Spaced Ranger said:
... (I vaguely remember seeing one, some time ago, somewhere).
I know that wasn't very helpful. So I found the references (have never implemented them myself ... but will):
GiCoCu - Reproduces Photoshop's handling of amp-files and Gimp's handling of color curve files in Avisynth
http://avisynth.org.ru/docs/english/externalfilters/gicocu.htm
Gradation Curves - edit the gradation curves similar to those in paint programs, with data import & export, for VirtualDub
http://members.chello.at/nagiller/vdub/index.html
and development thread
http://forum.doom9.org/showthread.php?t=133191
Using VirtualDub plug-ins in AviSynth (last post)
http://forum.doom9.org/showthread.php?p=1018607
How to achieve "film look" on PAL DV source - informative & insightful on what is nearly the same as our color correctings (with refs to above plug-ins)
http://forum.doom9.org/showthread.php?t=87791