MaskTools/CombMask
From Avisynth wiki
CombMask (clip[, int "thY1"[, int "thY2"]])
Plugin: MaskTools
This filter produces a mask showing areas that are combed. The thresholds work as for the other filters: after calculating the combing value, if this one is under thY1, the pixel is set to 0, over thY2, it is set to 255, and in between, it is set to the combing value divided by 256.
The combing value is (upper_pixel - pixel)*(lower_pixel - pixel). Thus, it is not normalized to the range 0..255, because if it was done, value would be close to 1 or 2, no more. That means you can use threshold higher than 255, even if they should not be useful.
Defaults are thY1 = 10 and thY2 = 10 (thus making a binary mask).
Back to MaskTools.
