Matchbox Shader for Regraining LS_Splineblur

I created a new shader specifically for regraining shots after I’ve used LS_Splineblur: (34.1 KB)

It takes the matte you used for Splineblur as the input, and outputs black where there’s pure black or pure white, and white for any shade of gray.
Perhaps there’s an easier way to regrain after using Splineblur, but I couldn’t think of anything.

I thought about calling it KE_Donut, but I think SplineBlurMatte is more helpful.