[ENHANCEMENT] Improve area mask feathering
Area mask feathering is not very good when the mask shape is oblong. If you adjust to get a good feather distance for the short edge, the long edge gets a crazy big feather. Not useful IMO.
Blending feather is really about distance of the blend. How many pixels depends on the resolution. It is nonsense to think an oblong shape needs more feather on the long ends because the internals are longer.
Here are a couple of screenshots showing an area mask and a vector mask. Both are the same size. On my monitor 1 inch by 10 inches. Same blend of 20%. I'm not saying the area mask should be exactly the same as a vector. Different strokes for different folks. I'm saying the area mask feather is not at all useful. Look at it.
The source of this post is this situation.
I wanted to remove the trees from the lake. Clone stamp does not work due to tonal gradients so I was masking in patches. I tried area masks and shifting in some open water. The trees are obviously long and skinny. Oblong. Once I had an area mask for a tree that blended nicely on the sides, the top end was overwriting the shoreline above. This due to the massive feather from the oblong mask shape. I tried two masks more square'ish, that overlapped, and what a pain. Then I got a brain, remembered vector masks and used them. They feather in a useful manner.
Anyway area masks are simpler to use and should have a generally useful feather property.