How to apply a curve to Y only on a clip(Y,U,V)?

[fjhdavid]

Is there a way to apply a Y curve only and in the Y,U,V space.
For example:

0 ->0
51->59
101->115
151->170
202->225
255->255

Thanks
Francois

PS: There is a filter named Gicocu which allows to use a photoshop or Gimp curve to be applied to a filter.
But Gicocu only works in the RGB space.

[FlimsyFeet]

There's probably a way to do something like this using the mt_lut filter from the MaskTools2 plugin.

[J_Darnley]

Didée did just this with Ylevels: http://avisynth.org/mediawiki/Ylevels

If you want/need to use GiCoCu then you could just fake it by doing something like:

chroma = last
Greyscale()
ConvertToRGB(matrix="PC.601")
GiCoCu()
ConvertToYV12(matrix="PC.601")
MergeChroma(chroma)

[fjhdavid]

J_Darnley,

I will stay with Gicocu and the "fake" you told me about, as Ylevels doesn't give me all the flexibility Gicocu gives (Ylevels has only, in facts, two "controls point"). Of course going with Gicocu needs to use a converttoRGB. This is the compromise...

Thanks
Francois