Subtract
From Avisynth wiki
Revision as of 15:33, 27 February 2016 by Raffriff42 (Talk | contribs)
Show the difference between two clips. Where the clips are equal, the output is 50% grey.
See filters with multiple input clips for the resulting clip properties.
Syntax
Subtract(clip clip1, clip clip2)
Examples
Show the difference between two clips, and make the difference blatantly obvious:
Subtract(A, B).Levels(65, 1, 255-64, 0, 255, coring=false)
Show the difference between adjacent frames:
Subtract(A, A.Trim(1, 0))
About offset of luma range
For YUV formats the valid Y range is 16-235, and Subtract takes this into account. This means that the following script
Subtract(A, B)
...will result in a "50% grey" clip with luma=126.
If you require a mathematically correct subtract function for 0-255 RGB or YUV data, use Overlay:
Overlay(A, B, mode="difference", pc_range=false)
