Item: Subtract Background Adaptive Action

**What does this action do?**
This action is designed for quickly masking out a subject by mimicking the background coloring and subtracting it.

**How does it work?**
This action reads the two furthest BG gradient colors, then using blending modes it subtracts that BG from the workspace, after this it compensates any discoloration by applying the same gradient and blending it again to get the negative reversed effect on the subject. Finally a copy of the original file is restored and clipped.

**Which backgrounds can be extracted?**
-    Solid colors [ white – grey – color ] .
-    2 color linear gradients [ vertical – horizontal ] only.

**What options are available per action?**
-    [Dark – bright] based on how bright or dark the subject is relative to the background.
-    [Fuzzy – normal] based on how smooth the edges are for your subject.

**known Restrictions:**
-    Requires closing all other open projects before playing.
-    Gradient background images will be squared in dimension.
-    Complex backgrounds / [radial – angular] gradients are not supported .
-    Imperfect results if subject and background share the same coloring. [action assumes the subject has transparency in it – can be improved by painting on bottom layer with a brush to get any missed parts].