alpha channel created by masks not "perceptual" in standard normal layer mode
GIMP version: 2.10.2 (flatpak) Operating System: debian stretch
Description of the bug
The transparency created by masks does not meet expectations standard layer mode "normal". I discovered the issue by applying the "drop shadow" operation (gegl)
- create foreground 2 background gradient
- try the same by applying solid background layer and solid foreground layer. Create a white2black gradient on foreground layer mask.
- toggle layer mode type "deprecated" vs. "standard" See attached xcf-file. The issue can also be felt, using the blurring operation on "RGBA" vs. "mask".
Expected result: perceptual equally spaced gradient Actual result: gradient is "perceptually nonlinear"
For my impression the layer mask in "standard normal layermode" erroneously is considered to be "linear" instead of "perceptual" (Gamma? TRC?)