mono mixer bug ?

[denzjos]

Gimp 3.0.4: Monomixer converts the colors of a photo directly to gray. I tested it with a simple orange layer and this was the result after activating the 'Monomixer' (Colors / Desaturate / Monomixer). A bug ? Using the 'Colour Picker Tool' on the gray layer give orange as result.

   

[rich2005]

It is because it applies as a layer effect (fx). I have noticed the same with other tools that initially apply a fx  The thumbnail in the layers dock is the same.

Once applied both thumbnails change to the effect.  This one applied to a selection.

   

edit: With a fx still active a colour picker work-around might be a new-from-visible top layer.

[Ofnuts]

Did you check the "Sample merged" option of the color picker?

[denzjos]

Load photo :
   
Activate 'Colours / Desaturate / Mono Mixer' (and didn't changed the sliders)
   
Result : (just click on 'OK')
   
When I use gimp 2.10.38 :
Activate 'Colours / Desaturate / Mono Mixer' (and didn't changed the sliders) :
   

[CmykStudent]

denzjos: Hi! If you look at the bottom of the dialogue in GIMP 2.10.28, you'll notice the "Preview" box is unchecked. If you check it, it should show the preview of the filter like in GIMP 3.

[denzjos]

(06-02-2025, 02:14 PM)Ofnuts Wrote: Did you check the "Sample merged" option of the color picker?

I can reproduce what I noticed yesterday with the 'Mono Mixer'. It's like rich mentioned.

---

(06-02-2025, 07:58 PM)CmykStudent Wrote: denzjos: Hi! If you look at the bottom of the dialogue in GIMP 2.10.28, you'll notice the "Preview" box is unchecked. If you check it, it should show the preview of the filter like in GIMP 3.

---

(06-02-2025, 12:11 PM)rich2005 Wrote: It is because it applies as a layer effect (fx). I have noticed the same with other tools that initially apply a fx  The thumbnail in the layers dock is the same.

Once applied both thumbnails change to the effect.  This one applied to a selection.



edit: With a fx still active a colour picker work-around might be a new-from-visible top layer.

OK, that's it.

[Ofnuts]

Bug already reported.

[rich2005]

Another twist on the colour picker question.

(1) The test image, color pick the center.
(2) After applying Mono Mixer and layer effect still active, original color showing
(3) The same test image, layer effect still active  but now in a layer group,

   

reminds me of the old IBM adage:
If it's there, and you can see it, it's real. 
If it's not there, and you can see it, it's virtual. 
If it's there, and you can't see it, it's transparent. 
If it's not there, and you can't see it, you erased it.

[denzjos]

(Yesterday, 12:48 PM)rich2005 Wrote: Another twist on the colour picker question.

(1) The test image, color pick the center.
(2) After applying Mono Mixer and layer effect still active, original color showing
(3) The same test image, layer effect still active  but now in a layer group,



reminds me of the old IBM adage:
If it's there, and you can see it, it's real. 
If it's not there, and you can see it, it's virtual. 
If it's there, and you can't see it, it's transparent. 
If it's not there, and you can't see it, you erased it.

'If it's not there, and you can't see it, you erased it.'
And sometimes, if you are not alert, it is lost forever...

[Ofnuts]

The version I had for the last was "If it's not there, and you can't see it, it is backordered"