Questions of HSX blending mode

Develop Artists Feedback & Testing
1

I first reported to amyspark that the blending mode used by “channels to layers” in GMIC could not restore the original image. But krita doesn’t seem to be responsible for internal code changes, so I went to pixls.us forum to communicate with them, this is their reply:

I think the problem is related to the slight differences between how blending modes are implemented in the different hosts that support G’MIC-Qt.
When I’ve implemented this filter, I’ve tried it on GIMP and it gave the same kind of result with the “Value” mode, as implemented in GIMP then.

Then I tested in gimp and krita respectively, and found that krita’s blending mode will lead to a significant change in saturation:

image
image491×494 38.6 KB

krita
image
image654×575 45.3 KB

gimp

My personal understanding is that when I use the “value” blending mode, I combine the “V” of the upper layer with the “H” and “s” of the below layer. So the saturation of the result should be the same as the layer below, and gimp is what I understand. Did krita use any other methods?

2

I know that GIMP treats alpha differently when doing the arithmetic manipulations involved with blending modes.
It may treat other things differently as well.
That might go some way towards explaining it.

3

It is obvious that gimp is equivalent to starting “inherit alpha”. This is different from all other software

This is normal. However, the results obtained by GMIC are consistent with gimp and more understandable. Krita in some cases, large changes in saturation seem strange

4

I can take a look into this too. I have to break a image into hsx channels and rebuild the final image again with blending modes. I am curious.

5

Krita’s HSY blending mode is consistent with that in other software. However, there are irregular changes in the color wheel.

Is HSX designed according to the standard of “Photoshop like”?

6

Yup Krita is not mixing HSV colors as it would be expected with the HSV blending modes.