/prerelease/gmic_gimp2.10_win64.zip) 2021-09-02 18:36

And there is no interference with my user.gmic file (temporarily removed)

11

But what happens when you set Scale=1 for instance ?

12

It will take much more time to process, but no difference in result. (preview and end-result)

13

So that’s not the same as with Scale=100 right?

14

The result is the same (also scale 100), but the computation time is different.

the only slider that makes difference, is the iterations slider

15

This is what I get with the gmicky image and different values of scales :

  • Scale=1:
    scale1

  • Scale=10:
    scale10

  • Scale=100:
    scale100

It’s not the same result. I’m using 3.0.0_pre (but 2.9.9 should render the same).

16

I will do the same and post here:

Original (no freaky details):
original

Everything hereafter with: Iterations=1 and Amplitude=2

Scale=1:
scale1
Scale=10:
scale1
Scale=100:
scale1

17

The strange thing here is, that the image is exactly the same for the website, it automatic stores it as the same image, but I uploaded it 3 times. (with different file names)

18

@David_Tschumperle:

The filter works with removing the alpha channel. (I just found out by accident)

1 Like
19

This tells me that there should be a guideline to factor in the existence of alpha channel when creating filters for the GUI version.

The general rules:
GIMP - Any number of channel from 1-4 ? Scaled to 32F * 255.
Krita - RGBA-32F scaled to 0-255 regardless of picture being in non-RGB space or not.
Paint.NET - RGBA-8I

Not sure for the rest. I’ll ping @PDN_GMIC.

1 Like
20

Great catch!

https://github.com/dtschump/gmic/commit/bedee63ba18c12c5f37405af1f35a261443995c3

Try to update your filters, it should work now.

Basically, if a filter should not deal with the alpha-channel of an image, then a usual construct would be something as:

repeat $! l[$>] split_opacity l[0]
   ... # Your filter code here
endl a c endl done

(it just preserves the initial alpha-channel).

Maybe @grosgood could be interested to add this construct into its tutorial pages :wink:

2 Likes
21

@garagecoder 's “LMS Adjustment” (G’MIC>Testing>Garagecoder>LMS Adjustment) can use this “treatment” too and then straight to the “Colors” filters. :smiley: