Jumping grey colors on Layermask
GIMP version: 2.10.22
Operating System: [Windows 10]
Package: [Installer from gimp.org]
Description of the bug
When painting grey colors with a pencil on a layermask I didn't get the RGB values I have selected but some similar colors. Doing then same painting on a layer (not layerMASK), everything is fine. See attachment.Greytest.xcf
Reproduction
Is the bug reproducible? [Always]
Reproduction steps:
- Make a new Gimp XCF
- add a layer without layermask and another layer with layermask. For the second select "show layer mask" to paint on mask instead of layer
- select pencil and set its color to RGB=(40,40,40) in 0..255 (not 0..100 !). Paint on the layer and on the layer mask. The color you will get on the layer mask is RGB=(37,37,37).
- In the attached file you can see on the layer mask, that the grey values you get, are jumping heavily when painting several lines in grey with RGB=28, 29, 30, 31, 32, ... while on the layer the colors are nearly the grey you have selected.
Painted on LayerMask: 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44 Gotten on LayerMask: 28, 28, 28, 28, 34, 34, 34, 34, 34, 37, 37, 37, 37, 42, 42, 42, 42
Expected result: Getting the same grey colors on layer and layer mask when painting with the same grey color. Getting no jumping colors.
Actual result: Jumping colors on layer mask, see attachment in the lower part. (It seems to me, that it's a problem of rounding when converting between the colors spaces ?)
Additional information
This problem doesn't exist in older versions (2.8 ?). After updating to 2.10 I found this problem when fading two pictures with a layermask. You can see the jumping grey colors of the layer mask as ugly stripes in the deep blue sky of the resulting picture.